Publications

Abstract

A central motif in neuronal networks is convergence, linking several input neurons to one target neuron. In visual cortex, convergence renders target neurons responsive to complex stimuli. Yet, convergence typically sends multiple stimuli to a target, and the behaviorally relevant stimulus must be selected. We used two stimuli, activating separate electrocorticographic V1 sites, and both activating an electrocorticographic V4 site equally strongly. When one of those stimuli activated one V1 site, it gamma synchronized (60-80 Hz) to V4. When the two stimuli activated two V1 sites, primarily the relevant one gamma synchronized to V4. Frequency bands of gamma activities showed substantial overlap containing the band of interareal coherence. The relevant V1 site had its gamma peak frequency 2-3 Hz higher than the irrelevant V1 site and 4-6 Hz higher than V4. Gamma-mediated interareal influences were predominantly directed from V1 to V4. We propose that selective synchronization renders relevant input effective, thereby modulating effective connectivity.

Abstract

Relational grammar was proposed in Suppes (1976) as a semantical grammar for natural language. Fragments considered so far are restricted to distributive notions. In this article, relational grammar is extended to collective notions.

Abstract

There are two competing hypotheses for the origin of the Indo-European language family. The conventional view places the homeland in the Pontic steppes about 6000 years ago. An alternative hypothesis claims that the languages spread from Anatolia with the expansion of farming 8000 to 9500 years ago. We used Bayesian phylogeographic approaches, together with basic vocabulary data from 103 ancient and contemporary Indo-European languages, to explicitly model the expansion of the family and test these hypotheses. We found decisive support for an Anatolian origin over a steppe origin. Both the inferred timing and root location of the Indo-European language trees fit with an agricultural expansion from Anatolia beginning 8000 to 9500 years ago. These results highlight the critical role that phylogeographic inference can play in resolving debates about human prehistory.

Abstract

The theory that language acquisition is guided and constrained by inborn linguistic knowledge is assessed. Specifically, the "no negative evidence" view, the belief that linguistic theory should be restricted in such a way that the grammars it allows can be learned by children on the basis of positive evidence only, is explored. Child language data are cited in order to investigate influential innatist approaches to language acquisition. Baker's view that children are innately constrained in significant ways with respect to language acquisition is evaluated. Evidence indicates that children persistently make overgeneralizations of the sort that violate the constrained view of language acquisition. Since children eventually do develop correct adult grammar, they must have other mechanisms for cutting back on these overgeneralizations. Thus, any hypothesized constraints cannot be justified on grounds that without them the child would end up with overly general grammar. It is necessary to explicate the mechanisms by which children eliminate their tendency toward overgeneralization.

Abstract

This study reports three experiments on how children learning Mandarin Chinese comprehend and use aspect markers. These experiments examine the role of lexical aspect in children's acquisition of grammatical aspect. Results provide converging evidence for children's early sensitivity to (1) the association between atelic verbs and the imperfective aspect markers zai, -zhe, and -ne, and (2) the association between telic verbs and the perfective aspect marker -le. Children did not show a sensitivity in their use or understanding of aspect markers to the difference between stative and activity verbs or between semelfactive and activity verbs. These results are consistent with Slobin's (1985) basic child grammar hypothesis that the contrast between process and result is important in children's early acquisition of temporal morphology. In contrast, they are inconsistent with Bickerton's (1981, 1984) language bioprogram hypothesis that the distinctions between state and process and between punctual and nonpunctual are preprogrammed into language learners. We suggest new ways of looking at the results in the light of recent probabilistic hypotheses that emphasize the role of input, prototypes and connectionist representations.

Abstract

This study considers the role of verbal working memory in sentence comprehension in typically developing English-speaking children. Fifty-six (N = 56) children aged 4;0–6;6 completed a test of language comprehension that contained sentences which varied in complexity, standardized tests of vocabulary and nonverbal intelligence, and three tests of memory that measured the three verbal components of Baddeley's model of Working Memory (WM): the phonological loop, the episodic buffer, and the central executive. The results showed that children experienced most difficulty comprehending sentences that contained noncanonical word order (passives and object relative clauses). A series of linear mixed effects models were run to analyze the contribution of each component of WM to sentence comprehension. In contrast to most previous studies, the measure of the central executive did not predict comprehension accuracy. A canonicity by episodic buffer interaction showed that the episodic buffer measure was positively associated with better performance on the noncanonical sentences. The results are discussed with reference to capacity-limit and experience-dependent approaches to language comprehension.

Abstract

In this study, we investigated the level of visual processing at which surface colour information improves the naming of colour diagnostic and noncolour diagnostic objects. Continuous electroencephalograms were recorded while participants performed a visual object naming task in which coloured and black-and-white versions of both types of objects were presented. The black-and-white and the colour presentations were compared in two groups of event-related potentials (ERPs): (1) The P1 and N1 components, indexing early visual processing; and (2) the N300 and N400 components, which index late visual processing. A colour effect was observed in the P1 and N1 components, for both colour and noncolour diagnostic objects. In addition, for colour diagnostic objects, a colour effect was observed in the N400 component. These results suggest that colour information is important for the naming of colour and noncolour diagnostic objects at different levels of visual processing. It thus appears that the visual system uses colour information, during naming of both object types, at early visual stages; however, for the colour diagnostic objects naming, colour information is also recruited during the late visual processing stages.

Abstract

his study investigates the interaction between surface and colour knowledge information during object recognition. In two different experiments, participants were instructed to decide whether two presented stimuli belonged to the same object identity. On the non-matching trials, we manipulated the shape and colour knowledge information activated by the two stimuli by creating four different stimulus pairs: (1) similar in shape and colour (e.g. TOMATO–APPLE); (2) similar in shape and dissimilar in colour (e.g. TOMATO–COCONUT); (3) dissimilar in shape and similar in colour (e.g. TOMATO–CHILI PEPPER) and (4) dissimilar in both shape and colour (e.g. TOMATO–PEANUT). The object pictures were presented in typical and atypical colours and also in black-and-white. The interaction between surface and colour knowledge showed to be contingent upon shape information: while colour knowledge is more important for recognising structurally similar shaped objects, surface colour is more prominent for recognising structurally dissimilar shaped objects.

Abstract

In this study, we used event-related potentials (ERPs) to evaluate the contribution of surface color and color knowledge information in object identification. We constructed two color-object verification tasks – a surface and a knowledge verification task – using high color diagnostic objects; both typical and atypical color versions of the same object were presented. Continuous electroencephalogram was recorded from 26 subjects. A cluster randomization procedure was used to explore the differences between typical and atypical color objects in each task. In the color knowledge task, we found two significant clusters that were consistent with the N350 and late positive complex (LPC) effects. Atypical color objects elicited more negative ERPs compared to typical color objects. The color effect found in the N350 time window suggests that surface color is an important cue that facilitates the selection of a stored object representation from long-term memory. Moreover, the observed LPC effect suggests that surface color activates associated semantic knowledge about the object, including color knowledge representations. We did not find any significant differences between typical and atypical color objects in the surface color verification task, which indicates that there is little contribution of color knowledge to resolve the surface color verification. Our main results suggest that surface color is an important visual cue that triggers color knowledge, thereby facilitating object identification.

Abstract

Humans display structural and functional asymmetries in brain organization, strikingly with respect to language and handedness. The molecular basis of these asymmetries is unknown. We report a genome-wide association study meta-analysis for a quantitative measure of relative hand skill in individuals with dyslexia [reading disability (RD)] (n = 728). The most strongly associated variant, rs7182874 (P = 8.68×10−9), is located in PCSK6, further supporting an association we previously reported. We also confirmed the specificity of this association in individuals with RD; the same locus was not associated with relative hand skill in a general population cohort (n = 2,666). As PCSK6 is known to regulate NODAL in the development of left/right (LR) asymmetry in mice, we developed a novel approach to GWAS pathway analysis, using gene-set enrichment to test for an over-representation of highly associated variants within the orthologs of genes whose disruption in mice yields LR asymmetry phenotypes. Four out of 15 LR asymmetry phenotypes showed an over-representation (FDR≤5%). We replicated three of these phenotypes; situs inversus, heterotaxia, and double outlet right ventricle, in the general population cohort (FDR≤5%). Our findings lead us to propose that handedness is a polygenic trait controlled in part by the molecular mechanisms that establish LR body asymmetry early in development.

Abstract

Multivariate pattern classification methods are increasingly applied to neuroimaging data in the context of both fundamental research and in brain-computer interfacing approaches. Such methods provide a framework for interpreting measurements made at the single-trial level with respect to a set of two or more distinct mental states. Here, we define an approach in which the output of a binary classifier trained on data from an auditory mismatch paradigm can be used for online tracking of perception and as a neurofeedback signal. The auditory mismatch paradigm is known to induce distinct perceptual states related to the presentation of high- and low-probability stimuli, which are reflected in event-related potential (ERP) components such as the mismatch negativity (MMN). The first part of this paper illustrates how pattern classification methods can be applied to data collected in an MMN paradigm, including discussion of the optimization of preprocessing steps, the interpretation of features and how the performance of these methods generalizes across individual participants and measurement sessions. We then go on to show that the output of these decoding methods can be used in online settings as a continuous index of single-trial brain activation underlying perceptual discrimination. We conclude by discussing several potential domains of application, including neurofeedback, cognitive monitoring and passive brain-computer interfaces

Abstract

Brain-computer interfaces (BCIs) are systems that use real-time analysis of neuroimaging data to determine the mental state of their user for purposes such as providing neurofeedback. Here, we investigate the feasibility of a BCI based on speech perception. Multivariate pattern classification methods were applied to single-trial EEG data collected during speech perception by native and non-native speakers. Two principal questions were asked: 1) Can differences in the perceived categories of pairs of phonemes be decoded at the single-trial level? 2) Can these same categorical differences be decoded across participants, within or between native-language groups? Results indicated that classification performance progressively increased with respect to the categorical status (within, boundary or across) of the stimulus contrast, and was also influenced by the native language of individual participants. Classifier performance showed strong relationships with traditional event-related potential measures and behavioral responses. The results of the cross-participant analysis indicated an overall increase in average classifier performance when trained on data from all participants (native and non-native). A second cross-participant classifier trained only on data from native speakers led to an overall improvement in performance for native speakers, but a reduction in performance for non-native speakers. We also found that the native language of a given participant could be decoded on the basis of EEG data with accuracy above 80%. These results indicate that electrophysiological responses underlying speech perception can be decoded at the single-trial level, and that decoding performance systematically reflects graded changes in the responses related to the phonological status of the stimuli. This approach could be used in extensions of the BCI paradigm to support perceptual learning during second language acquisition

Abstract

The present study used electrophysiological and behavioral measures to investigate the perception of an English stop consonant contrast by native English listeners and by native Dutch listeners who were highly proficient in English. A /ba/-/pa/ continuum was created from a naturally produced /pa/ token by removing successive periods of aspiration, thus reducing the voice onset time. Although aspiration is a relevant cue for distinguishing voiced and unvoiced labial stop consonants (/b/ and /p/) in English, prevoicing is the primary cue used to distinguish between these categories in Dutch. In the electrophysiological experiment, participants listened to oddball sequences containing the standard /pa/ stimulus and one of three deviant stimuli while the mismatch-negativity response was measured. Participants then completed an identification task on the same stimuli. The results showed that native English participants were more sensitive to reductions in aspiration than native Dutch participants, as indicated by shifts in the category boundary, by differing within-group patterns of mismatch-negativity responses, and by larger mean evoked potential amplitudes in the native English group for two of the three deviant stimuli. This between-group difference in the sensorineural processing of aspiration cues indicates that native language experience alters the way in which the acoustic features of speech are processed in the auditory brain, even following extensive second-language training.

Abstract

In numerous comprehension studies, across different languages, children have performed worse on object relatives (e.g., the dog that the cat chased) than on subject relatives (e.g., the dog that chased the cat). One possible reason for this is that the test sentences did not exactly match the kinds of object relatives that children typically experience. Adults and children usually hear and produce object relatives with inanimate heads and pronominal subjects (e.g., the car that we bought last year) (cf. Kidd et al., Language and Cognitive Processes 22: 860–897, 2007). We tested young 3-year old German- and English-speaking children with a referential selection task. Children from both language groups performed best in the condition where the experimenter described inanimate referents with object relatives that contained pronominal subjects (e.g., Can you give me the sweater that he bought?). Importantly, when the object relatives met the constraints identified in spoken discourse, children understood them as well as subject relatives, or even better. These results speak against a purely structural explanation for children's difficulty with object relatives as observed in previous studies, but rather support the usage-based account, according to which discourse function and experience with language shape the representation of linguistic structures.

Abstract

Both notional and grammatical number affect agreement during language production. To explore their workings, we investigated how semantic integration, a type of conceptual relatedness, produces variations in agreement (Solomon & Pearlmutter, 2004). These agreement variations are open to competing notional and lexical–grammatical number accounts. The notional hypothesis is that changes in number agreement reflect differences in referential coherence: More coherence yields more singularity. The lexical–grammatical hypothesis is that changes in agreement arise from competition between nouns differing in grammatical number: More competition yields more plurality. These hypotheses make opposing predictions about semantic integration. On the notional hypothesis, semantic integration promotes singular agreement. On the lexical–grammatical hypothesis, semantic integration promotes plural agreement. We tested these hypotheses with agreement elicitation tasks in two experiments. Both experiments supported the notional hypothesis, with semantic integration creating faster and more frequent singular agreement. This implies that referential coherence mediates the effect of semantic integration on number agreement.

Abstract

L2 listening can involve the phantom activation of words which are not actually in the input. All spoken-word recognition involves multiple concurrent activation of word candidates, with selection of the correct words achieved by a process of competition between them. L2 listening involves more such activation than L1 listening, and we report two studies illustrating this. First, in a lexical decision study, L2 listeners accepted (but L1 listeners did not accept) spoken non-words such as groof or flide as real English words. Second, a priming study demonstrated that the same spoken non-words made recognition of the real words groove, flight easier for L2 (but not L1) listeners, suggesting that, for the L2 listeners only, these real words had been activated by the spoken non-word input. We propose that further understanding of the activation and competition process in L2 lexical processing could lead to new understanding of L2 listening difficulty.

Abstract

This study investigates cross-language lexical competition in the bilingual mental lexicon. It provides evidence for the occurrence of inhibition as well as the commonly reported facilitation during the production of cognates (words with similar phonological form and meaning in two languages) in a mixed picture naming task by highly proficient Welsh-English bilinguals. Previous studies have typically found cognate facilitation. It has previously been proposed (with respect to non-cognates) that cross-language inhibition is limited to low-proficient bilinguals; therefore, we tested highly proficient, early bilinguals. In a mixed naming experiment (i.e., picture naming with language switching), 48 highly proficient, early Welsh-English bilinguals named pictures in Welsh and English, including cognate and non-cognate targets. Participants were English-dominant, Welsh-dominant, or had equal language dominance. The results showed evidence for cognate inhibition in two ways. First, both facilitation and inhibition were found on the cognate trials themselves, compared to non-cognate controls, modulated by the participants' language dominance. The English-dominant group showed cognate inhibition when naming in Welsh (and no difference between cognates and controls when naming in English), and the Welsh-dominant and equal dominance groups generally showed cognate facilitation. Second, cognate inhibition was found as a behavioral adaptation effect, with slower naming for non-cognate filler words in trials after cognates than after non-cognate controls. This effect was consistent across all language dominance groups and both target languages, suggesting that cognate production involved cognitive control even if this was not measurable in the cognate trials themselves. Finally, the results replicated patterns of symmetrical switch costs, as commonly reported for balanced bilinguals. We propose that cognate processing might be affected by two different processes, namely competition at the lexical-semantic level and facilitation at the word form level, and that facilitation at the word form level might (sometimes) outweigh any effects of inhibition at the lemma level. In sum, this study provides evidence that cognate naming can cause costs in addition to benefits. The finding of cognate inhibition, particularly for the highly proficient bilinguals tested, provides strong evidence for the occurrence of lexical competition across languages in the bilingual mental lexicon.

Abstract

Native and nonnative listeners categorized final /v/ versus /f/ in English nonwords. Fricatives followed phonetically long originally /v/-preceding or short originally /f/-preceding vowels. Vowel duration was constant for each participant and sometimes mismatched other voicing cues. Previous results showed that English but not Dutch listeners whose L1 has no final voicing contrast nevertheless used the misleading vowel duration for /v/-/f/ categorization. New analyses showed that Dutch listeners did use vowel duration initially, but quickly reduced its use, whereas the English listeners used it consistently throughout the experiment. Thus, nonnative listeners adapted to the stimuli more flexibly than native listeners did.

Abstract

This study investigates how inaccurate phoneme processing affects recognition of partially onset-overlapping pairs like DAFFOdil-DEFIcit and of minimal pairs like flash-flesh in second-language listening. Two cross-modal priming experiments examined differences between native (L1) and second-language (L2) listeners at two stages of lexical processing: first, the activation of intended and mismatching lexical representations and second, the competition between those lexical representations. Experiment 1 shows that truncated primes like daffo- and defi- activated lexical representations of mismatching words (either deficit or daffodil) more for L2 listeners than for L1 listeners. Experiment 2 shows that for minimal pairs, matching primes (prime: flash, target: FLASH) facilitated recognition of visual targets for L1 and L2 listeners alike, whereas mismatching primes (flesh, FLASH) inhibited recognition consistently for L1 listeners but only in a minority of cases for L2 listeners; in most cases, for them, primes facilitated recognition of both words equally strongly. Thus, L1 and L2 listeners' results differed both at the stages of lexical activation and competition. First, perceptually difficult phonemes activated mismatching words more for L2 listeners than for L1 listeners, and second, lexical competition led to efficient inhibition of mismatching competitors for L1 listeners but in most cases not for L2 listeners.

Abstract

Background: According to decades of research on affective motivation in the human brain, approach motivational states are supported primarily by the left hemisphere and avoidance states by the right hemisphere. The underlying cause of this specialization, however, has remained unknown. Here we conducted a first test of the Sword and Shield Hypothesis (SSH), according to which the hemispheric laterality of affective motivation depends on the laterality of motor control for the dominant hand (i.e., the "sword hand," used preferentially to perform approach actions) and the nondominant hand (i.e., the "shield hand," used preferentially to perform avoidance actions). Methodology/Principal Findings: To determine whether the laterality of approach motivation varies with handedness, we measured alpha-band power (an inverse index of neural activity) in right- and left-handers during resting-state electroencephalography and analyzed hemispheric alpha-power asymmetries as a function of the participants' trait approach motivational tendencies. Stronger approach motivation was associated with more left-hemisphere activity in right-handers, but with more right-hemisphere activity in left-handers. Conclusions: The hemispheric correlates of approach motivation reversed between right- and left-handers, consistent with the way they typically use their dominant and nondominant hands to perform approach and avoidance actions. In both right- and left-handers, approach motivation was lateralized to the same hemisphere that controls the dominant hand. This covariation between neural systems for action and emotion provides initial support for the SSH

Abstract

Three eye-tracking experiments investigated how phonological reductions (e.g., ‘‘puter’’ for ‘‘computer’’) modulate phonological competition. Participants listened to sentences extracted from a pontaneous speech corpus and saw four printed words: a target (e.g., ‘‘computer’’), a competitor similar to the canonical form (e.g., ‘‘companion’’), one similar to the reduced form (e.g.,
‘‘pupil’’), and an unrelated distractor. In Experiment 1, we presented canonical and reduced forms in a syllabic and in a sentence context. Listeners directed
their attention to a similar degree to both competitors independent of the
target’s spoken form. In Experiment 2, we excluded reduced forms and
presented canonical forms only. In such a listening situation, participants
showed a clear preference for the ‘‘canonical form’’ competitor. In Experiment 3, we presented canonical forms intermixed with reduced forms in a sentence context and replicated the competition pattern of Experiment 1. These data suggest that listeners penalize acoustic mismatches less strongly when listeningto reduced speech than when listening to fully articulated speech. We conclude
that flexibility to adjust to speech-intrinsic factors is a key feature of the spoken word recognition system.

Abstract

Previous research has shown that talker variability affects recognition memory for spoken words (Palmeri et al., 1993). This study examines whether additive noise is similarly retained in memory for spoken words. In a continuous recognition memory task, participants listened to a list of spoken words mixed with noise consisting of a pure tone or of high-pass filtered white noise. The noise and speech were in non-overlapping frequency bands. In Experiment 1, listeners indicated whether each spoken word in the list was OLD (heard before in the list) or NEW. Results showed that listeners were as accurate and as fast at recognizing a word as old if it was repeated with the same or different noise. In Experiment 2, listeners also indicated whether words judged as OLD were repeated with the same or with a different type of noise. Results showed that listeners benefitted from hearing words presented with the same versus different noise. These data suggest that spoken words and temporally-overlapping but spectrally non-overlapping noise are retained or reconstructed together for explicit, but not for implicit recognition memory. This indicates that the extent to which noise variability is retained seems to depend on the depth of processing

Abstract

In two eye-tracking experiments we examined whether wider discourse information helps
the recognition of reduced pronunciations (e.g., 'puter') more than the recognition of
canonical pronunciations of spoken words (e.g., 'computer'). Dutch participants listened to
sentences from a casual speech corpus containing canonical and reduced target words. Target
word recognition was assessed by measuring eye fixation proportions to four printed words
on a visual display: the target, a "reduced form" competitor, a "canonical form" competitor
and an unrelated distractor. Target sentences were presented in isolation or with a wider
discourse context. Experiment 1 revealed that target recognition was facilitated by wider
discourse information. Importantly, the recognition of reduced forms improved significantly
when preceded by strongly rather than by weakly supportive discourse contexts. This was not
the case for canonical forms: listeners' target word recognition was not dependent on the
degree of supportive context. Experiment 2 showed that the differential context effects in
Experiment 1 were not due to an additional amount of speaker information. Thus, these data
suggest that in natural settings a strongly supportive discourse context is more important for
the recognition of reduced forms than the recognition of canonical forms.

Abstract

In listeners' daily communicative exchanges, they most often hear casual speech, in which words are often produced with fewer segments, rather than the careful speech used in most psycholinguistic experiments. Three experiments examined phonological competition during the recognition of reduced forms such as [pjutər] for computer using a target-absent variant of the visual world paradigm. Listeners' eye movements were tracked upon hearing canonical and reduced forms as they looked at displays of four printed words. One of the words was phonologically similar to the canonical pronunciation of the target word, one word was similar to the reduced pronunciation, and two words served as unrelated distractors. When spoken targets were presented in isolation (Experiment 1) and in sentential contexts (Experiment 2), competition was modulated as a function of the target word form. When reduced targets were presented in sentential contexts, listeners were probabilistically more likely to first fixate reduced-form competitors before shifting their eye gaze to canonical-form competitors. Experiment 3, in which the original /p/ from [pjutər] was replaced with a “real” onset /p/, showed an effect of cross-splicing in the late time window. We conjecture that these results fit best with the notion that speech reductions initially activate competitors that are similar to the phonological surface form of the reduction, but that listeners nevertheless can exploit fine phonetic detail to reconstruct strongly reduced forms to their canonical counterparts.

Abstract

In traditional theories of language comprehension, syntactic and semantic processing are inextricably linked. This assumption has been challenged by the ‘Semantic Illusion Effect’ found in studies using Event Related brain Potentials. Semantically anomalous sentences did not produce the expected increase in N400 amplitude but rather one in P600 amplitude. To explain these findings, complex models have been devised in which an independent semantic processing stream can arrive at a sentence interpretation that may differ from the interpretation prescribed by the syntactic structure of the sentence. We review five such multi-stream models and argue that they do not account for the full range of relevant results because they assume that the amplitude of the N400 indexes some form of semantic integration. Based on recent evidence we argue that N400 amplitude might reflect the retrieval of lexical information from memory. On this view, the absence of an N400-effect in Semantic Illusion sentences can be explained in terms of priming. Furthermore, we suggest that semantic integration, which has previously been linked to the N400 component, might be reflected in the P600 instead. When combined, these functional interpretations result in a single-stream account of language processing that can explain all of the Semantic Illusion data.

Abstract

This study examined whether speech-on-speech masking is sensitive to variation in the degree of similarity between the target and the masker speech. Three experiments investigated whether speech-in-speech recognition varies across different background speech languages (English vs Dutch) for both English and Dutch targets, as well as across variation in the semantic content of the background speech (meaningful vs semantically anomalous sentences), and across variation in listener status vis-à-vis the target and masker languages (native, non-native, or unfamiliar). The results showed that the more similar the target speech is to the masker speech (e.g., same vs different language, same vs different levels of semantic content), the greater the interference on speech recognition accuracy. Moreover, the listener’s knowledge of the target and the background language modulate the size of the release from masking. These factors had an especially strong effect on masking effectiveness in highly unfavorable listening conditions. Overall this research provided evidence that that the degree of target-masker similarity plays a significant role in speech-in-speech recognition. The results also give insight into how listeners assign their resources differently depending on whether they are listening to their first or second language

Abstract

We employed a parametric psychophysical design in combination with functional imaging to examine the influence of metric changes in perceptual incongruence on perceptual alternation rates and cortical responses. Subjects viewed a bistable stimulus defined by incongruent depth cues; bistability resulted from incongruence between binocular disparity and monocular perspective cues that specify different slants (slant rivalry). Psychophysical results revealed that perceptual alternation rates were positively correlated with the degree of perceived incongruence. Functional imaging revealed systematic increases in activity that paralleled the psychophysical results within anterior intraparietal sulcus, prior to the onset of perceptual alternations. We suggest that this cortical activity predicts the frequency of subsequent alternations, implying a putative causal role for these areas in initiating bistable perception. In contrast, areas implicated in form and depth processing (LOC and V3A) were sensitive to the degree of slant, but failed to show increases in activity when these cues were in conflict.

Abstract

The Tzeltal language is spoken in a mountainous region of southern Mexico by some 280,000 Mayan corn farmers. This paper focuses on landscape and place vocabulary in the Tzeltal municipio of Tenejapa, where speakers use an absolute system of spatial reckoning based on the overall uphill (southward)/downhill (northward) slope of the land. The paper examines the formal and functional properties of the Tenejapa Tzeltal vocabulary labelling features of the local landscape and relates it to spatial vocabulary for describing locative relations, including the uphill/downhill axis for spatial reckoning as well as body part terms for specifying parts of locative grounds. I then examine the local place names, discuss their semantic and morphosyntactic properties, and relate them to the landscape vocabulary, to spatial vocabulary, and also to cultural narratives about events associated with particular places. I conclude with some observations on the determinants of landscape and place terminology in Tzeltal, and what this vocabulary and how it is used reveal about the conceptualization of landscape and places.

Abstract

A major finding in studies of early vocabulary acquisition has been that children tend to learn a lot of nouns early but make do with relatively few verbs, among which semantically general-purpose verbs like do, make, get, have, give, come, go, and be play a prominent role. The preponderance of nouns is explained in terms of nouns labelling concrete objects beings “easier” to learn than verbs, which label relational categories. Nouns label “natural categories” observable in the world, verbs label more linguistically and culturally specific categories of events linking objects belonging to such natural categories (Gentner 1978, 1982; Clark 1993). This view has been challenged recently by data from children learning certain non-Indo-European languges like Korean, where children have an early verb explosion and verbs dominate in early child utterances. Children learning the Mayan language Tzeltal also acquire verbs early, prior to any noun explosion as measured by production. Verb types are roughly equivalent to noun types in children’s beginning production vocabulary and soon outnumber them. At the one-word stage children’s verbs mostly have the form of a root stripped of affixes, correctly segmented despite structural difficulties. Quite early (before the MLU 2.0 point) there is evidence of productivity of some grammatical markers (although they are not always present): the person-marking affixes cross-referencing core arguments, and the completive/incompletive aspectual distinctions. The Tzeltal facts argue against a natural-categories explanation for childre’s early vocabulary, in favor of a view emphasizing the early effects of language-specific properties of the input. They suggest that when and how a child acquires a “verb” category is centrally influenced by the structural properties of the input, and that the semantic structure of the language - where the referential load is concentrated - plays a fundamental role in addition to distributional facts.

Abstract

When Tzeltal children in the Mayan community of Tenejapa, in southern Mexico, begin speaking, their production vocabulary consists predominantly of verb roots, in contrast to the dominance of nouns in the initial vocabulary of first‐language learners of Indo‐European languages. This article proposes that a particular Tzeltal conversational feature—known in the Mayanist literature as "dialogic repetition"—provides a context that facilitates the early analysis and use of verbs. Although Tzeltal babies are not treated by adults as genuine interlocutors worthy of sustained interaction, dialogic repetition in the speech the children are exposed to may have an important role in revealing to them the structural properties of the language, as well as in socializing the collaborative style of verbal interaction adults favor in this community.

Abstract

Whereas most research in SLA assumes the relationship between the first language (L1) and the second language (L2) to be unidirectional, this study investigates the possibility of a bidirectional relationship. We examine the domain of manner of motion, in which monolingual Japanese and English speakers differ both in speech and gesture. Parallel influences of the L1 on the L2 and the L2 on the L1 were found in production from native Japanese speakers with intermediate knowledge of English. These effects, which were strongest in gesture patterns, demonstrate that (a) bidirectional interaction between languages in the multilingual mind can occur even with intermediate proficiency in the L2 and (b) gesture analyses can offer insights on interactions between languages beyond those observed through analyses of speech alone.

Abstract

Abundant evidence across languages, structures, proficiencies, and modalities shows that properties of first languages influence performance in second languages. This paper presents an alternative perspective on the interaction between established and emerging languages within second language speakers by arguing that an L2 can influence an L1, even at relatively low proficiency levels. Analyses of the gesture viewpoint employed in English and Japanese descriptions of motion events revealed systematic between-language and within-language differences. Monolingual Japanese speakers used significantly more Character Viewpoint than monolingual English speakers, who predominantly employed Observer Viewpoint. In their L1 and their L2, however, native Japanese speakers with intermediate knowledge of English patterned more like the monolingual English speakers than their monolingual Japanese counterparts. After controlling for effects of cultural exposure, these results offer valuable insights into both the nature of cross-linguistic interactions within individuals and potential factors underlying gesture viewpoint.

Abstract

This work was supported by the Max Planck Institute for Psycholinguistics and the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO; MPI 56-384, The Dynamics of Multilingual Processing, awarded to M Gullberg and P Indefrey).

Abstract

This research received technical and financial support from Syracuse University, the Max Planck Institute for Psycholinguistics, and the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO; MPI 56-384, The Dynamics of Multilingual Processing, awarded to Marianne Gullberg and Peter Indefrey).

Abstract

This is a Spanish translation of Brown 1997.

Abstract

Linguistic expressions of time often draw on spatial language, which raises the question of whether cultural specificity in spatial language and cognition is reflected in thinking about time. In the Mayan language Tzeltal, spatial language relies heavily on an absolute frame of reference utilizing the overall slope of the land, distinguishing an “uphill/downhill” axis oriented from south to north, and an orthogonal “crossways” axis (sunrise-set) on the basis of which objects at all scales are located. Does this absolute system for calculating spa-tial relations carry over into construals of temporal relations? This question was explored in a study where Tzeltal consultants produced temporal expressions and performed two different non-linguistic temporal ordering tasks. The results show that at least five distinct schemata for conceptualizing time underlie Tzeltal linguistic expressions: (i) deictic ego-centered time, (ii) time as an ordered sequence (e.g., “first”/“later”), (iii) cyclic time (times of the day, seasons), (iv) time as spatial extension or location (e.g., “entering/exiting July”), and (v) a time vector extending uphillwards into the future. The non-linguistic task results showed that the “time moves uphillwards” metaphor, based on the absolute frame of reference prevalent in Tzeltal spatial language and thinking and important as well in the linguistic expressions for time, is not strongly reflected in responses on these tasks. It is argued that systematic and consistent use of spatial language in an absolute frame of reference does not necessarily transfer to consistent absolute time conceptualization in non-linguistic tasks; time appears to be more open to alternative construals.

Abstract

During unscripted speech, speakers coordinate the formulation of pre-linguistic messages with the linguistic processes that implement those messages into speech. We examine the process of constructing a contextually appropriate message and interfacing that message with utterance planning in English (the small butterfly) and Spanish (la mariposa pequeña) during an unscripted, interactive task. The coordination of gaze and speech during formulation of these messages is used to evaluate two hypotheses regarding the lower limit on the size of message planning units, namely whether messages are planned in units isomorphous to entire phrases or units isomorphous to single lexical items. Comparing the planning of fluent pre-nominal adjectives in English and post-nominal adjectives in Spanish showed that size information is added to the message later in Spanish than English, suggesting that speakers can prepare pre-linguistic messages in lexically-sized units. The results also suggest that the speaker can use disfluency to coordinate the transition from thought to speech.

Abstract

The Noir Marron are the direct descendants of thousands of African slaves deported to the Guyanas during the Atlantic Slave Trade and later escaped mainly from Dutch colonial plantations. Six ethnic groups are officially recognized, four of which are located in French Guyana: the Aluku, the Ndjuka, the Saramaka, and the Paramaka. The aim of this study was: (1) to determine the Noir Marron settlement through genetic exchanges with other communities such as Amerindians and Europeans; (2) to retrace their origins in Africa. Buffy-coat DNA from 142 Noir Marron, currently living in French Guyana, were analyzed using mtDNA (typing of SNP coding regions and sequencing of HVSI/II) and Y chromosomes (typing STR and SNPs) to define their genetic profile. Results were compared to an African database composed by published data, updated with genotypes of 82 Fon from Benin, and 128 Ahizi and 63 Yacouba from the Ivory-Coast obtained in this study for the same markers. Furthermore, the determination of the genomic subtype of HTLV-1 strains (env gp21 and LTR regions), which can be used as a marker of migration of infected populations, was performed for samples from 23 HTLV-1 infected Noir Marron and compared with the corresponding database. MtDNA profiles showed a high haplotype diversity, in which 99% of samples belonged to the major haplogroup L, frequent in Africa. Each haplotype was largely represented on the West African coast, but notably higher homologies were obtained with the samples present in the Gulf of Guinea. Y Chromosome analysis revealed the same pattern, i.e. a conservation of the African contribution to the Noir Marron genetic profile, with 98% of haplotypes belonging to the major haplogroup E1b1a, frequent in West Africa. The genetic diversity was higher than those observed in African populations, proving the large Noir Marron’s fatherland, but a predominant identity in the Gulf of Guinea can be suggested. Concerning HTLV-1 genotyping, all the Noir Marron strains belonged to the large Cosmopolitan A subtype. However, among them 17/23 (74%) clustered with the West African clade comprizing samples originating from Ivory-Coast, Ghana, Burkina-Fasso and Senegal, while 3 others clustered in the Trans-Sahelian clade and the remaining 3 were similar to strains found in individuals in South America. Through the combined analyses of three approaches, we have provided a conclusive image of the genetic profile of the Noir Marron communities studied. The high degree of preservation of the African gene pool contradicts the expected gene flow that would correspond to the major cultural exchanges observed between Noir Marron, Europeans and Amerindians. Marital practices and historical events could explain these observations. Corresponding to historical and cultural data, the origin of the ethnic groups is widely dispatched throughout West Africa. However, all results converge to suggest an individualization from a major birthplace in the Gulf of Guinea.

Abstract

The Noir Marron communities are the direct descendants of African slaves brought to the Guianas during the four centuries (16th to 19th) of the Atlantic slave trade. Among them, three major ethnic groups have been studied: the Aluku, the Ndjuka and the Saramaka. Their history led them to share close relationships with Europeans and Amerindians, as largely documented in their cultural records. The study of Gm polymorphisms of immunoglobulins may help to estimate the amount of gene flow linked to these cultural exchanges. Surprisingly, very low levels of European contribution (2.6%) and Amerindian contribution (1.7%) are detected in the Noir Marron gene pool. On the other hand, an African contribution of 95.7% redraws their origin to West Africa (FSTless-than-or-equals, slant0.15). This highly preserved African gene pool of the Noir Marron is unique in comparison to other African American populations of Latin America, who are notably more admixed

Abstract

The Hmong Diaspora is one of the widest modern human migrations. Mainly localised in South-East Asia, the United States of America, and metropolitan France, a small community has also settled the Amazonian forest of French Guiana. We have biologically analysed 62 individuals of this unique Guianese population through three complementary genetic markers: mitochondrial DNA (HVS-I/II and coding region SNPs), Y-chromosome (SNPs and STRs), and the Gm allotypic system. All genetic systems showed a high conservation of the Asian gene pool (Asian ancestry: mtDNA = 100.0%; NRY = 99.1%; Gm = 96.6%), without a trace of founder effect. When compared across various Asian populations, the highest correlations were observed with Hmong-Mien groups still living in South-East Asia (Fst < 0.05; P-value < 0.05). Despite a long history punctuated by exodus, the French Guianese Hmong have maintained their original genetic diversity.

Abstract

We investigated localization performance of simple targets in patient TN, who suffered bilateral damage of his primary visual cortex and shows complete cortical blindness. Using a two-alternative forced-choice paradigm, TN was asked to guess the position of left-right targets with goal-directed and discrete manual responses. The results indicate a clear dissociation between goal-directed and discrete responses. TN pointed toward the correct target location in approximately 75% of the trials but was at chance level with discrete responses. This indicates that the residual ability to localize an unseen stimulus depends critically on the possibility to translate a visual signal into a goal-directed motor output at least in certain forms of blindsight.

Abstract

Exploring the semantic encoding of a group of crosslinguistically uncommon “spatial-coordinate demonstratives”, this work establishes the existence of demonstratives whose function is to project angular search domains, thus invoking proper coordinate systems (or “frames of reference”). What is special about these distinctions is that they rely on a spatial asymmetry in relativizing a demonstrative referent (representing the Figure) to the deictic center (representing the Ground). A semantic typology of such demonstratives is constructed based on the nature of the asymmetries they employ. A major distinction is proposed between asymmetries outside the deictic Figure-Ground array (e.g., features of the larger environment) and those within it (e.g., facets of the speaker/addressee dyad). A unique system of the latter type, present in Jahai, an Aslian (Mon-Khmer) language spoken by groups of hunter-gatherers in the Malay Peninsula, is introduced and explored in detail using elicited data as well as natural conversational data captured on video. Although crosslinguistically unusual, spatial-coordinate demonstratives sit at the interface of issues central to current discourse in semantic-pragmatic theory: demonstrative function, deictic layout, and spatial frames of reference.

Abstract

This article investigates hydrological lexicon in Jahai, a Mon-Khmer language of the Malay Peninsula. Setting out from an analysis of the structural and semantic properties as well as the indigenous vs. borrowed origin of lexicon related to drainage, it teases out a set of distinct lexical systems for reference to and description of hydrological features. These include (1) indigenous nominal labels subcategorised by metaphor, (2) borrowed nominal labels, (3) verbals referring to properties and processes of water, (4) a set of motion verbs, and (5) place names. The lexical systems, functionally diverse and driven by different factors, illustrate that principles and strategies of geographical categorisation can vary systematically and profoundly within a single language.

Abstract

This special issue is the outcome of collaborative work on the relationship between language and landscape, carried out in the Language and Cognition Group at the Max Planck Institute for Psycholinguistics. The contributions explore the linguistic categories of landscape terms and place names in nine genetically, typologically and geographically diverse languages, drawing on data from first-hand fieldwork. The present introductory article lays out the reasons why the domain of landscape is of central interest to the language sciences and beyond, and it outlines some of the major patterns that emerge from the cross-linguistic comparison which the papers invite. The data point to considerable variation within and across languages in how systems of landscape terms and place names are ontologised. This has important implications for practical applications from international law to modern navigation systems.

Abstract

This special issue is the outcome of collaborative work on the relationship between language and landscape, carried out in the Language and Cognition Group at the Max Planck Institute for Psycholinguistics. The contributions explore the linguistic categories of landscape terms and place names in nine genetically, typologically and geographically diverse languages, drawing on data from first-hand fieldwork. The present introductory article lays out the reasons why the domain of landscape is of central interest to the language sciences and beyond, and it outlines some of the major patterns that emerge from the cross-linguistic comparison which the papers invite. The data point to considerable variation within and across languages in how systems of landscape terms and place names are ontologised. This has important implications for practical applications from international law to modern navigation systems.

Abstract

This paper reports tentatively some features of Semnam, a Central Aslian language spoken by some 250 people in the Perak valley, Peninsular Malaysia. It outlines the unusually rich phonemic system of this hitherto undescribed language (e.g. a vowel system comprising 36 distinctive nuclei), and proposes a practical orthography for it. It also includes the c. 1,250- item wordlist on which the analysis is based, collected intermittently in the field 2006-2008.

Abstract

Studies of agrammatic Broca's aphasia reveal a diverging pattern of performance in the comprehension of reflexive elements: offline, performance seems unimpaired, whereas online—and in contrast to both matching controls and Wernicke's patients—no antecedent reactivation is observed at the reflexive. Here we propose that this difference characterizes the agrammatic comprehension deficit as a result of slower-than-normal syntactic structure formation. To test this characterization, the comprehension of three Dutch agrammatic patients and matching control participants was investigated utilizing the cross-modal lexical decision (CMLD) interference task. Two types of reflexive-antecedent dependencies were tested, which have already been shown to exert distinct processing demands on the comprehension system as a function of the level at which the dependency was formed. Our hypothesis predicts that if the agrammatic system has a processing limitation such that syntactic structure is built in a protracted manner, this limitation will be reflected in delayed interpretation. Confirming previous findings, the Dutch patients show an effect of distinct processing demands for the two types of reflexive-antecedent dependencies but with a temporal delay. We argue that this delayed syntactic structure formation is the result of limited processing capacity that specifically affects the syntactic system.

Abstract

Cortical blindness refers to the loss of vision that occurs after destruction of the primary visual cortex. Although there is no sensory cortex and hence no conscious vision, some cortically blind patients show amygdala activation in response to facial or bodily expressions of emotion. Here we investigated whether direction of gaze could also be processed in the absence of any functional visual cortex. A well-known patient with bilateral destruction of his visual cortex and subsequent cortical blindness was investigated in an fMRI paradigm during which blocks of faces were presented either with their gaze directed toward or away from the viewer. Increased right amygdala activation was found in response to directed compared with averted gaze. Activity in this region was further found to be functionally connected to a larger network associated with face and gaze processing. The present study demonstrates that, in human subjects, the amygdala response to eye contact does not require an intact primary visual cortex.

Abstract

Nuclear receptors (NRs) form a large superfamily of transcription factors that participate in virtually every key biological process. They control development, fertility, gametogenesis and are misregulated in many cancers. Their enormous functional plasticity as transcription factors relates in part to NR-mediated interactions with hundreds of coregulatory proteins upon ligand (e.g., hormone) binding to their ligand binding domains (LBD), or following covalent modification. Some coregulator association relates to the distinct residues that shape a coactivator binding pocket termed AF-2, a surface groove that primarily determines the preference and specificity of protein–protein interactions. However, the highly conserved AF-2 pocket in the NR superfamily appears to be insufficient to account for NR subtype specificity leading to fine transcriptional modulation in certain settings. Additional protein–protein interaction surfaces, most notably on their LBD, may contribute to modulating NR function. NR coregulators and chaperones, normally much larger than the NR itself, may also bind to such interfaces. In the case of the androgen receptor (AR) LBD surface, structural and functional data highlighted the presence of another site named BF-3, which lies at a distinct but topographically adjacent surface to AF-2. AR BF-3 is a hot spot for mutations involved in prostate cancer and androgen insensitivity syndromes, and some FDA-approved drugs bind at this site. Structural studies suggested an allosteric relationship between AF-2 and BF-3, as occupancy of the latter affected coactivator recruitment to AF-2. Physiological relevant partners of AR BF-3 have not been described as yet. The newly discovered site is highly conserved among the steroid receptors subclass, but is also present in other NRs. Several missense mutations in the BF-3 regions of these human NRs are implicated in pathology and affect their function in vitro. The fact that AR BF-3 pocket is a druggable site evidences its pharmacological potential. Compounds that may affect allosterically NR function by binding to BF-3 open promising avenues to develop type-specific NR modulators.

Abstract

Much evidence has suggested that people conceive of time as flowing directionally in transverse space (e.g., from left to right for English speakers). However, this phenomenon has never been tested in a fully nonlinguistic paradigm where neither stimuli nor task use linguistic labels, which raises the possibility that time is directional only when reading/writing direction has been evoked. In the present study, English-speaking participants viewed a video where an actor sang a note while gesturing and reproduced the duration of the sung note by pressing a button. Results showed that the perceived duration of the note was increased by a long-distance gesture, relative to a short-distance gesture. This effect was equally strong for gestures moving from left to right and from right to left and was not dependent on gestures depicting movement through space; a weaker version of the effect emerged with static gestures depicting spatial distance. Since both our gesture stimuli and temporal reproduction task were nonlinguistic, we conclude that the spatial representation of time is nondirectional: Movement contributes, but is not necessary, to the representation of temporal information in a transverse timeline.

Abstract

Purpose: To investigate masking release for speech maskers for linguistically and phonetically close (English and Dutch) and distant (English and Mandarin) language pairs. Method: Thirty-two monolingual speakers of English with normal audiometric thresholds participated in the study. Data are reported for an English sentence recognition task in English and for Dutch and Mandarin competing speech maskers (Experiment 1) and noise maskers (Experiment 2) that were matched either to the long-term average speech spectra or to the temporal modulations of the speech maskers from Experiment 1. Results: Listener performance increased as the target-tomasker linguistic distance increased (English-in-English < English-in-Dutch < English-in-Mandarin). Conclusion: Spectral differences between maskers can account for some, but not all, of the variation in performance between maskers; however, temporal differences did not seem to play a significant role.

Abstract

Humans are the only species that uses communication to teach new knowledge to novices, usually to children (Tomasello, 1999 and Csibra and Gergely, 2006). This context of communication can employ “demonstrations” and it takes place with or without the help of objects (Clark, 1996). Previous research has focused on understanding the nature of demonstrations for very young children and with objects involved. However, little is known about the strategies used in demonstrating an action to an older child in comparison to another adult and without the use of objects, i.e., with gestures only. We tested if during demonstration of an action speakers use different degrees of iconicity in gestures for a child compared to an adult. 18 Italian subjects described to a camera how to make coffee imagining the listener as a 12-year-old child, a novice or an expert adult. While speech was found more informative both for the novice adult and for the child compared to the expert adult, the rate of iconic gestures increased and they were more informative and bigger only for the child compared to both of the adult conditions. Iconicity in gestures can be a powerful communicative strategy in teaching new knowledge to children in demonstrations and this is in line with claims that it can be used as a scaffolding device in grounding knowledge in experience (Perniss et al., 2010).

Abstract

We call those gestures “instrumental” that can enhance certain thinking processes of an agent by offering him representational models of his actions in a virtual space of imaginary performative possibilities. We argue that pointing is an instrumental gesture in that it represents geometrical information on one’s own gaze direction (i.e., a spatial model for attentional/ocular fixation/orientation), and provides a ritualized template for initiating gaze coordination and joint attention. We counter two possible objections, asserting respectively that the representational content of pointing is not constitutive, but derived from language, and that pointing directly solicits gaze coordination, without representing it. We consider two studies suggesting that attention and spatial perception are actively modified by one’s own pointing activity: the first study shows that pointing gestures help children link sets of objects to their corresponding number words; the second, that adults are faster and more accurate in counting when they point.

Abstract

Madagascar is located at the crossroads of the Asian and African worlds and is therefore of particular interest for studies on human population migration. Within the large human diversity of the Great Island, we focused our study on a particular ethnic group, the Antemoro. Their culture presents an important Arab-Islamic influence, but the question of an Arab biological inheritance remains unresolved. We analyzed paternal (n=129) and maternal (n=135) lineages of this ethnic group. Although the majority of Antemoro genetic ancestry comes from sub-Saharan African and Southeast Asian gene pools, we observed in their paternal lineages two specific haplogroups (J1 and T1) linked to Middle Eastern origins. This inheritance was restricted to some Antemoro sub-groups. Statistical analyses tended to confirm significant Middle Eastern genetic contribution. This study gives a new perspective to the large human genetic diversity in Madagascar

Abstract

Rapid response to danger holds an evolutionary advantage. In this positron emission tomography study, phobics were exposed to masked visual stimuli with timings that either allowed awareness or not of either phobic, fear-relevant (e.g., spiders to snake phobics), or neutral images. When the timing did not permit awareness, the amygdala responded to both phobic and fear-relevant stimuli. With time for more elaborate processing, phobic stimuli resulted in an addition of an affective processing network to the amygdala activity, whereas no activity was found in response to fear-relevant stimuli. Also, right prefrontal areas appeared deactivated, comparing aware phobic and fear-relevant conditions. Thus, a shift from top-down control to an affectively driven system optimized for speed was observed in phobic relative to fear-relevant aware processing.

Abstract

Word meaning processing in the brain involves ventrolateral temporal cortex, but a semantic contribution of the dorsal stream, especially frontocentral sensorimotor areas, has been controversial. We here examine brain activation during passive reading of object-related nouns from different semantic categories, notably animal, food, and tool words, matched for a range of psycholinguistic features. Results show ventral stream activation in temporal cortex along with category-specific activation patterns in both ventral and dorsal streams, including sensorimotor systems and adjacent pFC. Precentral activation reflected action-related semantic features of the word categories. Cortical regions implicated in mouth and face movements were sparked by food words, and hand area activation was seen for tool words, consistent with the actions implicated by the objects the words are used to speak about. Furthermore, tool words specifically activated the right cerebellum, and food words activated the left orbito-frontal and fusiform areas. We discuss our results in the context of category-specific semantic deficits in the processing of words and concepts, along with previous neuroimaging research, and conclude that specific dorsal and ventral areas in frontocentral and temporal cortex index visual and affective–emotional semantic attributes of object-related nouns and action-related affordances of their referent objects.

Abstract

Derivational morphology is a cross-linguistically dominant mechanism for word formation, combining existing words with derivational affixes to create new word forms. However, the neurocognitive mechanisms underlying the representation and processing of such forms remain unclear. Recent cross-linguistic neuroimaging research suggests that derived words are stored and accessed as whole forms, without engaging the left-hemisphere perisylvian network associated with combinatorial processing of syntactically and inflectionally complex forms. Using fMRI with a “simple listening” no-task procedure, we reexamine these suggestions in the context of the root-based combinatorially rich Italian lexicon to clarify the role of semantic transparency (between the derived form and its stem) and affix productivity in determining whether derived forms are decompositionally represented and which neural systems are involved. Combined univariate and multivariate analyses reveal a key role for semantic transparency, modulated by affix productivity. Opaque forms show strong cohort competition effects, especially for words with nonproductive suffixes (ventura, “destiny”). The bilateral frontotemporal activity associated with these effects indicates that opaque derived words are processed as whole forms in the bihemispheric language system. Semantically transparent words with productive affixes (libreria, “bookshop”) showed no effects of lexical competition, suggesting morphologically structured co-representation of these derived forms and their stems, whereas transparent forms with nonproductive affixes (pineta, pine forest) show intermediate effects. Further multivariate analyses of the transparent derived forms revealed affix productivity effects selectively involving left inferior frontal regions, suggesting that the combinatorial and decompositional processes triggered by such forms can vary significantly across languages.

Abstract

Real-time estimation of what we will do next is a crucial prerequisite
of purposive behavior. During the planning of goal-oriented actions, for
instance, the temporal and causal organization of upcoming subsequent
moves needs to be predicted based on our knowledge of events. A forward
computation of sequential structure is also essential for planning
contiguous discourse segments and syntactic patterns in language. The
neural encoding of sequential event knowledge and its domain dependency
is a central issue in cognitive neuroscience. Converging evidence shows
the involvement of a dedicated neural substrate, including the
prefrontal cortex and Broca's area, in the representation and the
processing of sequential event structure. After reviewing major
representational models of sequential mechanisms in action and language,
we discuss relevant neuropsychological and neuroimaging findings on the
temporal organization of sequencing and sequence processing in both
domains, suggesting that sequential event knowledge may be modularly
organized through prefrontal and frontal subregions.

Abstract

Dyslexia is a highly heritable learning disorder with a complex underlying genetic architecture. Over the past decade, researchers have pinpointed a number of candidate genes that may contribute to dyslexia susceptibility. Here, we provide an overview of the state of the art, describing how studies have moved from mapping potential risk loci, through identification of associated gene variants, to characterization of gene function in cellular and animal model systems. Work thus far has highlighted some intriguing mechanistic pathways, such as neuronal migration, axon guidance, and ciliary biology, but it is clear that we still have much to learn about the molecular networks that are involved. We end the review by highlighting the past, present, and future contributions of the Dutch Dyslexia Programme to studies of genetic factors. In particular, we emphasize the importance of relating genetic information to intermediate neurobiological measures, as well as the value of incorporating longitudinal and developmental data into molecular designs

Abstract

Recent genome wide association scans (GWAS) for reading and language abilities have pin-pointed promising new candidate loci. However, the potential contributions of these loci remain to be validated. In the present study, we tested 17 of the most significantly associated single nucleotide polymorphisms (SNPs) from these GWAS studies (p < 10−6 in the original studies) in a new independent population dataset from the Netherlands: known as FIOLA (Familial Influences On Literacy Abilities). This dataset comprised 483 children from 307 nuclear families, plus 505 adults (including parents of participating children), and provided adequate statistical power to detect the effects that were previously reported. The following measures of reading and language performance were collected: word reading fluency, nonword reading fluency, phonological awareness, and rapid automatized naming. Two SNPs (rs12636438, rs7187223) were associated with performance in multivariate and univariate testing, but these did not remain significant after correction for multiple testing. Another SNP (rs482700) was only nominally associated in the multivariate test. For the rest of the SNPs we did not find supportive evidence of association. The findings may reflect differences between our study and the previous investigations in respects such as the language of testing, the exact tests used, and the recruitment criteria. Alternatively, most of the prior reported associations may have been false positives. A larger scale GWAS meta-analysis than those previously performed will likely be required to obtain robust insights into the genomic architecture underlying reading and language.

Abstract

Although the typological contrast between Romance and Germanic languages as verb-framed versus satellite-framed (Talmy 1985) forms the background for many empirical studies on L2 acquisition, the inconclusive picture to date calls for more differentiated, fine-grained analyses. The present study goes beyond explanations based on this typological contrast and takes into account the sources from which spatial concepts are mainly derived in order to shape the trajectory traced by the entity in motion when moving through space: the entity in V-languages versus features of the ground in S-languages. It investigates why advanced French learners of English and German have difficulty acquiring the use of spatial concepts typical of the L2s to shape the trajectory, although relevant concepts can be expressed in their L1. The analysis compares motion event descriptions, based on the same sets of video clips, of L1 speakers of the three languages to L1 French-L2 English and L1 French-L2 German speakers, showing that the learners do not fully acquire the use of L2-specific spatial concepts. We argue that encoded concepts derived from the entity in motion vs. the ground lead to a focus on different aspects of motion events, in accordance with their compatibility with these sources, and are difficult to restructure in L2 acquisition.

Abstract

People often describe things that are similar as close and things that are dissimilar as far apart. Does the way people talk about similarity reveal something fundamental about the way they conceptualize it? Three experiments tested the relationship between similarity and spatial proximity that is encoded in metaphors in language. Similarity ratings for pairs of words or pictures varied as a function of how far apart the stimuli appeared on the computer screen, but the influence of distance on similarity differed depending on the type of judgments the participants made. Stimuli presented closer together were rated more similar during conceptual judgments of abstract entities or unseen object properties but were rated less similar during perceptual judgments of visual appearance. These contrasting results underscore the importance of testing predictions based on linguistic metaphors experimentally and suggest that our sense of similarity arises from our ability to combine available perceptual information with stored knowledge of experiential regularities.

Abstract

The idea that language shapes the way we think, often associated with Benjamin Whorf, has long been decried as not only wrong but also fundamentally wrong-headed. Yet, experimental evidence has reopened debate about the extent to which language influences nonlinguistic cognition, particularly in the domain of time. In this article, I will first analyze an influential argument against the Whorfian hypothesis and show that its anti-Whorfian conclusion is in part an artifact of conflating two distinct questions: Do we think in language? and Does language shape thought? Next, I will discuss crosslinguistic differences in spatial metaphors for time and describe experiments that demonstrate corresponding differences in nonlinguistic mental representations. Finally, I will sketch a simple learning mechanism by which some linguistic relativity effects appear to arise. Although people may not think in language, speakers of different languages develop distinctive conceptual repertoires as a consequence of ordinary and presumably universal neural and cognitive processes.

Abstract

Do people with different kinds of bodies think differently? According to the body-specificity hypothesis, people who interact with their physical environments in systematically different ways should form correspondingly different mental representations. In a test of this hypothesis, 5 experiments investigated links between handedness and the mental representation of abstract concepts with positive or negative valence (e.g., honesty, sadness, intelligence). Mappings from spatial location to emotional valence differed between right- and left-handed participants. Right-handers tended to associate rightward space with positive ideas and leftward space with negative ideas, but left-handers showed the opposite pattern, associating rightward space with negative ideas and leftward with positive ideas. These contrasting mental metaphors for valence cannot be attributed to linguistic experience, because idioms in English associate good with right but not with left. Rather, right- and left-handers implicitly associated positive valence more strongly with the side of space on which they could act more fluently with their dominant hands. These results support the body-specificity hypothesis and provide evidence for the perceptuomotor basis of even the most abstract ideas.

Abstract

Can children’s handedness influence how they represent abstract concepts like kindness and intelligence? Here we show that from an early age, right-handers associate rightward space more strongly with positive ideas and leftward space with negative ideas, but the opposite is true for left-handers. In one experiment, children indicated where on a diagram a preferred toy and a dispreferred toy should go. Right-handers tended to assign the preferred toy to a box on the right and the dispreferred toy to a box on the left. Left-handers showed the opposite pattern. In a second experiment, children judged which of two cartoon animals looked smarter (or dumber) or nicer (or meaner). Right-handers attributed more positive qualities to animals on the right, but left-handers to animals on the left. These contrasting associations between space and valence cannot be explained by exposure to language or cultural conventions, which consistently link right with good. Rather, right- and left-handers implicitly associated positive valence more strongly with the side of space on which they can act more fluently with their dominant hands. Results support the body-specificity hypothesis (Casasanto, 2009), showing that children with different kinds of bodies think differently in corresponding ways.

Abstract

How do we construct abstract ideas like justice, mathematics, or time-travel? In this paper we investigate whether mental representations that result from physical experience underlie people’s more abstract mental representations, using the domains of space and time as a testbed. People often talk about time using spatial language (e.g., a long vacation, a short concert). Do people also think about time using spatial representations, even when they are not using language? Results of six psychophysical experiments revealed that people are unable to ignore irrelevant spatial information when making judgments about duration, but not the converse. This pattern, which is predicted by the asymmetry between space and time in linguistic metaphors, was demonstrated here in tasks that do not involve any linguistic stimuli or responses. These findings provide evidence that the metaphorical relationship between space and time observed in language also exists in our more basic representations of distance and duration. Results suggest that our mental representations of things we can never see or touch may be built, in part, out of representations of physical experiences in perception and motor action.

Abstract

Young children answer questions with longer delays than adults do, and they don't reach typical adult response times until several years later. We hypothesized that this prolonged pattern of delay in children's timing results from competing demands: to give an answer, children must understand a question while simultaneously planning and initiating their response. Even as children get older and more efficient in this process, the demands on them increase because their verbal responses become more complex. We analyzed conversational question-answer sequences between caregivers and their children from ages 1;8 to 3;5, finding that children (1) initiate simple answers more quickly than complex ones, (2) initiate simple answers quickly from an early age, and (3) initiate complex answers more quickly as they grow older. Our results suggest that children aim to respond quickly from the start, improving on earlier-acquired answer types while they begin to practice later-acquired, slower ones.

Abstract

Learning a specific skill during childhood may partly determine the functional organization of the adult brain. This hypothesis led us to study oral language processing in illiterate subjects who, for social reasons, had never entered school and had no knowledge of reading or writing. In a brain activation study using PET and statistical parametric mapping, we compared word and pseudoword repetition in literate and illiterate subjects. Our study confirms behavioural evidence of different phonological processing in illiterate subjects. During repetition of real words, the two groups performed similarly and activated similar areas of the brain. In contrast, illiterate subjects had more difficulty repeating pseudowords correctly and did not activate the same neural structures as literates. These results are consistent with the hypothesis that learning the written form of language (orthography) interacts with the function of oral language. Our results indicate that learning to read and write during childhood influences the functional organization of the adult human brain.

Abstract

Last year was the 150th anniversary of Paul Broca's landmark case report on speech disorder that paved the way for subsequent studies of cortical localization of higher cognitive functions. However, many complex functions rely on the activity of distributed networks rather than single cortical areas. Hence, it is important to understand how brain regions are linked within large-scale networks and to map lesions onto connecting white matter tracts. To facilitate this network approach we provide a synopsis of classical neurological syndromes associated with frontal, parietal, occipital, temporal and limbic lesions. A review of tractography studies in a variety of neuropsychiatric disorders is also included. The synopsis is accompanied by a new atlas of the human white matter connections based on diffusion tensor tractography freely downloadable on http://www.natbrainlab.com. Clinicians can use the maps to accurately identify the tract affected by lesions visible on conventional CT or MRI. The atlas will also assist researchers to interpret their group analysis results. We hope that the synopsis and the atlas by allowing a precise localization of white matter lesions and associated symptoms will facilitate future work on the functional correlates of human neural networks as derived from the study of clinical populations. Our goal is to stimulate clinicians to develop a critical approach to clinico-anatomical correlative studies and broaden their view of clinical anatomy beyond the cortical surface in order to encompass the dysfunction related to connecting pathways.

Abstract

Development of proficient spoken language skills is disrupted by mutations of the FOXP2 transcription factor. A heterozygous missense mutation in the KE family causes speech apraxia, involving difficulty producing words with complex learned sequences of syllables. Manipulations in songbirds have helped to elucidate the role of this gene in vocal learning, but findings in non-human mammals have been limited or inconclusive. Here we performed a systematic study of ultrasonic vocalizations (USVs) of adult male mice carrying the KE family mutation. Using novel statistical tools, we found that Foxp2 heterozygous mice did not have detectable changes in USV syllable acoustic structure, but produced shorter sequences and did not shift to more complex syntax in social contexts where wildtype animals did. Heterozygous mice also displayed a shift in the position of their rudimentary laryngeal motor cortex layer-5 neurons. Our findings indicate that although mouse USVs are mostly innate, the underlying contributions of FoxP2 to sequencing of vocalizations are conserved with humans.

Abstract

Linguistic adaptation is a phenomenon where language representations change in response to linguistic input. Adaptation can occur on multiple linguistic levels such as phonology (tuning of phonotactic constraints), words (repetition priming), and syntax (structural priming). The persistent nature of these adaptations suggests that they may be a form of implicit learning and connectionist models have been developed which instantiate this hypothesis. Research on implicit learning, however, has also produced evidence that explicit chunk knowledge is involved in the performance of these tasks. In this review, we examine how these interacting implicit and explicit processes may change our understanding of language learning and processing.

Abstract

Both children and adults predict the content of upcoming language, suggesting that prediction is useful for learning as well as processing. We present an alternative model which can explain prediction behaviour as a by-product of language learning. We suggest that a consideration of language acquisition places important constraints on Pickering & Garrod's (P&G's) theory.

Abstract

RNAs processing other RNAs is very general in eukaryotes, but is not clear to what extent it is ancestral to eukaryotes. Here we focus on pre-mRNA splicing, one of the most important RNA-processing mechanisms in eukaryotes. In most eukaryotes splicing is predominantly catalysed by the major spliceosome complex, which consists of five uridine-rich small nuclear RNAs (U-snRNAs) and over 200 proteins in humans. Three major spliceosomal introns have been found experimentally in Giardia; one Giardia U-snRNA (U5) and a number of spliceosomal proteins have also been identified. However, because of the low sequence similarity between the Giardia ncRNAs and those of other eukaryotes, the other U-snRNAs of Giardia had not been found. Using two computational methods, candidates for Giardia U1, U2, U4 and U6 snRNAs were identified in this study and shown by RT-PCR to be expressed. We found that identifying a U2 candidate helped identify U6 and U4 based on interactions between them. Secondary structural modelling of the Giardia U-snRNA candidates revealed typical features of eukaryotic U-snRNAs. We demonstrate a successful approach to combine computational and experimental methods to identify expected ncRNAs in a highly divergent protist genome. Our findings reinforce the conclusion that spliceosomal small-nuclear RNAs existed in the last common ancestor of eukaryotes.

Abstract

Messenger ribonucleic acids (RNAs) contain a large number of cis-regulatory RNA elements that function in many types of post-transcriptional regulation. These cis-regulatory elements are often characterized by conserved structures and/or sequences. Although some classes are well known, given the wide range of RNA-interacting proteins in eukaryotes, it is likely that many new classes of cis-regulatory elements are yet to be discovered. An approach to this is to use computational methods that have the advantage of analysing genomic data, particularly comparative data on a large scale. In this study, a set of structural discovery algorithms was applied followed by support vector machine (SVM) classification. We trained a new classification model (CisRNA-SVM) on a set of known structured cis-regulatory elements from 3′-untranslated regions (UTRs) and successfully distinguished these and groups of cis-regulatory elements not been strained on from control genomic and shuffled sequences. The new method outperformed previous methods in classification of cis-regulatory RNA elements. This model was then used to predict new elements from cross-species conserved regions of human 3′-UTRs. Clustering of these elements identified new classes of potential cis-regulatory elements. The model, training and testing sets and novel human predictions are available at: http://mRNA.otago.ac.nz/CisRNA-SVM.

Abstract

This study examines the perception of paralinguistic intonational meanings deriving from Ohala’s Frequency Code (Experiment 1) and Gussenhoven’s Effort Code (Experiment 2) in British English and Dutch. Native speakers of British English and Dutch listened to a number of stimuli in their native language and judged each stimulus on four semantic scales deriving from these two codes: SELF-CONFIDENT versus NOT SELF-CONFIDENT, FRIENDLY versus NOT FRIENDLY (Frequency Code); SURPRISED versus NOT SURPRISED, and EMPHATIC versus NOT EMPHATIC (Effort Code). The stimuli, which were lexically equivalent across the two languages, differed in pitch contour, pitch register and pitch span in Experiment 1, and in pitch register, peak height, peak alignment and end pitch in Experiment 2. Contrary to the traditional view that the paralinguistic usage of intonation is similar across languages, it was found that British English and Dutch listeners differed considerably in the perception of “confident,” “friendly,” “emphatic,” and “surprised.” The present findings support a theory of paralinguistic meaning based on the universality of biological codes, which however acknowledges a languagespecific component in the implementation of these codes.

Abstract

RNA interference (RNAi) is a set of mechanisms which regulate gene expression in eukaryotes. Key elements of RNAi are small sense and antisense RNAs from 19 to 26 nucleotides generated from double-stranded RNAs. miRNAs are a major type of RNAi-associated small RNAs and are found in most eukaryotes studied to date. To investigate whether small RNAs associated with RNAi appear to be present in all eukaryotic lineages, and therefore present in the ancestral eukaryote, we studied two deep-branching protozoan parasites, Giardia intestinalis and Trichomonas vaginalis. Little is known about endogenous small RNAs involved in RNAi of these organisms. Using Illumina Solexa sequencing and genome-wide analysis of small RNAs from these distantly related deep-branching eukaryotes, we identified 10 strong miRNA candidates from Giardia and 11 from Trichomonas. We also found evidence of Giardia siRNAs potentially involved in the expression of variant-specific-surface proteins. In addition, 8 new snoRNAs from Trichomonas are identified. Our results indicate that miRNAs are likely to be general in ancestral eukaryotes, and therefore are likely to be a universal feature of eukaryotes.

Abstract

This paper investigates L2 learners’ use of intonation in reference maintenance in comparison to native speakers at three longitudinal points. Nominal referring expressions were elicited from two untutored Turkish learners of Dutch and five native speakers of Dutch via a film retelling task, and were analysed in terms of pitch span and word duration. Effects of two types of change in information states were examined, between new and given and between new and accessible. We found native-like use of word duration in both types of change early on but different performances between learners and development over time in one learner in the use of pitch span. Further, the use of morphosyntactic devices had different effects on the two learners. The inter-learner differences and late systematic use of pitch span, in spite of similar use of pitch span in learners’ L1 and L2, suggest that learning may play a role in the acquisition of intonation as a device for reference maintenance.

Abstract

The goal of this study is to examine how the degree of vowel-to-vowel coarticulation varies as a function of prosodic factors such as nuclear-pitch accent (accented vs. unaccented), level of prosodic boundary (Prosodic Word vs. Intermediate Phrase vs. Intonational Phrase), and position-in-prosodic-domain (initial vs. final). It is hypothesized that vowels in prosodically stronger locations (e.g., in accented syllables and at a higher prosodic boundary) are not only coarticulated less with their neighboring vowels, but they also exert a stronger influence on their neighbors. Measurements of tongue position for English /a i/ over time were obtained with Carsten’s electromagnetic articulography. Results showed that vowels in prosodically stronger locations are coarticulated less with neighboring vowels, but do not exert a stronger influence on the articulation of neighboring vowels. An examination of the relationship between coarticulation and duration revealed that (a) accent-induced coarticulatory variation cannot be attributed to a duration factor and (b) some of the data with respect to boundary effects may be accounted for by the duration factor. This suggests that to the extent that prosodically conditioned coarticulatory variation is duration-independent, there is no absolute causal relationship from duration to coarticulation. It is proposed that prosodically conditioned V-to-V coarticulatory reduction is another type of strengthening that occurs in prosodically strong locations. The prosodically driven coarticulatory patterning is taken to be part of the phonetic signatures of the hierarchically nested structure of prosody.

Abstract

This study tests whether potential differences in the perceptual robustness of speech sounds influence continuous-speech processes. Two phoneme-monitoring experiments examined place assimilation in Korean. In Experiment 1, Koreans monitored for targets which were either labials (/p,m/) or alveolars (/t,n/), and which were either unassimilated or assimilated to a following /k/ in two-word utterances. Listeners detected unaltered (unassimilated) labials faster and more accurately than assimilated labials; there was no such advantage for unaltered alveolars. In Experiment 2, labial–velar differences were tested using conditions in which /k/ and /p/ were illegally assimilated to a following /t/. Unassimilated sounds were detected faster than illegally assimilated sounds, but this difference tended to be larger for /k/ than for /p/. These place-dependent asymmetries suggest that differences in the perceptual robustness of segments play a role in shaping phonological patterns.

Abstract

English and Korean differ in how they lexicalize the components of motionevents. English characteristically conflates Motion with Manner, Cause, or Deixis, and expresses Path separately. Korean, in contrast, conflates Motion with Path and elements of Figure and Ground in transitive clauses for caused Motion, but conflates motion with Deixis and spells out Path and Manner separately in intransitive clauses for spontaneous motion. Children learningEnglish and Korean show sensitivity to language-specific patterns in the way they talk about motion from as early as 17–20 months. For example, learners of English quickly generalize their earliest spatial words — Path particles like up, down, and in — to both spontaneous and caused changes of location and, for up and down, to posture changes, while learners of Korean keep words for spontaneous and caused motion strictly separate and use different words for vertical changes of location and posture changes. These findings challenge the widespread view that children initially map spatial words directly to nonlinguistic spatial concepts, and suggest that they are influenced by the semantic organization of their language virtually from the beginning. We discuss how input and cognition may interact in the early phases of learning to talk about space.

Abstract

Models of speech production assume that syllables play a functional role in the process of word-form encoding in speech production. In this study, we investigate this claim and specifically provide evidence about the level at which syllables come into play. We report two studies using an odd-man-out variant of the implicit priming paradigm to examine the role of the syllable during the process of word formation. Our results show that this modified version of the implicit priming paradigm can trace the emergence of syllabic structure during spoken word generation. Comparing these results to prior syllable priming studies, we conclude that syllables emerge at the interface between phonological and phonetic encoding. The results are discussed in terms of the WEAVER++ model of lexical access.

Abstract

In the current paper, we asked at what level in the speech planning process speakers retrieve stored syllables. There is evidence that syllable structure plays an essential role in the phonological encoding of words (e.g., online syllabification and phonological word formation). There is also evidence that syllables are retrieved as whole units. However, findings that clearly pinpoint these effects to specific levels in speech planning are scarce. We used a naming variant of the implicit priming paradigm to contrast voice onset latencies for frequency-manipulated disyllabic Dutch pseudo-words. While prior implicit priming studies only manipulated the item's form and/or syllable structure overlap we introduced syllable frequency as an additional factor. If the preparation effect for syllables obtained in the implicit priming paradigm proceeds beyond phonological planning, i.e., includes the retrieval of stored syllables, then the preparation effect should differ for high- and low frequency syllables. The findings reported here confirm this prediction: Low-frequency syllables benefit significantly more from the preparation than high-frequency syllables. Our findings support the notion of a mental syllabary at a post-lexical level, between the levels of phonological and phonetic encoding.

Abstract

Although most bilinguals can translate with relative ease, the underlying neuro-cognitive processes are poorly understood. Using event-related brain potentials (ERPs) we investigated the temporal course of word translation. Participants translated words from and to their first (L1, Dutch) and second (L2, English) language while ERPs were recorded. Interlingual homographs (IHs) were included to introduce language conflict. IHs share orthographic form but have different meanings in L1 and L2 (e.g., room in Dutch refers to cream). Results showed that the brain distinguished between translation directions as early as 200 ms after word presentation: the P2 amplitudes were more positive in the L1L2 translation direction. The N400 was also modulated by translation direction, with more negative amplitudes in the L2L1 translation direction. Furthermore, the IHs were translated more slowly, induced more errors, and elicited more negative N400 amplitudes than control words. In a naming experiment, participants read aloud the same words in L1 or L2 while ERPs were recorded. Results showed no effect of either IHs or language, suggesting that task schemas may be crucially related to language control in translation. Furthermore, translation appears to involve conceptual processing in both translation directions, and the task goal appears to influence how words are processed.

Abstract

People spontaneously gesture when they speak (co-speech gestures) and when they solve problems silently (co-thought gestures). In this study, we first explored the relationship between these 2 types of gestures and found that individuals who produced co-thought gestures more frequently also produced co-speech gestures more frequently (Experiments 1 and 2). This suggests that the 2 types of gestures are generated from the same process. We then investigated whether both types of gestures can be generated from the representational use of the action generation process that also generates purposeful actions that have a direct physical impact on the world, such as manipulating an object or locomotion (the action generation hypothesis). To this end, we examined the effect of object affordances on the production of both types of gestures (Experiments 3 and 4). We found that individuals produced co-thought and co-speech gestures more often when the stimulus objects afforded action (objects with a smooth surface) than when they did not (objects with a spiky surface). These results support the action generation hypothesis for representational gestures. However, our findings are incompatible with the hypothesis that co-speech representational gestures are solely generated from the speech production process (the speech production hypothesis).

Abstract

This study investigated the motor strategy involved in mental rotation tasks by examining 2 types of spontaneous gestures (hand–object interaction gestures, representing the agentive hand action on an object, vs. object-movement gestures, representing the movement of an object by itself) and different types of verbal descriptions of rotation. Hand–object interaction gestures were produced earlier than object-movement gestures, the rate of both types of gestures decreased, and gestures became more distant from the stimulus object over trials (Experiments 1 and 3). Furthermore, in the first few trials, object-movement gestures increased, whereas hand–object interaction gestures decreased, and this change of motor strategies was also reflected in the type of verbal description of rotation in the concurrent speech (Experiment 2). This change of motor strategies was hampered when gestures were prohibited (Experiment 4). The authors concluded that the motor strategy becomes less dependent on agentive action on the object, and also becomes internalized over the course of the experiment, and that gesture facilitates the former process. When solving a problem regarding the physical world, adults go through developmental processes similar to internalization and symbolic distancing in young children, albeit within a much shorter time span.