Publications

Abstract

On seeing familiar persons, biographical (semantic) information is typically retrieved faster and more accurately than name information. Serial stage models explain this pattern by suggesting that access to the name follows the retrieval of semantic information. In contrast, interactive activation and competition (IAC) models hold that both processes start together but name retrieval is slower because of structural peculiarities. With a 2-choice go/no-go procedure based on a semantic and a name-related classification, the authors tested differential predictions of the 2 alternative models for reaction times (RTs) and lateralized readiness potentials (LRP). Both LRP (Experiment 1) and RT (Experiment 2) results are in line with IAC models of face identification and naming.

Abstract

We hypothesized that areas in the temporal lobe that have been implicated in the phonological processing of spoken words would also be activated during the generation and phonological processing of imagined speech. We tested this hypothesis using functional magnetic resonance imaging during a behaviorally controlled task of metrical stress evaluation. Subjects were presented with bisyllabic words and had to determine the alternation of strong and weak syllables. Thus, they were required to discriminate between weak-initial words and strong-initial words. In one condition, the stimuli were presented auditorily to the subjects (by headphones). In the other condition the stimuli were presented visually on a screen and subjects were asked to imagine hearing the word. Results showed activation of the supplementary motor area, inferior frontal gyrus (Broca's area) and insula in both conditions. In the superior temporal gyrus (STG) and in the superior temporal sulcus (STS) strong activation was observed during the auditory (perceptual) condition. However, a region located in the posterior part of the STS/STG also responded during the imagery condition. No activation of this same region of the STS was observed during a control condition which also involved processing of visually presented words, but which required a semantic decision from the subject. We suggest that processing of metrical stress, with or without auditory input, relies in part on cortical interface systems located in the posterior part of STS/STG. These results corroborate behavioral evidence regarding phonological loop involvement in auditory–verbal imagery.

Abstract

Different languages present a variety of ways of talking about emotional experience. Very commonly, feelings are described through the use of ‘body image constructions’ in which they are associated with processes in, or states of, specific body parts. The emotions and the body parts that are thought to be their locus and the kind of activity associated with these body parts vary cross-culturally. This study focuses on the meaning of three ‘body image constructions’ used to describe feelings similar to, but also different from, English ‘jealousy’, ‘envy’, and ‘covetousness’ in the West African language Ewe. It is demonstrated that a ‘moving body’, a pychologised eye, and red eyes are scripted for these feelings. It is argued that the expressions are not figurative and that their semantics provide good clues to understanding the cultural construction of emotions both emotions and the body.

Abstract

it is widely believed that the difference between regular and irregular verbs is restricted to form. This study questions that belief. We report a series of lexical statistics showing that irregular verbs cluster in denser regions in semantic space. Compared to regular verbs, irregular verbs tend to have more semantic neighbors that in turn have relatively many other semantic neighbors that are morphologically irregular. We show that this greater semantic density for irregulars is reflected in association norms, familiarity ratings, visual lexical-decision latencies, and word-naming latencies. Meta-analyses of the materials of two neuroimaging studies show that in these studies, regularity is confounded with differences in semantic density. Our results challenge the hypothesis of the supposed formal encapsulation of rules of inflection and support lines of research in which sensitivity to probability is recognized as intrinsic to human language.

Abstract

The notion of productivity is one which is central to the study of morphology.
It is a notion about which linguists frequently have intuitions. But it is a notion which still
remains somewhat problematic in the
literature on generative morphology some
15 years after Aronoff raised the issue in his (1976) monograph. In this paper we will review some of the definitions and measures of productivity discussed in the generative and pregenerative literature.
We will adopt the definition of productivity suggested by Schultink (1961) and propose
a number of statistical measures of productivity whose results, when
applied to a fixed corpus, accord nicely with our intuitive estimates of productivity, and which shed light on the quantitative weight of linguistic restrictions on word formation rules. Part of our
purpose here is also a very
simple one: to make
available a substantial
set of empirical data concerning
the productivity of
some of the major derivational
affixes of English.

Abstract

Changes in oscillatory brain dynamics can be studied by means of induced band power (IBP) analyses, which quantify event-related changes in amplitude of frequency-specific EEG rhythms. Such analyses capture EEG phenomena that are not part of traditional event-related potential measures. The present study investigated whether IBP changes in the δ, θ, and α frequency ranges are sensitive to syntactic violations in sentences. Subjects read sentences that either were correct or contained a syntactic violation. The violations were either grammatical gender agreement violations, where a prenominal adjective was not appropriately inflected for the head noun's gender, or number agreement violations, in which a plural quantifier was combined with a singular head noun. IBP changes of the concurrently measured EEG were computed in five frequency bands of 2-Hz width, individually adjusted on the basis of subjects' α peak, ranging approximately from 2 to 12 Hz. Words constituting a syntactic violation elicited larger increases in θ power than the same words in a correct sentence context, in an interval of 300–500 ms after word onset. Of all the frequency bands studied, this was true for the θ frequency band only. The scalp topography of this effect was different for different violations: following number violations a left-hemispheric dominance was found, whereas gender violations elicited a right-hemisphere dominance of the θ power increase. Possible interpretations of this effect are considered in closing.

Abstract

Oscillatory neuronal dynamics, observed in the human electroencephalogram (EEG) during language processing, have been related to the dynamic formation of functionally coherent networks that serve the role of integrating the different sources of information needed for understanding the linguistic input. To further explore the functional role of oscillatory synchrony during language processing, we quantified event-related EEG power changes induced by the presentation of open-class (OC) words and closed-class (CC) words in a wide range of frequencies (from 1 to 30 Hz), while subjects read a short story. Word presentation induced three oscillatory components: a theta power increase (4–7 Hz), an alpha power decrease (10–12 Hz), and a beta power decrease (16–21 Hz). Whereas the alpha and beta responses showed mainly quantitative differences between the two word classes, the theta responses showed qualitative differences between OC words and CC words: A theta power increase was found over left temporal areas for OC words, but not for CC words. The left temporal theta increase may index the activation of a network involved in retrieving the lexical–semantic properties of the OC items.

Abstract

Objective: To explore the reactivity of the theta and alpha rhythms during visuo-spatial working memory. Methods: One hundred and seventy-four subjects performed a delayed response task. They had to remember the spatial location of a target stimulus on a computer screen for a 1 or a 4 s retention interval. The target either remained visible throughout the entire interval (sensory trials) or disappeared after 150 ms (memory trials). Changes in induced band power (IBP) in the electroencephalogram (EEG) were analyzed in 4 narrow, individually adjusted frequency bands between 4 and 12 Hz. Results: After presentation of the target stimulus, a phasic power increase was found, irrespective of condition and delay interval, in the lower (roughly, 4–8 Hz) frequency bands, with a posterior maximum. During the retention interval, sustained occipital–parietal alpha power increase and frontal theta power decrease were found. Most importantly, the memory trials showed larger IBP decreases in the theta band over frontal electrodes than the sensory trials. Conclusions: The phasic power increase following target onset is interpreted to reflect encoding of the target location. The sustained theta decrease, which is larger for memory trials, is tentatively interpreted to reflect visuo-spatial working memory processes.

Abstract

By analyzing event-related changes in induced band power in narrow frequency bands of the human electroencephalograph, the present paper explores a possible functional role of the alpha and theta rhythms during the processing of words and of sentences. The results show a phasic power increase in the theta frequency range, together with a phasic power decrease in the alpha frequency range, following the presentation of words in a sentence. These effects may be related to word processing, either lexical or in relation to sentence context. Most importantly, there is a slow and highly frequency-specific increase in theta power as a sentence unfolds, possibly related to the formation of an episodic memory trace, or to incremental verbal working memory load.

Abstract

Previous research has suggested that the stimulus-preceding negativity (SPN) is largely independent of stimulus modality. In contrast, the scalp topography of the event related desynchronization (ERD) related to the anticipation of stimuli providing knowledge of results (KR) is modality dependent. These findings, combined with functional SPN research, lead to the hypothesis that anticipatory ERD reflects anticipatory attention, whereas the SPN mainly depends on the affective-motivational properties of the anticipated stimulus. To further investigate the prestimulus ERD, and compare this measure with the SPN, 12 participants performed a time-estimation task, and were informed about the quality of their time estimation by an auditory or a visual stimulus providing KR. The KR stimuli could be either intact or degraded. Auditory degraded KR stimuli were less effective than other KR stimuli in guiding subsequent behavior, and were preceded by a larger SPN. There were no effects of degradation on the SPN in the visual modality. Preceding auditory KR stimuli no ERD was present, whereas preceding visual stimuli an occipital ERD was found. However, contrary to expectation, the latter was larger preceding intact than preceding degraded stimuli. It is concluded that the data largely agree with an interpretation of the pre-KR SPN as a reflection of the anticipation of the affective-motivational value of KR stimuli, and of the prestimulus ERD as a perceptual anticipatory attention process.

Abstract

In many tasks the effects of frequency and age of acquisition (AoA) on reaction latencies are similar in size. However, in picture naming the AoA-effect is often significantly larger than expected on the basis of the frequency-effect. Previous explanations of this frequency-independent AoA-effect have attributed it to the organisation of the semantic system or to the way phonological word forms are stored in the mental lexicon. Using a semantic blocking paradigm, we show that semantic context effects on naming latencies are more pronounced for late-acquired than for early-acquired words. This interaction between AoA and naming context is likely to arise during lexical-semantic encoding, which we put forward as the locus for the frequency-independent AoA-effect.

Abstract

In the cyclic semantic blocking paradigm participants repeatedly name sets of objects with semantically related names (homogeneous sets) or unrelated names (heterogeneous sets). The naming latencies are typically longer in related than in unrelated sets. In we replicated this semantic blocking effect and demonstrated that the effect only arose after all objects of a set had been shown and named once. In , the objects of a set were presented simultaneously (instead of on successive trials). Evidence for semantic blocking was found in the naming latencies and in the gaze durations for the objects, which were longer in homogeneous than in heterogeneous sets. For the gaze-to-speech lag between the offset of gaze on an object and the onset of the articulation of its name, a repetition priming effect was obtained but no blocking effect. showed that the blocking effect for speech onset latencies generalized to new, previously unnamed lexical items. We propose that the blocking effect is due to refractory behaviour in the semantic system.

Abstract

We investigated the time course of conjunctive ''same''-''different'' judgements for visually presented object pairs by means of combined reaction time and on-line eye movement measurements. The analyses of viewing patterns, viewing times, and reaction times showed that participants engaged in a parallel self-terminating search for differences. In addition, the results obtained for objects differing in only one dimension suggest that processing times may depend on the relative codability of the stimulus dimensions. The results are reviewed in a broader framework in view of higher-order processes. We propose that overspecifications of colour, often found in object descriptions, may have an ''early'' visual rather than a ''late'' linguistic origin. In a parallel assessment of the detection materials, participants overspecified the objects' colour substantially more often than their size. We argue that referential overspecifications of colour are largely attributable to mechanisms of visual discrimination.

Abstract

Four experiments investigated the role of frequency information in compound production by independently varying the frequencies of the first and second constituent as well as the frequency of the compound itself. Pairs of Dutch noun-noun compounds were selected such that there was a maximal contrast for one frequency while matching the other two frequencies. In a position-response association task, participants first learned to associate a compound with a visually marked position on a computer screen. In the test phase, participants had to produce the associated compound in response to the appearance of the position mark, and we measured speech onset latencies. The compound production latencies varied significantly according to factorial contrasts in the frequencies of both constituting morphemes but not according to a factorial contrast in compound frequency, providing further evidence for decompositional models of speech production. In a stepwise regression analysis of the joint data of Experiments 1-4, however, compound frequency was a significant nonlinear predictor, with facilitation in the low-frequency range and a trend toward inhibition in the high-frequency range. Furthermore, a combination of structural measures of constituent frequencies and entropies explained significantly more variance than a strict decompositional model, including cumulative root frequency as the only measure of constituent frequency, suggesting a role for paradigmatic relations in the mental lexicon.

Abstract

Objective: Ample behavioral evidence suggests that distributional properties of the language environment influence the processing of speech. Yet, how these characteristics are reflected in neural processes remains largely unknown. The present ERP study investigates neurophysiological correlates of phonotactic probability: the distributional frequency of phoneme combinations. Methods: We employed an ERP measure indicative of experience-dependent auditory memory traces, the mismatch negativity (MMN). We presented pairs of non-words that differed by the degree of phonotactic probability in a codified passive oddball design that minimizes the contribution of acoustic processes. Results: In Experiment 1 the non-word with high phonotactic probability (notsel) elicited a significantly enhanced MMN as compared to the non-word with low phonotactic probability (notkel). In Experiment 2 this finding was replicated with a non-word pair with a smaller acoustic difference (notsel–notfel). An MMN enhancement was not observed in a third acoustic control experiment with stimuli having comparable phonotactic probability (so–fo). Conclusions: Our data suggest that auditory cortical responses to phoneme clusters are modulated by statistical regularities of phoneme combinations. Significance: This study indicates that the language environment is relevant in shaping the neural processing of speech. Furthermore, it provides a potentially useful design for investigating implicit phonological processing in children with anomalous language functions like dyslexia.

Abstract

In recent theorizing about language acquisition, children have often been credited with innate knowledge of rules that link thematic roles such as agent and patient to syntactic functions such as subject and direct object. These rules form the basis for the hypothesis that phrase-structure rules are established through 'semantic bootstrapping', and they are also invoked to explain the acquisition of verb subcategorization frames (for example, Pinker 1984). This study examines two versions of the hypothesis that linking rules are innate, pitting them against the alternative hypothesis that linking patterns are learned (as proposed, for example, by Foley and Van Valin 1984). The first version specifies linking rules through paired thematicsyntactic role hierarchies, and the second characterizes them as a function of verb semantic structure. When predictions of the two approaches are drawn out and tested against longitudinal spontaneous speech data from two children learning English, no support is found for the hypothesis that knowledge of linking is innate; ironically, in fact, the children had more trouble with verbs that should be easy to link than with those that should be more difficult. In contrast, the hypothesis that linking rules are learned is supported: at a relatively advanced age, the children began to produce errors that are best interpreted as overregularizations of a statistically predominant linking pattern to which they had become sensitive through linguistic experience.

Abstract

This thematic issue contains 11 papers first presented at a conference on The Structure of the Simple Clause in Language Acquisition', held at the Max Planck Institute in Nijmegen from November 9-13, 1987. The issue concentrates on first-language acquisition. Papers on developmental dysphasia. creolization, and adult language acquisition were also presented at the conference and are being published elsewhere.

Abstract

This paper compares some features of the interactional details of a Tenejapan (Mexico) court case with the features of social interaction characteristic of ordinary, casual encounters in this society. It is suggested that courtroom behaviour in Tenejapa is a very special form of interaction, in a context that uniquely allows for direct face-to-face confrontation in a society where a premium is placed on interactional restraint. Courtroom speech in Tenejapa directly contraverts norms and conventions that operate in other contexts, and women’s conventionalized polite ‘ways of putting things’ are here used sarcastically to be impolite. Thus, in this society, gender operates across contexts as a ‘master status’, but with gender meanings transformed in the different contexts: forms associated with superficial cooperation and agreement being used to emphasize lack of cooperation, disagreement, and hostility. The implications of this Tenejapan phenomenon for our understanding of the nature of relations between language and gender are explored.

Abstract

Prosodic influences on phonetic realizations of four Dutch consonants (/t d s z/) were examined. Sentences were constructed containing these consonants in word-initial position; the factors lexical stress, phrasal accent and prosodic boundary were manipulated between sentences. Eleven Dutch speakers read these sentences aloud. The patterns found in acoustic measurements of these utterances (e.g., voice onset time (VOT), consonant duration, voicing during closure, spectral center of gravity, burst energy) indicate that the low-level phonetic implementation of all four consonants is modulated by prosodic structure. Boundary effects on domain-initial segments were observed in stressed and unstressed syllables, extending previous findings which have been on stressed syllables alone. Three aspects of the data are highlighted. First, shorter VOTs were found for /t/ in prosodically stronger locations (stressed, accented and domain-initial), as opposed to longer VOTs in these positions in English. This suggests that prosodically driven phonetic realization is bounded by language-specific constraints on how phonetic features are specified with phonetic content: Shortened VOT in Dutch reflects enhancement of the phonetic feature {−spread glottis}, while lengthened VOT in English reflects enhancement of {+spread glottis}. Prosodic strengthening therefore appears to operate primarily at the phonetic level, such that prosodically driven enhancement of phonological contrast is determined by phonetic implementation of these (language-specific) phonetic features. Second, an accent effect was observed in stressed and unstressed syllables, and was independent of prosodic boundary size. The domain of accentuation in Dutch is thus larger than the foot. Third, within a prosodic category consisting of those utterances with a boundary tone but no pause, tokens with syntactically defined Phonological Phrase boundaries could be differentiated from the other tokens. This syntactic influence on prosodic phrasing implies the existence of an intermediate-level phrase in the prosodic hierarchy of Dutch.

Abstract

This study examines acoustic and aerodynamic characteristics of consonants in standard Korean and in Cheju, an endangered Korean language. The focus is on the well-known three-way distinction among voiceless stops (i.e., lenis, fortis, aspirated) and the two-way distinction between the voiceless fricatives /s/ and /s*/. While such a typologically unusual contrast among voiceless stops has long drawn the attention of phoneticians and phonologists, there is no single work in the literature that discusses a body of data representing a relatively large number of speakers. This study reports a variety of acoustic and aerodynamic measures obtained from 12 Korean speakers (four speakers of Seoul Korean and eight speakers of Cheju). Results show that, in addition to findings similar to those reported by others, there are three crucial points worth noting. Firstly, lenis, fortis, and aspirated stops are systematically differentiated from each other by the voice quality of the following vowel. Secondly, these stops are also differentiated by aerodynamic mechanisms. The aspirated and fortis stops are similar in supralaryngeal articulation, but employ a different relation between intraoral pressure and flow. Thirdly, our study suggests that the fricative /s/ is better categorized as “lenis” rather than “aspirated”. The paper concludes with a discussion of the implications of Korean data for theories of the voicing contrast and their phonological representations.

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

The scavenger receptor C-type lectin (SRCL) is an endothelial receptor that is similar in organization to type A scavenger receptors for modified low density lipoproteins but contains a C-type carbohydrate-recognition domain (CRD). Fragments of the receptor consisting of the entire extracellular domain and the CRD have been expressed and characterized. The extracellular domain is a trimer held together by collagen-like and coiled-coil domains adjacent to the CRD. The amino acid sequence of the CRD is very similar to the CRD of the asialoglycoprotein receptor and other galactose-specific receptors, but SRCL binds selectively to asialo-orosomucoid rather than generally to asialoglycoproteins. Screening of a glycan array and further quantitative binding studies indicate that this selectivity results from high affinity binding to glycans bearing the Lewis(x) trisaccharide. Thus, SRCL shares with the dendritic cell receptor DC-SIGN the ability to bind the Lewis(x) epitope. However, it does so in a fundamentally different way, making a primary binding interaction with the galactose moiety of the glycan rather than the fucose residue. SRCL shares with the asialoglycoprotein receptor the ability to mediate endocytosis and degradation of glycoprotein ligands. These studies suggest that SRCL might be involved in selective clearance of specific desialylated glycoproteins from circulation and/or interaction of cells bearing Lewis(x)-type structures with the vascular endothelium.

Abstract

Four cross-modal priming experiments and two forced-choice identification experiments investigated the use of suprasegmental cues to stress in the recognition of spoken English words, by native (English-speaking) and non- native (Dutch) listeners. Previous results had indicated that suprasegmental information was exploited in lexical access by Dutch but not by English listeners. For both listener groups, recognition of visually presented target words was faster, in comparison to a control condition, after stress-matching spoken primes, either monosyllabic (mus- from MUsic /muSEum) or bisyl labic (admi- from ADmiral/admiRAtion). For native listeners, the effect of stress-mismatching bisyllabic primes was not different from that of control primes, but mismatching monosyllabic primes produced partial facilitation. For non-native listeners, both bisyllabic and monosyllabic stress-mismatching primes produced partial facilitation. Native English listeners thus can exploit suprasegmental information in spoken-word recognition, but information from two syllables is used more effectively than information from one syllable. Dutch listeners are less proficient at using suprasegmental information in English than in their native language, but, as in their native language, use mono- and bisyllabic information to an equal extent. In forced-choice identification, Dutch listeners outperformed native listeners at correctly assigning a monosyllabic fragment (e.g., mus-) to one of two words differing in stress.

Abstract

We investigated cooperative problem solving in unrelated pairs of the cooperatively breeding cottontop tamarin, Saguinus oedipus, to assess the cognitive basis of cooperative behaviour in this species and to compare abilities with other apes and monkeys. A transparent apparatus was used that required extension of two handles at opposite ends of the apparatus for access to rewards. Resistance was applied to both handles so that two tamarins had to act simultaneously in order to receive rewards. In contrast to several previous studies of cooperation, both tamarins received rewards as a result of simultaneous pulling. The results from two experiments indicated that the cottontop tamarins (1) had a much higher success rate and efficiency of pulling than many of the other species previously studied, (2) adjusted pulling behaviour to the presence or absence of a partner, and (3) spontaneously developed sustained pulling techniques to solve the task. These findings suggest that cottontop tamarins understand the role of the partner in this cooperative task, a cognitive ability widely ascribed only to great apes. The cooperative social system of tamarins, the intuitive design of the apparatus, and the provision of rewards to both participants may explain the performance of the tamarins.

Abstract

Rhythmic categories such as morae in Japanese or stress units in English play a role in the perception of spoken
language. We examined this role in Japanese, since recent evidence suggests that morae may intervene as
structural units in word recognition. First, we found that traditional puns more often substituted part of a mora
than a whole mora. Second, when listeners reconstructed distorted words, e.g. panorama from panozema, responses
were faster and more accurate when only a phoneme was distorted (panozama, panorema) than when a
whole CV mora was distorted (panozema). Third, lexical decisions on the same nonwords were better predicted
by duration and number of phonemes from nonword uniqueness point to word end than by number of morae. Our
results indicate no role for morae in early spoken-word processing; we propose that rhythmic categories constrain
not initial lexical activation but subsequent processes of speech segmentation and selection among word candidates.

Abstract

Recognizing spoken language involves automatic activation of multiple candidate words. The process of selection between candidates is made more efficient by inhibition of embedded words (like egg in beg) that leave a portion of the input stranded (here, b). Results from European languages suggest that this inhibition occurs when consonants are stranded but not when syllables are stranded. The reason why leftover syllables do not lead to inhibition could be that in principle they might themselves be words; in European languages, a syllable can be a word. In Sesotho (a Bantu language), however, a single syllable cannot be a word. We report that in Sesotho, word recognition is inhibited by stranded consonants, but stranded monosyllables produce no more difficulty than stranded bisyllables (which could be Sesotho words). This finding suggests that the viability constraint which inhibits spurious embedded word candidates is not sensitive to language-specific word structure, but is universal.

Abstract

Three groups of listeners identified the vowel in CV and VC syllables produced by an American English talker. The listeners were (a) native speakers of American English, (b) native speakers of Australian English (different dialect), and (c) native speakers of Dutch (different language). The syllables were embedded in multispeaker babble at three signal-to-noise ratios (0 dB, 8 dB, and 16 dB). The identification performance of native listeners was significantly better than that of listeners with another language but did not significantly differ from the performance of listeners with another dialect. Dialect differences did however affect the type of perceptual confusions which listeners made; in particular, the Australian listeners’ judgements of vowel tenseness were more variable than the American listeners’ judgements, which may be ascribed to cross-dialectal differences in this vocalic feature. Although listening difficulty can result when speech input mismatches the native dialect in terms of the precise cues for and boundaries of phonetic categories, the difficulty is very much less than that which arises when speech input mismatches the native language in terms of the repertoire of phonemic categories available.

Abstract

One of a listener’s major tasks in understanding continuous speech in segmenting the speech signal into separate words. When listening conditions are difficult, speakers can help listeners by deliberately clear speech. We found that speakers do indeed attempt to makr word boundaries; moreover, they differentiate between word boundaries in a way which suggest they are sensitive to listener needs. Application of heuristic segmentation strategies makes word boundaries before strong syllables easiest for listeners to perceive; but under difficult listening conditions speakers pay more attention to marking word boundaries before weak syllables, i.e. they mark those boundaries which are otherwise particularly hard to perceive.

Abstract

Becoming a native listener is the necessary precursor to becoming a native speaker. Babies in the first year of life undertake a remarkable amount of work; by the time they begin to speak, they have perceptually mastered the phonological repertoire and phoneme co-occurrence probabilities of the native language, and they can locate familiar word-forms in novel continuous-speech contexts. The skills acquired at this early stage form a necessary part of adult listening. However, the same native listening skills also underlie problems in listening to a late-acquired non-native language, accounting for why in such a case listening (an innate ability) is sometimes paradoxically more difficult than, for instance, reading (a learned ability).

Abstract

SPEECH, in any language, is continuous; speakers provide few reliable cues to the boundaries of words, phrases, or other meaningful units. To understand speech, listeners must divide the continuous speech stream into portions that correspond to such units. This segmentation process is so basic to human language comprehension that psycholinguists long assumed that all speakers would do it in the same way. In previous research1,2, however, we reported that segmentation routines can be language-specific: speakers of French process spoken words syllable by syllable, but speakers of English do not. French has relatively clear syllable boundaries and syllable-based timing patterns, whereas English has relatively unclear syllable boundaries and stress-based timing; thus syllabic segmentation would work more efficiently in the comprehension of French than in the comprehension of English. Our present study suggests that at this level of language processing, there are limits to bilingualism: a bilingual speaker has one and only one basic language.

Abstract

It is a widely held belief that women talk more than men; but experimental evidence has suggested that this belief is mistaken. The present study investigated whether listener bias contributes to this mistake. Dialogues were recorded in mixed-sex and single-sex versions, and male and female listeners judged the proportions of talk contributed to the dialogues by each participant. Female contributions to mixed-sex dialogues were rated as greater than male contributions by both male and female listeners. Female contributions were more likely to be overestimated when they were speaking a dialogue part perceived as probably female than when they were speaking a dialogue part perceived as probably male. It is suggested that the misestimates are due to a complex of factors that may involve both perceptual effects such as misjudgment of rates of speech and sociological effects such as attitudes to social roles and perception of power relations.

Abstract

A model of speech segmentation in a stress language is proposed, according to which the occurrence of a strong syllable triggers segmentation of the speech signal, whereas occurrence of a weak syllable does not trigger segmentation. We report experiments in which listeners detected words embedded in nonsense bisyllables more slowly when the bisyllable had two strong syllables than when it had a strong and a weak syllable; mint was detected more slowly in mintayve than in mintesh. According to our proposed model, this result is an effect of segmentation: When the second syllable is strong, it is segmented from the first syllable, and successful detection of the embedded word therefore requires assembly of speech material across a segmentation position. Speech recognition models involving phonemic or syllabic recoding, or based on strictly left-to-right processes, do not predict this result. It is argued that segmentation at strong syllables in continuous speech recognition serves the purpose of detecting the most efficient locations at which to initiate lexical access. (C) 1988 by the American Psychological Association

Abstract

One of a listener's major tasks in understanding continuous speech is segmenting the speech signal into separate words. When listening conditions are difficult, speakers can help listeners by deliberately speaking more clearly. In four experiments, we examined how word boundaries are produced in deliberately clear speech. In an earlier report we showed that speakers do indeed mark word boundaries in clear speech, by pausing at the boundary and lengthening pre-boundary syllables; moreover, these effects are applied particularly to boundaries preceding weak syllables. In English, listeners use segmentation procedures which make word boundaries before strong syllables easier to perceive; thus marking word boundaries before weak syllables in clear speech will make clear precisely those boundaries which are otherwise hard to perceive. The present report presents supplementary data, namely prosodic analyses of the syllable following a critical word boundary. More lengthening and greater increases in intensity were applied in clear speech to weak syllables than to strong. Mean F0 was also increased to a greater extent on weak syllables than on strong. Pitch movement, however, increased to a greater extent on strong syllables than on weak. The effects were, however, very small in comparison to the durational effects we observed earlier for syllables preceding the boundary and for pauses at the boundary.

Abstract

The role of accent in reference resolution was investigated by monitoring eye fixations to lexical competitors (e.g., candy and candle ) as participants followed prerecorded instructions to move objects above or below fixed geometric shapes using a computer mouse. In Experiment 1, the first utterance instructed participants to move one object above or below a shape (e.g., “Put the candle/candy below the triangle”) and the second utterance contained an accented or deaccented definite noun phrase which referred to the same object or introduced a new entity (e.g., “Now put the CANDLE above the square” vs. “Now put the candle ABOVE THE SQUARE”). Fixations to the competitor (e.g., candy ) demonstrated a bias to interpret deaccented nouns as anaphoric and accented nouns as nonanaphoric. Experiment 2 used only accented nouns in the second instruction, varying whether the referent of this second instruction was the Theme of the first instruction (e.g., “Put the candle below the triangle”) or the Goal of the first instruction (e.g., “Put the necklace below the candle”). Participants preferred to interpret accented noun phrases as referring to a previously mentioned nonfocused entity (the Goal) rather than as introducing a new unmentioned entity.

Abstract

Participants' eye movements to four objects displayed on a computer screen were monitored as the participants clicked on the object named in a spoken instruction. The display contained pictures of the referent (e.g., a snake), a competitor that shared features with the visual representation associated with the referent's concept (e.g., a rope), and two distractor objects (e.g., a couch and an umbrella). As the first sounds of the referent's name were heard, the participants were more likely to fixate the visual competitor than to fixate either of the distractor objects. Moreover, this effect was not modulated by the visual similarity between the referent and competitor pictures, independently estimated in a visual similarity rating task. Because the name of the visual competitor did not overlap with the phonetic input, eye movements reflected word-object matching at the level of lexically activated perceptual features and not merely at the level of preactivated sound forms.

Abstract

Speech comprehension is resistant to acoustic distortion in the input, reflecting listeners' ability to adjust perceptual processes to match the speech input. For noise-vocoded sentences, a manipulation that removes spectral detail from speech, listeners' reporting improved from near 0% to 70% correct over 30 sentences (Experiment 1). Learning was enhanced if listeners heard distorted sentences while they knew the identity of the undistorted target (Experiments 2 and 3). Learning was absent when listeners were trained with nonword sentences (Experiments 4 and 5), although the meaning of the training sentences did not affect learning (Experiment 5). Perceptual learning of noise-vocoded speech depends on higher level information, consistent with top-down, lexically driven learning. Similar processes may facilitate comprehension of speech in an unfamiliar accent or following cochlear implantation.

Abstract

European cooperative effort seeks best practices architecture and procedures for international sites

Abstract

The article compares the integration of topic-related additive words at different stages of untutored L2 acquisition. Data stem from an ‘‘additive-elicitation task’’ that was designed in order to capture topic-related additive words in a context that is at the same time controlled for the underlying information structure and nondeviant from other kinds of narrative discourse. We relate the distinction between stressed and nonstressed forms of the German scope particles and adverbials auch ‘also’, noch ‘another’, wieder ‘again’, and immer noch ‘still’ to a uniform, information-structure-based principle: the stressed variants have scope over the topic information of the relevant utterances. It is then the common function of these additive words to express the additive link between the topic of the present utterance and some previous topic for which the same state of affairs is claimed to hold. This phenomenon has often been referred to as ‘‘contrastive topic,’’ but contrary to what this term suggests, these topic elements are by no means deviant from the default in coherent discourse. In the underlying information structure, the validity of some given state of affairs for the present topic must be under discussion. Topic-related additive words then express that the state of affairs indeed applies to this topic, their function therefore coming close to the function of assertion marking. While this functional correspondence goes along with the formal organization of the basic stages of untutored second-language acquisition, its expression brings linguistic constraints into conflict when the acquisition of finiteness pushes learners to reorganize their utterances according to target-language syntax.

Abstract

This paper examines the Papuan languages of Island Melanesia, with a view to considering their typological similarities and differences. The East Papuan languages are thought to be the descendants of the languages spoken by the original inhabitants of Island Melanesia, who arrived in the area up to 50,000 years ago. The Oceanic Austronesian languages are thought to have come into the area with the Lapita peoples 3,500 years ago. With this historical backdrop in view, our paper seeks to investigate the linguistic relationships between the scattered Papuan languages of Island Melanesia. To do this, we survey various structural features, including syntactic patterns such as constituent order in clauses and noun phrases and other features of clause structure, paradigmatic structures of pronouns, and the structure of verbal morphology. In particular, we seek to discern similarities between the languages that might call for closer investigation, with a view to establishing genetic relatedness between some or all of the languages. In addition, in examining structural relationships between languages, we aim to discover whether it is possible to distinguish between original Papuan elements and diffused Austronesian elements of these languages. As this is a vast task, our paper aims merely to lay the groundwork for investigation into these and related questions.

Abstract

We conducted four experiments to investigate the specificity of perceptual adjustments made to unusual speech sounds. Dutch listeners heard a female talker produce an ambiguous fricative [?] (between [f] and [s]) in [f]- or [s]-biased lexical contexts. Listeners with [f]-biased exposure (e.g., [witlo?]; from witlof, “chicory”; witlos is meaningless) subsequently categorized more sounds on an [εf]–[εs] continuum as [f] than did listeners with [s]-biased exposure. This occurred when the continuum was based on the exposure talker's speech (Experiment 1), and when the same test fricatives appeared after vowels spoken by novel female and male talkers (Experiments 1 and 2). When the continuum was made entirely from a novel talker's speech, there was no exposure effect (Experiment 3) unless fricatives from that talker had been spliced into the exposure talker's speech during exposure (Experiment 4). We conclude that perceptual learning about idiosyncratic speech is applied at a segmental level and is, under these exposure conditions, talker specific.

Abstract

Language is a uniquely human trait likely to have been a prerequisite for the development of human culture. The ability to develop articulate speech relies on capabilities, such as fine control of the larynx and mouth, that are absent in chimpanzees and other great apes. FOXP2 is the first gene relevant to the human ability to develop language. A point mutation in FOXP2 co-segregates with a disorder in a family in which half of the members have severe articulation difficulties accompanied by linguistic and grammatical impairment. This gene is disrupted by translocation in an unrelated individual who has a similar disorder. Thus, two functional copies of FOXP2 seem to be required for acquisition of normal spoken language. We sequenced the complementary DNAs that encode the FOXP2 protein in the chimpanzee, gorilla, orang-utan, rhesus macaque and mouse, and compared them with the human cDNA. We also investigated intraspecific variation of the human FOXP2 gene. Here we show that human FOXP2 contains changes in amino-acid coding and a pattern of nucleotide polymorphism, which strongly suggest that this gene has been the target of selection during recent human evolution.

Abstract

Investigation of the emotions entails reference to words and expressions conventionally used for the description of emotion experience. Important methodological issues arise for emotion researchers, and the issues are of similarly central concern in linguistic semantics more generally. I argue that superficial and/or inconsistent description of linguistic meaning can have seriously misleading results. This paper is firstly a critique of standards in emotion research for its tendency to underrate and ill-understand linguistic semantics. It is secondly a critique of standards in some approaches to linguistic semantics itself. Two major problems occur. The first is failure to distinguish between conceptually distinct meanings of single words, neglecting the well-established fact that a single phonological string can signify more than one conceptual category (i.e., that words can be polysemous). The second error involves failure to distinguish between two kinds of secondary uses of words: (1) those which are truly active “online” extensions, and (2) those which are conventionalised secondary meanings and not active (qua “extensions”) at all. These semantic considerations are crucial to conclusions one may draw about cognition and conceptualisation based on linguistic evidence.

Abstract

Central to cultural, social, and conceptual life are cognitive arti-facts, the perceptible structures which populate our world and mediate our navigation of it, complementing, enhancing, and altering available affordances for the problem-solving challenges of everyday life. Much work in this domain has concentrated on technological artifacts, especially manual tools and devices and the conceptual and communicative tools of literacy and diagrams. Recent research on hand gestures and other bodily movements which occur during speech shows that the human body serves a number of the functions of "cognitive technologies," affording the special cognitive advantages claimed to be associated exclusively with enduring (e.g., printed or drawn) diagrammatic representations. The issue is explored with reference to extensive data from video-recorded interviews with speakers of Lao in Vientiane, Laos, which show integration of verbal descriptions with complex spatial representations akin to diagrams. The study has implications both for research on cognitive artifacts (namely, that the body is a visuospatial representational resource not to be overlooked) and for research on ethnogenealogical knowledge (namely, that hand gestures reveal speakers' conceptualizations of kinship structure which are of a different nature to and not necessarily retrievable from the accompanying linguistic code).

Abstract

This article argues that it is not possible to establish distinctions between 'Lao', 'Thai', and 'Isan' as seperate languages or dialects by appealing to objective criteria. 'Lao', 'Thai', and 'Isan' are conceived linguistics varieties, and the ground-level reality reveals a great deal of variation, much of it not coinciding with the geographical boundaries of the 'Laos', 'Isan', and 'non-Isan Thailand' areas. Those who promote 'Lao', 'Thai', and/or 'Isan' as distinct linguistic varieties have subjective (e.g. political and/or sentimental) reasons for doing so. Objective linguistic criteria are not sufficient

Abstract

Anthropologists and linguists have long been aware that the body is explicitly referred to in conventional description of emotion in languages around the world. There is abundant linguistic data showing expression of emotions in terms of their imagined ‘locus’ in the physical body. The most important methodological issue in the study of emotions is language, for the ways people talk give us access to ‘folk descriptions’ of the emotions. ‘Technical terminology’, whether based on English or otherwise, is not excluded from this ‘folk’ status. It may appear to be safely ‘scientific’ and thus culturally neutral, but in fact it is not: technical English is a variety of English and reflects, to some extent, culture-specific ways of thinking (and categorising) associated with the English language. People — as researchers studying other people, or as people in real-life social association — cannot directly access the emotional experience of others, and language is the usual mode of ‘packaging’ one’s experience so it may be accessible to others. Careful description of linguistic data from as broad as possible a cross-linguistic base is thus an important part of emotion research. All people experience biological events and processes associated with certain thoughts (or, as psychologists say, ‘appraisals’), but there is more to ‘emotion’ than just these physiological phenomena. Speakers of some languages talk about their emotional experiences as if they are located in some internal organ such as ‘the liver’, yet they cannot localise feeling in this physical organ. This phenomenon needs to be understood better, and one of the problems is finding a method of comparison that allows us to compare descriptions from different languages which show apparently great formal and semantic variation. Some simple concepts including feel and body are universal or near-universal, and as such are good candidates for terms of description which may help to eradicate confusion and exoticism from cross-linguistic comparison and semantic typology. Semantic analysis reveals great variation in concepts of emotion across languages and cultures — but such analysis requires a sound and well-founded methodology. While leaving room for different approaches to the task, we suggest that such a methodology can be based on empirically established linguistic universal (or near-universal) concepts, and on ‘cognitive scenarios’ articulated in terms of these concepts. Also, we warn against the danger of exoticism involved in taking all body part references ‘literally’. Above all, we argue that what is needed is a combination of empirical cross-linguistic investigations and a theoretical and methodological awareness, recognising the impossibility of exploring other people’s emotions without keeping language in focus: both as an object and as a tool of study.

Abstract

This article addresses the recognition of reduced word forms, which are frequent in casual speech. We describe two experiments on Dutch showing that listeners only recognize highly reduced forms well when these forms are presented in their full context and that the probability that a listener recognizes a word form in limited context is strongly correlated with the degree of reduction of the form. Moreover, we show that the effect of degree of reduction can only partly be interpreted as the effect of the intelligibility of the acoustic signal, which is negatively correlated with degree of reduction. We discuss the consequences of our findings for models of spoken word recognition and especially for the role that storage plays in these models.

Abstract

Previous research has shown that the production of morphologically complex words in isolation is affected by the properties of morphologically, phonologically, or semantically similar words stored in the mental lexicon. We report five experiments with Dutch speakers that show that reading an inflectional word form in its linguistic context is also affected by analogical sets of formally similar words. Using the self-paced reading technique, we show in Experiments 1-3 that an incorrectly spelled suffix delays readers less if the incorrect spelling is in line with the spelling of verbal suffixes in other inflectional forms of the same verb. In Experiments 4 and 5, our use of the self-paced reading technique shows that formally similar words with different stems affect the reading of incorrect suffixal allomorphs on a given stem. These intra- and interparadigmatic effects in reading may be due to online processes or to the storage of incorrect forms resulting from analogical effects in production.

Abstract

Attention deficit/hyperactivity disorder (ADHD) is a common heritable disorder with a childhood onset. Molecular genetic studies of ADHD have previously focused on examining the roles of specific candidate genes, primarily those involved in dopaminergic pathways. We have performed the first systematic genomewide linkage scan for loci influencing ADHD in 126 affected sib pairs, using a ∼10-cM grid of microsatellite markers. Allele-sharing linkage methods enabled us to exclude any loci with a λs of ⩾3 from 96% of the genome and those with a λs of ⩾2.5 from 91%, indicating that there is unlikely to be a major gene involved in ADHD susceptibility in our sample. Under a strict diagnostic scheme we could exclude all screened regions of the X chromosome for a locus-specific λs of ⩾2 in brother-brother pairs, demonstrating that the excess of affected males with ADHD is probably not attributable to a major X-linked effect. Qualitative trait maximum LOD score analyses pointed to a number of chromosomal sites that may contain genetic risk factors of moderate effect. None exceeded genomewide significance thresholds, but LOD scores were >1.5 for regions on 5p12, 10q26, 12q23, and 16p13. Quantitative-trait analysis of ADHD symptom counts implicated a region on 12p13 (maximum LOD 2.6) that also yielded a LOD >1 when qualitative methods were used. A survey of regions containing 36 genes that have been proposed as candidates for ADHD indicated that 29 of these genes, including DRD4 and DAT1, could be excluded for a λs of 2. Only three of the candidates—DRD5, 5HTT, and CALCYON—coincided with sites of positive linkage identified by our screen. Two of the regions highlighted in the present study, 2q24 and 16p13, coincided with the top linkage peaks reported by a recent genome-scan study of autistic sib pairs.

Abstract

Developmental dyslexia, a specific impairment of reading ability despite adequate intelligence and educational opportunity, is one of the most frequent childhood disorders. Since the first documented cases at the beginning of the last century, it has become increasingly apparent that the reading problems of people with dyslexia form part of a heritable neurobiological syndrome. As for most cognitive and behavioural traits, phenotypic definition is fraught with difficulties and the genetic basis is complex, making the isolation of genetic risk factors a formidable challenge. Against such a background, it is notable that several recent studies have reported the localization of genes that influence dyslexia and other language-related traits. These investigations exploit novel research approaches that are relevant to many areas of human neurogenetics.

Abstract

Developmental disorders affecting speech and language are highly heritable, but very little is currently understood about the neuromolecular mechanisms that underlie these traits. Integration of data from diverse research areas, including linguistics, neuropsychology, neuroimaging, genetics, molecular neuroscience, developmental biology, and evolutionary anthropology, is becoming essential for unraveling the relevant pathways. Recent studies of the FOXP2 gene provide a case in point. Mutation of FOXP2 causes a rare form of speech and language disorder, and the gene appears to be a crucial regulator of embryonic development for several tissues. Molecular investigations of the central nervous system indicate that the gene may be involved in establishing and maintaining connectivity of corticostriatal and olivocerebellar circuits in mammals. Notably, it has been shown that FOXP2 was subject to positive selection in recent human evolution. Consideration of findings from multiple levels of analysis demonstrates that FOXP2 cannot be characterized as “the gene for speech,” but rather as one critical piece of a complex puzzle. This story gives a flavor of what is to come in this field and indicates that anyone expecting simple explanations of etiology or evolution should be prepared for some intriguing surprises.

Abstract

Developmental dyslexia is defined as a specific and significant impairment in reading ability that cannot be explained by deficits in intelligence, learning opportunity, motivation or sensory acuity. It is one of the most frequently diagnosed disorders in childhood, representing a major educational and social problem. It is well established that dyslexia is a significantly heritable trait with a neurobiological basis. The etiological mechanisms remain elusive, however, despite being the focus of intensive multidisciplinary research. All attempts to map quantitative-trait loci (QTLs) influencing dyslexia susceptibility have targeted specific chromosomal regions, so that inferences regarding genetic etiology have been made on the basis of very limited information. Here we present the first two complete QTL-based genome-wide scans for this trait, in large samples of families from the United Kingdom and United States. Using single-point analysis, linkage to marker D18S53 was independently identified as being one of the most significant results of the genome in each scan (P< or =0.0004 for single word-reading ability in each family sample). Multipoint analysis gave increased evidence of 18p11.2 linkage for single-word reading, yielding top empirical P values of 0.00001 (UK) and 0.0004 (US). Measures related to phonological and orthographic processing also showed linkage at this locus. We replicated linkage to 18p11.2 in a third independent sample of families (from the UK), in which the strongest evidence came from a phoneme-awareness measure (most significant P value=0.00004). A combined analysis of all UK families confirmed that this newly discovered 18p QTL is probably a general risk factor for dyslexia, influencing several reading-related processes. This is the first report of QTL-based genome-wide scanning for a human cognitive trait.

Abstract

Learning to talk is one of the most important milestones in human development, but we still have only a limited understanding of the way in which the process occurs. It normally takes just a few years to go from babbling newborn to fluent communicator. During this period, the child learns to produce a rich array of speech sounds through intricate control of articulatory muscles, assembles a vocabulary comprising thousands of words, and deduces the complicated structural rules that permit construction of meaningful sentences. All of this (and more) is achieved with little conscious effort.

Abstract

Purpose of review: The human brain supports acquisition mechanisms that can extract structural regularities implicitly from experience without the induction of an explicit model. Reber defined the process by which an individual comes to respond appropriately to the statistical structure of the input ensemble as implicit learning. He argued that the capacity to generalize to new input is based on the acquisition of abstract representations that reflect underlying structural regularities in the acquisition input. We focus this review of the implicit learning literature on studies published during 2004 and 2005. We will not review studies of repetition priming ('implicit memory'). Instead we focus on two commonly used experimental paradigms: the serial reaction time task and artificial grammar learning. Previous comprehensive reviews can be found in Seger's 1994 article and the Handbook of Implicit Learning. Recent findings: Emerging themes include the interaction between implicit and explicit processes, the role of the medial temporal lobe, developmental aspects of implicit learning, age-dependence, the role of sleep and consolidation. Summary: The attempts to characterize the interaction between implicit and explicit learning are promising although not well understood. The same can be said about the role of sleep and consolidation. Despite the fact that lesion studies have relatively consistently suggested that the medial temporal lobe memory system is not necessary for implicit learning, a number of functional magnetic resonance studies have reported medial temporal lobe activation in implicit learning. This issue merits further research. Finally, the clinical relevance of implicit learning remains to be determined.

Abstract

Genomewide quantitative-trait locus (QTL) linkage analysis was performed using a continuous measure of relative hand skill (PegQ) in a sample of 195 reading-disabled sibling pairs from the United Kingdom. This was the first genomewide screen for any measure related to handedness. The mean PegQ in the sample was equivalent to that of normative data, and PegQ was not correlated with tests of reading ability (correlations between −0.13 and 0.05). Relative hand skill could therefore be considered normal within the sample. A QTL on chromosome 2p11.2-12 yielded strong evidence for linkage to PegQ (empirical P=.00007), and another suggestive QTL on 17p11-q23 was also identified (empirical P=.002). The 2p11.2-12 locus was further analyzed in an independent sample of 143 reading-disabled sibling pairs, and this analysis yielded an empirical P=.13. Relative hand skill therefore is probably a complex multifactorial phenotype with a heterogeneous background, but nevertheless is amenable to QTL-based gene-mapping approaches.

Abstract

A locus on chromosome 2p12-16 has been implicated in dyslexia susceptibility by two independent linkage studies, including our own study of 119 nuclear twin-based families, each with at least one reading-disabled child. Nonetheless, no variant of any gene has been reported to show association with dyslexia, and no consistent clinical evidence exists to identify candidate genes with any strong a priori logic. We used 21 microsatellite markers spanning 2p12-16 to refine our 1-LOD unit linkage support interval to 12cM between D2S337 and D2S286. Then, in quantitative association analysis, two microsatellites yielded P values<0.05 across a range of reading-related measures (D2S2378 and D2S2114). The exon/intron borders of two positional candidate genes within the region were characterized, and the exons were screened for polymorphisms. The genes were Semaphorin4F (SEMA4F), which encodes a protein involved in axonal growth cone guidance, and OTX1, encoding a homeodomain transcription factor involved in forebrain development. Two non-synonymous single nucleotide polymorphisms were found in SEMA4F, each with a heterozygosity of 0.03. One intronic single nucleotide polymorphism between exons 12 and 13 of SEMA4F was tested for quantitative association, but no significant association was found. Only one single nucleotide polymorphism was found in OTX1, which was exonic but silent. Our data therefore suggest that linkage with reading disability at 2p12-16 is not caused by coding variants of SEMA4F or OTX1. Our study outlines the approach necessary for the identification of genetic variants causing dyslexia susceptibility in an epidemiological population of dyslexics.

Abstract

Dyslexia, a disorder of reading and spelling, is a heterogeneous neurological syndrome with a complex genetic and environmental aetiology. People with dyslexia differ in their individual profiles across a range of cognitive, physiological, and behavioural measures related to reading disability. Some or all of the subtypes of dyslexia might have partly or wholly distinct genetic causes. An understanding of the role of genetics in dyslexia could help to diagnose and treat susceptible children more effectively and rapidly than is currently possible and in ways that account for their individual disabilities. This knowledge will also give new insights into the neurobiology of reading and language cognition. Genetic linkage analysis has identified regions of the genome that might harbour inherited variants that cause reading disability. In particular, loci on chromosomes 6 and 18 have shown strong and replicable effects on reading abilities. These genomic regions contain tens or hundreds of candidate genes, and studies aimed at the identification of the specific causal genetic variants are underway.

Abstract

Theeffects of spatial filtering in functional magnetic resonance imaging were investigated by reevaluating the data of a previous study of episodic memory encoding at 2 × 2 × 4-mm3 resolution with use of a SPM99 analysis involving a Gaussian kernel of 8-mm full width at half maximum. In addition, a multisubject analysis of activated regions was performed by normalizing the functional images to an approximate Talairach brain atlas. In individual subjects, spatial filtering merged activations in anatomically separated brain regions. Moreover, small foci of activated pixels which originated from veins became blurred and hence indistinguishable from parenchymal responses. The multisubject analysis resulted in activation of the hippocampus proper, a finding which could not be confirmed by the activation maps obtained at high resolution. It is concluded that the validity of multisubject fMRI analyses can be considerably improved by first analyzing individual data sets at optimum resolution to assess the effects of spatial filtering and minimize the risk of signal contamination by macroscopically visible vessels.

Abstract

The role of gravity in spatial coordinate assignment and the mental representation of space were studiedin three experiments, varying different perceptual cues systematically: the retinal, the visual background, the vestibular, and proprioceptive information. Verbal descriptions of visually presented arrays were required under different head positions (straight/tilt) and under different gravitational conditions (gravity present/gravity absent). The results of two experiments conducted with 2 subjects who participated in a space flight revealed that subjects are able to adequately assign positions in space in the absence of gravitational information, and that they do this by using their head—retinal coordinates as primary references. This indicates that they cognitively adapted to the perceptually new situation.The findings from a third experiment conducted with a larger group of subjects under a condition in which the gravitational information was present but irrelevant to the task being solved (subjects were in a-horizontal 8upine-position) show that subjects, in general, are flexible in using cues other than gravitational ones as references when the latter cannot serve as a referential system. These findings, together with the observation that consistent spatial assignment is possible evenimmediately after first exposure to the perceptually totally novel situation of weightlessness, seem to suggest that the mental representation of space, onto which given perceptual information is mapped, is independent of a particular percept.

Abstract

BACKGROUND: There is a growing interest in the study of the genetic origins of comorbidity, a direct consequence of the recent findings of genetic loci that are seemingly linked to more than one disorder. There are several potential causes for these shared regions of linkage, but one possibility is that these loci may harbor genes with manifold effects. The established genetic correlation between reading disability (RD) and attention-deficit/hyperactivity disorder (ADHD) suggests that their comorbidity is due at least in part to genes that have an impact on several phenotypes, a phenomenon known as pleiotropy. METHODS: We employ a bivariate linkage test for selected samples that could help identify these pleiotropic loci. This linkage method was employed to carry out the first bivariate genome-wide analysis for RD and ADHD, in a selected sample of 182 sibling pairs. RESULTS: We found evidence for a novel locus at chromosome 14q32 (multipoint LOD=2.5; singlepoint LOD=3.9) with a pleiotropic effect on RD and ADHD. Another locus at 13q32, which had been implicated in previous univariate scans of RD and ADHD, seems to have a pleiotropic effect on both disorders. 20q11 is also suggested as a pleiotropic locus. Other loci previously implicated in RD or ADHD did not exhibit bivariate linkage. CONCLUSIONS: Some loci are suggested as having pleiotropic effects on RD and ADHD, while others might have unique effects. These results highlight the utility of this bivariate linkage method to study pleiotropy.

Abstract

In speaking and comprehending language, word information is retrieved from memory and combined into larger units (unification). Unification operations take place in parallel at the semantic, syntactic and phonological levels of processing. This article proposes a new framework that connects psycholinguistic models to a neurobiological account of language. According to this proposal the left inferior frontal gyrus (LIFG) plays an important role in unification. Research in other domains of cognition indicates that left prefrontal cortex has the necessary neurobiological characteristics for its involvement in the unification for language. I offer here a psycholinguistic perspective on the nature of language unification and the role of LIFG.

Abstract

Drawings of objects were presented in series of 54 each to 14 German speaking subjects with the tasks to indicate by button presses a) whether the grammatical gender of an object name was masculine ("der") or feminine ("die") and b) whether the depicted object was man-made or nature-made. The magnetoencephalogram (MEG) was recorded with a whole-head neuromagnetometer and task-specific patterns of brain activity were determined in the source space (Minimum Norm Estimates, MNE). A left-temporal focus of activity 150-275 ms after stimulus onset in the gender decision compared to the semantic classification task was discussed as indicating the retrieval of syntactic information, while a more expanded left hemispheric activity in the gender relative to the semantic task 300-625 ms after stimulus onset was discussed as indicating phonological encoding. A predominance of activity in the semantic task was observed over right fronto-central region 150-225 ms after stimulus-onset, suggesting that semantic and syntactic processes are prominent in this stage of lexical selection.

Abstract

Morphology is the study of the internal structure of words. A vigorous ongoing debate surrounds the question of how such internal structure is best accounted for: by means of lexical entries and deterministic symbolic rules, or by means of probabilistic subsymbolic networks implicitly encoding structural similarities in connection weights. In this review, we separate the question of subsymbolic versus symbolic implementation from the question of deterministic versus probabilistic structure. We outline a growing body of evidence, mostly external to the above debate, indicating that morphological structure is indeed intrinsically graded. By allowing probability into the grammar, progress can be made towards solving some long-standing puzzles in morphological theory.

Abstract

We advance the hypothesis here that the higher-than-average vocal pitch (FO) found for speech of Broca's aphasics in experimental settings is due, in part, to increased psychological stress. Two experiments were conducted which manipulated conversational constraints and the sentence forms to be produced by aphasic patients. Our study revealed significant differences between changes in vocal pitch of agrammatic Broca's aphasics versus those of Wernicke's aphasics and normal controls. It is suggested that the greater psychological stress experienced by the Broca's aphasics, but not by the Wernicke's aphasics, accounts for these observed differences.