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

Baseline correction plays an important role in past and current methodological debates in ERP research (e.g., the Tanner vs. Maess debate in the Journal of Neuroscience Methods), serving as a potential alternative to strong high‐pass filtering. However, the very assumptions that underlie traditional baseline also undermine it, implying a reduction in the signal‐to‐noise ratio. In other words, traditional baseline correction is statistically unnecessary and even undesirable. Including the baseline interval as a predictor in a GLM‐based statistical approach allows the data to determine how much baseline correction is needed, including both full traditional and no baseline correction as special cases. This reduces the amount of variance in the residual error term and thus has the potential to increase statistical power.

Abstract

M/EEG research using naturally spoken stories as stimuli has focused largely on speech and not
language processing. The temporal resolution of M/EEG is a two-edged sword, allowing for the
study of the fine acoustic structure of speech, yet easily overwhelmed by the temporal noise of
variation in constituent length. Recent theories on the neural encoding of linguistic structure
require the temporal resolution of M/EEG, yet suffer from confounds when studied on traditional,
heavily controlled stimuli. Recent methodological advances allow for synthesising naturalistic
designs and traditional, controlled designs into effective M/EEG research on naturalistic
language. In this review, we highlight common threads throughout the at-times distinct research
traditions of speech and language processing. We conclude by examining the tradeoffs and
successes of three M/EEG studies on fully naturalistic language paradigms and the future
directions they suggest.

Abstract

Although the N400 was originally discovered in a paradigm designed to elicit a P300 (Kutas and Hillyard, 1980), its relationship with the P300 and how both overlapping event-related potentials (ERPs) determine behavioral profiles is still elusive. Here we conducted an ERP (N = 20) and a multiple-response speed-accuracy tradeoff (SAT) experiment (N = 16) on distinct participant samples using an antonym paradigm (The opposite of black is white/nice/yellow with acceptability judgment). We hypothesized that SAT profiles incorporate processes of task-related decision-making (P300) and stimulus-related expectation violation (N400). We replicated previous ERP results (Roehm et al., 2007): in the correct condition (white), the expected target elicits a P300, while both expectation violations engender an N400 [reduced for related (yellow) vs. unrelated targets (nice)]. Using multivariate Bayesian mixed-effects models, we modeled the P300 and N400 responses simultaneously and found that correlation between residuals and subject-level random effects of each response window was minimal, suggesting that the components are largely independent. For the SAT data, we found that antonyms and unrelated targets had a similar slope (rate of increase in accuracy over time) and an asymptote at ceiling, while related targets showed both a lower slope and a lower asymptote, reaching only approximately 80% accuracy. Using a GLMM-based approach (Davidson and Martin, 2013), we modeled these dynamics using response time and condition as predictors. Replacing the predictor for condition with the averaged P300 and N400 amplitudes from the ERP experiment, we achieved identical model performance. We then examined the piecewise contribution of the P300 and N400 amplitudes with partial effects (see Hohenstein and Kliegl, 2015). Unsurprisingly, the P300 amplitude was the strongest contributor to the SAT-curve in the antonym condition and the N400 was the strongest contributor in the unrelated condition. In brief, this is the first demonstration of how overlapping ERP responses in one sample of participants predict behavioral SAT profiles of another sample. The P300 and N400 reflect two independent but interacting processes and the competition between these processes is reflected differently in behavioral parameters of speed and accuracy.

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

We present a critical review of computational models of generalization of simple grammar-like rules, such as ABA and ABB. In particular, we focus on models attempting to account for the empirical results of Marcus et al. (Science, 283(5398), 77–80 1999). In that study, evidence is reported of generalization behavior by 7-month-old infants, using an Artificial Language Learning paradigm. The authors fail to replicate this behavior in neural network simulations, and claim that this failure reveals inherent limitations of a whole class of neural networks: those that do not incorporate symbolic operations. A great number of computational models were proposed in follow-up studies, fuelling a heated debate about what is required for a model to generalize. Twenty years later, this debate is still not settled. In this paper, we review a large number of the proposed models. We present a critical analysis of those models, in terms of how they contribute to answer the most relevant questions raised by the experiment. After identifying which aspects require further research, we propose a list of desiderata for advancing our understanding on generalization.

Abstract

Different languages map semantic elements of spatial relations onto different lexical and syntactic units. These crosslinguistic differences raise important questions for language development in terms of how this variation is learned by children. We investigated how Turkish-, English-, and Japanese-speaking children (mean age 3;8) package the semantic elements of Manner and Path onto syntactic units when both the Manner and the Path of the moving Figure occur simultaneously and are salient in the event depicted. Both universal and language-specific patterns were evident in our data. Children used the semantic-syntactic mappings preferred by adult speakers of their own languages, and even expressed subtle syntactic differences that encode different relations between Manner and Path in the same way as their adult counterparts (i.e., Manner causing vs. incidental to Path). However, not all types of semantics-syntax mappings were easy for children to learn (e.g., expressing Manner and Path elements in two verbal clauses). In such cases, Turkish- and Japanese-speaking children frequently used syntactic patterns that were not typical in the target language but were similar to patterns used by English-speaking children, suggesting some universal influence. Thus, both language-specific and universal tendencies guide the development of complex spatial expressions.

Abstract

This article examines the grammar, use and meaning of fifteen verbs used in the Basic Locative Construction (BLC) of Likpe — a Ghana-Togo-Mountain language. The verbs fall into four semantic subclasses: (a) basic topological relations: t 'be.at', tk 'be.on', kpé 'be.in', and fi 'be.near'; (b) postural verbs: sí 'sit', ny 'stand', fáka 'hang', yóma 'hang', kps 'lean', fus 'squat', and labe 'lie'; (c) “distribution” verbs: kpó 'be spread, heaped,' and tí 'be covered'; and (d) “adhesion” verbs: má 'be griped, be fixed', mánkla 'be stuck to'. Likpe locative predications reflect an ontological commitment to the overall topological relation between Figure and Ground and are not focused just on the Figure or the Ground. Various factors determine the choice of “competing” verbs for particular scenarios: animacy, nonindividuation of the Figure, permanency of the configuration and the speaker's desire to be referentially precise or to present stereotypical information. It is demonstrated that in situations where there is a choice, speakers tend to use the more general verbs (stereotype information). The implications of this tendency for the development of a language from a multiverb language using several verbs (e.g., 15) in its BLC to using only a small-set of verbs in its BLC, just as some of Likpe's neighbors have done, are considered.

Abstract

This special issue is devoted to a relatively neglected topic in linguistics, namely the verbal component of locative statements. English tends, of course, to use a simple copula in utterances like “The cup is on the table”, but many languages, perhaps as many as half of the world's languages, have a set of alternate verbs, or alternate verbal affixes, which contrast in this slot. Often these are classificatory verbs of ‘sitting’, ‘standing’ and ‘lying’. For this reason, perhaps, Aristotle listed position among his basic (“noncomposite”) categories.

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

Ewe verbs covering the cutting and breaking domain divide into four morpho-syntactic classes that can be ranked according to agentivity. We demonstrate that the highly non-agentive break verbs participate in the causative-inchoative alternation while the highly agentive cut verbs do not, as expected from Guerssel et al.'s (1985) hypothesis. However, four verbs tso 'cut with precision', 'cut', 'snap-off', and dze 'split', are used transitively when an instrument is required for the severance to be effected, and intransitively when not. We reject a lexicalist analysis that would postulate polysemy for these verbs and argue for a construction approach.

Abstract

This special issue is devoted to a relatively neglected topic in linguistics, namely the verbal component of locative statements. English tends, of course, to use a simple copula in utterances like “The cup is on the table”, but many languages, perhaps as many as half of the world's languages, have a set of alternate verbs, or alternate verbal affixes, which contrast in this slot. Often these are classificatory verbs of 'sitting', 'standing' and 'lying'. For this reason, perhaps, Aristotle listed position among his basic (“noncomposite”) categories.

Abstract

Particles are little words that speakers use to signal the illocutionary force of utterances and/or express their attitude towards elements of the communicative situation, e.g. the addresses. This paper presents an overview of the classification, meaning and use of utterance particles in Ewe. It argues that they constitute a grammatical word class on functional and distributional grounds. The paper calls for a cross-cultural investigation of particles, especially in Africa, where they have been neglected for far too long.

Abstract

This paper presents the linguistic means of describing spatial relations in Ewe with particular emphasis on the grammar and meaning of adpositions. Ewe ( N iger-Congo ) has two sets of adpositions: prepositions, which have evolvedfrom verbs, and postpositions which have evolvedfrom nouns. The postpositions create places and are treated äs intrinsic parts or regions of the reference object in a spatial description. The prepositions provide the general orientation of a Figure (located object). It is demonstrated (hat spaiial relations, such äs those encapsulated in "the basic topological prepositions at, in and on" in English (Herskovits 1986: 9), are not encoded in single linguistic elements in Ewe, but are distributed over members of dijferent form classes in a syntagmatic string, The paper explores the r öle of compositionality andits interaction with pragmatics to yield understandings of spatial configurations in such a language where spatial meanings cannot he simply read off one form. The study also examines the diversity among languages in terms of the nature and obligatoriness of the coding of relational and ground Information in spatial constructions. It is argued that the ränge and type of distinctions discussed in the paper must be accountedfor in semantic typology and in the cross-linguistic investigation of spatial language and conceptualisation.

Abstract

Rapid automatized naming (RAN) of visual items is a powerful predictor of reading skills. However, the direction and locus of the association between RAN and reading is still largely unclear. Here we investigated whether literacy acquisition directly bolsters RAN efficiency for objects, adopting a strong methodological design, by testing three groups of adults matched in age and socioeconomic variables, who differed only in literacy/schooling: unschooled illiterate and ex-illiterate, and schooled literate adults. To investigate in a fine-grained manner whether and how literacy facilitates lexical retrieval, we orthogonally manipulated the word-form frequency (high vs. low) and phonological neighborhood density (dense vs. spare) of the objects’ names. We observed that literacy experience enhances the automaticity with which visual stimuli (e.g., objects) can be retrieved and named: relative to readers (ex-illiterate and literate), illiterate adults performed worse on RAN. Crucially, the group difference was exacerbated and significant only for those items that were of low frequency and from sparse neighborhoods. These results thus suggest that, regardless of schooling and age at which literacy was acquired, learning to read facilitates the access to and retrieval of phonological representations, especially of difficult lexical items.

Abstract

The brain's remarkable capacity to process spoken language virtually in real time requires fast and efficient information processing machinery. In this study, we investigated how frequency-specific brain dynamics relate to models of probabilistic language prediction during auditory narrative comprehension. We recorded MEG activity while participants were listening to auditory stories in Dutch. Using trigram statistical language models, we estimated for every word in a story its conditional probability of occurrence. On the basis of word probabilities, we computed how unexpected the current word is given its context (word perplexity) and how (un)predictable the current linguistic context is (word entropy). We then evaluated whether source-reconstructed MEG oscillations at different frequency bands are modulated as a function of these language processing metrics. We show that theta-band source dynamics are increased in high relative to low entropy states, likely reflecting lexical computations. Beta-band dynamics are increased in situations of low word entropy and perplexity possibly reflecting maintenance of ongoing cognitive context. These findings lend support to the idea that the brain engages in the active generation and evaluation of predicted language based on the statistical properties of the input signal.

Abstract

Referent accessibility influences expressions in speech and gestures in similar ways. Speakers mostly use richer forms as noun phrases (NPs) in speech and gesture more when referents have low accessibility, whereas they use reduced forms such as pronouns more often and gesture less when referents have high accessibility. We investigated the relationships between speech and gesture during reference tracking in a pro-drop language—Turkish. Overt pronouns were not strongly associated with accessibility but with pragmatic context (i.e., marking similarity, contrast). Nevertheless, speakers gestured more when referents were re-introduced versus maintained and when referents were expressed with NPs versus pronouns. Pragmatic context did not influence gestures. Further, pronouns in low-accessibility contexts were accompanied with gestures—possibly for reference disambiguation—more often than previously found for non-pro-drop languages in such contexts. These findings enhance our understanding of the relationships between speech and gesture at the discourse level.

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 main goal of the present study is to trace the consequences of local and global markedness for the processing of singular and plural nouns. Decompositional models such as proposed by (Pinker (1997); Pinker (1999)) and (Levelt et al. (1999)) predict a lexeme frequency effect and no effects of the frequencies of the singular and the plural forms. Experiments 1 and 4 reveal the expected lexeme frequency effect. Furthermore, in these experiments there are no clear independent effects of the frequencies of the inflected forms. However, the effects of Entropy and Relative Entropy that emerge from these experiments show that in production knowledge of the probabilities of the individual inflected forms do play a role, albeit indirectly. These entropy effects bear witness to the importance of paradigmatic organization of inflected forms in the mental lexicon, both at the level of individual lexemes (Entropy) and at the general level of the class of nouns (Relative Entropy).

Abstract

Autism is characterized by impairments in reciprocal social interaction and communication, and restricted and sterotyped patterns of interests and activities. Developmental difficulties are apparent before 3 years of age and there is evidence for strong genetic influences most likely involving more than one susceptibility gene. A two-stage genome search for susceptibility loci in autism was performed on 87 affected sib pairs plus 12 non-sib affected relative-pairs, from a total of 99 families identified by an international consortium. Regions on six chromosomes (4, 7, 10, 16, 19 and 22) were identified which generated a multipoint maximum lod score (MLS) > 1. A region on chromosome 7q was the most significant with an MLS of 3.55 near markers D7S530 and D7S684 in the subset of 56 UK affected sib-pair families, and an MLS of 2.53 in all 87 affected sib-pair families. An area on chromosome 16p near the telomere was the next most significant, with an MLS of 1.97 in the UK families, and 1.51 in all families. These results are an important step towards identifying genes predisposing to autism; establishing their general applicability requires further study.

Abstract

Patients with phosphoglucomutase (PGM1) deficiency, a congenital disorder of glycosylation (CDG) suffer from multiple disease phenotypes. Midline cleft defects are present at birth. Overtime, additional clinical phenotypes, which include severe hypoglycemia, hepatopathy, growth retardation, hormonal deficiencies, hemostatic anomalies, frequently lethal, early-onset of dilated cardiomyopathy and myopathy emerge, reflecting the central roles of the enzyme in (glycogen) metabolism and glycosylation. To delineate the pathophysiology of the tissue-specific disease phenotypes, we constructed a constitutive Pgm2 (mouse ortholog of human PGM1)-knockout (KO) mouse model using CRISPR-Cas9 technology. After multiple crosses between heterozygous parents, we were unable to identify homozygous life births in 78 newborn pups (P = 1.59897E-06), suggesting an embryonic lethality phenotype in the homozygotes. Ultrasound studies of the course of pregnancy confirmed Pgm2-deficient pups succumb before E9.5. Oral galactose supplementation (9 mg/mL drinking water) did not rescue the lethality. Biochemical studies of tissues and skin fibroblasts harvested from heterozygous animals confirmed reduced Pgm2 enzyme activity and abundance, but no change in glycogen content. However, glycomics analyses in serum revealed an abnormal glycosylation pattern in the Pgm2(+/-) animals, similar to that seen in PGM1-CDG.

Abstract

Speech planning is a sophisticated process. In dialog, it regularly starts in overlap with an incoming turn by a conversation partner. We show that planning spoken responses in overlap with incoming turns is associated with higher processing load than planning in silence. In a dialogic experiment, participants took turns with a confederate describing lists of objects. The confederate’s utterances (to which participants responded) were pre‐recorded and varied in whether they ended in a verb or an object noun and whether this ending was predictable or not. We found that response planning in overlap with sentence‐final verbs evokes larger task‐evoked pupillary responses, while end predictability had no effect. This finding indicates that planning in overlap leads to higher processing load for next speakers in dialog and that next speakers do not proactively modulate the time course of their response planning based on their predictions of turn endings. The turn‐taking system exerts pressure on the language processing system by pushing speakers to plan in overlap despite the ensuing increase in processing load.

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

This study investigates the potential influence of Latin syntax on the development of analytic verb forms in a well-defined and concrete instance of language contact, the Old French translation of a Latin Gospel. The data show that the formation of verb forms in the Old French was remarkably independent from the Latin original. While the Old French text closely follows the narrative of the Latin Gospel, its usage of compound verb forms is not dictated by the source text, as reflected e.g. in the quasi-omnipresence of the relative sequence finite verb + pp, which – with a few exceptions – all trace back to a different structure in the Latin text. Engels (VerenigdeStaten) Another important innovative difference in the Old French is the widespread use of aveir ‘have’ as an auxiliary, unknown in Latin. The article examines in detail the relation between the verbal forms in the two texts, showing that the translation is in line with of grammar. The usage of compound verb forms in the Old French Gospel is therefore autonomous rather than contact stimulated, let alone contact induced. The results challenge Blatt’s (1957) assumption identifying compound verb forms as a shared feature in European languages that should be ascribed to Latin influence.

Abstract

If a conversation is to proceed smoothly, the participants have to take turns to speak. Studies of conversation have shown that there are signals which speakers give to inform listeners that they are willing to hand over the conversational turn1−4. Some of these signals are part of the text (for example, completion of syntactic segments), some are non-verbal (such as completion of a gesture), but most are carried by the pitch, timing and intensity pattern of the speech; for example, both pitch and loudness tend to drop particularly low at the end of a speaker's turn. When one speaker interrupts another, the two can be said to be disputing who has the turn. Interruptions can occur because one participant tries to dominate or disrupt the conversation. But it could also be the case that mistakes occur in the way these subtle turn-yielding signals are transmitted and received. We demonstrate here that many interruptions in an interview with Mrs Margaret Thatcher, the British Prime Minister, occur at points where independent judges agree that her turn appears to have finished. It is suggested that she is unconsciously displaying turn-yielding cues at certain inappropriate points. The turn-yielding cues responsible are identified.

Abstract

A recent semantic theory of nominal concepts by Löbner [1] posits that–due to their inherent uniqueness and relationality properties–noun concepts can be classified into four concept types (CTs): sortal, individual, relational, functional. For sortal nouns the default determination is indefinite (a stone), for individual nouns it is definite (the sun), for relational and functional nouns it is possessive (his ear, his father). Incongruent determination leads to a concept type shift: his father (functional concept: unique, relational)–a father (sortal concept: non-unique, non-relational). Behavioral studies on CT shifts have demonstrated a CT congruence effect, with congruent determiners triggering faster lexical decision times on the subsequent noun than incongruent ones [2, 3]. The present ERP study investigated electrophysiological correlates of congruent and incongruent determination in German noun phrases, and specifically, whether the CT congruence effect could be indexed by such classic ERP components as N400, LAN or P600. If incongruent determination affects the lexical retrieval or semantic integration of the noun, it should be reflected in the amplitude of the N400 component. If, however, CT congruence is processed by the same neuronal mechanisms that underlie morphosyntactic processing, incongruent determination should trigger LAN or/and P600. These predictions were tested in two ERP studies. In Experiment 1, participants just listened to noun phrases. In Experiment 2, they performed a wellformedness judgment task. The processing of (in)congruent CTs (his sun vs. the sun) was compared to the processing of morphosyntactic and semantic violations in control conditions. Whereas the control conditions elicited classic electrophysiological violation responses (N400, LAN, & P600), CT-incongruences did not. Instead they showed novel concept-type specific response patterns. The absence of the classic ERP components suggests that CT-incongruent determination is not perceived as a violation of the semantic or morphosyntactic structure of the noun phrase.

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 compared the performance of young (college-aged) and older (50+years) speakers in a single object and a multiple object naming task and assessed their susceptibility to semantic and phonological context effects when producing words amidst semantically or phonologically similar or dissimilar words. In single object naming, there were no performance differences between the age groups. In multiple object naming, we observed significant age-related slowing, expressed in longer gazes to the objects and slower speech. In addition, the direction of the phonological context effects differed for the two groups. The results of a supplementary experiment showed that young speakers, when adopting a slow speech rate, coordinated their eye movements and speech differently from the older speakers. Our results imply that age-related slowing in connected speech is not a direct consequence of a slowing of lexical retrieval processes. Instead, older speakers might allocate more processing capacity to speech monitoring processes, which would slow down their concurrent speech planning processes

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

Previous research has demonstrated that language use can vary depending on the context of situation. The present paper extends this finding by comparing word predictability differences between 14 speech registers ranging from highly informal conversations to read-aloud books. We trained 14 statistical language models to compute register-specific word predictability and trained a register classifier on the perplexity score vector of the language models. The classifier distinguishes perfectly between samples from all speech registers and this result generalizes to unseen materials. We show that differences in vocabulary and sentence length cannot explain the speech register classifier’s performance. The combined results show that speech registers differ in word predictability.

Abstract

- * indicates joint first authorship - Abstract: A range of demographic variables influence how much speech young children hear. However, because studies have used vastly different sampling methods, quantitative comparison of interlocking demographic effects has been nearly impossible, across or within studies. We harnessed a unique collection of existing naturalistic, day-long recordings from 61 homes across four North American cities to examine language input as a function of age, gender, and maternal education. We analyzed adult speech heard by 3- to 20-month-olds who wore audio recorders for an entire day. We annotated speaker gender and speech register (child-directed or adult-directed) for 10,861 utterances from female and male adults in these recordings. Examining age, gender, and maternal education collectively in this ecologically-valid dataset, we find several key results. First, the speaker gender imbalance in the input is striking: children heard 2--3x more speech from females than males. Second, children in higher-maternal-education homes heard more child-directed speech than those in lower-maternal education homes. Finally, our analyses revealed a previously unreported effect: the proportion of child-directed speech in the input increases with age, due to a decrease in adult-directed speech with age. This large-scale analysis is an important step forward in collectively examining demographic variables that influence early development, made possible by pooled, comparable, day-long recordings of children's language environments. The audio recordings, annotations, and annotation software are readily available for re-use and re-analysis by other researchers.

Abstract

Most people like symmetry, and symmetry has been extensively used in visual art and architecture. In this study, we compared preference for images of abstract and familiar objects in the original format or when containing perfect bilateral symmetry. We created pairs of images for different categories: male faces, female faces, polygons, smoothed version of the polygons, flowers, and landscapes. This design allows us to compare symmetry preference in different domains. Each observer saw all categories randomly interleaved but saw only one of the two images in a pair. After recording preference, we recorded a rating of how salient the symmetry was for each image, and measured how quickly observers could decide which of the two images in a pair was symmetrical. Results reveal a general preference for symmetry in the case of shapes and faces. For landscapes, natural (no perfect symmetry) images were preferred. Correlations with judgments of saliency were present but generally low, and for landscapes the salience of symmetry was negatively related to preference. However, even within the category where symmetry was not liked (landscapes), the separate analysis of original and modified stimuli showed an interesting pattern: Salience of symmetry was correlated positively (artificial) or negatively (original) with preference, suggesting different effects of symmetry within the same class of stimuli based on context and categorization.

Abstract

It is known that cortical networks operate on the edge of instability, in which oscillations can appear. However, the influence of this dynamic regime on performance in decision making, is not well understood. In this work, we propose a population model of decision making based on a winner-take-all mechanism. Using this model, we demonstrate that local slow inhibition within the competing neuronal populations can lead to Hopf bifurcation. At the edge of instability, the system exhibits ambiguity in the decision making, which can account for the perceptual switches observed in human experiments. We further validate this model with fMRI datasets from an experiment on semantic priming in perception of ambivalent (male versus female) faces. We demonstrate that the model can correctly predict the drop in the variance of the BOLD within the Superior Parietal Area and Inferior Parietal Area while watching ambiguous visual stimuli.

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

The murine homologues of the loci for McLeod syndrome (XK), Dent's disease (CICN5), and synaptophysin (SYP) have been mapped to the proximal region of the mouse X chromosome and positioned with respect to other conserved loci in this region using a total of 948 progeny from two separate Mus musculus x Mus spretus backcrosses. In the mouse, the order of loci and evolutionary breakpoints (EB) has been established as centromere-(DXWas70, DXHXF34h)-EB-Clcn5-(Syp, DXMit55, DXMit26)-Tfe3-Gata1-EB-Xk-Cybb-telomere. In the proximal region of the human X chromosome short arm, the position of evolutionary breakpoints with respect to key loci has been established as DMD-EB-XK-PFC-EB-GATA1-C1CN5-EB-DXS1272E-ALAS2-E B-DXF34-centromere. These data have enabled us to construct a high-resolution genetic map for the approximately 3-cM interval between DXWas70 and Cybb on the mouse X chromosome, which encompasses 10 loci. This detailed map demonstrates the power of high-resolution genetic mapping in the mouse as a means of determining locus order in a small chromosomal region and of providing an accurate framework for the construction of physical maps.

Abstract

Linguistic diversity, now and in the past, is widely regarded to be independent of biological changes that took place after the emergence of Homo sapiens. We show converging evidence from paleoanthropology, speech biomechanics, ethnography, and historical linguistics that labiodental sounds (such as “f” and “v”) were innovated after the Neolithic. Changes in diet attributable to food-processing technologies modified the human bite from an edge-to-edge configuration to one that preserves adolescent overbite and overjet into adulthood. This change favored the emergence and maintenance of labiodentals. Our findings suggest that language is shaped not only by the contingencies of its history, but also by culturally induced changes in human biology.

Abstract

Humans are nature’s most intelligent and prolific users of external props and aids (such as written texts, slide-rules and software packages). Here we introduce a method for investigating how people make active use of their task environment during problem-solving and apply this approach to the non-verbal Raven Advanced Progressive Matrices test for fluid intelligence. We designed a click-and-drag version of the Raven test in which participants could create different external spatial configurations while solving the puzzles. In our first study, we observed that the click-and-drag test was better than the conventional static test at predicting academic achievement of university students. This pattern of results was partially replicated in a novel sample. Importantly, environment-altering actions were clustered in between periods of apparent inactivity, suggesting that problem-solvers were delicately balancing the execution of internal and external cognitive operations. We observed a systematic relationship between this critical phasic temporal signature and improved test performance. Our approach is widely applicable and offers an opportunity to quantitatively assess a powerful, although understudied, feature of human intelligence: our ability to use external objects, props and aids to solve complex problems.

Abstract

In recent years, neuroimaging research in cognitive neuroscience has increasingly used multivariate pattern analysis (MVPA) to investigate higher cognitive functions. Here we present DDTBOX, an open-source MVPA toolbox for electroencephalography (EEG) data. DDTBOX runs under MATLAB and is well integrated with the EEGLAB/ERPLAB and Fieldtrip toolboxes (Delorme and Makeig 2004; Lopez-Calderon and Luck 2014; Oostenveld et al. 2011). It trains support vector machines (SVMs) on patterns of event-related potential (ERP) amplitude data, following or preceding an event of interest, for classification or regression of experimental variables. These amplitude patterns can be extracted across space/electrodes (spatial decoding), time (temporal decoding), or both (spatiotemporal decoding). DDTBOX can also extract SVM feature weights, generate empirical chance distributions based on shuffled-labels decoding for group-level statistical testing, provide estimates of the prevalence of decodable information in the population, and perform a variety of corrections for multiple comparisons. It also includes plotting functions for single subject and group results. DDTBOX complements conventional analyses of ERP components, as subtle multivariate patterns can be detected that would be overlooked in standard analyses. It further allows for a more explorative search for information when no ERP component is known to be specifically linked to a cognitive process of interest. In summary, DDTBOX is an easy-to-use and open-source toolbox that allows for characterising the time-course of information related to various perceptual and cognitive processes. It can be applied to data from a large number of experimental paradigms and could therefore be a valuable tool for the neuroimaging community.

Abstract

The Mayan languages Tzeltal and Yucatec have large form classes of “dispositional” roots which lexicalize spatial properties such as orientation, support/suspension/blockage of motion, and configurations of parts of an entity with respect to other parts. But speakers of the two languages deploy this common lexical resource quite differently. The roots are used in both languages to convey dispositional information (e.g., answering “how” questions), but Tzeltal speakers also use them in canonical locative descriptions (e.g., answering “where” questions), whereas Yucatec speakers only use dispositionals in locative predications when prompted by the context to focus on dispositional properties. We describe the constructions used in locative and dispositional descriptions in response to two different picture stimuli sets. Evidence against the proposal that Tzeltal uses dispositionals to compensate for its single, semantically generic preposition (Brown 1994; Grinevald 2006) comes from the finding that Tzeltal speakers use relational spatial nominals in the “Ground phrase” — the expression of the place at which an entity is located — about as frequently as Yucatec speakers. We consider several alternative hypotheses, including a possible larger typological difference that leads Tzeltal speakers, but not Yucatec speakers, to prefer “theme-specific” verbs not just in locative predications, but in any predication involving a theme argument.

Abstract

We examine universals and crosslinguistic variation in constraints on event segmentation. Previous typological studies have focused on segmentation into syntactic (Pawley 1987) or intonational units (Givón 1991). We argue that the correlation between such units and semantic/conceptual event representations is language-specific. As an alternative, we introduce the MACRO-EVENT PROPERTY (MEP): a construction has the MEP if it packages event representations such that temporal operators necessarily have scope over all subevents. A case study on the segmentation of motion events into macro-event expressions in eighteen genetically and typologically diverse languages has produced evidence of two types of design principles that impact motion-event segmentation: language-specific lexicalization patterns and universal constraints on form-to-meaning mapping.

Abstract

There are currently a number of psycholinguistic models in which processing at a particular level of representation is characterized by the generation of multiple outputs, with resolution involving the use of information from higher levels of processing. Surprisingly, models with this architecture have been characterized as autonomous within the domain of word recognition and as interactive within the domain of sentence processing. We suggest that the apparent internal confusion is not, as might be assumed, due to fundamental differences between lexical and syntactic processing. Rather, we believe that the labels in each domain were chosen in order to obtain maximal contrast between a new model and the model or models that were currently dominating the field.

Abstract

There are currently a number of psycholinguistic models in which processing at a particular level of representation is characterized by the generation of multiple outputs, with resolution - but not generation - involving the use of information from higher levels of processing. Surprisingly, models with this architecture have been characterized as autonomous within the domain of word recognition but as interactive within the domain of sentence processing. We suggest that the apparent confusion is not, as might be assumed, due to fundamental differences between lexical and syntactic processing. Rather, we believe that the labels in each domain were chosen in order to obtain maximal contrast between a new model and the model or models that were currently dominating the field. The contradiction serves to highlight the inadequacy of a simple autonomy/interaction dichotomy for characterizing the architectures of current processing models.

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

Disfluencies, like 'uh', have been shown to help listeners anticipate reference to low-frequency words. The associative account of this 'disfluency bias' proposes that listeners learn to associate disfluency with low-frequency referents based on prior exposure to non-arbitrary disfluency distributions (i.e., greater probability of low-frequency words after disfluencies). However, there is limited evidence for listeners actually tracking disfluency distributions online. The present experiments are the first to show that adult listeners, exposed to a typical or more atypical disfluency distribution (i.e., hearing a talker unexpectedly say uh before high-frequency words), flexibly adjust their predictive strategies to the disfluency distribution at hand (e.g., learn to predict high-frequency referents after disfluency). However, when listeners were presented with the same atypical disfluency distribution but produced by a non-native speaker, no adjustment was observed. This suggests pragmatic inferences can modulate distributional learning, revealing the flexibility of, and constraints on, distributional learning in incremental language comprehension.

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

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

Previous studies have shown a significant association between reading skills and the performance on visuo-motor tasks. In order to clarify whether reading and writing skills modulate non-linguistic domains, we investigated the performance of two literacy groups on a visuo-motor integration task with non-linguistic stimuli. Twenty-one illiterate participants and twenty matched literate controls were included in the experiment. Subjects were instructed to use the right or the left index finger to point to and touch a randomly presented target on the right or left side of a touch screen. The results showed that the literate subjects were significantly faster in detecting and touching targets on the left compared to the right side of the screen. In contrast, the presentation side did not affect the performance of the illiterate group. These results lend support to the idea that having acquired reading and writing skills, and thus a preferred left-to-right reading direction, influences visual scanning. (JINS, 2007, 13, 359–364

Abstract

This paper investigates stress assignment in Dutch aphasic patients in non-word repetition, as well as in real-word and non-word reading. Performance on the non-word reading task was similar for the aphasic patients and the control group, as mainly regular stress was assigned to the targets. However, there were group differences on the real-word reading and non-word repetition tasks. Unlike the non-brain-damaged group, the patients showed a strong regularization tendency in their repetition of irregular patterns. The patients’ stress error patterns suggest an impairment in retention or retrieval of targets with irregular stress patterns. Limited verbal short-term memory is proposed as a possible underlying cause for the stress difficulties.

Abstract

Interference in picture naming occurs from representing a partner's preparations to speak (Gambi, van de Cavey, & Pickering, 2015). We tested the origins of this interference using a simple non-communicative joint naming task based on Gambi et al. (2015), where response latencies indexed interference from partner task and partner speech content, and eye fixations to partner objects indexed overt attention. Experiment 1 contrasted a partner-present condition with a control partner-absent condition to establish the role of the partner in eliciting interference. For latencies, we observed interference from the partner's task and speech content, with interference increasing due to partner task in the partner-present condition. Eye-tracking measures showed that interference in naming was not due to overt attention to partner stimuli but to broad expectations about likely utterances. Experiment 2 examined whether an equivalent non-verbal task also elicited interference, as predicted from a language as joint action framework. We replicated the finding of interference due to partner task and again found no relationship between overt attention and interference. These results support Gambi et al. (2015). Individuals co-represent a partner's task while speaking, and doing so does not require overt attention to partner stimuli.

Abstract

Existing work shows that readers often interpret grammatical errors (e.g., The key to the cabinets *were shiny) and sentence-level blends (“without-blend”: Claudia left without her headphones *off) in a non-literal fashion, inferring that a more frequent or more canonical utterance was intended instead. This work examines how interlocutor identity affects the processing and interpretation of anomalous sentences. We presented anomalies in the context of “emails” attributed to various writers in a self-paced reading paradigm and used comprehension questions to probe how sentence interpretation changed based upon properties of the item and properties of the “speaker.” Experiment 1 compared standardised American English speakers to L2 English speakers; Experiment 2 compared the same standardised English speakers to speakers of a non-Standardised American English dialect. Agreement errors and without-blends both led to more non-literal responses than comparable canonical items. For agreement errors, more non-literal interpretations also occurred when sentences were attributed to speakers of Standardised American English than either non-Standardised group. These data suggest that understanding sentences relies on expectations and heuristics about which utterances are likely. These are based upon experience with language, with speaker-specific differences, and upon more general cognitive biases.

Abstract

Computation in neuronal assemblies is putatively reflected in the excitatory and inhibitory cycles of activation distributed throughout the brain. In speech and language processing, coordination of these cycles resulting in phase synchronization has been argued to reflect the integration of information on different timescales (e.g. segmenting acoustics signals to phonemic and syllabic representations; (Giraud and Poeppel 2012 Nat. Neurosci.15, 511 (doi:10.1038/nn.3063)). A natural extension of this claim is that phase synchronization functions similarly to support the inference of more abstract higher-level linguistic structures (Martin 2016 Front. Psychol.7, 120; Martin and Doumas 2017 PLoS Biol. 15, e2000663 (doi:10.1371/journal.pbio.2000663); Martin and Doumas. 2019 Curr. Opin. Behav. Sci.29, 77–83 (doi:10.1016/j.cobeha.2019.04.008)). Hale et al. (Hale et al. 2018 Finding syntax in human encephalography with beam search. arXiv 1806.04127 (http://arxiv.org/abs/1806.04127)) showed that syntactically driven parsing decisions predict electroencephalography (EEG) responses in the time domain; here we ask whether phase synchronization in the form of either inter-trial phrase coherence or cross-frequency coupling (CFC) between high-frequency (i.e. gamma) bursts and lower-frequency carrier signals (i.e. delta, theta), changes as the linguistic structures of compositional meaning (viz., bracket completions, as denoted by the onset of words that complete phrases) accrue. We use a naturalistic story-listening EEG dataset from Hale et al. to assess the relationship between linguistic structure and phase alignment. We observe increased phase synchronization as a function of phrase counts in the delta, theta, and gamma bands, especially for function words. A more complex pattern emerged for CFC as phrase count changed, possibly related to the lack of a one-to-one mapping between ‘size’ of linguistic structure and frequency band—an assumption that is tacit in recent frameworks. These results emphasize the important role that phase synchronization, desynchronization, and thus, inhibition, play in the construction of compositional meaning by distributed neural networks in the brain.

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

This paper describes the lexical resources for expressing events of cutting and breaking (C&B hereafter) in the Mayan language Tzeltal. This notional set of verbs is not a class in any grammatical sense; C&B verbs are formally undistinguishable from many other transitive state-change verbs. But they nicely reveal the characteristic specificity of Tzeltal verb semantics: C&B actions are finely differentiated according to the spatial and textural properties of the theme object, with no superordinate term meaning 'either cut in general' or 'break in general'. The paper characterizes the semantics of these verbs and shows that in the great majority of cases it does not predict their argument structure.

Abstract

This is a Spanish translation of Brown 1997.

Abstract

The human brain can process facial expressions of emotions rapidly and without awareness. Several studies in patients with damage to their primary visual cortices have shown that they may be able to guess the emotional expression on a face despite their cortical blindness. This non-conscious processing, called affective blindsight, may arise through an intact subcortical visual route that leads from the superior colliculus to the pulvinar, and thence to the amygdala. This pathway is thought to process the crude visual information conveyed by the low spatial frequencies of the stimuli.

In order to investigate whether this is the case, we studied a patient (TN) with bilateral cortical blindness and affective blindsight. An fMRI paradigm was performed in which fearful and neutral expressions were presented using faces that were either unfiltered, or filtered to remove high or low spatial frequencies. Unfiltered fearful faces produced right amygdala activation although the patient was unaware of the presence of the stimuli. More importantly, the low spatial frequency components of fearful faces continued to produce right amygdala activity while the high spatial frequency components did not. Our findings thus confirm that the visual information present in the low spatial frequencies is sufficient to produce affective blindsight, further suggesting that its existence could rely on the subcortical colliculo-pulvino-amygdalar pathway.

Abstract

The present study investigates the development of am in the speech of one English-speaking child, Scarlett (aged 4;6–5;6). We show that am is infrequent in the speech addressed to children; the acquisition of this form of BE presents a unique insight into the processes underlying language development because children have little evidence regarding its correct use. Scarlett produced a pervasive error where she overextended are to first-person singular contexts where am was required (e.g., I'm are trying, When are I'm finished?). Am gradually emerged in her speech on what appears to be a construction-specific basis. The findings of the study are used in support of a usage-based, constructivisit approach to language development.

Abstract

Most people have left‐hemisphere dominance for various aspects of language processing, but only roughly 1% of the adult population has atypically reversed, rightward hemispheric language dominance (RHLD). The genetic‐developmental program that underlies leftward language laterality is unknown, as are the causes of atypical variation. We performed an exploratory whole‐genome‐sequencing study, with the hypothesis that strongly penetrant, rare genetic mutations might sometimes be involved in RHLD. This was by analogy with situs inversus of the visceral organs (left‐right mirror reversal of the heart, lungs and so on), which is sometimes due to monogenic mutations. The genomes of 33 subjects with RHLD were sequenced and analyzed with reference to large population‐genetic data sets, as well as 34 subjects (14 left‐handed) with typical language laterality. The sample was powered to detect rare, highly penetrant, monogenic effects if they would be present in at least 10 of the 33 RHLD cases and no controls, but no individual genes had mutations in more than five RHLD cases while being un‐mutated in controls. A hypothesis derived from invertebrate mechanisms of left‐right axis formation led to the detection of an increased mutation load, in RHLD subjects, within genes involved with the actin cytoskeleton. The latter finding offers a first, tentative insight into molecular genetic influences on hemispheric language dominance.

Abstract

Recent years have seen rapid technological development of devices that can record communicative behavior as participants go about daily life. This paper is intended as an end-to-end methodological guidebook for potential users of these technologies, including researchers who want to study children’s or adults’ communicative behavior in everyday contexts. We explain how long-format speech environment (LFSE) recordings provide a unique view on language use and how they can be used to complement other measures at the individual and group level. We aim to help potential users of these technologies make informed decisions regarding research design, hardware, software, and archiving. We also provide information regarding ethics and implementation, issues that are difficult to navigate for those new to this technology, and on which little or no resources are available. This guidebook offers a concise summary of information for new users and points to sources of more detailed information for more advanced users. Links to discussion groups and community-augmented databases are also provided to help readers stay up-to-date on the latest developments.

Abstract

Odor naming is enhanced in communities where communication about odors is a central part of daily life (e.g., wine experts, flavorists, and some hunter‐gatherer groups). In this study, we investigated how expert knowledge and daily experience affect the ability to name odors in a group of experts that has not previously been investigated in this context—Iranian herbalists; also called attars—as well as cooks and laypeople. We assessed naming accuracy and consistency for 16 herb and spice odors, collected judgments of odor perception, and evaluated participants' odor meta‐awareness. Participants' responses were overall more consistent and accurate for more frequent and familiar odors. Moreover, attars were more accurate than both cooks and laypeople at naming odors, although cooks did not perform significantly better than laypeople. Attars' perceptual ratings of odors and their overall odor meta‐awareness suggest they are also more attuned to odors than the other two groups. To conclude, Iranian attars—but not cooks—are better odor namers than laypeople. They also have greater meta‐awareness and differential perceptual responses to odors. These findings further highlight the critical role that expertise and type of experience have on olfactory functions.

Abstract

FOXP proteins form a subfamily of evolutionarily conserved transcription factors involved in the development and functioning of several tissues, including the central nervous system. In humans, mutations in FOXP1 and FOXP2 have been implicated in cognitive deficits including intellectual disability and speech disorders. Drosophila exhibits a single ortholog, called FoxP, but due to a lack of characterized mutants, our understanding of the gene remains poor. Here we show that the dimerization property required for mammalian FOXP function is conserved in Drosophila. In flies, FoxP is enriched in the adult brain, showing strong expression in ~1000 neurons of cholinergic, glutamatergic and GABAergic nature. We generate Drosophila loss-of-function mutants and UAS-FoxP transgenic lines for ectopic expression, and use them to characterize FoxP function in the nervous system. At the cellular level, we demonstrate that Drosophila FoxP is required in larvae for synaptic morphogenesis at axonal terminals of the neuromuscular junction and for dendrite development of dorsal multidendritic sensory neurons. In the developing brain, we find that FoxP plays important roles in α-lobe mushroom body formation. Finally, at a behavioral level, we show that Drosophila FoxP is important for locomotion, habituation learning and social space behavior of adult flies. Our work shows that Drosophila FoxP is important for regulating several neurodevelopmental processes and behaviors that are related to human disease or vertebrate disease model phenotypes. This suggests a high degree of functional conservation with vertebrate FOXP orthologues and established flies as a model system for understanding FOXP related pathologies.

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

Oligodendrocyte gene expression is downregulated in stress-related neuropsychiatric disorders,
including depression. In mice, chronic social stress (CSS) leads to depression-relevant changes
in brain and emotional behavior, and the present study shows the involvement of oligodendrocytes in this model. In C57BL/6 (BL/6) mice, RNA-sequencing (RNA-Seq) was conducted with
prefrontal cortex, amygdala and hippocampus from CSS and controls; a gene enrichment database for neurons, astrocytes and oligodendrocytes was used to identify cell origin of deregulated genes, and cell deconvolution was applied. To assess the potential causal contribution of
reduced oligodendrocyte gene expression to CSS effects, mice heterozygous for the oligodendrocyte gene cyclic nucleotide phosphodiesterase (Cnp1) on a BL/6 background were studied;
a 2 genotype (wildtype, Cnp1+/−
) × 2 environment (control, CSS) design was used to investigate
effects on emotional behavior and amygdala microglia. In BL/6 mice, in prefrontal cortex and
amygdala tissue comprising gray and white matter, CSS downregulated expression of multiple
oligodendroycte genes encoding myelin and myelin-axon-integrity proteins, and cell deconvolution identified a lower proportion of oligodendrocytes in amygdala. Quantification of oligodendrocyte proteins in amygdala gray matter did not yield evidence for reduced translation,
suggesting that CSS impacts primarily on white matter oligodendrocytes or the myelin transcriptome. In Cnp1 mice, social interaction was reduced by CSS in Cnp1+/− mice specifically;
using ionized calcium-binding adaptor molecule 1 (IBA1) expression, microglia activity was
increased additively by Cnp1+/− and CSS in amygdala gray and white matter. This study provides back-translational evidence that oligodendrocyte changes are relevant to the pathophysiology and potentially the treatment of stress-related neuropsychiatric disorders.

Abstract

We report on an analysis of spontaneous gesture production in 2‐year‐old children who come from three countries (Italy, United Kingdom, Australia) and who speak two languages (Italian, English), in an attempt to tease apart the influence of language and culture when comparing children from different cultural and linguistic environments. Eighty‐seven monolingual children aged 24–30 months completed an experimental task measuring their comprehension and production of nouns and predicates. The Italian children scored significantly higher than the other groups on all lexical measures. With regard to gestures, British children produced significantly fewer pointing and speech combinations compared to Italian and Australian children, who did not differ from each other. In contrast, Italian children produced significantly more representational gestures than the other two groups. We conclude that spoken language development is primarily influenced by the input language over gesture production, whereas the combination of cultural and language environments affects gesture production.

Abstract

Cognitive development is shaped by interactions between cognitive architecture and environmental experiences
of the growing brain. We examined the extent to which this interaction during development could be observed in
language processing. We focused on age of acquisition (AoA) effects in reading, where early-learned words tend
to be processed more quickly and accurately relative to later-learned words. We implemented a computational
model including representations of print, sound and meaning of words, with training based on children’s gradual
exposure to language. The model produced AoA effects in reading and lexical decision, replicating the larger
effects of AoA when semantic representations are involved. Further, the model predicted that AoA would relate
to differing use of the reading system, with words acquired before versus after literacy onset with distinctive
accessing of meaning and sound representations. An analysis of behaviour from the English Lexicon project was
consistent with the predictions: Words acquired before literacy are more likely to access meaning via sound,
showing a suppressed AoA effect, whereas words acquired after literacy rely more on direct print to meaning
mappings, showing an exaggerated AoA effect. The reading system reveals vestigial traces of acquisition reflected
in differing use of word representations during reading.

Abstract

Diversity of vocabulary knowledge and quantity of language exposure prior to literacy are key predictors of reading development. However, diversity and quantity of exposure are difficult to distinguish in behavioural studies, and so the causal relations with literacy are not well known. We tested these relations by training a connectionist triangle model of reading that learned to map between semantic; phonological; and, later, orthographic forms of words. The model first learned to map between phonology and semantics, where we manipulated the quantity and diversity of this preliterate language experience. Then the model learned to read. Both diversity and quantity of exposure had unique effects on reading performance, with larger effects for written word comprehension than for reading fluency. The results further showed that quantity of preliteracy language exposure was beneficial only when this was to a varied vocabulary and could be an impediment when exposed to a limited vocabulary.

Abstract

Adopting an eyetracking paradigm, we investigated the role of H*L, L*HL, L*H, H*LH, and deaccentuation at the intonational phrase-final position in online processing of information status in British English in natural speech. The role of H*L, L*H and deaccentuation was also examined in diphonesynthetic speech. It was found that H*L and L*HL create a strong bias towards newness, whereas L*H, like deaccentuation, creates a strong bias towards givenness. In synthetic speech, the same effect was found for H*L, L*H and deaccentuation, but it was delayed. The delay may not be caused entirely by the difference in the segmental quality between synthetic and natural speech. The pitch accent H*LH, however, appears to bias participants' interpretation to the target word, independent of its information status. This finding was explained in the light of the effect of durational information at the segmental level on word recognition.

Abstract

Non-protein-coding RNAs represent a large proportion of transcribed sequences in eukaryotes. These RNAs often function in large RNA–protein complexes, which are catalysts in various RNA-processing pathways. As RNA processing has become an increasingly important area of research, numerous non-messenger RNAs have been uncovered in all the model eukaryotic organisms. However, knowledge on RNA processing in deep-branching eukaryotes is still limited. This study focuses on the identification of non-protein-coding RNAs from the diplomonad parasite Giardia intestinalis, showing that a combined experimental and computational search strategy is a fast method of screening reduced or compact genomes. The analysis of our Giardia cDNA library has uncovered 31 novel candidates, including C/D-box and H/ACA box snoRNAs, as well as an unusual transcript of RNase P, and double-stranded RNAs. Subsequent computational analysis has revealed additional putative C/D-box snoRNAs. Our results will lead towards a future understanding of RNA metabolism in the deep-branching eukaryote Giardia, as more ncRNAs are characterized.

Abstract

Abstract Mandarin categorizes cutting and breaking events on the basis of fine semantic distinctions in the causal action and the caused result. I demonstrate the semantics of Mandarin C&B verbs from the perspective of event encoding and categorization as well as argument structure alternations. Three semantically different types of predicates can be identified: verbs denoting the C&B action subevent, verbs encoding the C&B result subevent, and resultative verb compounds (RVC) that encode both the action and the result subevents. The first verb of an RVC is basically dyadic, whereas the second is monadic. RVCs as a whole are also basically dyadic, and do not undergo detransitivization.

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

We explore the role of the acoustic consequences of domain-initial strengthening in spoken-word recognition. In two cross-modal identity-priming experiments, listeners heard sentences and made lexical decisions to visual targets, presented at the onset of the second word in two-word sequences containing lexical ambiguities (e.g., bus tickets, with the competitor bust). These sequences contained Intonational Phrase (IP) or Prosodic Word (Wd) boundaries, and the second word's initial Consonant and Vowel (CV, e.g., [tI]) was spliced from another token of the sequence in IP- or Wd-initial position. Acoustic analyses showed that IP-initial consonants were articulated more strongly than Wd-initial consonants. In Experiment 1, related targets were post-boundary words (e.g., tickets). No strengthening effect was observed (i.e., identity priming effects did not vary across splicing conditions). In Experiment 2, related targets were pre-boundary words (e.g., bus). There was a strengthening effect (stronger priming when the post-boundary CVs were spliced from IP-initial than from Wd-initial position), but only in Wd-boundary contexts. These were the conditions where phonetic detail associated with domain-initial strengthening could assist listeners most in lexical disambiguation. We discuss how speakers may strengthen domain-initial segments during production and how listeners may use the resulting acoustic correlates of prosodic strengthening during word recognition.

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

Speakers use external auditory feedback to monitor their own speech. Feedback distortion has been found to increase activity in the superior temporal areas. Using fMRI, the present study investigates the neural correlates of processing verbal feedback without distortion. In a blocked design, the following conditions were presented: (1) overt picture-naming, (2) overt picture-naming while pink noise was presented to mask external feedback, (3) covert picture-naming, (4) listening to the picture names (previously recorded from participants' own voices), and (5) listening to pink noise. The results show that auditory feedback processing involves a network of different areas related to general performance monitoring and speech-motor control. These include the cingulate cortex and the bilateral insula, supplementary motor area, bilateral motor areas, cerebellum, thalamus and basal ganglia. Our findings suggest that the anterior cingulate cortex, which is often implicated in error-processing and conflict-monitoring, is also engaged in ongoing speech monitoring. Furthermore, in the superior temporal gyrus, we found a reduced response to speaking under normal feedback conditions. This finding is interpreted in the framework of a forward model according to which, during speech production, the sensory consequence of the speech-motor act is predicted to attenuate the sensitivity of the auditory cortex. Hum Brain Mapp 2007. © 2007 Wiley-Liss, Inc.

Abstract

This study addressed how bilingual speakers switch between their first and second language when speaking. Event-related brain potentials (ERPs) and naming latencies were measured while unbalanced German (L1)-Dutch (L2) speakers performed a picture-naming task. Participants named pictures either in their L1 or in their L2 (blocked language conditions), or participants switched between their first and second language unpredictably (mixed language condition). Furthermore, form similarity between translation equivalents (cognate status) was manipulated. A cognate facilitation effect was found for L1 and L2 indicating phonological activation of the non-response language in blocked and mixed language conditions. The ERP data also revealed small but reliable effects of cognate status. Language switching resulted in equal switching costs for both languages and was associated with a modulation in the ERP waveforms (time windows 275-375 ms and 375-475 ms). Mixed language context affected especially the L1, both in ERPs and in latencies, which became slower in L1 than L2. It is suggested that sustained and transient components of language control should be distinguished. Results are discussed in relation to current theories of bilingual language processing.

Abstract

Koriat (1981) demonstrated that an association from the target to a preceding prime, in the absence of an association from the prime to the target, facilitates lexical decision and referred to this effect as "backward priming". Backward priming is of relevance, because it can provide information about the mechanism underlying semantic priming effects. Following Neely (1991), we distinguish three mechanisms of priming: spreading activation, expectancy, and semantic matching/integration. The goal was to determine which of these mechanisms causes backward priming, by assessing effects of backward priming on a language-relevant ERP component, the N400, and reaction time (RT). Based on previous work, we propose that the N400 priming effect reflects expectancy and semantic matching/integration, but in contrast with RT does not reflect spreading activation. Experiment 1 shows a backward priming effect that is qualitatively similar for the N400 and RT in a lexical decision task. This effect was not modulated by an ISI manipulation. Experiment 2 clarifies that the N400 backward priming effect reflects genuine changes in N400 amplitude and cannot be ascribed to other factors. We will argue that these backward priming effects cannot be due to expectancy but are best accounted for in terms of semantic matching/integration.

Abstract

In a semantic priming paradigm, the effects of different levels of processing on the N400 were assessed by changing the task demands. In the lexical decision task, subjects had to discriminate between words and nonwords and in the physical task, subjects had to discriminate between uppercase and lowercase letters. The proportion of related versus unrelated word pairs differed between conditions. A lexicality test on reaction times demonstrated that the physical task was performed nonlexically. Moreover, a semantic priming reaction time effect was obtained only in the lexical decision task. The level of processing clearly affected the event-related potentials. An N400 priming effect was only observed in the lexical decision task. In contrast, in the physical task a P300 effect was observed for either related or unrelated targets, depending on their frequency of occurrence. Taken together, the results indicate that an N400 priming effect is only evoked when the task performance induces the semantic aspects of words to become part of an episodic trace of the stimulus event.

Abstract

Interactive effects between allelic variants of the serotonin transporter (5-HTT) promoter-linked polymorphic region (5-HTTLPR) and stressors on depression symptoms have been documented, as well as questioned, by meta-analyses. Translational models of constitutive 5-htt reduction and experimentally controlled stressors often led to inconsistent behavioral and molecular findings and often did not include females. The present study sought to investigate the effect of 5-htt genotype, maternal separation, and sex on the expression of stress-related candidate genes in the rat hippocampus and frontal cortex. The mRNA expression levels of Avp, Pomc, Crh, Crhbp, Crhr1, Bdnf, Ntrk2, Maoa, Maob, and Comt were assessed in the hippocampus and frontal cortex of 5-htt ± and 5-htt +/+ male and female adult rats exposed, or not, to daily maternal separation for 180 min during the first 2 postnatal weeks. Gene- and brain region-dependent, but sex-independent, interactions between 5-htt genotype and maternal separation were found. Gene expression levels were higher in 5-htt +/+ rats not exposed to maternal separation compared with the other experimental groups. Maternal separation and 5-htt +/− genotype did not yield additive effects on gene expression. Correlative relationships, mainly positive, were observed within, but not across, brain regions in all groups except in non-maternally separated 5-htt +/+ rats. Gene expression patterns in the hippocampus and frontal cortex of rats exposed to maternal separation resembled the ones observed in rats with reduced 5-htt expression regardless of sex. These results suggest that floor effects of 5-htt reduction and maternal separation might explain inconsistent findings in humans and rodents

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.