Publications

Abstract

Q fever, caused by Coxiella burnetii, is a zoonosis with a worldwide distribution. A large rural area in the southeast of the Netherlands was heavily affected by Q fever between 2007 and 2009. This initiated the development of a robust and internally controlled multiplex quantitative PCR (qPCR) assay for the detection of C. burnetii DNA in veterinary and environmental matrices on suspected Q fever-affected farms. The qPCR detects three C. burnetii targets (icd, com1, and IS1111) and one Bacillus thuringiensis internal control target (cry1b). Bacillus thuringiensis spores were added to samples to control both DNA extraction and PCR amplification. The performance of the qPCR assay was investigated and showed a high efficiency; a limit of detection of 13.0, 10.6, and 10.4 copies per reaction for the targets icd, com1, and IS1111, respectively; and no crossreactivity with the nontarget organisms tested. Screening for C. burnetii DNA on 29 suspected Q fever-affected farms during the Q fever epidemic in 2008 showed that swabs from dust-accumulating surfaces contained higher levels of C. burnetii DNA than vaginal swabs from goats or sheep. PCR inhibition by coextracted substances was observed in some environmental samples, and 10- or 100-fold dilutions of samples were sufficient to obtain interpretable signals for both the C. burnetii targets and the internal control. The inclusion of an internal control target and three C. burnetii targets in one multiplex qPCR assay showed that complex veterinary and environmental matrices can be screened reliably for the presence of C. burnetii DNA during an outbreak. © 2011, American Society for Microbiology.

Abstract

Book reading shows large individual variability and correlates with better language ability and more empathy. This makes reading exposure an interesting variable to study. Research in English suggests that an author recognition test is the most reliable objective assessment of reading frequency. In this article, we describe the efforts we made to build and test a Dutch author recognition test (DART for older participants and DART_R for younger participants). Our data show that the test is reliable and valid, both in the Netherlands and in Belgium (split-half reliability over .9 with university students, significant correlations with language abilities) and can be used with a young, non-university population. The test is free to use for research purposes.

Abstract

Several neurodevelopmental disorders are associated with preference for routine and challenging behavior following changes to routines. We examine individuals with Prader–Willi syndrome, who show elevated levels of this behavior, to better understand how previous experience of a routine can affect challenging behavior elicited by disruption to that routine. Play based challenges exposed 16 participants to routines, which were either adhered to or changed. Temper outburst behaviors, heart rate and movement were measured. As participants were exposed to routines for longer before a change (between 10 and 80 min; within participants), more temper outburst behaviors were elicited by changes. Increased emotional arousal was also elicited, which was indexed by heart rate increases not driven by movement. Further study will be important to understand whether current intervention approaches that limit exposure to changes, may benefit from the structured integration of flexibility to ensure that the opportunity for routine establishment is also limited.

Abstract

Acquisition and processing of written and spoken language is an impressive cognitive accomplishment considering the complexity of the tasks. While only humans seem to have evolved to the fullest extent the capacity that underpins these remarkable feats of development and civilization, the exact nature of such capacity has been subject to ongoing research. In this chapter, we focus on language competence and what makes it unique among the communication systems of different species. We then elaborate on the classical debate between nativist and environmentalist accounts of language acquisition, with reference to evidence for and against the critical period hypothesis. After introducing the regularity embedded in different languages and particularly in drastically different orthographies, we present behavioral and neurophysiological evidence for the sensitivity to systematic mapping between orthography and phonology. Because learning to read is to master such mapping, we assume that the ability to use statistical learning to appreciate the dependency among items would contribute to literacy acquisition. Empirical results from behavioral and neuroimaging experiments conducted in our and other laboratories provide support for the close link between statistical learning and literacy acquisition in native and foreign language. Such findings highlight the significance of domain-general statistical learning to domain-specific language acquisition, and point to an important direction for theories and practices of language education.

Abstract

Use of peripheral blood- or bone marrow-derived progenitors for ischemic heart repair is a feasible option to induce neo-vascularization in ischemic tissues. These cells, named Endothelial Progenitors Cells (EPCs), have been extensively characterized phenotypically and functionally. The clinical efficacy of cardiac repair by EPCs cells remains, however, limited, due to cell autonomous defects as a consequence of risk factors. The devise of “enhancement” strategies has been therefore sought to improve repair ability of these cells and increase the clinical benefit

Abstract

The cognitive- and neurosciences have supposed that the perceptual world of the individual is dominated by vision, followed closely by audition, but that olfaction is merely vestigial. Aslian-speaking communities (Austroasiatic, Malay Peninsula) challenge this view. For the Jahai - a small group of rainforest foragers - odor plays a central role in both culture and language. Jahai ideology revolves around a complex set of beliefs that structures the human relationship with the supernatural. Central to this relationship are hearing, vision, and olfaction. In Jahai language, olfaction also receives special attention. There are at least a dozen or so abstract descriptive odor categories that are basic, everyday terms. This lexical elaboration of odor is not unique to the Jahai but can be seen across many contemporary Austroasiatic languages and transcends major cultural and environmental boundaries. These terms appear to be inherited from ancestral language states, suggesting a longstanding preoccupation with odor in this part of the world. Contrary to the prevailing assumption in the cognitive sciences, these languages and cultures demonstrate that odor is far from vestigial in humans.

Abstract

This work explores the linguistic encoding of reciprocal events in Jahai (Aslian, Mon-Khmer, Malay Peninsula) on the basis of linguistic descriptions of the video stimuli of the ‘Reciprocal constructions and situation type’ task (Evans et al. 2004). Reciprocal situation types find expression in three different constructions: distributive verb forms, reciprocal verb forms, and adjunct phrases containing a body part noun. Distributives represent the dominant strategy, reciprocal forms and body part adjuncts being highly restricted across event types and consultants. The distributive and reciprocal morphemes manifest intricate morphological processes typical of Aslian languages. The paper also addresses some analytical problems raised by the data, such as structural ambiguity and restrictions on derivation, as well as individual variation.

Abstract

This paper explores the linguistic encoding of placement and removal events in Jahai (Austroasiatic, Malay Peninsula) on the basis of descriptions from a video elicitation task. It outlines the structural characteristics of the descriptions and isolates semantically a set of situation types that find expression in lexical opposites: (1) putting/taking, (2) inserting/extracting, (3) dressing/undressing, and (4) placing/removing one’s body parts. All involve deliberate and controlled placing/removing of a solid Figure object in relation to a Ground which is not a human recipient. However, they differ as to the identity of and physical relationship between Figure and Ground. The data also provide evidence of variation in how semantic roles are mapped onto syntactic constituents: in most situation types, Agent, Figure and Ground associate with particular constituent NPs, but some placement events are described with semantically specialised verbs encoding the Figure and even the Ground.

Abstract

In individuals with synaesthesia specific sensory stimulation leads to unusual concurrent perceptions in the same or a different modality. Recent studies have demonstrated a high co-occurrence between synaesthesia and autism spectrum disorder (ASD), a condition also characterized by altered perception. A potentially shared characteristic of synaesthesia and ASD is a bias towards local (detail-focussed) perception. We investigated whether a bias towards local perception is indeed shared between synaesthesia and ASD. In a neurotypical population, we studied the relation between the degree of autistic traits (measured by the AQ) and the degree of grapheme-colour synaesthesia (measured by a consistency task), as well as whether both are related to a local bias in tasks assessing local/global visual perception. A positive correlation between total AQ scores and the degree of synaesthesia was found. Our study extends previous studies that found a high ASD-synaesthesia co-occurrence in clinical populations. Consistent with the hypothesized local perceptual bias in ASD, scores on the AQ-attention to detail subscale were related to increased performance on an Embedded Figures Task (EFT), and we found evidence for a relation to reduced susceptibility to visual illusions. We found no relation between autistic traits and local visual perception in a motion coherence task (MCT). Also, no relation between synaesthesia and local visual perception was found, although a reduced susceptibility to visual illusions resembled the results obtained for AQ-atttention to detail subscale. A suggested explanation for the absence of a relationship between the degree of synaesthesia and a local bias is that a possible local bias might be more pronounced in supra-threshold synaesthetes (compared to neurotypicals).

Abstract

This study presents an analysis of over 4000 tokens of words produced as variants with and without schwa in a French corpus of radio-broadcasted speech. In order to determine which of the many variables mentioned in the literature influence variant choice, 17 predictors were tested in the same analysis. Only five of these variables appeared to condition variant choice. The question of the processing stage, or locus, of this alternation process is also addressed in a comparison of the variables that predict variant choice with the variables that predict the acoustic duration of schwa in variants with schwa. Only two variables predicting variant choice also predict schwa duration. The limited overlap between the predictors for variant choice and for schwa duration, combined with the nature of these variables, suggest that the variants without schwa do not result from a phonetic process of reduction; that is, they are not the endpoint of gradient schwa shortening. Rather, these variants are generated early in the production process, either during phonological encoding or word-form retrieval. These results, based on naturally produced speech, provide a useful complement to on-line production experiments using artificial speech tasks.

Abstract

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

Abstract

The field of infancy research faces a difficult challenge: some questions require samples that are simply too large for any one lab to recruit and test. ManyBabies aims to address this problem by forming large-scale collaborations on key theoretical questions in developmental science, while promoting the uptake of Open Science practices. Here, we look back on the first project completed under the ManyBabies umbrella – ManyBabies 1 – which tested the development of infant-directed speech preference. Our goal is to share the lessons learned over the course of the project and to articulate our vision for the role of large-scale collaborations in the field. First, we consider the decisions made in scaling up experimental research for a collaboration involving 100+ researchers and 70+ labs. Next, we discuss successes and challenges over the course of the project, including: protocol design and implementation, data analysis, organizational structures and collaborative workflows, securing funding, and encouraging broad participation in the project. Finally, we discuss the benefits we see both in ongoing ManyBabies projects and in future large-scale collaborations in general, with a particular eye towards developing best practices and increasing growth and diversity in infancy research and psychological science in general. Throughout the paper, we include first-hand narrative experiences, in order to illustrate the perspectives of researchers playing different roles within the project. While this project focused on the unique challenges of infant research, many of the insights we gained can be applied to large-scale collaborations across the broader field of psychology.

Abstract

This study examined whether musical training, ethnicity, and experience with a natural tone language influenced sensitivity to tone while listening to an artificial tone language. The language was designed with three tones, modeled after level-tone African languages. Participants listened to a 15-min random concatenation of six 3-syllable words. Sensitivity to tone was assessed using minimal pairs differing only in one syllable (nonword task: e.g., to-kà-su compared to ca-fí-to) or only in tone (tone task: e.g., to-kà-su compared to to-ká-su). Proficiency in an East Asian heritage language was the strongest predictor of success on the tone task. Asians without tone language experience were no better than other ethnic groups. We conclude by considering implications for research on second language learning, especially as approached through artificial language learning.

Abstract

Pediatric myelodysplastic syndrome (MDS) is a heterogeneous disease covering a spectrum ranging from aplasia (RCC) to myeloproliferation (RAEB(t)). In adult-type MDS there is increasing evidence for abnormal function of the bone-marrow microenvironment. Here, we extensively studied the mesenchymal stromal cells (MSCs) derived from children with MDS. MSCs were expanded from the bone-marrow of 17 MDS patients (RCC: n = 10 and advanced MDS: n = 7) and pediatric controls (n = 10). No differences were observed with respect to phenotype, differentiation capacity, immunomodulatory capacity or hematopoietic support. mRNA expression analysis by Deep-SAGE revealed increased IL-6 expression in RCC- and RAEB(t)-MDS. RCC-MDS MSC expressed increased levels of DKK3, a protein associated with decreased apoptosis. RAEB(t)-MDS revealed increased CRLF1 and decreased DAPK1 expressions. This pattern has been associated with transformation in hematopoietic malignancies. Genes reported to be differentially expressed in adult MDS-MSC did not differ between MSC of pediatric MDS and controls. An altered mRNA expression profile, associated with cell survival and malignant transformation, of MSC derived from children with MDS strengthens the hypothesis that the micro-environment is of importance in this disease. Our data support the understanding that pediatric and adult MDS are two different diseases. Further evaluation of the pathways involved might reveal additional therapy targets.

Abstract

An aberrant interaction between hematopoietic stem cells and mesenchymal stromal cells has been linked to disease and shown to contribute to the pathophysiology of hematologic malignancies in murine models. Juvenile myelomonocytic leukemia is an aggressive malignant disease affecting young infants. Here we investigated the impact of juvenile myelomonocytic leukemia on mesenchymal stromal cells. Mesenchymal stromal cells were expanded from bone marrow samples of patients at diagnosis (n=9) and after hematopoietic stem cell transplantation (n=7; from 5 patients) and from healthy children (n=10). Cells were characterized by phenotyping, differentiation, gene expression analysis (of controls and samples obtained at diagnosis) and in vitro functional studies assessing immunomodulation and hematopoietic support. Mesenchymal stromal cells from patients did not differ from controls in differentiation capacity nor did they differ in their capacity to support in vitro hematopoiesis. Deep-SAGE sequencing revealed differential mRNA expression in patient-derived samples, including genes encoding proteins involved in immunomodulation and cell-cell interaction. Selected gene expression normalized during remission after successful hematopoietic stem cell transplantation. Whereas natural killer cell activation and peripheral blood mononuclear cell proliferation were not differentially affected, the suppressive effect on monocyte to dendritic cell differentiation was increased by mesenchymal stromal cells obtained at diagnosis, but not at time of remission. This study shows that active juvenile myelomonocytic leukemia affects the immune response-related gene expression and function of mesenchymal stromal cells. In contrast, the differential gene expression of hematopoiesis-related genes could not be supported by functional data. Decreased immune surveillance might contribute to the therapy resistance and progression in juvenile myelomonocytic leukemia.

Abstract

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

Abstract

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

Abstract

Previous studies have suggested that altered asymmetry of the planum temporale (PT) is associated with neurodevelopmental disorders, including dyslexia, schizophrenia, and autism. Shared genetic factors have been suggested to link PT asymmetry to these disorders. In a dataset of unrelated subjects from the general population (UK Biobank, N= 18,057), we found that PT volume asymmetry had a significant heritability of roughly 14%. In genome-wide association analysis, two loci were significantly associated with PT asymmetry, including a coding polymorphism within the gene ITIH5 that is predicted to affect the protein’s function and to be deleterious (rs41298373, P=2.01×10−15), and a locus that affects the expression of the genes BOK and DTYMK (rs7420166, P=7.54×10-10). DTYMK showed left-right asymmetry of mRNA expression in post mortem PT tissue. Cortex-wide mapping of these SNP effects revealed influences on asymmetry that went somewhat beyond the PT. Using publicly available genome-wide association statistics from large-scale studies, we saw no significant genetic correlations of PT asymmetry with autism spectrum disorder, attention deficit hyperactivity disorder, schizophrenia, educational attainment or intelligence. Of the top two individual loci associated with PT asymmetry, rs41298373 showed a tentative association with intelligence (unadjusted P=0.025), while the locus at BOK/DTYMK showed tentative association with educational attainment (unadjusted Ps<0.05). These findings provide novel insights into the genetic contributions to human brain asymmetry, but do not support a substantial polygenic association of PT asymmetry with cognitive variation and mental disorders, as far as can be discerned with current sample sizes.

Abstract

Research into recurrent, highly conventionalized “formulaic” sequences has shown a processing advantage compared to “novel” (non-formulaic) language. Studies of individual types of formulaic sequence often acknowledge the contribution of specific factors, but little work exists to compare the processing of different types of phrases with fundamentally different properties. We use eye-tracking to compare the processing of three types of formulaic phrases—idioms, binomials, and collocations—and consider whether overall frequency can explain the advantage for all three, relative to control phrases. Results show an advantage, as evidenced through shorter reading times, for all three types. While overall phrase frequency contributes much of the processing advantage, different types of phrase do show additional effects according to the specific properties that are relevant to each type: frequency, familiarity, and decomposability for idioms; predictability and semantic association for binomials; and mutual information for collocations. We discuss how the results contribute to our understanding of the representation and processing of multiword lexical units more broadly.

Abstract

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

Abstract

Do people with different kinds of bodies think differently? According to the bodyspecificity hypothesis (Casasanto 2009), they should. In this article, I review evidence that right- and left-handers, who perform actions in systematically different ways, use correspondingly different areas of the brain for imagining actions and representing the meanings of action verbs. Beyond concrete actions, the way people use their hands also influences the way they represent abstract ideas with positive and negative emotional valence like “goodness,” “honesty,” and “intelligence,” and how they communicate about them in spontaneous speech and gesture. Changing how people use their right and left hands can cause them to think differently, suggesting that motoric differences between right- and left-handers are not merely correlated with cognitive differences. Body-specific patterns of motor experience shape the way we think, communicate, and make decisions

Abstract

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

Abstract

Bodily mimicry often makes the mimickee have more positive feelings about the mimicker. Yet, little is known about the causes of mimicry’s social effects. When people mimic each other’s bodily movements face to face, they can either adopt a mirrorwise perspective (moving in the same absolute direction) or an anatomical perspective (moving in the same direction relative to their own bodies). Mirrorwise mimicry maximizes visuo-spatial similarity between the mimicker and mimickee, whereas anatomical mimicry maximizes the similarity in the states of their motor systems. To compare the social consequences of visuo-spatial and motoric similarity, we asked participants to converse with an embodied virtual agent (VIRTUO), who mimicked their head movements either mirrorwise, anatomically, or not at all. Compared to participants who were not mimicked, those who were mimicked mirrorwise tended to rate VIRTUO more positively, but those who were mimicked anatomically rated him more negatively. During face-to-face conversation, mirrorwise and anatomical mimicry have opposite social consequences. Results suggest that visuo-spatial similarity between mimicker and mimickee, not similarity in motor system activity, gives rise to the positive social effects of bodily mimicry.

Abstract

Right- and left-handers implicitly associate positive ideas like "goodness"and "honesty"more strongly with their dominant side
of space, the side on which they can act more fluently, and negative ideas more strongly with their nondominant side. Here we show that right-handers’ tendency to associate "good" with "right" and "bad" with "left" can be reversed as a result of both
long- and short-term changes in motor fluency. Among patients who were right-handed prior to unilateral stroke, those with disabled left hands associated "good" with "right," but those with disabled right hands associated "good" with "left,"as natural left-handers do. A similar pattern was found in healthy right-handers whose right or left hand was temporarily handicapped in the laboratory. Even a few minutes of acting more fluently with the left hand can change right-handers’ implicit associations between space and emotional valence, causing a reversal of their usual judgments. Motor experience plays a causal role in shaping abstract thought.

Abstract

Introduction
The Sapir-Whorf hypothesis (a.k.a. the Whorfian hypothesis) concerns the relationship between language and thought. Neither the anthropological linguist Edward Sapir (b. 1884–d. 1939) nor his student Benjamin Whorf (b. 1897–d. 1941) ever formally stated any single hypothesis about the influence of language on nonlinguistic cognition and perception. On the basis of their writings, however, two proposals emerged, generating decades of controversy among anthropologists, linguists, philosophers, and psychologists. According to the more radical proposal, linguistic determinism, the languages that people speak rigidly determine the way they perceive and understand the world. On the more moderate proposal, linguistic relativity, habits of using language influence habits of thinking. As a result, people who speak different languages think differently in predictable ways. During the latter half of the 20th century, the Sapir-Whorf hypothesis was widely regarded as false. Around the turn of the 21st century, however, experimental evidence reopened debate about the extent to which language shapes nonlinguistic cognition and perception. Scientific tests of linguistic determinism and linguistic relativity help to clarify what is universal in the human mind and what depends on the particulars of people’s physical and social experience.
General Overviews and Foundational Texts

Writing on the relationship between language and thought predates Sapir and Whorf, and extends beyond the academy. The 19th-century German philosopher Wilhelm von Humboldt argued that language constrains people’s worldview, foreshadowing the idea of linguistic determinism later articulated in Sapir 1929 and Whorf 1956 (Humboldt 1988). The intuition that language radically determines thought has been explored in works of fiction such as Orwell’s dystopian fantasy 1984 (Orwell 1949). Although there is little empirical support for radical linguistic determinism, more moderate forms of linguistic relativity continue to generate influential research, reviewed from an anthropologist’s perspective in Lucy 1997, from a psychologist’s perspective in Hunt and Agnoli 1991, and discussed from multidisciplinary perspectives in Gumperz and Levinson 1996 and Gentner and Goldin-Meadow 2003.

Abstract

Daylong at-home audio recordings from 10 Tseltal Mayan children (0;2–3;0; Southern Mexico) were analyzed for how often children engaged in verbal interaction with others and whether their speech environment changed with age, time of day, household size, and number of speakers present. Children were infrequently directly spoken to, with most directed speech coming from adults, and no increase with age. Most directed speech came in the mornings, and interactional peaks contained nearly four times the baseline rate of directed speech. Coarse indicators of children's language development (babbling, first words, first word combinations) suggest that Tseltal children manage to extract the linguistic information they need despite minimal directed speech. Multiple proposals for how they might do so are discussed.

Abstract

How do children learn to map linguistic forms onto their intended meanings? This chapter begins with an introduction to some theoretical and analytical tools used to study communicative acts. It then turns to communicative act development in spoken and signed language acquisition, including both the early scaffolding and production of communicative acts (both non-verbal and verbal) as well as their later links to linguistic development and Theory of Mind. The chapter wraps up by linking research on communicative act development to the acquisition of conversational skills, cross-linguistic and individual differences in communicative experience during development, and human evolution. Along the way, it also poses a few open questions for future research in this domain.

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

Members of the Tre2/Bub2/Cdc16 (TBC), lysin motif (LysM), domain catalytic (TLDc) protein family are associated with multiple neurodevelopmental disorders, although their exact roles in disease remain unclear. For example, nuclear receptor coactivator 7 (NCOA7) has been associated with autism, although almost nothing is known regarding the mode-of-action of this TLDc protein in the nervous system. Here we investigated the molecular function of NCOA7 in neurons and generated a novel mouse model to determine the consequences of deleting this locus in vivo. We show that NCOA7 interacts with the cytoplasmic domain of the vacuolar (V)-ATPase in the brain and demonstrate that this protein is required for normal assembly and activity of this critical proton pump. Neurons lacking Ncoa7 exhibit altered development alongside defective lysosomal formation and function; accordingly, Ncoa7 deletion animals exhibited abnormal neuronal patterning defects and a reduced expression of lysosomal markers. Furthermore, behavioural assessment revealed anxiety and social defects in mice lacking Ncoa7. In summary, we demonstrate that NCOA7 is an important V-ATPase regulatory protein in the brain, modulating lysosomal function, neuronal connectivity and behaviour; thus our study reveals a molecular mechanism controlling endolysosomal homeostasis that is essential for neurodevelopment.

Abstract

Background: Functional neuroimaging supports the hypothesis that auditory verbal hallucinations (AVH) in schizophrenia result from altered functional connectivity between perisylvian language regions, although the extent to which AVH are also associated with an altered tract anatomy is less clear.

Methods: Twenty-eight patients with schizophrenia subdivided into 17 subjects with a history of AVH and 11 without a history of hallucinations and 59 age- and IQ-matched healthy controls were recruited. The number of streamlines, fractional anisotropy (FA), and mean diffusivity were measured along the length of the arcuate fasciculus and its medial and lateral components.

Results: Patients with schizophrenia had bilateral reduction of FA relative to controls in the arcuate fasciculi (p < .001). Virtual dissection of the subcomponents of the arcuate fasciculi revealed that these reductions were specific to connections between posterior temporal and anterior regions in the inferior frontal and parietal lobe. Also, compared with controls, the reduction in FA of these tracts was highest, and bilateral, in patients with AVH, but in patients without AVH, this reduction was reported only on the left.

Conclusions: These findings point toward a supraregional network model of AVH in schizophrenia. They support the hypothesis that there may be selective vulnerability of specific anatomical connections to posterior temporal regions in schizophrenia and that extensive bilateral damage is associated with a greater vulnerability to AVH. If confirmed by further studies, these findings may advance our understanding of the anatomical factors that are protective against AVH and predictive of a treatment response.

Abstract

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

Abstract

Previous work found that single-session focused attention meditation (FAM) enhanced motor sequence learning through increased cognitive control as a mechanistic action, although electrophysiological correlates of sequence learning performance following FAM were not investigated. We measured the persistent frontal N2 event-related potential (ERP) that is closely related to cognitive control processes and its ability to predict behavioural measures. Twenty-nine participants were randomised to one of three conditions reflecting the level of FAM experienced prior to a serial reaction time task (SRTT): 21 sessions of FAM (FAM21, N = 12), a single FAM session (FAM1, N = 9) or no preceding FAM control (Control, N = 8). Continuous 64-channel EEG were recorded during SRTT and N2 amplitudes for correct trials were extracted. Component amplitude, regions of interests, and behavioural outcomes were compared using mixed effects regression models between groups. FAM21 exhibited faster reaction time performances in majority of the learning blocks compared to FAM1 and Control. FAM21 also demonstrated a significantly more pronounced N2 over majority of anterior and central regions of interests during SRTT compared to the other groups. When N2 amplitudes were modelled against general learning performance, FAM21 showed the greatest rate of amplitude decline over anterior and central regions. The combined results suggest that FAM training provided greater cognitive control enhancement for improved general performance, and less pronounced effects for sequence-specific learning performance compared to the other groups. Importantly, FAM training facilitates dynamic modulation of cognitive control: lower levels of general learning performance was supported by greater levels of activation, whilst higher levels of general learning exhibited less activation.

Abstract

Lexicalized theories of syntax often assume that verb-structure regularities are mediated by lemmas, which abstract over variation in verb tense and aspect. German syntax seems to challenge this assumption, because verb position depends on tense and aspect. To examine how German speakers link these elements, a structural priming study was performed which varied syntactic structure, verb position (encoded by tense and aspect), and verb overlap. Abstract structural priming was found, both within and across verb position, but priming was larger when the verb position was the same between prime and target. Priming was boosted by verb overlap, but there was no interaction with verb position. The results can be explained by a lemma model where tense and aspect are linked to structural choices in German. Since the architecture of this lemma model is not consistent with results from English, a connectionist model was developed which could explain the cross-linguistic variation in the production system. Together, these findings support the view that language learning plays an important role in determining the nature of structural priming in different languages

Abstract

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

Abstract

Background: Eukaryotic cells possess a complex network of RNA machineries which function in RNA-processing and cellular regulation which includes transcription, translation, silencing, editing and epigenetic control. Studies of model organisms have shown that many ncRNAs of the RNA-infrastructure are highly conserved, but little is known from non-model protists. In this study we have conducted a genome-scale survey of medium-length ncRNAs from the protozoan parasites Giardia intestinalis and Trichomonas vaginalis. Results: We have identified the previously ‘missing’ Giardia RNase MRP RNA, which is a key ribozyme involved in pre-rRNA processing. We have also uncovered 18 new H/ACA box snoRNAs, expanding our knowledge of the H/ ACA family of snoRNAs. Conclusions: Results indicate that Giardia intestinalis and Trichomonas vaginalis, like their distant multicellular relatives, contain a rich infrastructure of RNA-based processing. From here we can investigate the evolution of RNA processing networks in eukaryotes.

Abstract

Studies on children’s use of intonation in reference are few in number but are diverse in terms of theoretical frameworks and intonational parameters. In the current review, I present a re-analysis of the referents in each study, using a three-dimension approach (i.e. referential givenness-newness, relational givenness-newness, contrast), discuss the use of intonation at two levels (phonetic, phonological), and compare findings from different studies within a single framework. The patterns stemming from these studies may be limited in generalisability but can serve as initial hypotheses for future work. Furthermore, I examine the role of input as available in infant direct speech in the acquisition of intonational encoding of referents. In addition, I discuss how future research can advance our knowledge.

Abstract

1 Introduction In spoken sentence processing, listeners do not wait till the end of a sentence to decipher what message is conveyed. Rather, they make predictions on the most plausible interpretation at every possible point in the auditory signal on the basis of all kinds of linguistic information (e.g., Eberhard et al. 1995; Alman and Kamide 1999, 2007). Intonation is one such kind of linguistic information that is efficiently used in spoken sentence processing. The evidence comes primarily from recent work on online reference resolution conducted in the visual-world eyetracking paradigm (e.g., Tanenhaus et al. 1995). In this paradigm, listeners are shown a visual scene containing a number of objects and listen to one or two short sentences about the scene. They are asked to either inspect the visual scene while listening or to carry out the action depicted in the sentence(s) (e.g., 'Touch the blue square'). Listeners' eye movements directed to each object in the scene are monitored and time-locked to pre-defined time points in the auditory stimulus. Their predictions on the upcoming referent and sources for the predictions in the auditory signal are examined by analysing fixations to the relevant objects in the visual scene before the acoustic information on the referent is available

Abstract

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

Abstract

This paper investigates the lexical semantics of placement verbs in Mandarin. The majority of Mandarin placement verbs are directional verb compounds (e.g., na2-xia4-lai2 ‘take-descend-come’). They are composed of two or three verbs in a fixed order, each encoding certain semantic components of placement events. The first verb usually conveys object manipulation and the second and the third verbs indicate the Path of motion, including Deixis. The first verb, typically encoding object manipulation, can be semantically general or specific: two general verbs, fang4 ‘put’ and na2 ‘take’, have large but constrained extensional categories, and a number of specific verbs are used based on the Manner of manipulation of the Figure object, the relationship between and the physical properties of Figure and Ground, intentionality of the Agent, and the type of instrument.

Abstract

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

Abstract

While detecting genetic variations underlying brain structures helps reveal mechanisms of neural disorders, high data dimensionality poses a major challenge for imaging genomic association studies. In this work, we present the application of a recently proposed approach, parallel independent component analysis with reference (pICA-R), to investigate genomic factors potentially regulating gray matter variation in a healthy population. This approach simultaneously assesses many variables for an aggregate effect and helps to elicit particular features in the data. We applied pICA-R to analyze gray matter density (GMD) images (274,131 voxels) in conjunction with single nucleotide polymorphism (SNP) data (666,019 markers) collected from 1,256 healthy individuals of the Brain Imaging Genetics (BIG) study. Guided by a genetic reference derived from the gene GNA14, pICA-R identified a significant SNP-GMD association (r = −0.16, P = 2.34 × 10−8), implying that subjects with specific genotypes have lower localized GMD. The identified components were then projected to an independent dataset from the Mind Clinical Imaging Consortium (MCIC) including 89 healthy individuals, and the obtained loadings again yielded a significant SNP-GMD association (r = −0.25, P = 0.02). The imaging component reflected GMD variations in frontal, precuneus, and cingulate regions. The SNP component was enriched in genes with neuronal functions, including synaptic plasticity, axon guidance, molecular signal transduction via PKA and CREB, highlighting the GRM1, PRKCH, GNA12, and CAMK2B genes. Collectively, our findings suggest that GNA12 and GNA14 play a key role in the genetic architecture underlying normal GMD variation in frontal and parietal regions

Abstract

This paper gives an overview of recent studies on the use of phonological cues (accent placement and choice of accent type) to mark focus in Dutch-speaking children aged between 1;9 and 8;10. It is argued that learning to use phonological cues to mark focus is a gradual process. In the light of the findings in these studies, a first proposal is put forward on the developmental path to adult-like phonological focus-marking in Dutch.

Abstract

This study examined how four- to five-year-olds and seven- to eight-year-olds used intonation (accent placement and accent type) to encode topic and focus in Dutch. Naturally spoken declarative sentences with either sentence-initial topic and sentence-final focus or sentence-initial focus and sentence-final topic were elicited via a picture-matching game. Results showed that the four- to five-year-olds were adult-like in topic-marking, but were not yet fully adult-like in focus-marking, in particular, in the use of accent type in sentence-final focus (i.e. showing no preference for H*L). Between age five and seven, the use of accent type was further developed. In contrast to the four- to five-year-olds, the seven- to eight-year-olds showed a preference for H*L in sentence-final focus. Furthermore, they used accent type to distinguish sentence-initial focus from sentence-initial topic in addition to phonetic cues.

Abstract

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

Abstract

Two experiments examined whether perceptual recovery from Korean consonant-cluster simplification is based on language-specific phonological knowledge. In tri-consonantal C1C2C3 sequences such as /lkt/ and /lpt/ in Seoul Korean, either C1 or C2 can be completely deleted. Seoul Koreans monitored for C2 targets (/p/ or / k/, deleted or preserved) in the second word of a two-word phrase with an underlying /l/-C2-/t/ sequence. In Experiment 1 the target-bearing words had contextual lexical-semantic support. Listeners recovered deleted targets as fast and as accurately as preserved targets with both Word and Intonational Phrase (IP) boundaries between the two words. In Experiment 2, contexts were low-pass filtered. Listeners were still able to recover deleted targets as well as preserved targets in IP-boundary contexts, but better with physically-present targets than with deleted targets in Word-boundary contexts. This suggests that the benefit of having target acoustic-phonetic information emerges only when higher-order (contextual and phrase-boundary) information is not available. The strikingly efficient recovery of deleted phonemes with neither acoustic-phonetic cues nor contextual support demonstrates that language-specific phonological knowledge, rather than language-universal perceptual processes which rely on fine-grained phonetic details, is employed when the listener perceives the results of a continuous-speech process in which reduction is phonetically complete.

Abstract

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

Abstract

We investigated the role of syllables during speech planning in English by measuring syllable-frequency effects. So far, syllable-frequency effects in English have not been reported. English has poorly defined syllable boundaries, and thus the syllable might not function as a prominent unit in English speech production. Speakers produced either monosyllabic (Experiment 1) or disyllabic (Experiment 2–4) pseudowords as quickly as possible in response to symbolic cues. Monosyllabic targets consisted of either high- or low-frequency syllables, whereas disyllabic items contained either a 1st or 2nd syllable that was frequency-manipulated. Significant syllable-frequency effects were found in all experiments. Whereas previous findings for disyllables in Dutch and Spanish—languages with relatively clear syllable boundaries—showed effects of a frequency manipulation on 1st but not 2nd syllables, in our study English speakers were sensitive to the frequency of both syllables. We interpret this sensitivity as an indication that the production of English has more extensive planning scopes at the interface of phonetic encoding and articulation.

Abstract

People spontaneously produce gestures when they solve problems or explain their solutions to a problem. In this chapter, we will review and discuss evidence on the role of representational gestures in problem solving. The focus will be on our recent experiments (Chu & Kita, 2008), in which we used Shepard-Metzler type of mental rotation tasks to investigate how spontaneous gestures revealed the development of problem solving strategy over the course of the experiment and what role gesture played in the development process. We found that when solving novel problems regarding the physical world, adults go through similar symbolic distancing (Werner & Kaplan, 1963) and internalization (Piaget, 1968) processes as those that occur during young children’s cognitive development and gesture facilitates such processes.

Abstract

When solving spatial problems, people often spontaneously produce hand gestures. Recent research has shown that our knowledge is shaped by the interaction between our body and the environment. In this article, we review and discuss evidence on: 1) how spontaneous gesture can reveal the development of problem solving strategies when people solve spatial problems; 2) whether producing gestures can enhance spatial problem solving performance. We argue that when solving novel spatial problems, adults go through deagentivization and internalization processes, which are analogous to young children’s cognitive development processes. Furthermore, gesture enhances spatial problem solving performance. The beneficial effect of gesturing can be extended to non-gesturing trials and can be generalized to a different spatial task that shares similar spatial transformation processes.

Abstract

Co-thought gestures are hand movements produced in silent, noncommunicative, problem-solving situations. In the study, we investigated whether and how such gestures enhance performance in spatial visualization tasks such as a mental rotation task and a paper folding task. We found that participants gestured more often when they had difficulties solving mental rotation problems Experiment 1). The gesture-encouraged group solved more mental rotation problems correctly than did the gesture-allowed and gesture-prohibited groups (Experiment 2). Gestures produced by the gesture-encouraged group enhanced performance in the very trials in which they were produced Experiments 2 & 3). Furthermore, gesture frequency decreased as the participants in the gesture-encouraged group solved more problems (Experiments 2 & 3). In addition, the advantage of the gesture-encouraged group persisted into subsequent spatial visualization problems in which gesturing was prohibited: another mental rotation block (Experiment 2) and a newly introduced paper folding task (Experiment 3). The results indicate that when people have difficulty in solving spatial visualization problems, they spontaneously produce gestures to help them, and gestures can indeed improve performance. As they solve more problems, the spatial computation supported by gestures becomes internalized, and the gesture frequency decreases. The benefit of gestures persists even in subsequent spatial visualization problems in which gesture is prohibited. Moreover, the beneficial effect of gesturing can be generalized to a different spatial visualization task when two tasks require similar spatial transformation processes. We conclude that gestures enhance performance on spatial visualization tasks by improving the internal computation of spatial transformations.

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

Methods
The present study provides a systematic analysis of co-speech gestures which spontaneously accompany the description of actions in a group of PD patients (N = 23, Hoehn and Yahr Stage III or less) and age-matched healthy controls (N = 22). The analysis considers different co-speech gesture types, using established classification schemes from the field of gesture research. The analysis focuses on the rate of these gestures as well as on their qualitative nature. In doing so, the analysis attempts to overcome several methodological shortcomings of research in this area.
Results
Contrary to expectation, gesture rate was not significantly affected in our patient group, with relatively mild PD. This indicates that co-speech gestures could compensate for speech problems. However, while gesture rate seems unaffected, the qualitative precision of gestures representing actions was significantly reduced.
Conclusions
This study demonstrates the feasibility of carrying out fine-grained, detailed analyses of gestures in PD and offers insights into an as yet neglected facet of communication in patients with PD. Based on the present findings, an important next step is the closer investigation of the qualitative changes in gesture (including different communicative situations) and an analysis of the heterogeneity in co-speech gesture production in PD.

Abstract

Background: The concept of fluency is widely used to dichotomously classify aphasia syndromes in both research and clinical practice. Despite its ubiquity, reliability of fluency measurement is reduced due to its multi-dimensional nature and the variety of methods used to measure it.
Aims: The primary aim of the study was to determine what factors contribute to judgements of fluency in aphasia, identifying methodological and linguistic sources of disagreement.
Methods & Procedures: We compared fluency classifications generated according to fluency scores on the revised Western Aphasia Battery (WAB-R) to clinical impressions of fluency for 254 English-speaking people with aphasia (PwA) from the AphasiaBank database. To determine what contributed to fluency classifications, we examined syndrome diagnoses and measured the predictive strength of 18 spontaneous speech variables extracted from retellings of the Cinderella story. The variables were selected to represent three dimensions predicted to underlie fluency: grammatical competence, lexical retrieval, and the facility of speech production.
Outcomes & Results: WAB-R fluency classifications agreed with 83% of clinician classifications, although agreement was much greater for fluent than nonfluent classifications. The majority of mismatches were diagnosed with anomic or conduction aphasia by the WAB-R but Broca's aphasia by clinicians. Modifying the WAB-R scale improved the extent to which WAB-R fluency categories matched clinical impressions. Fluency classifications were predicted by a combination of variables, including aspects of grammaticality, lexical retrieval and speech production. However, fluency classification by WAB-R was largely predicted by severity, whereas the presence or absence of apraxia of speech was the largest predictor of fluency classifications by clinicians.
Conclusions: Fluency judgements according to WAB-R scoring and those according to clinical impression showed some common influences, but also some differences that contributed to mismatches in fluency categorization. We propose that, rather than using dichotomous fluency categories, which can mask sources of disagreement, fluency should be explicitly identified relative to the underlying deficits (word-finding, grammatical formulation, speech production, or a combination) contributing to each individual PwA's fluency profile. Identifying what contributes to fluency disruptions is likely to generate more reliable diagnoses and provide more concrete guidance regarding therapy, avenues we are pursuing in ongoing research.

Abstract

When people talk, they gesture. Gesture is a fundamental component of language that contributes meaningful and unique information to a spoken message and reflects the speaker's underlying knowledge and experiences. Theoretical perspectives of speech and gesture propose that they share a common conceptual origin and have a tightly integrated relationship, overlapping in time, meaning, and function to enrich the communicative context. We review a robust literature from the field of psychology documenting the benefits of gesture for communication for both speakers and listeners, as well as its important cognitive functions for organizing spoken language, and facilitating problem-solving, learning, and memory. Despite this evidence, gesture has been relatively understudied in populations with neurogenic communication disorders. While few studies have examined the rehabilitative potential of gesture in these populations, others have ignored gesture entirely or even discouraged its use. We review the literature characterizing gesture production and its role in intervention for people with aphasia, as well as describe the much sparser literature on gesture in cognitive communication disorders including right hemisphere damage, traumatic brain injury, and Alzheimer's disease. The neuroanatomical and behavioral profiles of these patient populations provide a unique opportunity to test theories of the relationship of speech and gesture and advance our understanding of their neural correlates. This review highlights several gaps in the field of communication disorders which may serve as a bridge for applying the psychological literature of gesture to the study of language disorders. Such future work would benefit from considering theoretical perspectives of gesture and using more rigorous and quantitative empirical methods in its approaches. We discuss implications for leveraging gesture to explore its untapped potential in understanding and rehabilitating neurogenic communication disorders.

Abstract

We report the results of a cross-cultural investigation of person-body reasoning in the United Kingdom and northern Brazilian Amazon (Marajo´ Island). The study provides evidence that directly bears upon divergent theoretical claims in cognitive psychology and anthropology, respectively, on the cognitive origins and cross-cultural incidence of mind-body dualism. In a novel reasoning task, we found that participants across the two sample populations parsed a wide range of capacities similarly in terms of the capacities’ perceived anchoring to bodily function. Patterns of reasoning concerning the respective roles of physical and biological properties in sustaining various capacities did vary between sample populations, however. Further, the data challenge prior ad-hoc categorizations in the empirical literature on the developmental origins of and cognitive constraints on psycho-physical reasoning (e.g., in afterlife concepts). We suggest cross-culturally validated categories of ‘‘Body Dependent’’ and ‘‘Body Independent’’ items for future developmental and cross-cultural research in this emerging area.

Abstract

Recent game-theoretic simulation and analytical models have demonstrated that cooperative strategies mediated by indicators of cooperative potential, or “tags,” can invade, spread, and resist invasion by noncooperators across a range of population-structure and cost-benefit scenarios. The plausibility of these models is potentially relevant for human evolutionary accounts insofar as humans possess some phenotypic trait that could serve as a reliable tag. Linguistic markers, such as accent and dialect, have frequently been either cursorily defended or promptly dismissed as satisfying the criteria of a reliable and evolutionarily viable tag. This paper integrates evidence from a range of disciplines to develop and assess the claim that speech accent mediated the evolution of tag-based cooperation in humans. Existing evidence warrants the preliminary conclusion that accent markers meet the demands of an evolutionarily viable tag and potentially afforded a cost-effective solution to the challenges of maintaining viable cooperative relationships in diffuse, regional social networks.

Abstract

Summary Non-coding RNAs (ncRNAs) have been implicated in the epigenetic marking of many genes. Short regulatory ncRNAs, including miRNAs, siRNAs, piRNAs and snoRNAs as well as long ncRNAs such as Xist and Air are discussed in light of recent research of mechanisms regulating chromatin marking and RNA editing. The topic is expanding rapidly so we will concentrate on examples to highlight the main mechanisms, including simple mechanisms where complementary binding affect methylation or RNA sites. However, other examples especially with the long ncRNAs highlight very complex regulatory systems with multiple layers of ncRNA control.

Abstract

Common wisdom has it that Buddhism enhances compassion and self-other integration. We put this assumption to empirical test by comparing practicing Taiwanese Buddhists with well-matched atheists. Buddhists showed more evidence of self-other integration in the social Simon task, which assesses the degree to which people co-represent the actions of a coactor. This suggests that self-other integration and task co-representation vary as a function of religious practice.

Abstract

Congenital anomalies of the kidney and urinary tract (CAKUT) constitute one of the most frequent birth defects and represent the most common cause of chronic kidney disease in the first three decades of life. Despite the discovery of dozens of monogenic causes of CAKUT, most pathogenic pathways remain elusive. We performed whole-exome sequencing (WES) in 551 individuals with CAKUT and identified a heterozygous de novo stop-gain variant in ZMYM2 in two different families with CAKUT. Through collaboration, we identified in total 14 different heterozygous loss-of-function mutations in ZMYM2 in 15 unrelated families. Most mutations occurred de novo, indicating possible interference with reproductive function. Human disease features are replicated in X. tropicalis larvae with morpholino knockdowns, in which expression of truncated ZMYM2 proteins, based on individual mutations, failed to rescue renal and craniofacial defects. Moreover, heterozygous Zmym2-deficient mice recapitulated features of CAKUT with high penetrance. The ZMYM2 protein is a component of a transcriptional corepressor complex recently linked to the silencing of developmentally regulated endogenous retrovirus elements. Using protein-protein interaction assays, we show that ZMYM2 interacts with additional epigenetic silencing complexes, as well as confirming that it binds to FOXP1, a transcription factor that has also been linked to CAKUT. In summary, our findings establish that loss-of-function mutations of ZMYM2, and potentially that of other proteins in its interactome, as causes of human CAKUT, offering new routes for studying the pathogenesis of the disorder.

Abstract

Speech processing can often take place in adverse listening conditions that involve the mixing of speech and background noise. In this study, we investigated processing dependencies between background noise and indexical speech features, using a speeded classification paradigm (Garner, 1974; Exp. 1), and whether background noise is encoded and represented in memory for spoken words in a continuous recognition memory paradigm (Exp. 2). Whether or not the noise spectrally overlapped with the speech signal was also manipulated. The results of Experiment 1 indicated that background noise and indexical features of speech (gender, talker identity) cannot be completely segregated during processing, even when the two auditory streams are spectrally nonoverlapping. Perceptual interference was asymmetric, whereby irrelevant indexical feature variation in the speech signal slowed noise classification to a greater extent than irrelevant noise variation slowed speech classification. This asymmetry may stem from the fact that speech features have greater functional relevance to listeners, and are thus more difficult to selectively ignore than background noise. Experiment 2 revealed that a recognition cost for words embedded in different types of background noise on the first and second occurrences only emerged when the noise and the speech signal were spectrally overlapping. Together, these data suggest integral processing of speech and background noise, modulated by the level of processing and the spectral separation of the speech and noise.

Abstract

Incremental comprehension of head-final constructions can reveal structural attachment preferences for ambiguous phrases. This study investigates
how temporarily ambiguous PPs are processed in Dutch verb-final constructions. In De aannemer heeft op het dakterras bespaard/gewerkt ‘The
contractor has on the roof terrace saved/worked’, the PP is locally ambiguous between attachment as argument and as adjunct. This ambiguity is
resolved by the sentence-final verb. In a self-paced reading task, we manipulated the argument/adjunct status of the PP, and its position relative to the
verb. While we found no reading-time differences between argument and
adjunct PPs, we did find that transitive verbs, for which the PP is an argument, were read more slowly than intransitive verbs, for which the PP is an adjunct. We suggest that Dutch parsers have a preference for adjunct attachment of preverbal PPs, and discuss our findings in terms of incremental
parsing models that aim to minimize costly reanalysis.

Abstract

A key challenge in understanding stories and conversations is the comprehension of ‘anaphora’, words that refer back to previously mentioned words or concepts (‘antecedents’). In psycholinguistic theories, anaphor comprehension involves the initial activation of the antecedent and its subsequent integration into the unfolding representation of the narrated event. A recent proposal suggests that these processes draw upon the brain’s recognition memory and language networks, respectively, and may be dissociable in patterns of neural oscillatory synchronization (Nieuwland & Martin, 2017). We addressed this proposal in an electroencephalogram (EEG) study with pre-registered data acquisition and analyses, using event-related potentials (ERPs) and neural oscillations. Dutch participants read two-sentence mini stories containing proper names, which were repeated or new (ease of activation) and semantically coherent or incoherent with the preceding discourse (ease of integration). Repeated names elicited lower N400 and Late Positive Component amplitude than new names, and also an increase in theta-band (4-7 Hz) synchronization, which was largest around 240-450 ms after name onset. Discourse-coherent names elicited an increase in gamma-band (60-80 Hz) synchronization compared to discourse-incoherent names. This effect was largest around 690-1000 ms after name onset and exploratory beamformer analysis suggested a left frontal source. We argue that the initial activation and subsequent discourse-level integration of referents can be dissociated with event-related EEG activity, and are associated with respectively theta- and gamma-band activity. These findings further establish the link between memory and language through neural oscillations.

Abstract

During conversation, interlocutors often produce their utterances with little overlap or gap between their turns. But what mechanism underlies this striking ability to time articulation appropriately? In 2 verbal yes/no question-answering experiments, we investigated whether listeners use the speech rate of questions to time articulation of their answers. In Experiment 1, we orthogonally manipulated the speech rate of the context (e.g., Do you have a . . .) and final word (e.g., dog?) of questions using time-compression, so that each component was spoken at the natural rate or twice as a fast. Listeners responded earlier when the context was speeded rather than natural, suggesting they used the speaker’s context rate to time answer articulation. Additionally, listeners responded earlier when the speaker’s final syllable was speeded than natural, regardless of context rate, suggesting they adjusted the timing of articulation after listening to a single syllable produced at a different rate. We replicated this final word effect in Experiment 2, which also showed that our speech rate manipulation did not influence the timing of response preparation. Together, these findings suggest listeners use speech rate information to time articulation when answering questions

Abstract

Listeners quickly learn to understand speech that has been distorted, and this process is enhanced when comprehension is constrained by higher-level knowledge. In three experiments, we investigated whether this knowledge enhances comprehension of distorted speech because it allows listeners to predict (1) the meaning of the distorted utterance, or (2) the lower-level wordforms. Participants listened to question-answer sequences, in which questions were clearly-spoken but answers were noise-vocoded. Comprehension (Experiment 1) and learning (Experiment 2) were enhanced when listeners could use the question to predict the semantics of the distorted answer, but were not enhanced by predictions of answer form. Form predictions enhanced comprehension only when questions and answers were significantly separated by time and intervening linguistic material (Experiment 3). Together, these results suggest that high-level semantic predictions enhance comprehension and learning, with form predictions playing only a minimal role.

Abstract

In three experiments, listeners detected vowel or consonant targets in lists of CV syllables constructed from five vowels and five consonants. Responses were faster in a predictable context (e.g., listening for a vowel target in a list of syllables all beginning with the same consonant) than in an unpredictable context (e.g., listening for a vowel target in a list of syllables beginning with different consonants). In Experiment 1, the listeners’ native language was Dutch, in which vowel and consonant repertoires are similar in size. The difference between predictable and unpredictable contexts was comparable for vowel and consonant targets. In Experiments 2 and 3, the listeners’ native language was Spanish, which has four times as many consonants as vowels; here effects of an unpredictable consonant context on vowel detection were significantly greater than effects of an unpredictable vowel context on consonant detection. This finding suggests that listeners’ processing of phonemes takes into account the constitution of their language’s phonemic repertoire and the implications that this has for contextual variability.

Abstract

The issue addressed in this study is whether propositional integration and world-knowledge inference can be distinguished as separate processes during the comprehension of Dutch omdat (because) sentences. “Propositional integration” refers to the process by which the reader establishes the type of relation between two clauses or sentences. “World-knowledge inference” refers to the process of deriving the general causal relation and checking it against the reader's world knowledge. An eye-tracking experiment showed that the presence of the conjunction speeds up the processing of the words immediately following the conjunction, and slows down the processing of the sentence final words in comparison to the absence of the conjunction. A second, subject-paced reading experiment replicated the reading time findings, and the results of a verification task confirmed that the effect at the end of the sentence was due to inferential processing. The findings evidence integrative processing and inferential processing, respectively.

Abstract

Several theoretical accounts have been proposed with respect to the issue how quickly the implicit causality verb bias affects the understanding of sentences such as “John beat Pete at the tennis match, because he had played very well”. They can be considered as instances of two viewpoints: the focusing and the integration account. The focusing account claims that the bias should be manifest soon after the verb has been processed, whereas the integration account claims that the interpretation is deferred until disambiguating information is encountered. Up to now, this issue has remained unresolved because materials or methods have failed to address it conclusively. We conducted two experiments that exploited the visual world paradigm and ambiguous pronouns in subordinate because clauses. The first experiment presented implicit causality sentences with the task to resolve the ambiguous pronoun. To exclude strategic processing, in the second experiment, the task was to answer simple comprehension questions and only a minority of the sentences contained implicit causality verbs. In both experiments, the implicit causality of the verb had an effect before the disambiguating information was available. This result supported the focusing account.

Abstract

As the creation of signed language resources is gaining speed world-wide, the need for standards in this field becomes more acute. This paper discusses the state of the field of signed language resources, their metadata descriptions, and annotations that are typically made. It then describes the role that ISOcat may play in this process and how it can stimulate standardisation without imposing standards. Finally, it makes some initial proposals for the thematic domain ‘sign language’ that was introduced in 2011.

Abstract

A basic question for the study of the mental lexicon is whether there are morphological representations and processes that are independent of phonology and semantics. According to a prominent tradition, morphological relatedness requires semantic transparency: semantically transparent words are related in meaning to their stems, while semantically opaque words are not. This study examines the question of morphological relatedness using intra-modal auditory priming by Dutch prefixed verbs. The key conditions involve semantically transparent prefixed primes (e.g., aanbieden ‘offer’, with the stem bieden, also ‘offer’) and opaque primes (e.g., verbieden ‘forbid’). Results show robust facilitation for both transparent and opaque pairs; phonological (Experiment 1) and semantic (Experiment 2) controls rule out the possibility that these other types of relatedness are responsible for the observed priming effects. The finding of facilitation with opaque primes suggests that morphological processing is independent of semantic and phonological representations. Accordingly, the results are incompatible with theories that make semantic overlap a necessary condition for relatedness, and favor theories in which words may be related in ways that do not require shared meaning. The general discussion considers several specific proposals along these lines, and compares and contrasts questions about morphological relatedness of the type found here with the different but related question of whether there is morphological decomposition of complex forms or not.

Abstract

A current theoretical view proposes that infants converge on the speech categories of their native language by attending to frequency distributions that occur in the acoustic input. To date, the only empirical support for this statistical learning hypothesis comes from studies where a single, salient dimension was manipulated. Additional evidence is sought here, by introducing a less salient pair of categories supported by multiple cues. We exposed English-learning infants to a multi-cue bidimensional grid ranging between retroflex and alveolopalatal sibilants in prevocalic position. This contrast is substantially more difficult according to previous cross-linguistic and perceptual research, and its perception is driven by cues in both the consonantal and the following vowel portions. Infants heard one of two distributions (flat, or with two peaks), and were tested with sounds varying along only one dimension. Infants' responses differed depending on the familiarization distribution, and their performance was equally good for the vocalic and the frication dimension, lending some support to the statistical hypothesis even in this harder learning situation. However, learning was restricted to the retroflex category, and a control experiment showed that lack of learning for the alveolopalatal category was not due to the presence of a competing category. Thus, these results contribute fundamental evidence on the extent and limitations of the statistical hypothesis as an explanation for infants' perceptual tuning.

Abstract

Within the debate on the mechanisms underlying infants’ perceptual acquisition, one hypothesis proposes that infants’ perception is directly affected by the acoustic implementation of sound categories in the speech they hear. In consonance with this view, the present study shows that individual variation in fine-grained, subphonemic aspects of the acoustic realization of /s/ in caregivers’ speech predicts infants’ discrimination of this sound from the highly similar /∫/, suggesting that learning based on acoustic cue distributions may indeed drive natural phonological acquisition.

Abstract

Adults' phonotactic learning is affected by perceptual biases. One such bias concerns learning of constraints affecting groups of sounds: all else being equal, learning constraints affecting a natural class (a set of sounds sharing some phonetic characteristic) is easier than learning a constraint affecting an arbitrary set of sounds. This perceptual bias could be a given, for example, the result of innately guided learning; alternatively, it could be due to human learners’ experience with sounds. Using artificial grammars, we investigated whether such a bias arises in development, or whether it is present as soon as infants can learn phonotactics. Seven-month-old English-learning infants fail to generalize a phonotactic pattern involving fricatives and nasals, which does not form a coherent phonetic group, but succeed with the natural class of oral and nasal stops. In this paper, we report an experiment that explored whether those results also follow in a cohort of 4-month-olds. Unlike the older infants, 4-month-olds were able to generalize both groups, suggesting that the perceptual bias that makes phonotactic constraints on natural classes easier to learn is likely the effect of experience.

Abstract

In most of the world, people have regular exposure to multiple accents. Therefore, learning to quickly process accented speech is a prerequisite to successful communication. In this paper, we examine work on the perception of accented speech across the lifespan, from early infancy to late adulthood. Unfamiliar accents initially impair linguistic processing by infants, children, younger adults, and older adults, but listeners of all ages come to adapt to accented speech. Emergent research also goes beyond these perceptual abilities, by assessing links with production and the relative contributions of linguistic knowledge and general cognitive skills. We conclude by underlining points of convergence across ages, and the gaps left to face in future work.

Abstract

Features serve two main functions in the phonology of languages: they encode the distinction between pairs of contrastive phonemes (distinctive function); and they delimit sets of sounds that participate in phonological processes and patterns (classificatory function). We summarize evidence from a variety of experimental paradigms bearing on the functional relevance of phonological features. This research shows that while young infants may use abstract phonological features to learn sound patterns, this ability becomes more constrained with development and experience. Furthermore, given the lack of overlap between the ability to learn a pair of words differing in a single feature and the ability to learn sound patterns based on features, we argue for the separation of the distinctive and the classificatory function.

Abstract

Talking about odors and flavors is difficult for most people, yet experts appear to be able to convey critical information about wines in their reviews. This seems to be a contradiction, and wine expert descriptions are frequently received with criticism. Here, we propose a method for probing the language of wine reviews, and thus offer a means to enhance current vocabularies, and as a by-product question the general assumption that wine reviews are gibberish. By means of two different quantitative analyses—support vector machines for classification and Termhood analysis—on a corpus of online wine reviews, we tested whether wine reviews are written in a consistent manner, and thus may be considered informative; and whether reviews feature domain-specific language. First, a classification paradigm was trained on wine reviews from one set of authors for which the color, grape variety, and origin of a wine were known, and subsequently tested on data from a new author. This analysis revealed that, regardless of individual differences in vocabulary preferences, color and grape variety were predicted with high accuracy. Second, using Termhood as a measure of how words are used in wine reviews in a domain-specific manner compared to other genres in English, a list of 146 wine-specific terms was uncovered. These words were compared to existing lists of wine vocabulary that are currently used to train experts. Some overlap was observed, but there were also gaps revealed in the extant lists, suggesting these lists could be improved by our automatic analysis.

Abstract

The mother-offspring bond is one of the strongest and most essential social bonds. Following is a detailed behavioral report of a female chimpanzee two days after her 16-month-old infant died, on the first day that the mother is observed to create distance between her and the corpse. A series of repeated approaches and retreats to and from the body are documented, along with detailed accounts of behaviors directed toward the dead infant by the mother and other group members. The behavior of the mother toward her dead infant not only highlights the maternal contribution to the mother-infant relationship but also elucidates the opportunities chimpanzees have to learn about the sensory cues associated with death, and the implications of death for the social environment.

Abstract

Social tolerance is a core aspect of primate social relationships with implications for the evolution of cooperation, prosociality and social learning. We measured the social tolerance of bonobos in an experiment recently validated with chimpanzees to allow for a comparative assessment of group-level tolerance, and found that the bonobo group studied here exhibited lower social tolerance on average than chimpanzees. Furthermore, following the Relational Model [de Waal, 1996], we investigated whether bonobos responded to an increased potential for social conflict with tolerance, conflict avoidance or conflict escalation, and found that only behaviours indicative of conflict escalation differed across conditions. Taken together, these findings contribute to the current debate over the level of social tolerance of bonobos and lend support to the position that the social tolerance of bonobos may not be notably high compared with other primates.

Abstract

Definition Prosocial behavior is any behavior performed by one individual that results in a benefit for another individual. Prosocial motivations, prosocial preferences, or other-regarding preferences refer to the psychological predisposition to behave in the best interest of another individual. A behavior need not be costly to the actor to be considered prosocial, thus the concept is distinct from altruistic behavior which requires that the actor incurs some cost when providing a benefit to another.

Abstract

Studies of animal behavior consistently demonstrate that the social environment impacts cooperation, yet the effect of social dynamics has been largely excluded from studies of human cooperation. Here, we introduce a novel approach inspired by nonhuman primate research to address how social hierarchies impact human cooperation. Participants competed to earn hierarchy positions and then could cooperate with another individual in the hierarchy by investing in a common effort. Cooperation was achieved if the combined investments exceeded a threshold, and the higher ranked individual distributed the spoils unless control was contested by the partner. Compared to a condition lacking hierarchy, cooperation declined in the presence of a hierarchy due to a decrease in investment by lower ranked individuals. Furthermore, hierarchy was detrimental to cooperation regardless of whether it was earned or arbitrary. These findings mirror results from nonhuman primates and demonstrate that hierarchies are detrimental to cooperation. However, these results deviate from nonhuman primate findings by demonstrating that human behavior is responsive to changing hierarchical structures and suggests partnership dynamics that may improve cooperation. This work introduces a controlled way to investigate the social influences on human behavior, and demonstrates the evolutionary continuity of human behavior with other primate species.

Abstract

Researchers have struggled to obtain a clear account of the evolution of prosocial behaviour despite a great deal of recent effort. The aim of this review is to take a brief step back from addressing the question of evolutionary origins of prosocial behaviour in order to identify contextual factors that are contributing to variation in the expression of prosocial behaviour and hindering progress towards identifying phylogenetic patterns. Most available data come from the Primate Order, and the choice of contextual factors to consider was informed by theory and practice, including the nature of the relationship between the potential donor and recipient, the communicative behaviour of the recipients, and features of the prosocial task including whether rewards are visible and whether the prosocial choice creates an inequity between actors. Conclusions are drawn about the facilitating or inhibiting impact of each of these factors on the expression of prosocial behaviour, and areas for future research are highlighted. Acknowledging the impact of these contextual features on the expression of prosocial behaviours should stimulate new research into the proximate mechanisms that drive these effects, yield experimental designs that better control for potential influences on prosocial expression, and ultimately allow progress towards reconstructing the evolutionary origins of prosocial behaviour.

Abstract

The social factors that influence cooperation have remained largely uninvestigated but have the potential to explain much of the variation in cooperative behavior observed in the natural world. We show here that certain dimensions of the social environment, namely the size of the social group, the degree of social tolerance expressed, the structure of the dominance hierarchy, and the patterns of dispersal, may influence the emergence and stability of cooperation in predictable ways. Furthermore, the social environment experienced by a species over evolutionary time will have shaped their cognition to provide certain strengths and strategies that are beneficial in their species‟ social world. These cognitive adaptations will in turn impact the likelihood of cooperating in a given social environment. Experiments with one primate species, the cottontop tamarin, illustrate how social dynamics may influence emergence and stability of cooperative behavior in this species. We then take a more general viewpoint and argue that the hypotheses presented here require further experimental work and the addition of quantitative modeling to obtain a better understanding of how social dynamics influence the emergence and stability of cooperative behavior in complex systems. We conclude by pointing out subsequent specific directions for models and experiments that will allow relevant advances in the understanding of the emergence of cooperation.