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1.
Cogn Sci ; 47(11): e13373, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37950700

RESUMEN

Discovering the meaning of novel communicative cues is challenging and amounts to navigating an unbounded hypothesis space. Several theories posit that this problem can be simplified by relying on positive expectations about the cognitive utility of communicated information. These theories imply that learners should assume that novel communicative cues tend to have low processing costs and high cognitive benefits. We tested this hypothesis in three studies in which toddlers (N = 90) searched for a reward hidden in one of several containers. In all studies, an adult communicated the reward's location with an unfamiliar and ambiguous cue. We manipulated the processing costs (operationalized as inferential chain length) and cognitive benefits (operationalized as informativeness) of the possible interpretations of the cues. Toddlers processing of novel communicative cues were guided by expectations of low processing costs (Study 1) and high cognitive benefits (Studies 2 and 3). More specifically, toddlers treated novel cues as if they were easy to process, informative, and accurate, even when provided with repeated evidence to the contrary. These results indicate that, from toddlerhood onward, expectations of cognitive utility shape the processing of novel communicative cues. These data also reveal that toddlers, who are in the process of learning the language and communicative conventions of people around them, exert a pressure favoring cognitive efficiency in communicative systems.


Asunto(s)
Señales (Psicología) , Motivación , Adulto , Humanos , Preescolar , Aprendizaje , Comunicación , Lenguaje
2.
PLoS One ; 17(7): e0270502, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35789339

RESUMEN

Informativeness (defined as reduction of uncertainty) is central in human communication. In the present study, we investigate baboons' sensitivity to informativeness by manipulating the informativity of a cue relative to a response display and by allowing participants to anticipate their answers or to wait for a revealed answer (with variable delays). Our hypotheses were that anticipations would increase with informativity, while response times to revealed trials would decrease with informativity. These predictions were verified in Experiment 1. In Experiments 2 and 3, we manipulated rewards (rewarding anticipation responses at 70% only) to see whether reward tracking alone could account for the results in Experiment 1. We observed that the link between anticipations and informativeness disappeared, but not the link between informativeness and decreased RTs for revealed trials. Additionally, in all three experiments, the number of correct answers in revealed trials with fast reaction times (< 250ms) increased with informativeness. We conclude that baboons are sensitive to informativeness as an ecologically sound means to tracking reward.


Asunto(s)
Papio papio , Animales , Haplorrinos , Humanos , Papio , Tiempo de Reacción/fisiología , Recompensa
3.
Cogn Sci ; 46(2): e13103, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35122298

RESUMEN

Anticipating the learning consequences of actions is crucial to plan efficient information seeking. Such a capacity is needed for learners to determine which actions are most likely to result in learning. Here, we tested the early ontogeny of the human capacity to anticipate the amount of learning gained from seeing. In study 1, we tested infants' capacity to anticipate the availability of sight. Fourteen-month-old infants (N = 72) were invited to search for a toy hidden inside a container. The participants were faster to attempt at opening a shutter when this action allowed them to see inside the container. Moreover, this effect was specifically observed when seeing inside the container was potentially useful to the participants' goals. Thus, infants anticipated the availability of sight, and they calibrated their information-seeking behaviors accordingly. In studies 2 and 3, we tested toddlers' capacity to anticipate whether data would be cognitively useful for their goals. Two-and-a-half-year-olds (N = 72) had to locate a target character hidden among distractors. The participants flipped the characters more often, and were comparatively faster to initiate this action when it yielded access to visual data allowing them to locate the target. Thus, toddlers planned their information-seeking behaviors by anticipating the cognitive utility of sight. In contrast, toddlers did not calibrate their behaviors to the cognitive usefulness of auditory data. These results suggest that cognitive models of learning guide toddlers' search for information. The early developmental onset of the capacity to anticipate future learning gains is crucial for active learning.


Asunto(s)
Conocimiento , Preescolar , Humanos , Lactante
4.
Cognition ; 218: 104954, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34813994

RESUMEN

This paper investigates the cognitive mechanisms supporting humans' interpretation of requests for information. Learners can only search for a piece of information if they know that they are ignorant about it. Thus, in principle, the interpretation of requests for information could be guided by representations of Socratic ignorance (tracking what people know that they do not know). Alternatively, the interpretation of requests for information could be simplified by relying primarily on simple knowledge tracking (i.e., merely tracking what people know). We judged these hypotheses by testing two-and-a-half-year-old toddlers (N = 18), five- to seven-year-old children (N = 72), and adults (N = 384). In our experiments, a speaker asked a question that could be disambiguated by tracking her state of knowledge. We manipulated the speakers' visuals to modulate the complexity of the ignorance representation required to disambiguate their questions. Toddlers showed no tendency to appeal to representations of Socratic ignorance when disambiguating questions (Pilot S1). Five- to seven-year-olds exhibited a similar pattern of results, and they performed better when information requests could be disambiguated using simple knowledge tracking (Studies 1a-1b). Adults used representations of Socratic ignorance to interpret questions, but were more confident when simple knowledge tracking was sufficient to disambiguate information requests (Studies 2-3). Moreover, adults disambiguated questions as if speakers could request information about things that they were ignorant of, even when speakers had no reason to know about their ignorance (Studies 3-4). Thus, the interpretation of requests for information rests primarily on simple knowledge tracking-and not on representations of Socratic ignorance-a heuristic that reduces processing costs.


Asunto(s)
Conocimiento , Adulto , Niño , Preescolar , Femenino , Humanos
5.
Front Psychol ; 10: 1767, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31417474
6.
Front Psychol ; 10: 957, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31156492

RESUMEN

One of the most studied scales in the literature on scalar implicatures is the quantifier scale. While the truth of some is entailed by the truth of all, some is felicitous only when all is false. This opens the possibility that some would be felicitous if, e.g., almost all of the objects in the restriction of the quantifier have the property ascribed by the nuclear scope. This prediction from the standard theory of quantifier interpretation clashes with native speakers' intuitions. In Experiment 1 we report a questionnaire study on the perception of quantifier meanings in English, French, Slovenian, and German which points to a cross-linguistic variation with respect to the perception of numerical bounds of the existential quantifier. In Experiment 2, using a picture choice task, we further examine whether the numerical bound differences correlate with differences in pragmatic interpretations of the quantifier some in English and quelques in French and interpret the results as supporting our hypothesis that some and its cross-linguistic counterparts are subjected to different processes of pragmatic enrichment.

7.
Neuroimage Clin ; 19: 454-465, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29984154

RESUMEN

The ARX (Aristaless Related homeoboX) gene was identified in 2002 as responsible for XLAG syndrome, a lissencephaly characterized by an almost complete absence of cortical GABAergic interneurons, and for milder forms of X-linked Intellectual Disability (ID) without apparent brain abnormalities. The most frequent mutation found in the ARX gene, a duplication of 24 base pairs (c.429_452dup24) in exon 2, results in a recognizable syndrome in which patients present ID without primary motor impairment, but with a very specific upper limb distal motor apraxia associated with a pathognomonic hand-grip, described as developmental Limb Kinetic Apraxia (LKA). In this study, we first present ARX expression during human fetal brain development showing that it is strongly expressed in GABAergic neuronal progenitors during the second and third trimester of pregnancy. We show that although ARX expression strongly decreases towards the end of gestation, it is still present after birth in some neurons of the basal ganglia, thalamus and cerebral cortex, suggesting that ARX also plays a role in more mature neuron functioning. Then, using morphometric brain MRI in 13 ARX patients carrying c.429_452dup24 mutation and in 13 sex- and age-matched healthy controls, we show that ARX patients have a significantly decreased volume of several brain structures including the striatum (and more specifically the caudate nucleus), hippocampus and thalamus as well as decreased precentral gyrus cortical thickness. We observe a significant correlation between caudate nucleus volume reduction and motor impairment severity quantified by kinematic parameter of precision grip. As basal ganglia are known to regulate sensorimotor processing and are involved in the control of precision gripping, the combined decrease in cortical thickness of primary motor cortex and basal ganglia volume in ARX dup24 patients is very likely the anatomical substrate of this developmental form of LKA.


Asunto(s)
Ganglios Basales/metabolismo , Genes Homeobox/genética , Proteínas de Homeodominio/genética , Mutación/genética , Factores de Transcripción/genética , Apraxia Ideomotora/genética , Proteína Doblecortina , Femenino , Fuerza de la Mano/fisiología , Humanos , Interneuronas/metabolismo , Neuronas/metabolismo , Embarazo , Ácido gamma-Aminobutírico/metabolismo
8.
J Acoust Soc Am ; 143(1): EL1, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29390762

RESUMEN

This study investigated whether early bilingualism and early musical training positively influence the ability to discriminate between prosodic patterns corresponding to different syntactic structures in otherwise phonetically identical sentences in an unknown language. In a same-different discrimination task, participants (N = 108) divided into four groups (monolingual non-musicians, monolingual musicians, bilingual non-musicians, and bilingual musicians) listened to pairs of short sentences in a language unknown to them (French). In discriminating phonetically identical but prosodically different sentences, musicians, bilinguals, and bilingual musicians outperformed the controls. However, there was no interaction between bilingualism and musical training to suggest an additive effect. These results underscore the significant role of both types of experience in enhancing the listeners' sensitivity to prosodic information.

9.
Dev Psychol ; 54(2): 293-307, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29154651

RESUMEN

The goal of the current study was to statistically evaluate the reliable scalability of a set of tasks designed to assess Theory of Mind (ToM) without language as a confounding variable. This tool might be useful to study ToM in populations where language is impaired or to study links between language and ToM. Low verbal versions of the ToM tasks proposed by Wellman and Liu (2004) for their scale were tested in 234 children (2.5 years to 11.9 years). Results showed that 5 of the tasks formed a scale according to both Guttman and Rasch models whereas all 6 tasks could form a scale according to the Rasch model only. The main difference from the original scale was that the Explicit False Belief task could be included whereas the Knowledge Access (KA) task could not. The authors argue that the more verbal version of the KA task administered in previous studies could have measured language understanding rather than ToM. (PsycINFO Database Record


Asunto(s)
Lenguaje , Pruebas Psicológicas , Teoría de la Mente , Factores de Edad , Niño , Preescolar , Femenino , Humanos , Masculino , Psicología Infantil , Factores Sexuales
10.
Int J Lang Commun Disord ; 52(6): 816-830, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28470886

RESUMEN

BACKGROUND: According to the linguistic determinism approach, knowledge of sentential complements such as: John says that the earth is flat plays a crucial role in theory of mind (ToM) development by providing a means to represent explicitly people's mental attitudes and beliefs. This approach predicts that mastery of complements determines successful belief reasoning across explicit ToM tasks, even low-verbal ones, and across populations. AIMS: (1) To investigate the link between a low-verbal ToM-task and complements in Specific Language Impairment (SLI), (2) To determine whether this population shows similar ToM performance to that of children with Autism Spectrum Disorder (ASD) or those with Typical Development (TD) once these groups are matched on competency for complements, (3) To explore whether complements conveying a falsehood without jeopardizing the veracity of the entire sentence, such as complements of verbs of communication, are more crucial for belief attribution than complements which do not have this property, namely complements of verbs of perception, (?John sees that the earth is flat). METHODS & PROCEDURES: Children with SLI (n = 20), with ASD (n = 34) and TD (n = 30) completed sentence-picture-matching tasks assessing complementation with communication and perception verbs, as well as a picture-sequencing task assessing ToM. Children were furthermore evaluated for general grammatical and lexical abilities and non-verbal IQ. OUTCOMES & RESULTS: Results reveal that competency on complements relates to ToM performance with a low-verbal task in SLI, and that SLI, ASD and TD groups of equivalent performance on complements also perform similarly for ToM. Results further suggest that complements with an independent truth-value are the only ones to show a significant relation to ToM performance after teasing out the impact of non-verbal reasoning. CONCLUSIONS & IMPLICATIONS: This study suggests that clinical groups of different aetiologies as well as TD children perform comparably for ToM once they have similar complementation skills. Findings further highlight that specific types of complements, namely those with an independent truth value, relate in a special way to mentalizing. Future work should determine whether these specific structures could be effective in ToM remediation programmes.


Asunto(s)
Desarrollo del Adolescente , Trastorno del Espectro Autista/psicología , Encéfalo/fisiopatología , Lenguaje Infantil , Trastornos del Lenguaje/psicología , Habla , Teoría de la Mente , Adolescente , Factores de Edad , Trastorno del Espectro Autista/diagnóstico , Trastorno del Espectro Autista/fisiopatología , Niño , Comprensión , Femenino , Humanos , Trastornos del Lenguaje/diagnóstico , Trastornos del Lenguaje/fisiopatología , Pruebas del Lenguaje , Masculino , Comunicación no Verbal , Vocabulario
11.
Front Psychol ; 8: 743, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28553246

RESUMEN

The role of syntax in belief attribution (BA) is not completely understood in healthy adults and understudied in adults with autism spectrum disorder. Embedded syntax could be useful either for the development of Theory of Mind (ToM) (Emergence account) or more generally over the lifespan (Reasoning account). Two hypotheses have been explored, one suggesting that embedding itself (Relatives and Complement sentences and Metarepresentation account) is important for ToM and another one considering that the embedding of a false proposition into a true one (Complement sentences and Misrepresentation account) is important. The goals of this study were to evaluate (1) the role of syntax in ToM (Emergence vs. Reasoning account), (2) the type of syntax implied in ToM (Metarepresentation vs. Misrepresentation account), and (3) the verbally mediated strategies which compensate for ToM deficits in adults with Asperger Syndrome (AS). Fifty NeuroTypical (NT) adults and 22 adults with AS were involved in a forced-choice task including ±ToM tasks (BA and a control task, physical causation, PC) under four Interference conditions (silence, syllable repetition, relative sentences repetition, and complement sentences repetition). The non-significant ±ToM × Interference interaction effect in the NT group did not support the Reasoning account and thus suggests that syntax is useful only for ToM development (i.e., Emergence account). Results also indicated that repeating complement clauses put NT participants in a dual task whereas repeating relative clauses did not, suggesting that repeating relatives is easier for NT than repeating complements. This could be an argument in favor of the Misrepresentation account. However, this result should be interpreted with caution because our results did not support the Reasoning account. Moreover, AS participants (but not NT participants) were more disrupted by ±ToM tasks when asked to repeat complement sentences compared to relative clause sentences. This result is in favor of the Misrepresentation account and indirectly suggests verbally mediated strategies for ToM in AS. To summarize, our results are in favor of the Emergence account in NT and of Reasoning and Misrepresentation accounts in adults with AS. Overall, this suggests that adults with AS use complement syntax to compensate for ToM deficits.

12.
Front Psychol ; 7: 1500, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27826259

RESUMEN

Scalar implicatures, the phenomena where a sentence like "The pianist played some Mozart sonatas" is interpreted, as "The pianist did not play all Mozart sonatas" have been given two different analyses. Neo-Griceans (NG) claim that this interpretation is based on lexical scales (e.g., ), where the stronger term (e.g., all) implies the weaker term (e.g., some), but the weaker term (e.g., some) implicates the negation of the stronger term (i.e., some = not all). Post-Griceans (PG) deny that this is the case and offer a context-based inferential account for scalar implicatures. While scalar implicatures have been extensively investigated, with results apparently in favor of PG accounts, the psychological reality of lexical scales has not been put to the test. This is what we have done in the present experiment, with a lexical decision task using lexical scales in a masked priming paradigm. While PG accounts do not attribute any role for lexical scales in the computation of scalar implicatures, NG accounts suggest that lexical scales are the core mechanism behind the computation of scalar implicatures, and predict that weaker terms in a scale should prime stronger terms more than the reverse because stronger words are necessary to the interpretation of weaker words, while stronger words can be interpreted independently of weaker words. Our results provided evidence in favor of the psychological existence of scales, leading to the first clear experimental support for the NG account.

13.
Springerplus ; 5(1): 1451, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27652027

RESUMEN

In this contribution we will address the main puzzling empirical issues that have been formulated around Free Indirect Discourse (FID): the constraints on the use of first person pronouns and of proper names (as well as of definite descriptions), the reasons why different grammatical features (person, gender, number) give rise to presuppositions that must be resolved at different levels of interpretation in FID, the factors that account for the observation that person and tense behave similarly in FID. At the same time, we will also discuss the main controversies to which the ongoing debate on FID has given rise in the literature, showing that Schlenker (Mind Lang 19(3):279-304, 2004)'s distinction between a Context of Thought (CT) and a Context of Utterance (CU) still provides a fundamentally valid insight into the nature of FID, in spite of many qualifications that are necessary and some well-motivated criticism. However, our main task here is more ambitious than simply taking a stand on the many unsettled controversies surrounding FID. In fact, we claim that Schlenker's split between CU and CT can be derived in a principled way from the inner nature of FID as a linguistic process of 'phenomenal identification', whereby a Higher Experiencer attempts at reproducing (at a distinct time) the phenomenal experience proper to a Lower Experiencer. This distinction between qualitatively identified but numerically distinct experiences provides the conceptual basis for the derivation of virtually all remarkable properties of FID (including its somehow intermediate status between Direct and Indirect Discourse), while connecting, at the same time, with some intriguing semantic properties of first-person pronouns, such as the different varieties of de se readings.

14.
Dev Psychol ; 52(11): 1843-1857, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27668661

RESUMEN

Two experiments with preschoolers (36 to 78 months) and 8-year-old children (Experiment 1, N = 173; Experiment 2, N = 132) investigated the development of children's resource distribution in dominance contexts. On the basis of the distributive justice literature, 2 opposite predictions were tested. Children could match resource allocation with the unequal social setting they observe and thus favor a dominant individual over a subordinate 1. Alternatively, children could choose to compensate the subordinate if they consider that the dominance asymmetry should be counteracted. Two experiments using a giving task (Experiment 1) and a taking task (Experiment 2) led to the same results. In both experiments, children took dominance into account when allocating resources. Moreover, their distributive decisions were similarly affected by age: Although 3- and 4-year-old children favored the dominant individual, 5-year-old children showed no preference and 8-year-old children strongly favored the subordinate. Several mechanisms accounting for this developmental pattern are discussed. (PsycINFO Database Record


Asunto(s)
Desarrollo Infantil , Asignación de Recursos , Predominio Social , Factores de Edad , Niño , Preescolar , Femenino , Humanos , Masculino , Juego e Implementos de Juego , Justicia Social
15.
Front Psychol ; 7: 381, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27047413

RESUMEN

There is now general agreement about the optionality of scalar implicatures: the pragmatic interpretation will be accessed depending on the context relative to which the utterance is interpreted. The question, then, is what makes a context upper- (vs. lower-) bounding. Neo-Gricean accounts should predict that contexts including factual information will enhance the rate of pragmatic interpretations. Post-Gricean accounts should predict that contexts including psychological attributions will enhance the rate of pragmatic interpretations. We tested two factors using the quantifier scale : (1) the existence of factual information that facilitates the computation of pragmatic interpretations in the context (here, the cardinality of the domain of quantification) and (2) the fact that the context makes the difference between the semantic and the pragmatic interpretations of the target sentence relevant, involving psychological attributions to the speaker (here a question using all). We did three experiments, all of which suggest that while cardinality information may be necessary to the computation of the pragmatic interpretation, it plays a minor role in triggering it; highlighting the contrast between the pragmatic and the semantic interpretations, while it is not necessary to the computation of the pragmatic interpretation, strongly mandates a pragmatic interpretation. These results favor Sperber and Wilson's (1995) post-Gricean account over Chierchia's (2013) neo-Gricean account. Overall, this suggests that highlighting the relevance of the pragmatic vs. semantic interpretations of the target sentence makes a context upper-bounding. Additionally, the results give a small advantage to the post-Gricean account.

16.
PLoS One ; 11(2): e0149717, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26918704

RESUMEN

BACKGROUND: Intellectual Disability (ID) is characterized by deficits in intellectual functions such as reasoning, problem-solving, planning, abstract thinking, judgment, and learning. As new avenues are emerging for treatment of genetically determined ID (such as Down's syndrome or Fragile X syndrome), it is necessary to identify objective reliable and sensitive outcome measures for use in clinical trials. OBJECTIVE: We developed a novel visual analogical reasoning paradigm, inspired by the Progressive Raven's Matrices, but appropriate for Intellectually Disabled patients. This new paradigm assesses reasoning and inhibition abilities in ID patients. METHODS: We performed behavioural analyses for this task (with a reaction time and error rate analysis, Study 1) in 96 healthy controls (adults and typically developed children older than 4) and 41 genetically determined ID patients (Fragile X syndrome, Down syndrome and ARX mutated patients). In order to establish and quantify the cognitive strategies used to solve the task, we also performed an eye-tracking analysis (Study 2). RESULTS: Down syndrome, ARX and Fragile X patients were significantly slower and made significantly more errors than chronological age-matched healthy controls. The effect of inhibition on error rate was greater than the matrix complexity effect in ID patients, opposite to findings in adult healthy controls. Interestingly, ID patients were more impaired by inhibition than mental age-matched healthy controls, but not by the matrix complexity. Eye-tracking analysis made it possible to identify the strategy used by the participants to solve the task. Adult healthy controls used a matrix-based strategy, whereas ID patients used a response-based strategy. Furthermore, etiologic-specific reasoning differences were evidenced between ID patients groups. CONCLUSION: We suggest that this paradigm, appropriate for ID patients and developmental populations as well as adult healthy controls, provides an objective and quantitative assessment of visual analogical reasoning and cognitive inhibition, enabling testing for the effect of pharmacological or behavioural intervention in these specific populations.


Asunto(s)
Discapacidad Intelectual/psicología , Pensamiento , Adolescente , Adulto , Estudios de Casos y Controles , Cognición , Síndrome de Down/fisiopatología , Síndrome de Down/psicología , Femenino , Síndrome del Cromosoma X Frágil/fisiopatología , Síndrome del Cromosoma X Frágil/psicología , Proteínas de Homeodominio/genética , Humanos , Discapacidad Intelectual/genética , Discapacidad Intelectual/fisiopatología , Masculino , Persona de Mediana Edad , Mutación , Factores de Transcripción/genética , Adulto Joven
17.
Front Psychol ; 6: 1434, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26441802

RESUMEN

While most evolutionary scenarios for language see it as a communication system with consequences on the language-ready brain, there are major difficulties for such a view. First, language has a core combination of features-semanticity, discrete infinity, and decoupling-that makes it unique among communication systems and that raise deep problems for the view that it evolved for communication. Second, extant models of communication systems-the code model of communication (Millikan, 2005) and the ostensive model of communication (Scott-Phillips, 2015) cannot account for language evolution. I propose an alternative view, according to which language first evolved as a cognitive tool, following Fodor's (1975, 2008) Language of Thought Hypothesis, and was then exapted (externalized) for communication. On this view, a language-ready brain is a brain profoundly reorganized in terms of connectivity, allowing the human conceptual system to emerge, triggering the emergence of syntax. Language as used in communication inherited its core combination of features from the Language of Thought.

18.
Cogn Process ; 16 Suppl 1: 355-8, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26224273

RESUMEN

Situated cognition seems incompatible with strong decoupling, where representations are deployed in the absence of their targets and are not oriented toward physical action. Yet, in art consumption, the epitome of a strongly decoupled cognitive process, the artwork is a physical part of the environment and partly controls the perception of its target by the audience, leading to immersion. Hence, art consumption combines strong decoupling with situated cognition.


Asunto(s)
Arte , Cognición/fisiología , Ambiente , Percepción/fisiología , Humanos
19.
J Cogn Neurosci ; 26(11): 2552-63, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24893746

RESUMEN

Growing evidence suggests that semantic knowledge is represented in distributed neural networks that include modality-specific structures. Here, we examined the processes underlying the acquisition of words from different semantic categories to determine whether the emergence of visual- and action-based categories could be tracked back to their acquisition. For this, we applied correspondence analysis (CA) to ERPs recorded at various moments during acquisition. CA is a multivariate statistical technique typically used to reveal distance relationships between words of a corpus. Applied to ERPs, it allows isolating factors that best explain variations in the data across time and electrodes. Participants were asked to learn new action and visual words by associating novel pseudowords with the execution of hand movements or the observation of visual images. Words were probed before and after training on two consecutive days. To capture processes that unfold during lexical access, CA was applied on the 100-400 msec post-word onset interval. CA isolated two factors that organized the data as a function of test sessions and word categories. Conventional ERP analyses further revealed a category-specific increase in the negativity of the ERPs to action and visual words at the frontal and occipital electrodes, respectively. The distinct neural processes underlying action and visual words can thus be tracked back to the acquisition of word-referent relationships and may have its origin in association learning. Given current evidence for the flexibility of language-induced sensory-motor activity, we argue that these associative links may serve functions beyond word understanding, that is, the elaboration of situation models.


Asunto(s)
Aprendizaje por Asociación/fisiología , Encéfalo/fisiología , Percepción de Movimiento/fisiología , Semántica , Percepción del Habla/fisiología , Estimulación Acústica , Electroencefalografía , Potenciales Evocados , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Estimulación Luminosa , Psicolingüística , Adulto Joven
20.
Orphanet J Rare Dis ; 9: 25, 2014 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-24528893

RESUMEN

BACKGROUND: The c.429_452dup24 of the ARX gene is a rare genetic anomaly, leading to X-Linked Intellectual Disability without brain malformation. While in certain cases c.429_452dup24 has been associated with specific clinical patterns such as Partington syndrome, the consequence of this mutation has been also often classified as "non-specific Intellectual Disability". The present work aims at a more precise description of the clinical features linked to the c.429_452dup24 mutation. METHODS: We clinically reviewed all affected patients identified in France over a five-year period, i.e. 27 patients from 12 different families. Detailed cognitive, behavioural, and motor evaluation, as well as standardized videotaped assessments of oro-lingual and gestural praxis, were performed. In a sub-group of 13 ARX patients, kinematic and MRI studies were further accomplished to better characterize the motor impairment prevalent in the ARX patients group. To ensure that data were specific to the ARX gene mutation and did not result from low-cognitive functioning per se, a group of 27 age- and IQ-matched Down syndrome patients served as control. RESULTS: Neuropsychological and motor assessment indicated that the c.429_452dup24 mutation constitutes a recognizable clinical syndrome: ARX patients exhibiting Intellectual Disability, without primary motor impairment, but with a very specific upper limb distal motor apraxia associated with a pathognomonic hand-grip. Patients affected with the so-called Partington syndrome, which involves major hand dystonia and orolingual apraxia, exhibit the most severe symptoms of the disorder. The particular "reach and grip" impairment which was observed in all ARX patients, but not in Down syndrome patients, was further characterized by the kinematic data: (i) loss of preference for the index finger when gripping an object, (ii) major impairment of fourth finger deftness, and (iii) a lack of pronation movements. This lack of distal movement coordination exhibited by ARX patients is associated with the loss of independent digital dexterity and is similar to the distortion of individual finger movements and posture observed in Limb Kinetic Apraxia. CONCLUSION: These findings suggest that the ARX c.429_452dup24 mutation may be a developmental model for Limb Kinetic Apraxia.


Asunto(s)
Apraxias/genética , Extremidades/fisiopatología , Duplicación de Gen , Proteínas de Homeodominio/genética , Modelos Biológicos , Factores de Transcripción/genética , Adolescente , Adulto , Fenómenos Biomecánicos , Estudios de Casos y Controles , Niño , Síndrome de Down/fisiopatología , Humanos , Mutación , Adulto Joven
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