Units

Research Unit in Cognitive Neurosciences

Person in charge of the Unit : Oui

UNESCOG investigates the organisation and functioning of the language and cognitive system while taking its biological substrate into account.Experimental psychologists, neuropsychologists and electrophysiologists work on both normal and brain-damaged individuals in the following domains: audio-visual interactions, auditory and visual attention, speech perception and recognition, reading disturbances, cognitive consequences of schooling, literacy and ageing, organisation of the semantic system, retrieval of information from memory (in particular episodic and prospective), re-education of working memory, impairments of executive functions and of social representations due to brain lesion. Besides experimental approaches from cognitive psychology and neuropsyclology, UNESCOG's researchers employ methods of neuropsychological patient examination and of cerebral imagery (recording of evoked potentials and of hemodynamic changes).

Projetcs

Neuropsychological studies of auditory agnosia

Brain-damaged patients who display deficits of auditory stimuli recognition are examined. We study, in particular, the deficits of music processing and the consequences of auditory neglect on the phonological and semantic processing of speech.

The origin of written word recognition deficits in dyslexia: Exploring the visual perception deficit hypothesis and visual training effects

The phonological deficit that is observed in most dyslexics is probably not the onlycause fortheir reading difficulties. Other reasons for their problems in forming orthographic representations may be the capacity to categorize or to memorize abstract visualinformation. In the present research project, we aim to investigate these different underlying cognitive processes. In a second step we willexplore whether these processes are sensitive to visual training.

Relations between the mental representations of numbers and the mental representation of musical tones

We explore the parallels between the mental representations of music and numbers through spatial associations of response codes effects (e.g. the 'SNARC' and 'SMARC' effects). To this aim, we have adapted to musical stimuli a classical experimental paradigm from the number cognition field. This methods studies the spatial representations through the occurrence of facilitation and interference effects caused by the congruence or incongruence between a spatial response apparatus and a hypothetical mental representation. We also study the interactions between pitch height and number magnitude with the same paradigm applied to sung numbers. In addition, the effect of musical expertise on these representations is examined.

Consequences of schooling and literacy on language and cognition

The cognitive consequences of illiteracy are studied by comparing adults who were not alphabetized for socioeconomic reasons to controls who were alphabetized at adult age in alphabetic and non-alphabetic writing systems. Concerning language, both capacities of conscious, explicit analysis of speech and of perceptual processing of spoken words are examined. Concerning the other aspects of cognition, the following capacities are investigated: memory processes, problem solving, executive processes, semantic memory and its organization, and visual perception and cognition.

Psycholinguistic units involved in speech recognition

Investigation of the prelexical units involved in the recognition of speech in French, which is compared to other languages. The paradigms used are the phonological priming and the induction of perceptual errors. One examines also the possible influence of orthographic representations on speech attentional strategies and on speech conscious analysis.

Automaticity and bidirectionality in synesthesia

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Relations between music and language in perception and memory for songs

These studies, conducted on non-musician participants, are aimed at testing the boundaries of separability between language and music. More specifically, we study the independence or the interactions between the phonological and semantic dimensions of the lyrics and the melodic dimension of the tune of sung stimuli. Our methods include behavioral measures (Garner's and Stroop's paradigms) as electrophy-siological ones (Event related potentials and Magnetoencéphalography).

Auditory and visual attention.

Studies on auditory and visual attention are carried out by using brain imagery (PET-Scan) and behavioral examination of both healthy subjects and brain-damaged patients. They are aimed at investigating several hypotheses concerning the etiology of attentional deficits and allow the study of associations between the deficits observed in the two modalities. Comparative studies of the spatial and temporal attention processes are also carried out in both modalities.

Reciprocal influences between emotion, approach or withdrawal motivation, and cognitive control

We propose to systematically study the influence of emotion on the different components of cognitive control (selective attention, flexibility of attention, inhibition of a dominant response). Firstly, influences of induced emotional-motivational approach or withdrawal states on the subjects' performances in tasks requiring some components of cognitive control will be studied. Secondly, we will investigate the influence of the emotional content ' particularly of negative valence or taboo content ' of auditory verbal or non verbal stimuli on subjects' performances, for the same tasks. These cognitive tasks will consist in situations of attentional manipulation (attentional deployment task, auditory emotional cueing ') and of inhibition of a dominant response (signal stop task, adaptation of the Hayling test, emotional Stroop '). Congruency and incongruency effects between emotional-motivational state and emotional valence of the stimuli will be studied. We will moreover investigate the influence of voluntary cognitive control on the emotional-motivational state of the subjects and on the effects linked to emotional valence of the stimuli.

Functional relations between language and music processing

Many real-word events do not occur randomly: they can be anticipated or predicted on the basis of the statistical regularities between successive events. Since humans' sensitivity to the sequential structure of the world is a crucial dimension of information processing, it can probably been exploited in a similar way diverse knowledge domains. We explore this possibility by comparing musical to linguistic processing in either sequence learning tasks or in learning artificial 'languages'.

Influence of orthographic knowledge on speech representations.

L'influence de connaissances dépendant de la litératie s'observe à différents niveaux représentationnels. Au niveau métaphonologique, notre groupe a montré que la conscience des phonèmes est présente dans les populations lettrées dans un système alphabétique, mais absente chez les illettrés. Chez les lettrés, l'influence des connaissances orthographiques dans des tâches auditives qui impliquent des composantes métaphonologiques est aussi indubitable. Plus récemment, nous avons contribué à montrer que les connaissances orthographiques affectent les processus de reconnaissance de la parole dans des tâches en ligne comme la décision lexicale, et avons étudié l'émergence de cet effet chez les jeunes apprenti-lecteurs. Notre nouveau projet combine cette recherche fondamentale avec l'application des résultats au domaine clinique. Les techniques comportementales, d'électroencéphalographie et de stimulation magnétique transcranienne seront utilisées pour examiner le profil de performance des enfants ayant des troubles d'apprentissage de la lecture (notamment la dyslexie) et les substrats neuronaux qui pourraient être à l'origine de leurs troubles. L'objectif est d'établir un diagnostic plus précis de ces troubles et éventuellement de proposer une approche de remédiation complémentaire.