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Patient studies

Friday, September 30th,   2011 [17:20 - 19:20]

PS_1.050 - Prader-Willi Syndrome: Is the executive deficit independent from mental retardation?

Chevalère, J. 1 , Postal, V. 1 , Jauregi, J. 2 , Copet, P. 3 , Laurier, V. 3 & Thuilleaux, D. 3

1 Laboratoire de Psychologie, Santé et Qualité de Vie EA 4139, Université Bordeaux Segalen, France.
2 Euskal Herriko Unibertsitatea- University of the Basque Country Psikologia Fakultatea, Donostia, Spain.
3 Hôpital Marin AP-AH, Unité Prader-Willi, Hendaye, France.

The Prader-Willi syndrome (PWS) is a genetically determined neurodevelopmental disorder characterized by a mild intellectual impairment and a maladaptative behaviour including hyperphagia, temper tantrums, and obsessive/compulsive traits. The aim of this study is to determine if the SPW is associated with a deficit of executive functions and whether the executive deficit is related to mental retardation or represents a clearly separable complaint. Thirteen adults with PWS were compared to age-mached control adults on three executive functions tasks. The results show that PWS individuals have poorer performance than controls in the updating task, in the planning task, and in the four subtests of the cognitive estimation task ; Weight estimation; Quantity estimation; Time estimation, Dimension estimation. After controlling Total IQ, the effect of group persists only on the Quantity estimation. The results confirm that the SPW have an impairment of executive functions which seems related to a mental retardation.

PS_1.051 - A neuro-computational account of lexical development in Williams Syndrome children

Mayor, J.

Basque Center on Cognition, Brain and Language, Donostia, Spain

Williams Syndrome (WS) children possess relatively large vocabularies when compared to their other, impaired, cognitive skills. However, their language acquisition is delayed, their vocabulary spurt is less marked than for typically-developping infants, categorisation skills are weak when their vocabulary is already large and they do not respond taxonomically. This pattern of findings led Nazzi and Bertoncini (2003) to suggest that WS children acquire a large "proto-lexicon" by gradually attaching several exemplars of a category to their appropriate sound pattern in an associationist mechanism. This hypothesis is tested by hindering the formation of visual categories in a model of early word learning (Mayor and Plunkett, 2010) so as to mimic WS weak categorisation skills. In the absence of lesions, the model accounts for the emergence of taxonomic responding and displays a vocabulary spurt. Generalisation of word-object associations relies on categorical representations. In contrast, when categorisation is impaired, lexical acquisition is delayed, a vocabulary spurt is absent and word-object associations are not generalised. However, through repetitive labelling events, the system is still able to map several object exemplars to their appropriate sound patterns in a fashion described in Nazzi & Bertoncini (2003), thereby leading to the formation of a surprisingly large vocabulary.

PS_1.052 - Rhythms can overcome temporal orienting deficit after right prefrontal damage

Triviño, M. 1 , Arnedo, M. 2 , Lupiañez, J. 2 , Chirivella, J. 3 & Correa, A. 2

1 Hospital Universitario San Rafael. Granada, Spain
2 Departamento de Psicología Experimental y Fisiología del Comportamiento. Universidad de Granada. Granada, Spain.
3 Hospital Nisa Aguas Vivas. Valencia, Spain.

The main aim of this study was to explore whether the use of automatic temporal preparation processes can overcome the deficit in the controlled temporal preparation processes shown by patients with frontal damage (i.e. Temporal Orienting and Foreperiod effects). Two tasks were administered to a group of 15 frontal patients, and a group of 15 matched control subjects: a Symbolic Cued task where the predictive information was provided by a symbolic cue (short line-early vs. long line-late) and a Rhythm Cued task where the predictive information was provided by a rhythm (fast rhythm-early vs. slow rhythm-late). Firstly, in the Symbolic Cued task, patients with right frontal damage showed a specific deficit in Temporal Orienting effect, while the Foreperiod effect was impaired in both groups of patients. Secondly, in the Rhythm Cued task, there was an improvement of both Temporal Orienting and Foreperiod effects in right frontal group, while the left frontal group showed a significant deficit of both effects. These findings show that automatic processes of temporal preparation facilitate the use of implicit temporal information, as well as they provide a novel suggestion for a neural model in which automatic temporal preparation is left-lateralized and controlled temporal preparation is right-lateralized.

PS_1.053 - Exploring APOE e4 genotype effects in healthy young adults: structures or cognitive strategies?

Rusted, J. 1 , Broulidakis, J. 1 , Dowell, N. 2 & Ruest, T. 1

1 Sussex University, Brighton BN1 9QH, UK
2 Brighton and Sussex Medical School, Brighton, UK.

The APOE e4 genotype is associated with higher risk for cognitive impairment and dementia in older adulthood. In younger adults, however, a number of studies report carriers of this allele perform better on cognitive tasks than their age-matched non-e4 peers. We present behavioural and structural imaging data to explore differences between healthy e4 carriers and their non-e4 counterparts. First we examine structural MR imaging data, to examine whether there are subtle differences in normal appearing brain tissue that might produce cognitive benefits in e4 carriers. Second, we collected verbal fluency data, using switching and clustering indices, to distinguish any strategy differences that may account for a previously reported advantage of e4 over non-e4 carriers on this task. Behavioural results suggest e4 carriers may use more effective cognitive strategies; structural imaging data identified higher density white matter in e4 carriers, suggesting also greater neural efficiency. We discuss the impllications of these findings in relation to the APOE genotype effects observed in older adults.

PS_1.054 - Reading and spelling in deaf children with cochlear implant in primary school

Colin, S. 1 , Ecalle, J. 2 , Truy, E. 3 , Lina-Granade, G. 3 & Magnan, A. 2

1 Université de Lyon, Université Lumière Lyon 2, Laboratoire Education, Cultures & Politique (ECP), 86 rue Pasteur, F-69007 Lyon, France.
2 Université de Lyon, Université Lumière Lyon 2, CNRS, Laboratoire d’Etude des Mécanismes Cognitifs (E.M.C), EA 3082, 5 avenue Pierre Mendès France, F-69676 Bron, France.
3 Université Claude Bernard Lyon 1, CNRS, UMR5020 Neurosciences sensorielles, Comportement, Cognition, F-69366, Lyon, France / Hospices Civils de Lyon, Hôpital Edouard Herriot, Département d'ORL, de Chirurgie Cervico-Maxillo-Faciale et d

Objective: The aim of this study was to examine the literacy skills of deaf children in primary school with cochlear implantation (“CI”) and exposed to Cued Speech (“CS”, manual system aimed at resolving the ambiguity inherent in lipreading). We predicted (1) an effect of the early implantation; (2) a contribution of early exposition to CS. Participants: 120 deaf and hearing children from grade 2 to 5 took part in the study; deaf sub-groups were formed on the basis of the age at implantation (earlier vs lately) and exposition to CS (earlier vs lately). Method: Phonological, silent reading (word recognition and sentence comprehension), word spelling and vocabulary tests were administrated. Results: They showed (1) a significant contribution of CI after having controlled chronological age in different scores only at the beginning of the learning (grades 2 and 3), suggesting a decrease of this effect in the time ; (2) that CS exposition contributed to 2-3% of the overall variance in scores but was not significant in the different grades, suggesting that the conditions in which CS is proposed to implanted children could be a more precise factor to examine its potential contribution in learning to read and spell. Researches are pending.

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