Characteristics of contralesional and ipsilesional saccades in hemianopic patients

Autor: Sylvie Chokron, Karine Doré-Mazars, Dorine Vergilino-Perez, Christelle Lemoine, Céline Cavézian, Alexandra Fayel
Přispěvatelé: Vision Action Cognition (VAC (URP_7326)), Université de Paris (UP), Unité Fonctionnelle Vision et Cognition, Fondation Ophtalmologique Rothschild, Laboratoire psychologie de la perception (LPP), Département d'Etudes Cognitives - ENS Paris (DEC), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Descartes - Paris 5 (UPD5)-Centre National de la Recherche Scientifique (CNRS), Neuroimagerie cognitive - Psychologie cognitive expérimentale (UNICOG-U992), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Saclay (COmUE)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Centre National de la Recherche Scientifique (CNRS), Université Paris Cité (UPCité), Fondation Ophtalmologique Adolphe de Rothschild [Paris], École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Saclay
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Experimental Brain Research
Experimental Brain Research, Springer Verlag, 2014, 232 (3), pp.903-917. ⟨10.1007/s00221-013-3803-y⟩
Experimental Brain Research, 2014, 232 (3), pp.903-917. ⟨10.1007/s00221-013-3803-y⟩
ISSN: 0014-4819
1432-1106
DOI: 10.1007/s00221-013-3803-y⟩
Popis: International audience; In order to further our understanding of actionblindsight, four hemianopic patients suffering from visual field loss contralateral to a unilateral occipital lesion were compared to six healthy controls during a double task of verbally reported target detection and saccadic responsestoward the target. Three oculomotor tasks were used: a fixation task (i.e., without saccade) and two saccade tasks (eliciting reflexive and voluntary saccades, using step and overlap 600 ms paradigms, respectively), in separate sessions. The visual target was briefly presented at two different eccentricities (5° and 8°), in the right or left visual hemifield. Blank trials were interleaved with target trials, and signal detection theory was applied. Despite their hemifield defect, hemianopic patients retained the ability to direct a saccade toward their contralesional hemifield, whereas verbal detection reports were at chance level. however, saccade parameters (latency and amplitude) were altered by the defect. saccades to the contralesional hemifield exhibited longer latencies and shorter amplitudes compared to those of the healthy group, whereas only the latencies of reflexive saccades to the ipsilesional hemifield were altered. Furthermore, healthy participants showed the expected latency difference between reflexive and voluntary saccades, with the latter longer than the former. this difference was not found in three out of four patients in either hemifield. Our results show action-blindsight for saccades, but also show that unilateral occipital lesions have effects on saccade generation in both visual hemifields.
Databáze: OpenAIRE
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