1 3 Exp Brain Res (2014) 232:903–917 DOI 10.1007/s00221-013-3803-y RESEARCH ARTICLE Characteristics of contralesional and ipsilesional saccades in hemianopic patients Alexandra Fayel · Sylvie Chokron · Céline Cavézian · Dorine Vergilino-Perez · Christelle Lemoine · Karine Doré-Mazars Received: 10 December 2012 / Accepted: 29 November 2013 / Published online: 24 December 2013 © Springer-Verlag Berlin Heidelberg 2013 hemifield. Blank trials were interleaved with target tri- als, 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 volun- tary 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 sac- cades, but also show that unilateral occipital lesions have effects on saccade generation in both visual hemifields. Keywords Action-blindsight · Saccadic eye movements · Occipital cortex · Homonymous hemianopia Introduction Traditionally, geniculostriate lesions were considered to result in complete and permanent visual loss in the topo- graphically corresponding area of the visual field (Hol- mes 1918). However, a number of studies with monkeys, and later with humans (for review, see Weiskrantz 2004; Cowey 2010), have demonstrated that some visual func- tions remain in the absence of acknowledged awareness, after lesions of the striate cortex but not after prechiasmatic lesions (Perenin and Jeannerod 1975; Leigh and Zee 1980). These abilities, called “blindsight” (Weiskrantz et al. 1974), are not observed in all patients (e.g., Blythe et al. 1987; Abstract In order to further our understanding of action- blindsight, 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 responses toward 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 ses- sions. The visual target was briefly presented at two dif- ferent eccentricities (5° and 8°), in the right or left visual A. Fayel · D. Vergilino-Perez · C. Lemoine · K. Doré-Mazars (*) Laboratoire Vision Action Cognition, EAU 01, INC, IUPDP, Institut de Psychologie, Université Paris Descartes, Sorbonne Paris Cité, 71 Avenue Edouard Vaillant, 92774 Boulogne-Billancourt Cedex, France e-mail: karine.dore@parisdescartes.fr S. Chokron Unité Fonctionnelle Vision et Cognition, Fondation Ophtalmologique A. de Rothschild, 25 rue Manin, 75019 Paris, France S. Chokron Laboratoire de Psychologie de la Perception, UMR 8158, CNRS, INC, Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints-Pères, 75006 Paris, France C. Cavézian INSERM U 992, Cognitive Neuroimaging unit F91-191, Gif-sur-Yvette, France D. Vergilino-Perez · K. Doré-Mazars Institut Universitaire de France, Paris, France C. Lemoine CNRS, Centre National de la Recherche Scientifique, Paris, France