Phantoms on the hands: Influence of the body on brief synchiric visual percepts

NEUROPSYCHOLOGIA

卷:82

Article

Medina, Jared^1,2  Drebing, Daniel E.²  Hamilton, Roy H.²  Coslett, H. Branch² 

[1] Univ Delaware, Dept Psychol, Newark, DE 19716 USA

[2] Univ Penn, Dept Neurol, Ctr Cognit Neurosci, Philadelphia, PA 19104 USA

关键词: Synchiria;    Body schema;    Peripersonal space;    Magnocellular;    Transient visual system;   

DOI  :  10.1016/j.neuropsychologia.2016.01.016

来源: Elsevier

【 摘 要 】

Recent studies have found preferential responses for brief, transient visual stimuli near the hands, suggesting a link between magnocellular visual processing and peripersonal representations. We report an individual with a right hemisphere lesion whose illusory phantom percepts may be attributable to an impairment in the peripersonal system specific to transient visual stimuli. When presented with a single, brief (250 ms) visual stimulus to her ipsilesional side, she reported visual percepts on both sides synchiria. These contralesional phantoms were significantly more frequent when visual stimuli were presented on the hands versus off the hands. We next manipulated stimulus duration to examine the relationship between these phantom percepts and transient visual processing. We found a significant position by duration interaction, with substantially more phantom synchiric percepts on the hands for brief compared to sustained stimuli. This deficit provides novel evidence both for preferential processing of transient visual stimuli near the hands, and for mechanisms that, when damaged, result in phantom percepts. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

Free