No visual responses in denervated V1high‐resolution functional magnetic resonance imaging of a blindsight patient
作者:
Petra Stoerig,
Andreas Kleinschmidt,
Jens Frahm,
期刊:
NeuroReport
(OVID Available online 1998)
卷期:
Volume 9,
issue 1
页码: 21-25
ISSN:0959-4965
年代: 1998
出版商: OVID
关键词: Blindsight;Cortical blindness;fMRI;Functional activation;Human;Striate Cortex;Visual field defect;Visual stimulation
数据来源: OVID
摘要:
FOLLOWING severe cranio-cerebral trauma that affected the optic radiation, patient FS suffers from an incomplete macula-splitting hemianopia. Within the hemianopic field, FS exhibits blindsight, i.e. he detects and discriminates visual stimuli he cannot (consciously) see. We performed functional magnetic resonance imaging (fMRI) at high spatial resolution using a large flickering stimulus field to assess visual responsiveness of deafferented V1. Contrasting strong activation of the normal contralesional visual cortex, ipsilesional V1 displayed no stimulus-related MRI signal changes. However, activation was observed in ipsilesional extrastriate cortex. We conclude that blindsight does not depend on functional islands of tissue preserved within the deafferented striate cortex.
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