On the "blindness" of blindsight: What is the evidence for phenomenal awareness in the absence of primary visual cortex (V1)?. (May 2019)

• Record Type: Journal Article
• Authors: Mazzi, Chiara; Savazzi, Silvia; Silvanto, Juha
• Is Part Of: Neuropsychologia. Volume 128(2019)
• Page Start: 103
• Page End: 108
• Publication Date: 2019-05
• Subjects: Primary visual cortex (V1) -- Phenomenal awareness -- Blindsight -- Hemianopic completion -- After-images -- Transcranial magnetic stimulation; Neuropsychology -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Neuropsychologie -- Périodiques; Neuropsychology; Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.neuropsychologia.2017.10.029
• Languages: English
• ISSNs: 0028-3932

Abstract

Abstract: Blindsight has been central to theories of phenomenal awareness; that a lesion to primary visual cortex (V1) abolishes all phenomenal awareness while unconscious visual functions can remain has led to the view that this region plays a crucial role in generating visual consciousness. However, since the early 20th century, there have been reports, many of which controversial, of phenomenal awareness in patients with V1 lesions. These reports include selective sparing of motion awareness, hemianopic completion and visual aftereffects. More recently, there have been successful attempts of inducing visual qualia with noninvasive brain stimulation. Here we critically review this evidence and discuss their implications to theoretical understanding of phenomenal awareness. Highlights: We review evidence on whether phenomenal visual awareness is possible without V1. Some evidence from hemianopic completion, afterimages and motion perception. TMS can induce visual qualia in the blind field of hemianopic patients. V1 appears not to be necessary for awareness in all circumstances.