Spatial attention speeds discrimination without awareness in blindsight.
An intimate relationship is often assumed between visual attention and visual awareness. Using a subject, patient GY, with the neurological condition of "blindsight" we show that although attention may be a necessary precursor to visual awareness it is not a sufficient one. Using a Posner endogenous spatial cueing paradigm we showed that the time our subject needed to discriminate the orientation of a stimulus was reduced if he was cued to the location of the stimulus. This reaction-time advantage was obtained without any decrease in discrimination accuracy and cannot therefore be attributed to speed-error trade-off or differences in bias between cued and uncued locations. As a result of his condition GY was not aware of the stimuli to which processing was attentionally facilitated. Attention cannot, therefore be a sufficient condition for awareness.
Kentridge
R W
RW
Cognitive Neuroscience Research Unit, Department of Psychology, Science Laboratories, South Road, Durham DH1 3LE, UK. robert.kentridge@durham.ac.uk
Heywood
C A
CA
Weiskrantz
L
L
D000328:Adult; D001288:Attention / Q000502:physiology*; D001364:Awareness / Q000502:physiology*; D001766:Blindness / Q000503:physiopathology / Q000523:psychology; D001925:Brain Damage, Chronic / Q000503:physiopathology; D003243:Consciousness / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology*; D006801:Humans; D008297:Male; D017603:Signal Detection, Psychological; D013028:Space Perception / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*; D014793:Visual Cortex / Q000503:physiopathology; D014794:Visual Fields / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*