Spatial attention speeds discrimination without awareness in blindsight.

Area of Science:

• Cognitive Neuroscience
• Neuroscience of Vision
• Psychology of Perception

Background:

• The relationship between visual attention and visual awareness is often assumed to be intimate.
• Blindsight, a neurological condition, presents an opportunity to investigate this relationship by dissociating visual processing from conscious awareness.

Purpose of the Study:

• To investigate whether visual attention is a sufficient condition for visual awareness.
• To explore the relationship between attention and awareness using a patient with blindsight.

Main Methods:

• Utilized a Posner endogenous spatial cueing paradigm with patient GY, who has blindsight.
• Measured reaction times and discrimination accuracy for visual stimuli at cued and uncued locations.
• Assessed awareness of stimuli despite attentional facilitation.

Main Results:

• Reaction times for stimulus orientation discrimination were reduced when the location was cued.
• This reaction-time advantage occurred without a decrease in discrimination accuracy.
• Patient GY reported no awareness of stimuli at attentionally facilitated locations.

Conclusions:

• Visual attention is not a sufficient condition for visual awareness.
• These findings demonstrate a dissociation between attention and awareness in blindsight.
• Attention may be a necessary but not sufficient precursor for conscious visual experience.