Agnosopnosia
Blindsight broadly refers to the paradoxical neurological condition where patients with a visual field defect due to a cortical lesion nevertheless demonstrate implicit residual visual sensitivity within their field cut.
Through a selective review of the blindsight literature Danckert and Rossetti propose a new taxonomy for the subtypes of residual abilities described in blindsight. Those patients able to accurately act upon blindness field stimuli (e.g. by pointing or saccading towards them) are classified as having 'action-blindsight', those whose residual functions can be said to rely to some extent upon attentive processing of blind field stimuli are classified as demonstrating 'attention-blindsight', while finally, patients who have somewhat accurate perceptual judgements for blind field stimuli despite a complete lack of any conscious percept, are classified as having 'agnosopsia'–literally meaning 'not knowing what one sees'.
Danckert and Rossetti also address the possible neurological substrates of these residual sensory processes. The second aim was to investigate the most striking subtype of blindsight, action-blindsight.
They reviewed the data relevant to this subtype and the hypotheses proposed to account for it, before speculating on how action-blindsight may inform there normal models of visuomotor control 1).