Blindsight

Synonyms

Cortical blindness; Riddoch-Syndrome

Definition

The term Blindsight has been coined to describe a seemingly paradoxical clinical phenomenon that arises following injury to primary visual cortex (V1): While patients with Blindsight appear to lack any conscious visual experience, they are sometimes still able to detect visual stimuli when carefully tested (Weiskrantz et al. 1974).

Introduction

Selective lesions of V1 that spare the rest of the brain are rather uncommon in the clinic. Yet several intriguing cases have been described that typically arose from selective traumatic injuries or strokes. Standard clinical tests commonly reveal spatially restricted blindness, also called scotoma, in the part of the visual field affected by the lesion. If the scotoma spans the visual hemifield opposite the affected cortical hemisphere, this type of blindness is often diagnosed as hemianopia. The terms Blindsight or Riddoch-Syndrome were developed in academic contexts (Weiskrantz et al. 1974...