Blindsight

Action blindsight

Action blindsight

Type of blindsight, can accurately act on objects in blind field (e.g. pointing, follow with eyes)

Attention blindsight

Type of blindsight, actions rely on having some process of attentive awareness

Agnosopsia

Type of blindsight, “have somewhat accurate perceptual judgements for blind field stimuli despite a complete lack of any conscious percept”

Affective blindsight

Type of blindsight, can distinguish between emotion-related stimuli such as facial expressions

V1 (primary visual cortex)

Area of the brain that receives, integrates, and processes visual information relayed from the retinas. Damage results in the absence of conscious sight.

Superior colliculus

Anatomy, a large multimodal structure involved in directing the head and eyes to particular locations in visual space. Receives input from the retina and visual cortex. Thought to be involved in alternative sight pathways in blindsight.

Striate cortex

Anatomy, involved in integrating images seen by both eyes to create depth (stereopsis).

Lateral geniculate nucleus (LGN)

Anatomy, a small ovoid ventral projection of the thalamus where the thalamus connects with the optic nerve. Gateway/relay station through which visual info reaches the cerebral cortex. Relays visual info from retina to V1 and receives feedback from V1.

Pulvinar

Anatomy, receives multiple inputs from subdivisions of the visual cortex, superior colliculus, and retina. Implicated in visual attention and control of eye movements. Projects into the extrastriate cortex.

Extrastriate cortex

Anatomy, basically rest of occipital cortex divided into specialised areas for different aspects of sight. Receives direct projection from the pulvinar, thus bypassing V1 and making blindsight possible.

Amygdala

Anatomy, linked to visual awareness of objects. Receives neutral visual information from the visual cortex to be encoded with emotional and motivational significance, then returns it to the visual cortex to be re-processed. Activity can reflect location and emotional significance of visual stimuli.