Katana VentraIP

Two-streams hypothesis

The two-streams hypothesis is a model of the neural processing of vision as well as hearing.[1] The hypothesis, given its initial characterisation in a paper by David Milner and Melvyn A. Goodale in 1992, argues that humans possess two distinct visual systems.[2] Recently there seems to be evidence of two distinct auditory systems as well. As visual information exits the occipital lobe, and as sound leaves the phonological network, it follows two main pathways, or "streams". The ventral stream (also known as the "what pathway") leads to the temporal lobe, which is involved with object and visual identification and recognition. The dorsal stream (or, "how pathway") leads to the parietal lobe, which is involved with processing the object's spatial location relative to the viewer and with speech repetition.

: where the patient can only describe single objects without the ability to perceive it as a component of a set of details or objects in a context (as in a scenario, e.g. the forest for the trees).

Simultanagnosia

: where the patient cannot use visuospatial information to guide arm movements.

Optic ataxia

: where the patient is unaware of the contralesional half of space (that is, they are unaware of things in their left field of view and focus only on objects in the right field of view; or appear unaware of things in one field of view when they perceive them in the other). For example, a person with this disorder may draw a clock, and then label all twelve of the numbers on one side of the face and consider the drawing complete.

Hemispatial neglect

: inability to perceive motion.

Akinetopsia

: inability to produce discretionary or volitional movement in the absence of muscular disorders.

Apraxia

Language processing in the brain

Vision for perception and vision for action

Visual memory

Visual cortex

Visual system

Magnocellular cell

Tectopulvinar pathway

Auditory system

Object recognition (cognitive science)

Medial superior temporal area

Arcuate fasciculus

Occipital lobe

Lateral pulvinar nucleus

Pulvinar nuclei

Phantom contour

Parasol cell

Constructional apraxia

Lateral geniculate nucleus

Blindsight

Koniocellular cell