Association+Visual+Cortex

Medially and along the lateral convexity. There are also extra-striatal visual association and assimilaton areas located in the superior parietal (area 7) and inferior and middle temporal lobes
 * Location**

18 and 19
 * Broadman's Areas**

-Translation and interpretations of visual impressions transmitted from area 17. -Determination of precise geometric form -Assimilation of sugnals from the primary cortex
 * Primary Functions **

Although simple and complex cells are found in the association cortex, this region is predominantly populated by hypercomplex (both higher and lower order) neurons
 * Cortical Structure**

In contrast to the neurons within area 17, many of the cells within area 18 receive binocular input and can be activated by either eye. It is via the action of these cells that one is able to gather information regarding distance, discrepancies in stimulus location and thus determine depth and achieve stereoscopic vision. Some association neurons will only fire when a target is a definite distance from the eye.

Many of the neurons in this region, particularly area 19, receive higher order converging input from the parietal and temporal lobe. E.g. in addition to visual input, neurons in the superior portions of area 19 respond to tactile and proproceptive stimuli, whereas those in the inferior portions respond to auditory signals. It is probably in this manner (in conjunction with subcortical connections with, for example, the superior colliculus) that one is able to orient toward and gaze upon an auditory stimulus as well as maintain stablization of the head (via proproceptive-vestbibular input) while engaged in visual search.

Hallucinations Electrical stimulation of or lesions involving areas 18 and 19 can produce complex visual hallucinations -Images of men, animals, various objects and geometric figures -Liliputian-type individuals, including micropsias and macropsias <span style="font-family: 'Times New Roman',serif; font-size: 11pt;">-Objects may seem to become telescoped/far away, or, when approached, objects may seem to loom and become exceedingly large.
 * Damage/Injuries**

<span style="font-family: 'Times New Roman',serif; font-size: 11pt;">Complex hallucinations are usually quite vivid and fully formed and the patient may think what he sees is a real. <span style="font-family: 'Times New Roman',serif; font-size: 11pt;">Example: Person hallucinated a butterfly then attempted to catch it when area 19 was electrically stimulated.

<span style="font-family: 'Times New Roman',serif; font-size: 11pt;">Complex hallucinations, although usually associated with tumors or abnormal activation of the visual association area, have also been reported with parietal-occipital involvement, occipital-temporal, or inferior-temporal damage, or with lesions of the occipital pole and convexity.

<span style="font-family: 'Times New Roman',serif; font-size: 11pt;">Laterality: although simple hallucinations are likely following damage to either hemisphere, complex hallucinations are usually associated with right rather than left cerebral lesions.