Prosopagnosia+(Face+Blindness)

===Brain Regions Involved when viewing and categorizing faces and other complex stimuli === -Medial temporal lobe -Right parahippocampal gyrus (in conjunction with areas 19, 37, 36) -Inferior and middle temporal lobe

Electrical stimulation of these areas
-Hallucinations and memories of faces of complex visual stimuli

-Disrupts visual-spatial memory for faces in general -Inability to correctly label emotion faces.
 * Posterior right temporal gyrus: **

Lesions/Damage
- loss of the ability to recognize faces -Severe disturbances involving visual discrimination learning and retention -Difficulty performing visual closure and recognizing incomplete figural stimuli (different shapes and patterns and objects which differ in regard to size or color)
 * Inferior temporal lobe **

-Severe disturbance in the ability to recognize the faces of friends, loved ones, or pets -Discriminate and identify even facial affect
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Right temporal-occipital region **

<span style="color: #000000; font-family: 'Times New Roman',serif;">With gradual deterioration and degeneration of the right inferior temporal lobe, patients may suffer a progressive prosopagnosia.

<span style="color: #000000; font-family: 'Times New Roman',serif;">Some patients may in fact be unable to recognize their own face in the mirror.

<span style="color: #000000; font-family: 'Times New Roman',serif;">Presumably, the inability to recognize faces is due to the destruction of facial recognition neurons, including those within the amygdala and hippocampus (which becomes activated when memorizing faces. However, because, at a neocortical level, global facial recognition cells appear to be in a minority whereas those specialized for analyzing facial parts are more numerous, the ability to recognize facial details is therefore more likely to be preserved following inferior temporal destruction -particularly if the left temporal lobe is spared.

<span style="color: #000000; font-family: 'Times New Roman',serif;">Role of the Amygdala
<span style="color: #000000; font-family: 'Times New Roman',serif;">As facial stimuli are also social emotional stimuli, and facial recognition, for example, that of a friend or loved one, is generally associated with emotional feelings the amygdala plays a strong role. <span style="color: #000000; font-family: 'Times New Roman',serif;">It is via the face that emotional intent and affective states, including threat or fear, is conveyed--information that is processed by the amygdala. <span style="color: #000000; font-family: 'Times New Roman',serif;">Damage to the overlying temporal lobe may result in deficiencies in this capacity. <span style="color: #000000; font-family: 'Times New Roman',serif;">It is perhaps for this reason, that some patients with prosopagnosia are also unable to recognize their pets or their homes--the emotional significance of these stimuli can no longer be evoked. These stimuli are no longer personalized and thus cannot be recognized.

<span style="color: #000000; font-family: 'Times New Roman',serif;">Lateralization & Facial Recognition.
<span style="color: #000000; font-family: 'Times New Roman',serif;">Although patients with prosopagnosia often suffer from bilateral injuries, in many cases the lesions are restricted to the right hemisphere.

<span style="color: #000000; font-family: 'Times New Roman',serif;">Disturbances involving facial recognition do not usually occur with isolated left cerebral lesions.
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Right hemisphere: **<span style="color: #000000; font-family: 'Times New Roman',serif;"> dominant in regard to the recognition of both familiar and unfamiliar faces
 * <span style="font-family: 'Times New Roman',serif;">Left hemisphere: **<span style="font-family: 'Times New Roman',serif;"> Involved in the recognition of famous faces

Agnosias
<span style="color: #000000; font-family: 'Times New Roman',serif;">When the Inferior temporal lobe is damaged, in addition to prosopagnosia there may occur difficulty identifying various familiar stimuli and objects, e.g. utensils, cars, as well as differentiating among similar visual stimuli. Many patients also have difficulty with color recognition. Frequently these types of agnosic disturbances are related to left cerebral or bilateral dysfunction.