Also, higher prevalences of left-handedness and left-eye dominance seem to occur.Ophthalmologic issues are common in WS. Up to 75% of subjects in some studies have strabismus (ocular misalignment), particularly esotropia, due to inherent subnormal binocular visual function
and cognitive deficits in visuospatial construction. People with WS have problems with visual processing, but this is related to difficulty in dealing with complex spatial relationships rather than depth perception per se. Nervous system
Because of missing multiple genes, many effects on the brain are seen, including abnormalities in the cerebellum, right parietal lobe, and left frontal cortical regions. This pattern is consistent with the visual-spatial disabilities and problems with behavioral timing often seen in WS.Frontal-cerebellar pathways, involved in behavioral timing, are often abnormally developed in people with WS, which may be related to their deficits in coordination and execution of fine motor tasks such as drawing and writing. In addition, people with WS often exhibit gross motor difficulties, including trouble walking downstairs,  overactive motor reflexes (hyperreflexia), and hyperactive, involuntary movement of the eyes (nystagmus).Williams syndrome is also noteworthy for exhibiting abnormalities in the parietal-dorsal areas of the neocortex, but not the ventral areas. The parietal-dorsal area handles visual processing that supports visual-spatial analysis of the environment, while the ventral is related to semantic recognition of visual stimuli, and the recognition of faces.
Thus, people with WS are often able to visually identify and recognize whole objects, and refer to them by name, but struggle with visuospatial construction (seeing an object as being composed of many smaller parts, and recreating it) and orienting themselves in space.People with WS are often affable and hyperverbal, demonstrating the decreased inhibition ability that stems from dorsal-frontal deficits. Some studies suggest that the amygdala of a person with Williams syndrome has greater volume than the average persons (though it is smaller than average in childhood). In general, neuroimaging studies demonstrate that people with WS have diminished amygdala reactivity in response to socially frightening stimuli (such as disapproving faces), but demonstrate hyperreactivity in the amygdala when presented with nonsocial fear stimuli (such as frightening animals). This may partially account for the apparent absence of social inhibition observed in people with the syndrome, as well as the prevalence of anxious symptoms (but see fear for details on the relationship between the amygdala and fear response). Also, some evidence indicates that people with WS exhibit  amygdalal hyperactivity when viewing happy facial expressions. They are talkative and eager to please, indicating a cocktail party personality.Increased volume and activation of the left auditory cortex has been observed in people with WS, which has been interpreted as a neural correlation of patients rhythm propensity and fondness of music. Similar sizes of the auditory cortex have been previously reported only in professional musicians.