angular gyrus

n. A visible bulge on the posterior parietal lobe close to the occipital and temporal lobes (parietal-temporal-occipital junction). It corresponds to the Brodmann’s area 39. Located at the junction of the temporal, parietal, and occipital lobes, the angular gyrus is limited by the supramarginal gyrus of the parietal lobe, the posterior-superior temporal gyrus, the inferior parietal lobule, and the occipital lobe. Lesions in the left hemisphere angular gyrus can be associated with the so- called Gerstmann’s syndrome (or angular gyrus syndrome), which includes acalculia, agraphia, right-left confusion, and finger agnosia. So-called semantic aphasia has also been described in cases of left angular gyrus pathology. Right hemisphere angular gyrus lesions can result in spatial disturbances, constructional defects, and hemispatial neglect. Angular gyrus is considered as a cortical area involved in cross-modal association among somatosensory (body-knowledge) information, auditory information, and visual information. Learning to read and to write is probably heavily dependent on this brain area. Developmentally, the angular gyrus is one of the last to mature functionally and anatomically, and those abilities related to the angular activity (such as reading, writing, and calculations) develop late. - AA