Sunday, February 13, 2011

Parahippocampal Gyrus

The parahippocampal gyrus is a cortical region of the cerebrum, located on the inferior surface of the temporal lobe, on each cerebral hemisphere, lying between the hippocampal and collateral sulci. It envelops the hippocampus. The parahippocampal gyrus forms the lower part of the fornicate gyrus, extending from behind the splenium corporis callosi forward along the dentate gyrus of the hippocampus from which it is demarcated by the hippocampal sulcus.

The function of the parahippocampal gyrus is to encode and recognize scenes, rather than faces or objects. Functional Magnetic Resonance Imaging (FMRI) studies indicate that this region of the brain becomes highly active when human subjects view topographical scene stimuli such as images of landscapes, cityscapes, or rooms. Additional research has increased the probability that the right parahippocampal gyrus in particular has functions beyond the contextualizing of visual background. Tests by a California-based group led by Katherine P. Rankin indicate that the lobe may play a crucial role in identifying social context as well, including paralinguistic elements of verbal communication.