 300px|thumbnail|right|diagram labeling planum temporale in green. the planum temporale is the cortical area just posterior to the auditory cortex (heschl's gyrus) within the sylvian fissure. it is a triangular region which forms the heart of wernicke's area, one of the most important functional areas for language.the brain from top to bottom original studies on this area found that the planum temporale was one of the most asymmetric regions in the brain, with this area being up to ten times larger in the left cerebral hemisphere than the right. ==location== the planum temporale makes up the superior surface of the superior temporal gyrus to the parietal lobe. the posterior extent of the planum temporale has been variably defined, which has led to disputes to estimates of size and degree of asymmetry. ==asymmetry== the planum temporale shows a significant asymmetry. in 65% of all individuals the left planum temporale appears to be more developed, while the right planum temporale is more developed in only 10%. in some peopleâs brains, the planum temporale is more than five times larger on the left than on the right, making it the most asymmetrical structure in the brain. evidence for this asymmetry has also been seen in great apes. this greater size of the left planum temporale compared with the right is already present in the fetus, where it can be observed starting from the 31st week of gestation. this observation strengthens the hypothesis of a genetic predisposition for brain asymmetry, however the effect of fetal experience has 
Brain