The largest part of the human brain, the cerebral cortex, is divided into several areas known as lobes, each of which serve different functions. One portion of the parietal lobe, known as the angular gyrus, is located just above the temporal lobe, and behind a fold in the parietal lobe called the supramarginal gyrus. Another name for this area is Brodmann area 39.
Several important functions related to processing language, mathematics, and other cognitive skills are related to the angular gyrus. Language skills such as understanding metaphors are contained within this area. Individuals with damage to the angular gyrus are often unable to comprehend that there are two layers of meaning to metaphors. Instead, they would only understand the basic literal meaning of a metaphorical statement.
Similar functions, such as interpreting visual stimuli in linguistic terms, seem to be served by this region of the parietal lobe. Another theory is that it assists in converting words that are read into internal monologue. The location of the angular gyrus, between areas that interpret visual and auditory stimuli, seems to lend support to these interpretations.
Unlike other brain areas that contribute toward recognizing the sounds or appearance of words, the angular gyrus seems to help process semantic meanings. Many linguistic areas predominantly use the left half of the brain, but both the right and left gyrii seem to be involved in semantic processing. The many inputs that this area receives from different senses may assist in helping it identify words and categorize them as having specific meanings.
Calculation skills are assisted by the angular gyrus, at least in part. When this is damaged, individuals are sometimes unable to perform basic arithmetic. Studies that involved functional imaging showed that this region in the left half of the brain works with another region, the left inferior frontal gyrus, allowed for the retrieval of arithmetic rules. This retrieval allowed experimental subjects to produce exact answers for calculation problems. Greater activity between these two regions is associated with increased mathematics skills.
An interesting and unique role of this region of the brain may be associated with some out of body experiences. Researchers found that when the angular gyrus was stimulated, subjects experienced differences in where they perceived their own body in relation to its true location. One woman felt a presence behind her after stimulation, and another subject reported feeling that he was actually on the ceiling.
