|Brain: Angular gyrus|
|Figure one illustrates significant language areas of the brain. Brodmann area 39 is highlighted in red.|
|Drawing of a cast to illustrate the relations of the brain to the skull. (Angular gyrus labeled at upper left, in yellow section.)|
The angular gyrus is a region of the brain in the parietal lobe, that lies near the superior edge of the temporal lobe, and immediately posterior to the supramarginal gyrus; it is involved in a number of processes related to language and cognition. It is Brodmann area 39 of the human brain.
Use in language
Geschwind proposes that written word is translated to internal monologue via the angular gyrus.
V. S. Ramachandran, director of the Center for Brain and Cognition at the University of California, San Diego, directed a study that showed that the angular gyrus is at least partially responsible for understanding metaphors. Right-handed patients who had damage to their left angular gyrus and whose speaking and comprehending English was seemingly unaffected, could not grasp the dual nature of metaphor.
Given a common metaphorical phrase, each patient could give only a literal meaning. If pressed, they could invent a wild interpretation but it was well off the mark.
In another exercise, the patients all failed to be able to describe a bulbous object as "booba" and a jagged object as "kiki," whereas more than 90% of unaffected subjects succeeded in the test. This showed an inability to connect visual stimuli to language.
The fact that the angular gyrus is proportionately much larger in hominids than other primates, and its strategic location at the crossroads of areas specialized for processing touch, hearing and vision, leads Ramachandran to believe that it is critical both to conceptual metaphors and to cross-modal abstractions more generally.
Recent experiments have demonstrated the possibility that stimulation of the angular gyrus is the cause of out-of-body experiences.  Stimulation of the angular gyrus in one experiment caused a woman to perceive a phantom existence behind her. Another such experiment gave the test subject the feeling of being on the ceiling. This is attributed to a discrepancy in the actual position of the body, and the mind's perceived location of the body. This phenomenon is similar to phantom limb syndrome.
- Arzy, S., Seeck, M., Ortigue, S., Spinelli, L., Blanke, O., 2006. Induction of an illusory shadow person: Stimulation of a site on the brain's left hemisphere prompts the creepy feeling that somebody is close by. Nature, 443(21), pp.287.