Researchers at the University of California, San Diego have identified the area of the brain, the retrosplenial cortex, that helps put together the necessary spatial information for navigation.
What is the “conjunction junction”?
The researchers referred to this area as “conjunction junction” as it serves as an intermediary between the different areas of the brains that generate different forms of spatial mapping.
Douglas Nitz, associate professor of cognitive science in the UC San Diego Division of Social Sciences explains:
“these different forms of spatial information, generated in distinct structures, must be combined and related to each other in an organized fashion in order for an agent to effectively move through the world. Our study shows that the retrosplenial cortex is an area of the brain that is simultaneously sensitive to mapping interior and exterior spaces and may be a kind of ‘conjunction junction,’ putting together all the necessary information for successful navigation.”
People with damage to the retrosplenial cortex can experience what is known as directional amnesia.
UCDS graduate student Andrew Alexander, who is the first author on the paper, explains that a person with damage to this area “knows where things are in the world but won’t be able to place the route that they need to get between them.”
Since the retrosplenial cortex is one of the first areas of the brain to degenerate in early stage Alzheimers, understanding this connection could lead to the development of simple navigation-based tests to detect the disease.
Alexander, A. S., & Nitz, D. A. (2015). Retrosplenial cortex maps the conjunction of internal and external spaces. Nature Neuroscience.