Scientific American February 2020 pp31-35 Neuroscience “The Brain’s Social Road Maps”. “Neural circuits that track our whereabouts in space and time may also play vital roles in determining how we relate to people”. By Matthew Shafer and Daniela Schiller
Researchers are beginning to better understand how the brain captures and saves information we gather about our physical and social environment. Two areas of the brain, the hippocampus and entorhinal cortex, are especially involved in scaffolding cellular circuits that act to give us a rendering of time and space. From many maps, we create models of our environment allowing us to infer, improvise, imagine and adapt to new circumstances. We might find ourselves on a new path but using our mental maps we recognize embedded landmarks and improvise a shorter route.
Surprisingly, research findings suggest we map our social environment similarly. Instead of X and Y coordinates we map our acquaintances in social space by the dimensions of Power in the Social Group (From Less -> More) and Our personal Affiliation with that or any person (From Close-> Distant). In this way, within the hippocampus are stored records of facts and events. As an example, “When we see a photograph of someone or hear or see a person’s name, the same hippocampal cells will fire…”. If the hippocampus is damaged one struggles to remember details from the past.
The neurobiology of this mapping relies on the distribution and action of certain types of nerve cells or neurons. There are “place” cells that when activated encode our relative representation of space. Accompanying place cells are “grid” cells that are populated in a triangle and fire when we cross into or out of the triangle. Together they “provides a means to locate oneself in space and determine distance and direction”. This work earned O’Keefe and Moser the 2014 Nobel Prize in Medicine and Physiology. Another cell type, called “Reward” cells fire more rapidly as you approach the desired target while other cells help decipher speed, direction and time.
Using MRI scans researchers have determined that we simulate past and future paths even while we sleep. All of this allows us leverage what we know rather than improvise with each new endeavor. “Mental maps do more than help us find short cuts through physical space they enable us to navigate life itself”. Read the article for more detail.