Collating memories of what happened based on where it happened


We keep in mind things from our own first-person viewpoint, the method we experienced them. The hippocampus is the area where these egocentric, episodic memories are made. Yet the hippocampus likewise encodes spatial details in an extremely non-egocentric way, utilizing location cells and grid cells to form a generalized map of the external environment. How does one area of the brain handle both of these?

James Knierim’s laboratory at Hopkins has actually reconciled this appearing disparity in a way Talmudic in its neatness: there’s no contradiction! Egocentric spatial details is encoded by one population of nerve cells in the hippocampus, and allocentric spatial details is encoded by a various population of cells in the hippocampus. Voila, issue resolved.

Neuroscientists like Knierim utilize the word “allocentric” to signify a method of coding spatial details that specifies the place of an item relative to other things, instead of relative to the self. (Psychologists utilize it to explain somebody whose interest, attention, and actions are concentrated on others instead of themselves.) In any case, its reverse is egocentric: spatial details (and/or one’s interest) with the self as the main referral.

Knierim’s laboratory taped the activities of 2 various neuronal populations in rats going through labyrinths. Both cell populations were formerly understood to supply sensory details to the hippocampus, where episodic memories are made. One supplies an unbiased spatial structure, an internal representation of the external world in which the experience to be kept in mind might occur. The other was believed to supply the material– the “what” of the memory– to put inside that psychological matrix.

This material is undoubtedly egocentric. Knierim’s brand-new work revealed that, contrary to forecasts, these material encoding nerve cells likewise fired in a location-dependent method, simply in a really subjective way. The do not fire when the rat passes over specific areas in the environment, like grid cells do; they fire when the rat takes a look at specific things, putting those things in area however in an egocentric structure.

It is difficult to leave our own heads. Various individuals keep in mind the exact same occasions in a different way. We can’t assist it; we see those occasions from various locations, rather actual various viewpoints. And, a minimum of in rats, those egocentric perspectives get encoded into long term memories.

Science,2018 DOI: 101126/ science.aau4940( About DOIs).