“Spatial computing” enables flexible working memory

Amazing stuff!

"... A new study provides a novel explanation for how the brain distinctly manages the general and specific components of such cognitive demands.

The research ... shows that the brain creates distinct spaces in the cortex for each general rule and controls those patches with brain rhythms, a concept the authors call “spatial computing.” This system, evident in the study’s experiments in animals, explains how the brain can easily sustain a consistent understanding of a process even when the specific contents keep changing (like the time and temperature for bread versus cookies). It also answers a few questions neuroscientists have wrestled with about the physiological operations that underlie working memory. ...
Years of research ... have shown that working memory tasks are governed by an interplay of brain rhythms at distinct frequencies. Slower beta waves carry information about task rules and selectively yield to faster gamma waves when it’s time to execute operations such as storing information from the senses or reading it out when recall is needed. ...

spatial computing theory. Individual neurons representing information items can be scattered widely around the cortex, but the rule that’s applied to them is based on the patch of the network they are in. Those patches are determined by the pattern of beta and gamma waves. ...
"Regardless of if they preferred the same external stimulus or not, many neurons shared similar patterns of activity during working memory. And these patterns switched from task to task. It also appeared that neurons that were closer together within prefrontal cortex more often shared the same pattern. ...
In this way, individual neurons encoding specific items of information can be selectively associated with general rules by the brain waves controlling the patches they inhabit. In any given patch, all the neurons may be excited somewhat by the gamma waves, but the ones representing the item that fits the rule will spike the most. ..."

From the abstract:

"Working memory (WM) allows us to remember and selectively control a limited set of items. Neural evidence suggests it is achieved by interactions between bursts of beta and gamma oscillations. However, it is not clear how oscillations, reflecting coherent activity of millions of neurons, can selectively control individual WM items. Here we propose the novel concept of spatial computing where beta and gamma interactions cause item-specific activity to flow spatially across the network during a task. This way, control-related information such as item order is stored in the spatial activity independent of the detailed recurrent connectivity supporting the item-specific activity itself. The spatial flow is in turn reflected in low-dimensional activity shared by many neurons. We verify these predictions by analyzing local field potentials and neuronal spiking. We hypothesize that spatial computing can facilitate generalization and zero-shot learning by utilizing spatial component as an additional information encoding dimension."

“Spatial computing” enables flexible working memory | MIT News | Massachusetts Institute of Technology The brain applies rhythms to physical patches of the cortex to selectively control just the right neurons at the right times to do the right things.

Working memory control dynamics follow principles of spatial computing (open access)

Fig. 1: Disassociation between gamma and spiking