The human brain regions responsible for working memory content are also used to gauge the quality, or uncertainty, of memories, a team of scientists has found. The study, funded by the National Eye Institute, uncovers how these neural responses allow us to act and make decisions based on how sure we are about our memories.
“Access to the uncertainty in our working memory enables us to determine how much to ‘trust’ our memory in making decisions,” explains Hsin-Hung Li, a postdoctoral fellow in New York University’s Department of Psychology and Center for Neural Science and the lead author of the paper, which appears in the journal Neuron. “Our research is the first to reveal that the neural populations that encode the content of working memory also represent the uncertainty of memory.”
Working memory, which enables us to maintain information in our minds, is an essential cognitive system that is involved in almost every aspect of human behavior—notably decision-making and learning.
“It is not only crucial for the brain to remember things, but also to weigh how good the memory is: How certain are we that a specific memory is accurate?” explains Li. “If we feel that our memory for the previously viewed online item is poor, or uncertain, we would scroll back and check that item again in order to ensure an accurate comparison.”
While studies on human behaviors have shown that people are able to evaluate the quality of their memory, less clear is how the brain achieves this.
More specifically, it had previously been unknown whether the brain regions that hold the memorized item also register the quality of that memory.
The researchers conducted a pair of experiments to better understand how the brain stores working memory information and how, simultaneously, the brain represents the uncertainty—or, how good the memory is—of remembered items.