The amygdala, a walnut-sized brain region traditionally associated with emotional responses, plays a far broader role in memory formation than previously understood, according to research that could inform new treatments for memory disorders.
The study, published in Nature Neuroscience, found that the amygdala acts as a filter, tagging specific experiences for storage in long-term memory whilst allowing others to be forgotten. This function extends well beyond the region’s known involvement in fear-related memories.
Researchers at Cedars-Sinai Health Sciences University recorded single-neuron activity in 112 surgical patients who had electrodes implanted to monitor epileptic seizures. Participants viewed novel images and were later asked to recall them.
The team discovered that specific types of neurons in the amygdala respond selectively to particular categories of images, such as faces, animals or landscapes. The stronger these category neurons reacted when a person first viewed an image, the better that person could later recall it.
“Our results demonstrate that the activity of specific kinds of neurons in the amygdala predicts, while the person sees an image for the first time, whether that image will later be remembered,” said Ueli Rutishauser, director of the Center for Neural Science and Medicine at Cedars-Sinai and the study’s corresponding author.
The findings were replicated across two different datasets within the study, made possible through a multi-institutional consortium funded by the NIH BRAIN initiative.
The researchers suggest these findings have clinical implications for understanding memory impairments in conditions such as Alzheimer’s disease and temporal lobe epilepsy. The amygdala could represent a new target for treating these disorders using neuromodulation or cellular therapies.
Source: Xiao J et al. Stimulus-specific recruitment of human amygdala neurons predicts episodic memory encoding success. Nature Neuroscience (2026). DOI: 10.1038/s41593-026-02493-9
