Cells sensitive to particular picture categories responded more strongly when patients first saw images they later remembered. The peer-reviewed human study found the pattern in two datasets collected during epilepsy monitoring. The association persisted after accounting for emotional responses, extending the amygdala’s proposed role in memory beyond experiences carrying strong feelings.
Brain cells responding selectively to particular kinds of pictures were more active when people first saw images they later recognised. A peer-reviewed human study led by Cedars-Sinai linked this response in the amygdala, a deep brain region associated with emotion, to successful image-memory formation. The finding appeared in two datasets collected while patients performed visual memory tasks.[1], [2]
Participants were undergoing intracranial electrode monitoring for drug-resistant epilepsy. Clinical needs determined where their electrodes were placed. In the first task, 42 patients viewed unfamiliar pictures of people, food, animals, cars and landscapes. After a delay of 10–30 minutes, they took a recognition test mixing previously presented pictures with new ones and rated their confidence. The team recorded 1,871 neurons across six brain regions, including 575 in the amygdala.[1]
The memory association occurred when an image belonged to a cell’s preferred category. The association persisted after adjustment for the pictures’ emotional character and arousal. A second task involving 95 patients reproduced the principal pattern. Successful encoding also coincided with closer timing between amygdala cell activity and electrical activity in the hippocampus, another memory-related region. These observational recordings in clinical cohorts establish an association during visual tasks; the study tested neither drugs nor stimulation to improve memory.[1]
