Memory's echo: Vivid remembering reactivates sensory-specific cortex

TLDR

The brain may reactivate sensory cortex during retrieval of sensory‑specific information. The study aimed to determine whether vivid recall of pictures and sounds reactivates sensory cortex. Participants learned picture and sound items and performed a recall test while undergoing event‑related fMRI. Visual and auditory cortex were differentially activated during recall, overlapping with perception‑activated regions and more represented in late than early sensory cortex, indicating reactivation of sensory regions during vivid recall.

Abstract

A fundamental question in human memory is how the brain represents sensory-specific information during the process of retrieval. One hypothesis is that regions of sensory cortex are reactivated during retrieval of sensory-specific information (1). Here we report findings from a study in which subjects learned a set of picture and sound items and were then given a recall test during which they vividly remembered the items while imaged by using event-related functional MRI. Regions of visual and auditory cortex were activated differentially during retrieval of pictures and sounds, respectively. Furthermore, the regions activated during the recall test comprised a subset of those activated during a separate perception task in which subjects actually viewed pictures and heard sounds. Regions activated during the recall test were found to be represented more in late than in early visual and auditory cortex. Therefore, results indicate that retrieval of vivid visual and auditory information can be associated with a reactivation of some of the same sensory regions that were activated during perception of those items.