Awake suppression after brief exposure to a familiar stimulus

Newly learned information undergoes a process of awake reactivation shortly after the learning offset and we recently demonstrated that this effect can be observed as early as area V1. However, reactivating all experiences can be wasteful and unnecessary, especially for familiar stimuli. Therefore, here we tested whether awake reactivation occurs differentially for new and familiar stimuli. Subjects completed a brief visual task on a stimulus that was either novel or highly familiar due to extensive prior training on it. Replicating our previous results, we found that awake reactivation occurred in V1 for the novel stimulus. On the other hand, brief exposure to the familiar stimulus led to ‘awake suppression’ such that neural activity patterns immediately after exposure to the familiar stimulus diverged from the patterns associated with that stimulus. Further, awake reactivation was observed selectively in V1, whereas awake suppression had similar strength across areas V1–V3. These results are consistent with the presence of a competition between local awake reactivation and top-down awake suppression, with suppression becoming dominant for familiar stimuli.
Bang & Rahnev tested whether awake reactivation occurs differentially for new and familiar stimuli, given that reactivating all experiences can be wasteful. They expose participants to brief visual tasks in which the stimulus was either novel or familiar. They observed that whilst novel stimuli were associated with reactivation of cortical area V1, familiar stimuli led to ‘awake suppression’ in which neural activity diverged from patterns previously associated with that stimulus. The results support the existence of competition between local awake reactivation and top-down awake suppression, with suppression being dominant for familiar stimuli.