The representations held in working memory are inherently noisy, but attention directed to relevant objects can effectively enhance their fidelity. While recent working memory models suggest that memory representations are distributed across sensory and cognitive-control brain regions, it remains unknown how multiple brain networks generate this attentional gain in fidelity. Here, we investigated the contributions of the distinct brain networks in maintaining and enhancing memory representations using psychophysical modeling and fMRI. Human listeners performed an auditory syllable pitch-discrimination task, in which they received valid (vs. neutral) retro-active cues to selectively attend to one of the two syllable categories maintained in memory. Valid (vs. neutral) retro-cues facilitated task performance, eliciting faster recall and enhanced recall precision of syllables in memory. Valid retro-cues also led to increased neural activation in fronto-parietal and cingulo-opercular networks, but not in sensory-specific superior temporal cortex. Multivariate pattern analysis as a proxy for representational fidelity in memory revealed that attended syllable objects were maintained in distributed areas across superior temporal, frontal, parietal, and sensorimotor brain areas. However, neural fidelity in left superior temporal sulcus and its enhancement through attention-to-memory best predicted the ensuing individual gain in recall precision of auditory objects from memory. These results demonstrate that maintaining versus attentionally enhancing auditory memory representations are functionally separable mechanisms across distributed brain regions.
bioRxiv Subject Collection: Neuroscience