Choice-related activity and neural encoding in primary auditory cortex and lateral belt during feature-selective attention

Abstract

Selective attention is necessary to sift through, form a coherent percept of, and make behavioral decisions on the vast amount of information present in most sensory environments. How and where selective attention is employed in cortex and how this perceptual information then informs the relevant behavioral decisions is still not well understood. Studies probing selective attention and decision making in visual cortex have been enlightening as to how sensory attention might work in that modality; whether or not similar mechanisms are employed in auditory attention is not yet clear. Therefore, we trained rhesus macaques on a feature selective attention task, where they switched between reporting changes in temporal (amplitude modulation, AM) and spectral (carrier bandwidth) features of a broadband noise stimulus. We investigated how the encoding of these features by single neurons in primary (A1) and secondary (middle lateral belt, ML) auditory cortex were affected by the different attention conditions. We found that neurons in A1 and ML showed mixed-selectivity to the sound and task features. We found no difference in AM encoding between the attention conditions. We found that choice-related activity in both A1 and ML neurons shifts between attentional conditions. This finding suggests that choice-related activity in auditory cortex does not simply reflect motor preparation or action, and supports the relationship between reported choice-related activity and the decision and perceptual process.

An Emergent Population Code in Primary Auditory Cortex Supports Selective Attention to Spectral and Temporal Sound Features

“…In that study, context encoding is interpreted as important for flexible switching between "selection rules," with remarkably similar context encoding between A1 and PFC. Considering our results alongside this previous study, a reasonable interpretation is that A1 not only participates in the representation of sensory information but also the behavioral context in which sounds are perceived (Mohn et al, 2021). Indeed, previous studies report taskrelated changes in single-neuron A1 activity that could be explained as providing crucial task context-related information (Buran et al, 2014;Jaramillo et al, 2014;Guo et al, 2017;Yao et al, 2019;Zempeltzi et al, 2020).…”