Changes in neural readout of response magnitude during auditory streaming do not correlate with behavioral choice in the auditory cortex

A fundamental goal of the auditory system is to group stimuli from the auditory environment into a perceptual unit (i.e., “stream”) or segregate the stimuli into multiple different streams. Although previous studies have clarified the psychophysical and neural mechanisms that may underlie this ability, the relationship between these mechanisms remains elusive. Here, we recorded multiunit activity (MUA) from the auditory cortex of monkeys while they participated in an auditory-streaming task consisting of interleaved low- and high-frequency tone bursts. As the streaming stimulus unfolded over time, MUA amplitude habituated; the magnitude of this habituation was correlated with the frequency difference between the tone bursts. An ideal-observer model could classify these time- and frequency-dependent changes into reports of “one stream” or “two streams” in a manner consistent with the behavioral literature. However, because classification was not modulated by the monkeys’ behavioral choices, this MUA habituation may not directly reflect perceptual reports. [Display omitted] •Record neural activity while monkeys participate in an objective auditory-streaming task•Activity habituates as the low- and high-frequency streaming sequences unfold over time•Decoder classifies activity as “two streams” as sequence frequency difference increases•Classification is invariant to monkeys’ choices, inconsistent with prominent model Banno et al. test the neural correlates of streaming in the auditory cortex. As the frequency difference between the sequences increases, an ideal observer consistently classifies neural activity as “two streams.” However, because this classification is independent of the monkeys’ choices, it suggests that this activity may not reflect perceptual reports.