Accumulating evidence suggests that cognitive factors such as rules and attention can modulate sensory processing through top-down influences. However, the neural mechanisms transforming cross-modal inputs into rule-guided perceptions remain unclear. Therefore, in this study, we recorded neuronal activity in the posterior parietal cortex (PPC) and primary auditory cortex (A1) of rats during an audiovisual rule-switching task to investigate how rules are dynamically encoded and modulate sensory processing. By tracking the dynamic neural encoding of internally estimated task rules on a trial-by-trial basis, our single-neuron analyses suggested that the PPC may proactively represent task rules before decision-making, whereas A1 may contribute to monitoring auditory-task performance by enhancing rule-related signals following errors. Both regions showed a preferential representation of conflicting rule combinations, suggesting a specialized mechanism for efficient conflict resolution. Accordingly, we dissociated stimulus-driven responses from rule-modulated responses and observed a within-trial transformation from sensory encoding to rule-weighted representations, progressing from physical features to behavioral relevance, although integration remained limited. Taken together, these results suggest that the PPC-A1 circuit dynamically encodes rules and reshapes sensory processing to implement structured computations for flexible behaviors.
Zhong et al. (Tue,) studied this question.