The task-dependent changes in auditory cortical representations play a crucial role in the emergence of categorical perception and decision-making in downstream brain regions. In the auditory system, these changes are thought to arise hierarchically, with primary auditory cortex (A1) building an overcomplete representation of sensory inputs. This overcomplete representation allows for a flexible and selective readout of behaviorally relevant information in non-primary auditory cortex (dPEG) and further downstream regions.
During the challenging tone-in-noise detection task, task engagement caused categorical sound representations to emerge in dPEG, where the neural population selectively enhanced the representation of task-relevant features. This selective enhancement is crucial for guiding behavioral choices and decision-making processes. The hierarchical processing model suggests that A1 forms a high-dimensional representation of sensory inputs, and dPEG selectively decodes task-relevant features from this representation. This process enables downstream brain regions to extract behaviorally relevant information for making categorical decisions.
The task-dependent changes in auditory cortical representations, therefore, set the stage for the emergence of categorical perception and decision-making in downstream brain regions by providing a structured and organized representation of sensory information that is essential for guiding behavior.