A predictive processing account of card sorting: Fast proactive and reactive frontoparietal cortical dynamics during inference and learning of perceptual categories

For decades a common assumption in Cognitive Neuroscience has been that prefrontal executive control is mainly engaged during target detection (Posner & Petersen, 1990, 3: 25–42, Ann Rev Neurosci.). More recently, predictive processing theories of frontal function under the Bayesian brain hypothesis emphasize a key role of proactive control for anticipatory action selection (i.e., planning as active inference). Here, we review evidence of fast and widespread electroencephalographic (EEG) and magnetoencephalographic (MEG) fronto-temporo-parietal cortical activations elicited by feedback cues and target cards in the Wisconsin Card Sorting Test (WCST). This evidence is best interpreted when considering negative and positive feedback as predictive cues (i.e., sensory outcomes) for proactively updating beliefs about unknown perceptual categories. Such predictive cues inform posterior beliefs about high-level hidden categories governing subsequent response selection at target onset. Quite remarkably, these new views concur with Don Stuss' early findings concerning two broad classes of P300 cortical responses evoked by feedback cues and target cards in a computerized WCST analogue. Stuss' discussion of those P300 responses —in terms of the resolution of uncertainty about response (policy) selection, and the subject's expectancies for future perceptual or motor activities and their timing— were prescient of current predictive processing and active (Bayesian) inference theories. From these new premises, a domain-general frontoparietal cortical network is rapidly engaged during two temporarily distinct stages of inference and learning of perceptual categories that underwrite goal-directed card sorting behavior, and they each engage prefrontal executive functions in fundamentally distinct ways.