The task novelty paradox: Flexible control of inflexible neural pathways during rapid instructed task learning

HIGHLIGHTSEvidence for an inflexible prepared reflex effect in simple novel tasks.Flexible hubs in frontoparietal cortex support rapid instructed task learning.Frontoparietal influences on task‐implementing regions may temporarily reduce flexibility.Reactive control may counteract planning‐induced inflexibility.Anterior prefrontal cortex may enable complex novel task performance by reducing temporary inflexibility. ABSTRACT Rapid instructed task learning (RITL) is one of the most remarkable human abilities, when considered from both computational and evolutionary perspectives. A key feature of RITL is that it enables new goals to be immediately pursued (and shared) following formation of task representations. Although RITL is a form of cognitive control that engenders immense flexibility, it also seems to produce inflexible activation of action plans in inappropriate contexts. We argue that this “prepared reflex” effect arises because RITL is implemented in the brain via a “flexible hub” mechanism, in which top‐down influences from the frontoparietal control network reroute pathways among procedure‐implementing brain areas (e.g., perceptual and motor areas). Specifically, we suggest that RITL‐based proactive control ‐ the preparatory biasing of task‐relevant functional network routes ‐ results in inflexible associative processing, demanding compensation in the form of increased reactive (in‐the‐moment) control. Thus, RITL produces a computational trade‐off, in which the top‐down influences of flexible hubs increase overall cognitive flexibility, but at the cost of temporally localized inflexibility (the prepared reflex effect).