GENERALIZABILITY AND MECHANISMS OF LEARNED FLEXIBILITY INDUCED THROUGH SWITCH PROBABILITY MANIPULATION
The brain dynamically alters its production of flexible behavior: cognitive flexibility increases when demand is high. In task switching experiments, past exposure to a high demand for flexibility in conjunction with specific temporal contexts leads to learned switch readiness such that future exposures to those contexts will cue flexibility. According to a recent proposal (Dreisbach & Fröber, 2019), learned switch readiness following switch demands is supported by a concurrent activation (CA) cognitive mechanism whereby both sets of task rules are kept available in working memory despite only using one at a time. This can be differentiated from a competing candidate mechanism, working memory updating (WMU) thresholds which determine the ease of replacing one task’s rules with another. The WMU mechanism is expected to cause a global increase in flexibility while CA is conceptualized as limited to task-specific associations. To test whether learned switch readiness represents a global or limited change in the cognitive system, I conducted two experiments that both involved learning switch readiness in one context and generalizing it in another. In Experiment 1, I replicated and extended findings that switch probability manipulations can modulate voluntary switch rates (VSR), indicating one type of generalizability. However, in Experiment 2, I found that flexibility learned through switch probability manipulations did not transfer to new tasks when the task rules were changed but contextual cues remained the same, demonstrating a limit: learned switch readiness does not generalize across tasks. These findings together suggest that CA is likely the mechanism behind learned switch readiness.