Investigating the shift between externally and internally oriented cognition; a novel task-switching paradigm

Despite our constant need to flexibly balance internal and external information, research on cognitive flexibility has focused solely on shifts between externally oriented tasks. In contrast, switches across internally oriented processes (and self-referential cognition specifically), and between internal and external domains have never been investigated. Here, we report a novel task-switching paradigm developed to explore the behavioural signatures associated with cognitive flexibility when self-referential, as well as more traditional external processes, are involved. 200 healthy volunteers completed an online task. In each trial, participants performed one of four possible tasks on written words, as instructed by a pre-stimulus cue. These included two externally and two internally oriented tasks: assessing whether the third letter was a consonant, or the penultimate letter was a vowel vs. assessing whether the adjective applied to their personality, or if it described a bodily sensation they were currently experiencing. 40% of trials involved switches to another task and these were equally distributed across within-external, within-internal, internal-to-external and external-to-internal switches. We found higher response times (RT) for switches compared to repetitions both in the external and internal domain, thus demonstrating the presence of switch costs in self-referential tasks for the first time. We also found higher RTs for between-domain switches compared to switches within each domain. We propose that these effects originate from the goal-directed engagement of different domain-specific cognitive systems that flexibly communicate and share domain-general control features.