The attentional switching framework: A dual process account of how the brain switches when attention switches

The capacity to flexibly shift attention between external and internal events is critical for everyday tasks, yet research on how this shifting operates at the cognitive and neural level is still emerging. Here, we examined the question: How does the brain switch when attention switches between external and internal states? We propose the Attentional Switching Framework, which postulates that switching between external and internal attention states involves two seemingly opposing mechanisms subserved by distinct neural bases. First, based on our Resource Dependent Account, the regulation of attentional switching involves a domain-general mechanism that determines when and how the focus of attention shifts between external and internal states. This mainly recruits a similar set of brain regions and pathways when switching to either attention state, suggesting a common neural mechanism that initiates the attentional switch. Second, according to our Resource Independent Account, the maintenance of external and internal attention states involves domain-specific representations. These representations primarily recruit distinct brain regions and pathways, suggesting largely dissociable neural mechanisms that maintain the representation of each attention state. Together, we propose that when attention switches, the brain engages a dual process system involving a common mechanism that supports the regulation of switching and dissociable mechanisms that supports the representation of attention states. In highlighting the role of distinct operations of various brain regions and pathways underlying attentional switching, our framework reconciles apparent contradictions regarding whether common or distinct mechanisms are involved in switching between external and internal attention and presents important real-world applications and clinical implications.