Concurrent selection of internal goals and external sensations during visual search

Flexible goal-directed behavior relies on selecting relevant internal goal representations and external sensations. Yet, these selection processes have classically been studied in isolation, leaving unclear how they are coordinated in time to support behavior. To address this, we developed a visual search task to simultaneously track selection among internal search goals held in working memory and external search targets in the environment. Capitalizing on sensitive gaze and neural markers, we provide proof-of-principle evidence in humans that internal and external selection processes do not necessarily take turns in a strictly serial manner but can develop concurrently. These concurrent processes are supported by largely nonoverlapping neural activity patterns in the human brain and can be performed effectively even when engaging opposite spatial locations in working memory and perception. Our findings challenge views portraying brain states as being either internally or externally focused and bring insight into how internal and external selection processes work together to yield efficient search behavior.