Undirected thought: neural determinants and correlates.

Area of Science:

• Cognitive Neuroscience
• Neuroscience
• Psychology

Background:

• Undirected thought, encompassing spontaneous thought, stimulus-independent thought, and mind wandering, constitutes a substantial portion of human mental experience.
• Historically, neuroscientific research has predominantly focused on goal-directed thinking, leaving undirected thought processes less explored.

Purpose of the Study:

• To review the current state of research on the neural underpinnings of undirected thought.
• To examine the roles of various brain networks, including the default mode network, executive system, and temporal lobe memory network, in supporting undirected thought.
• To present novel findings on functional connectivity between large-scale brain networks during mind wandering.

Main Methods:

• Review of existing neuroscientific literature on undirected thought.
• Analysis of research paradigms, including task-based, rest-based, and introspective first-person reports.
• Investigation of functional connectivity between brain networks using neuroimaging techniques during mind wandering.

Main Results:

• Undirected thought is not exclusively linked to a single brain system, contrary to some literature.
• The default mode network, executive system, and temporal lobe memory network are all significantly involved in undirected thought.
• Novel findings indicate positive functional connectivity between default and executive networks, and negative connectivity between the default network and primary sensory cortices during mind wandering.

Conclusions:

• The default and executive networks exhibit cooperative functional connectivity, supporting undirected thought processes.
• This cooperation occurs when primary sensory cortices are less engaged with external perceptual information.
• Future research should continue to integrate diverse methodologies, including introspective reports, to fully understand the neural basis of undirected thought.