Prefrontal cortical activation associated with prospective memory while walking around a real-world street...

Area of Science:

• Cognitive Neuroscience
• Neuroimaging

Background:

• Rostral prefrontal cortex (area 10) activation is frequently observed in prospective memory (PM) tasks.
• The precise mental processes indexed by this activation remain unclear, with theories suggesting environmental monitoring, spontaneous intention retrieval, or a combination.

Purpose of the Study:

• To differentiate between cognitive neuroscience theories of rostral PFC function during PM.
• To investigate the spatial and temporal patterns of prefrontal cortex activation in naturalistic settings.

Main Methods:

• Utilized portable functional near-infrared spectroscopy (fNIRS) to record brain activity in 19 participants performing a PM task in a real-world urban environment.
• Participants responded to social and non-social PM cues while navigating a street.
• Employed a GLM-based method (AIDE) to identify functional events and map their spatial distribution relative to participant location.

Main Results:

• Widespread activation in medial and right hemisphere rostral prefrontal cortex (BA 10) was associated with maintaining both social and non-social intentions.
• Lateral prefrontal cortex (BA 45 and 46) showed increased activation during social intention maintenance compared to non-social.
• Functional events aggregated spatially and temporally around intention retrieval and execution points, with BA 10 showing the highest frequency of events during PM conditions.

Conclusions:

• Mobile fNIRS is a viable tool for studying higher cognitive functions of the prefrontal cortex in real-world, ambulatory settings.
• The "brain-first" approach allows linking hemodynamic changes to specific locations and behaviors, aiding the understanding of brain-cognition links.
• Findings support a role for rostral PFC in integrating intention retrieval and execution within naturalistic environments.