Within-Subject Correlation Analysis to Detect Functional Areas Associated With Response Inhibition

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Functional Magnetic Resonance Imaging (fMRI)

Background:

• Functional brain areas are often identified using across-subject correlation between behavior and brain activity.
• Within-subject correlation analysis examines cognitive fluctuations over shorter time scales within an individual.

Purpose of the Study:

• To apply within-subject correlation analysis to the stop-signal task to investigate response inhibition.
• To explore how brain activity related to response inhibition fluctuates within a single subject over time.

Main Methods:

• Within-subject correlation analysis was performed on fMRI data from the stop-signal task.
• Correlation between stop-signal reaction time (SSRT) and brain activity related to response inhibition was calculated across runs.
• Regions of interest (anterior cingulate cortex and cerebellum) were analyzed separately for earlier and later parts of the runs.

Main Results:

• Negative correlations between SSRT and brain activity were found in the anterior cingulate cortex and cerebellum.
• A dissociation pattern emerged: negative correlations predominated in earlier runs, while positive correlations were more common in later runs.
• The anterior cingulate cortex showed dominant negative correlation in earlier runs, unlike the cerebellum, suggesting run-by-run fluctuations in inhibitory mechanisms.

Conclusions:

• Within-subject analysis provides complementary insights to across-subject analysis in fMRI studies of response inhibition.
• Dynamic, run-by-run fluctuations in neural mechanisms underlying response inhibition can be detected using within-subject correlation.
• The findings suggest distinct, time-varying neural processes contribute to response inhibition.