Methamphetamine Modulates Functional Connectivity Signatures of Sustained Attention and Arousal.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychopharmacology

Background:

• Previous studies indicate psychostimulants enhance sustained attention by altering brain functional connectivity.
• The specific effects of methamphetamine (MA) on attention networks in healthy adults require further investigation.

Purpose of the Study:

• To investigate how a single 20 mg dose of methamphetamine (MA) affects sustained attention and associated large-scale brain network organization in healthy adults.
• To determine if MA selectively impacts behavioral and functional magnetic resonance imaging (fMRI) connectivity signatures of sustained attention and arousal.

Main Methods:

• A within-subject design was employed with 76 healthy participants undergoing two fMRI scanning sessions.
• Participants received either MA (20 mg) or a placebo in a counterbalanced order.
• Behavioral performance on a sustained attention task and fMRI connectivity were assessed under both conditions.

Main Results:

• Methamphetamine administration led to improved sustained attention task performance.
• MA enhanced functional connectivity patterns associated with heightened sustained attention and arousal.
• These network changes were observed consistently in both resting-state and task-based fMRI, indicating MA's broad influence on attention- and arousal-related networks.

Conclusions:

• Methamphetamine modulates sustained attention and large-scale brain networks involved in attention and arousal, consistent with findings for other psychostimulants.
• The study underscores the value of psychostimulants like MA as tools for understanding brain-behavior relationships and validating brain-based biomarkers.