Group-Level fMRI Analysis of Caffeine Effects: Data-Driven and Connectivity-Based Approaches

Motivation: Caffeine, a widely used psychoactive substance, affects brain function and physiology, including cognitive performance, heart rate, and respiration. Understanding its impact on brain networks during cognitive tasks and resting states is crucial for both cognitive neuroscience and clinical research. Goal(s): This study aims to investigate the effects of caffeine on brain activity during arithmetic tasks and resting states using fMRI. Approach: Group and subject-level ICA analyses were used to examine brain connectivity patterns. Results: Caffeine altered brain network dynamics, shifting the DMN and IPS regions across conditions. It increased frontal involvement in the DMN during rest and modified subject-specific connectivity. Impact: This study sheds light on how caffeine modulates brain networks, influencing both cognitive task performance and resting-state connectivity. These findings could help refine understanding of caffeine's neurophysiological effects and improve interpretations of brain activity in cognitive and physiological states.