Reverse BOLD Improves Efficiency for Brain Response to Faces

Christopher Glielmi¹, George A. James¹, Zhihao Li¹, Xiaoping Hu¹

Simultaneous electroencephalography (EEG) and fMRI are advantageous because they provide concurrent measures of neural electrical activity at high temporal resolution and hemodynamics at high spatial resolution. While EEG-only sessions can present trials every 1-3 seconds for efficient averaging, event-related fMRI typically requires much longer interstimulus intervals. We propose a new stimulation protocol in which long periods of trials are interleaved with missing trials, leading to a reverse BOLD response and increasing EEG trials per reversed BOLD trial. We confirm the integrity of the reverse BOLD response by comparing it to the regular BOLD response for visual processing of faces.