Cuspis: A MATLAB Suite for Tasks Investigating Heart-Brain Interactions during fMRI

Abstract

Cuspis (Latin: [kuspis], meaning “sharp point”) is a MATLAB suite for presenting visual stimuli at different phases of the cardiac cycle and is designed to work with an MRI-compatible setup. Cuspis currently reads the electrocardiogram, detects the R-wave according to a user-defined threshold, and displays a visual stimulus with a specific stimulus onset asynchrony. To achieve this, Cuspis works in concert with the BIOPAC Hardware API [1] and Psychtoolbox [2, 3]. The software was developed for tasks investigating heart-brain interactions during functional Magnetic Resonance Imaging, but, in principle, it can be used with different imaging techniques (e.g., electroencephalography), in behavioural research, as well as to trigger stimuli contingent on other bodily rhythms (e.g., respiratory cycle).

Keywords

• interoception
• baroreceptor firing
• cardiac cycle manipulation
• ecg
• fmri
• heart-brain interactions
• bodily rhythms
• matlab
• psychtoolbox