Poster A18, Saturday, March 24, 1:30–3:30 pm, Exhibit Hall C
A Cross-Correlation Analysis of the Relationship Between Central and Autonomic Nervous System Activity at Rest
Derek Spangler1, Jean Vettel1, Matthew Cieslak2, Barry Giesbrecht2, Scott Grafton2, Gold Okafor2, Viktoriya Babenko2, Javier Garcia1, Justin Brooks1; 1U.S. Army Research Laboratory, 2University of California, Santa Barbara
Bidirectional communication between the central and autonomic nervous system is critical to predominant theories of stress and emotion. However, empirical investigations of the extent to which the brain leads autonomic activity, and vice versa, are lacking. To this end, the current study monitored blood oxygen level dependent (BOLD) responses in 46 subjects (Mean age= 22.37, SD= 3.67) using functional magnetic resonance imaging (fMRI) while collecting impedance cardiography and electrocardiography during a 5-minute resting state. The electrocardiography and impedance signals were utilized to compute the root mean square of successive differences in interbeat intervals (RMSSD) and pre-ejection period (PEP) as metrics of cardiac parasympathetic and sympathetic control, respectively. Regions of interest in the fMRI data were pre-selected as members of the central autonomic network (e.g., amygdala, nucleus tractus solitarius, anterior cingulate cortex, insula) and the supplementary motor area (SMA). Autonomic and BOLD data were averaged in 30s windows and then cross-correlated to estimate the lead-lag relationships between brain and autonomic activity. Preliminary results reveal a biphasic cross-correlation structure consistent with BOLD and autonomic waveforms that oscillate at a similar frequency with a fixed phase delay. This oscillatory relationship occurs at low frequencies (< 0.1 Hz), which is consistent with previously defined functional modulations in the default mode network. These findings are interpreted in the light of bidirectional feedback loops between the brain and body that serve to maintain autonomic balance and homeostasis.
Topic Area: EMOTION & SOCIAL: Other