Determining the latency between spontaneous respiration fluctuations and BOLD signal changes
Bandettini P, Smith M, Birn R
National Institute of Mental Health
The blood oxygenation level dependent (BOLD) fMRI signal is influenced by spontaneous fluctuations in respiration during rest, yet the latency between respiration changes and BOLD changes has not been fully characterized. The goal of this study is to measure the magnitude and latency of BOLD signal changes due to variations in respiration at rest. These are compared to measurements from a hypercapnic stress. Signal changes to variations in respirations were found to be delayed by ~9 seconds relative to measured respiration changes. Amplitudes and latencies of these BOLD changes during rest were spatially correlated with changes from a hypercapnic stress.