From the heart to the brain: A study of heartbeat contingent scalp potentials

Abstract

Heartbeat perception has become the most widely studied example of visceral perception. In the present study scalp potentials contingent to the visceral event "heartbeat" were investigated. Scalp potentials, averaged time-locked to the EKG-R-wave, were studied at Fz, Cz, and Pz under four conditions: resting (baseline), heartbeat discrimination task, signal detection task, and heartbeat discrimination task after physical exercise. 22 subjects were assigned to the two groups "good" and "poor" perceivers, according to their performance in an initial heartbeat perception test. Event related potentials (ERPs) of "good" perceivers were more stable across conditions than those of "poor" perceivers. Peak latency within the range of 200 to 300 ms differed significantly between conditions. A principal component analysis performed on the ERP averages extracted five components. Subsequent ANOVAs across factor scores yielded significant main effects for the "groups" factor, experimental conditions and electrode sites. The strongest effects occurred over the frontal region in the latency range of 250-400 ms (following the EKG-R-wave). These were found to be not due to artifactual EKG influences.

A cortical potential reflecting cardiac function

“…Our work is predicated on studies describing afferent ''interoceptive'' potentials triggered on the heart (17)(18)(19)(20)29). However, in contrast to previous findings, our research represents a demonstration of cortically recorded indices of cardiac function in a clinical population.…”

“…These ECG measures were recorded as extra EEG channel data, referenced to linked ear electrodes, and preprocessed in an identical manner to EEG data. PQRS-T complexes in additional ECG leads were then identified in Matlab (Mathworks, Billerica, MA) using custom-written software, allowing 800-ms epochs (100 ms before ECG R wave to 700 ms after ECG R wave) (17) to be selected in SPM5. EEG dud electrodes were removed from averaged HEPs for each task condition and replaced with the average of four surrounding electrodes.…”

“…Electroencephalography (EEG) has higher temporal resolution than techniques such as positron emission tomography or functional MRI (fMRI), although is limited with respect to inferring neuroanatomical generators of surface potentials. EEG methods have been applied to the study of afferent cardiac signals, where a heartbeat-evoked potential (HEP) has been described (17)(18)(19)(20). The circumscribed location of this HEP to frontal and central scalp (17,18,21,22) and particularly the observation that its amplitude predicts individual differences in interoceptive awareness (accuracy of heartbeat perception) (19) is consistent with a cardiac afferent source, arising from myocardial, carotid sinus and/or aortic arch baroreceptors, or perhaps mechanoreceptors within tissue distended by ejected blood (23)(24)(25).…”

The neural subjective frame: from bodily signals to perceptual consciousness

“…In humans, the cortical processing associated with the afferent signals from the cardiovascular system can be studied by measuring the heart-evoked response (HER). The HER is an evoked potential to heartbeats, obtained by averaging electroencephalogram (EEG) activity locked to the main peak of the electrocardiogram (ECG; [38]; for review, see [39]). The HER is characterized by a broad frontal and frontocentral distribution.…”

Brain Responses to Cardiac Electrical Stimulation: A New EEG Method for Evaluating Cardiac Sensation

“…CEPs associated with cardiac sensation were first examined as heartbeat evoked potentials (HEPs) which are CEPs triggered by an R wave of the ECG and show a positive potential shift of about 250-600 ms after the R wave (Jones et al 1986;Schandry et al 1986;Montaya et al 1993;Dirlish et al 1997Dirlish et al , 1998Pollatos and Schandry 2004;Pollatos et al 2005;Gray et al 2007). HEPs are associated with cardiac sensation as evidenced by the fact that HEP amplitudes are greater in subjects with good heartbeat perception compared with those without it (Pollatos and Schandry 2004;Pollatos et al 2005).…”