[Show abstract][Hide abstract] ABSTRACT: The perception of visceral signals plays a crucial role in many theories of emotions. The present study was designed to investigate the relationship between interoceptive awareness and emotion-related brain activity. 44 participants (16 male, 28 female) first underwent a heartbeat perception task and then were categorised either as good (n = 22) or poor heartbeat perceivers (n = 22). A total of 60 different pictures (pleasant, unpleasant, neutral) from the International Affective Picture System served as emotional stimuli. EEG (61 electrodes) and EOG were recorded during slide presentation. After each slide, the subjects had to rate emotional valence and arousal on a 9-point self-report scale. Good heartbeat perceivers scored the emotional slides significantly more arousing than poor heartbeat perceivers; no differences were found in the emotional valence ratings. The visually evoked potentials of good and poor heartbeat perceivers showed significant differences in the P300 and in the slow-wave latency ranges. Statistical analyses revealed significantly higher P300 mean amplitudes for good heartbeat perceivers (averaged across all 60 slides) than for poor heartbeat perceivers. In the slow-wave range, this effect was found for affective slides only. Heartbeat perception scores correlated significantly and positively with both the mean arousal rating as well as with the mean amplitudes in the P300 time window and the slow-wave window. Our results demonstrate a strong relationship between the perception of cardiac signals and the cortical processing of emotional stimuli, as would be postulated for example by the James-Lange theory of emotions.
Full-text · Article · Jan 2006 · Cognitive Brain Research
[Show abstract][Hide abstract] ABSTRACT: Afferent signals from the body play an important role for emotional and motivational aspects of behavior. Nevertheless, little is known about the cortical and subcortical structures involved in interoceptive processes. Recently, a functional MRI study demonstrated that insula, somatomotor, and cingulated cortices are activated when subjects focus attention on their heartbeats. Aside from the use of imaging data, cardiac awareness has frequently been studied by using the heartbeat-evoked potential (HEP), a brain wave that appears contingent on the heartbeat. The present study aimed at localizing sources of the HEP. Multichannel EEG was recorded in 44 subjects while they performed a heartbeat perception task. This task was used to quantify interoceptive awareness and to subdivide the subjects into good and poor heartbeat perceivers. Analyses showed highest HEP amplitudes over frontal and frontocentral electrode locations in the time range of later than 200 ms after R-wave onset. By means of a BESA dipole-source-analysis, four sources of the HEP were identified which were located in the anterior cingulate, the right insula, the prefrontal cortex, and the left secondary somatosensory cortex. Good heartbeat perceivers showed both significantly higher HEP amplitudes and higher dipole strength than poor heartbeat perceivers in all four cortical sources. We conclude that the identified structures are involved in the processing of cardiac signals, whereby anterior cingulate and right insula seem to serve as interoceptive centers for cardioception.
Full-text · Article · Sep 2005 · Human Brain Mapping