Datensatz

Zusammenfassung

Introduction: Internal bodily states influence perceptual, affective and cognitive processes. Our group has recently provided evidence that the detection of somatosensory near-threshold stimuli increases during the late phase of the cardiac cycle (diastole). In the present study, we aim to confirm the increase in detection of somatosensory stimuli during diastole and to determine if this enhanced detection goes along with improved “objective” performance of stimulus localization. Furthermore, we investigate the neural correlates of differential somatosensory perception during the cardiac cycle in the EEG. Methods: 40 healthy volunteers (21 female), (age: 27±4 years) were tested in the experiment. Participants expected an electrical stimulus on the index or the middle finger of their left hand in every trial. After stimulation, they performed a “Yes/No Detection” and a “Two Alternative Forced Choice Localization” task. Meanwhile, ECG and EEG data were recorded from participants. R peaks and T wave ends were detected in the ECG data. Circular and binary analysis relative to cardiac phase were done. Results: We found that near-threshold electrical stimuli are more likely to be detected at later phases of the cardiac cycle whereas they are more likely to be missed at earlier phases. Even though somatosensory detection varies across cardiac cycle, somatosensory localization is not altered. These variations of somatosensory perception during the cardiac cycle go along with differences in ERPs. Discussion: The cardiac cycle has an effect on the yes/no detection performance which contains a subjective bias. However, it does not influence the 2AFC localization performance which is subjective- bias free. ERPs may be able to reflect this “dissociation of subjective versus objective performance” across the cardiac cycle.