Graphical and statistical techniques for cardiac cycle time (phase) dependent changes in interbeat interval: problems with the Jennings et al. (1991) proposals

Interactions between cardiac activity and conscious somatosensory perception

Fluctuations in the heart's activity can modulate the access of external stimuli to consciousness. The link between perceptual awareness and cardiac signals has been investigated mainly in the visual and auditory domain. Here, we investigated whether the phase of the cardiac cycle and the prestimulus heart rate influence conscious somatosensory perception. We also tested how conscious detection of somatosensory stimuli affects the heart rate. Electrocardiograms (ECG) of 33 healthy volunteers were recorded while applying near-threshold electrical pulses at a fixed intensity to the left index finger. Conscious detection was not uniformly distributed across the cardiac cycle but significantly higher in diastole than in systole. We found no evidence that the heart rate before a stimulus influenced its detection, but hits (correctly detected somatosensory stimuli) led to a more pronounced cardiac deceleration than misses. Our findings demonstrate interactions between cardiac activity and conscious somatosensory perception, which highlights the importance of internal bodily states for sensory processing beyond the auditory and visual domain.

Promise versus reality in relation to the unitary orienting reflex: A case study examining the role of theory in psychophysiology

We commonly teach beginning science students that theory generates hypotheses which direct our research, framing our experimental observations; and that in turn, these supply the data which support or contradict theory, allowing its self-correction and further development. These propositions are explored here in the context of psychophysiology, concentrating on examples in relation to the Orienting Reflex (OR). It is demonstrated that the realist approach generally portrayed in our teaching about theory and theory testing is not the dominant ethos in this field. Indeed, we pay little more than lip-service to the ideal we teach about. One outcome described here is that the promise offered us by the OR in the 1960s has not been realised. It is argued that this failure may be symptomatic of much of science, suggesting that we need to consciously work to raise the perceived value of theory. The ideation element of theoretical activity can be fostered, and it is argued that we need to do so explicitly at a number of levels in the education of our students, beginning in the early coursework stages and continuing in their research training and development.