Psychophysiology
-
Acoustic startle stimuli inhibit pain, but whether this is due to a cross-modal inhibitory process or some other mechanism is uncertain. To investigate this, electrical stimulation of the sural nerve either preceded or followed an acoustic startle stimulus (by 200 ms) or was presented alone in 30 healthy participants. Five electrical stimuli, five acoustic startle stimuli, 10 startle + electrical stimuli, and 10 electrical + startle stimuli were presented in mixed order at intervals of 30-60 s. ⋯ These findings suggest that acoustic startle stimuli transiently inhibit nociceptive processing and, conversely, that electrical stimuli inhibit subsequent auditory processing. These inhibitory effects do not seem to involve spinal gating as nociceptive flexion reflexes to the electric shock were unaffected by stimulus order. Thus, cross-modal interactions at convergence points in the brainstem or higher centers may inhibit responses to the second stimulus in a two-stimulus train.
-
Research links perfectionism, the tendency to hold and pursue unrealistically high standards, to negative mental health outcomes such as eating disorders, anxiety, and depression. Previous research used high frequency heart rate variability (HF-HRV) to measure recovery from stress during a mindfulness meditation in perfectionistic university students and found that only nonperfectionists demonstrated HF-HRV recovery from stress, suggesting that mindfulness was not effective for perfectionists. However, the mindfulness meditation did not incorporate a nonjudgment element, which may be a key component for perfectionists. ⋯ HR results suggest that both mindfulness conditions and "nothing" encouraged cardiovascular recovery, but that the mindfulness conditions showed even further recovery during the last five minutes of the meditations. HF-HRV results indicated that participants in the nonjudgment mindfulness condition had marginally higher HF-HRV during the last five minutes of the meditation than at baseline, while participants in the other conditions did not. Therefore, mindfulness with a focus on nonjudgment of emotions may be especially important to help perfectionists improve HF-HRV after failure.
-
Slow, deep breathing is being used as a self-management intervention for various health conditions including pain and hypertension. Stimulation of the arterial baroreceptors and increased vagal modulation are among the proposed mechanisms for the therapeutic effects of slow, deep breathing. We investigated whether adding inspiratory threshold load can enhance the cardiovascular responses to controlled breathing at the frequency of 0.1 Hz, a common form of slow, deep breathing. ⋯ These results suggest that applying small inspiratory threshold loads during controlled breathing at 0.1 Hz increases cardiac vagal modulation by this breathing exercise. This effect seems to be mediated by stronger stimulation of the arterial baroreceptors because of larger systolic blood pressure swings along the respiratory cycle. The potential benefit of long-term practice of controlled breathing at 0.1 Hz with inspiratory threshold loads on baroreflex function and cardiac vagal control needs to be investigated, particularly in pain and hypertension patients.
-
Extinction of conditioned fear serves as a laboratory model for the mechanism of action underlying exposure treatment with patients suffering from anxiety disorders. Thus, an enhanced understanding of individual differences in extinction learning may help to improve exposure procedures by tailoring treatment plans to the specific needs of the patient. Vagally mediated heart rate variability (vmHRV) is a promising candidate to investigate individual differences in extinction learning because vmHRV is influenced by an inhibitory prefrontal-amygdala network that is similarly implied in extinction learning. ⋯ In Study 1 (conditional discrimination task), we found that low vmHRV levels are associated with higher CS+ potentiation during instructed extinction. In Study 2 (differential cue conditional task), we observed an association between individual vmHRV levels and defensive responding during CS- presentations and, in later instructed extinction trials, during intertrial intervals. These findings indicate an overactive defensive system in individuals with low levels of vmHRV that interferes with their ability to recognize safety and thus is associated with a general perception of unsafety.
-
An individual's sense of personal responsibility is crucial for adaptive functioning in ever-changing social situations. This study investigated how the sense of personal responsibility affected the neural dynamics of anticipating one's own pain and another person's pain, using EEG. Participants played a cooperation game in which either the participant (self-context) or the confederate (other-context) received a mild electric shock whenever one of them erred. ⋯ When the shock was delivered to the participants, the P2 was smaller when there was no responsibility than when there was shared or full responsibility. When participants observed the painful facial expressions of the confederates, the P300 was not sensitive to responsibility level. Our results suggest that responsibility level modulates FRN and P300 in anticipation of pain experienced by both self and others, reflecting the attentional and affective experiences in both pain- and empathy-related processes.