Psychophysiology
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Randomized Controlled Trial
Relaxation training assisted by heart rate variability biofeedback: Implication for a military predeployment stress inoculation protocol.
Decreased heart rate variability (HRV) is associated with posttraumatic stress disorder (PTSD) and depression symptoms, but PTSD's effects on the autonomic stress response and the potential influence of HRV biofeedback in stress relaxation training on improving PTSD symptoms are not well understood. The objective of this study was to examine the impact of a predeployment stress inoculation training (PRESTINT) protocol on physiologic measures of HRV in a large sample of the military population randomly assigned to experimental HRV biofeedback-assisted relaxation training versus a control condition. ⋯ Autonomic reactivity was also found to be related to PTSD and self-reported use of mental health services. Future PRESTINT training could be appropriate for efficiently teaching self-help skills to reduce the psychological harm following trauma exposure by increasing the capacity for parasympathetically modulated reactions to stress and providing a coping tool (i.e., relaxation method) for use following a stressful situation.
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Randomized Controlled Trial
Stress following extinction learning leads to a context-dependent return of fear.
It has been suggested that extinction-based therapy benefits from administration of the stress hormone cortisol. However, it is unclear whether similar effects can be obtained by inducing stress instead of administering cortisol, and whether the effects also persist if memory is tested in a different context (renewal test) or after exposure to an aversive stimulus (reinstatement). The present study therefore applied a fear conditioning (context A, day 1) and extinction (context B, day 2) paradigm in healthy men. ⋯ Fear retrieval was tested in contexts A and B on day 3. Postextinction stress increased skin conductance responses to the extinguished stimulus in the retrieval and reinstatement test especially in the acquisition context. The context-dependent return of fear may reflect enhancing effects of stress on the consolidation of contextual cues.
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This study investigated responses to near-wins (i.e., nonwin outcomes that were close to a major win, and their counterpart, near-losses (nonwin outcomes that are proximal to a major loss) in a decision-making task, measuring (a) luck ratings, (b) adjustment of bet amount, and (c) facial muscle reactivity at zygomaticus and corrugator sites. Compared to full-misses, near-wins decreased self-perceived luck and near-losses increased self-perceived luck, consistent with the effects of upward versus downward counterfactual thinking, respectively. ⋯ There were no significant facial EMG effects of near-losses. We infer that near-wins engender some appetitive processing, despite their objective nonwin status.
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The P3b component of ERPs has been proposed to reflect decisions or, alternatively, activation of stimulus-response links or, alternatively, to depend on stimulus processing only. These three views make different predictions about how difficulty of response selection will affect the oddball effect. ⋯ Difficult response selection with rare targets was also reflected by a large frontocentral negativity, which could be separated from P3b when intervals were varied between targets and ancillary stimuli, and, therefore, did not cause P3b reduction. It is concluded that the usual increase of P3b with rare task-relevant targets depends on the existence of readily available stimulus-response links.
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Randomized Controlled Trial
Energized by love: thinking about romantic relationships increases positive affect and blood glucose levels.
We assessed the impact of thinking of a current romantic partner on acute blood glucose responses and positive affect over a short period of time. Participants in romantic relationships were randomly assigned to reflect on their partner, an opposite-sex friend, or their morning routine. ⋯ Reported positive affect following reflection was positively associated with increases in glucose, but only for individuals who reflected on their partner, suggesting this physiological response reflects eustress. These findings add to the literature on eustress in relationships and have implications for relationship processes.