Physiological Factors Linking Insecure Attachment to Psychopathology: A Systematic Review

Although many studies have documented associations between insecure attachment and psychopathology, attachment may not confer risk for psychopathology independently, but rather through its interaction with emotional, social, and biological factors. Understanding the variables through which attachment may lead to psychopathology is therefore important. Within this domain of research, the role of physiological factors is poorly investigated. What are the relevant domains and why, when, or for whom do they influence mental disorders relating to attachment? The current systematic review aims to answer these questions. Results reveal that physiological indices of emotional regulation play a role in explaining and/or determining the relationship between attachment and psychopathology. Specifically: (1) combined with insecure attachment, higher skin conductance level (SCL), lower cardiac slowing, and respiratory sinus arrhythmia modulation (RSA) contribute to different psychopathological indicators and behavioral/psychological dysfunctions, although the latter predicts a contradictory pattern of findings; (2) insecure-avoidant attachment is more consistently linked with stress and emotional dysregulation when combined with RSA, while anxious attachment confers risk of depressive symptoms when combined with SCL. We concluded our discussion of the results of seven studies by outlining a plan to move the field forward. We discuss the quality of the assessment, methodological limitations, and future directions, highlighting the need to extend the research to clinical samples.

Enhanced cardiac vagal tone in mental fatigue: Analysis of heart rate variability in Time-on-Task, recovery, and reactivity

Heart Rate Variability (HRV) has been suggested as a useful tool to assess fatigue-sensitive psychological operations. The present study uses a between and within-subject design with a cognitively demanding task and a documentary viewing condition, to examine the temporal profile of HRV during reactivity, Time-on-Task (ToT), and recovery. In the cognitive task group, participants worked on a bimodal 2-back task with a game-like character (the Gatekeeper task) for about 1.5 hours, followed by a 12-minute break, and a post-break block of performance (about 18 min). In the other group, participants watched documentaries. We hypothesized an increasing vagal-mediated HRV as a function of Time spent on the Gatekeeper task and no HRV change in the documentary viewing group. We also analyzed the trial-based post-response cardiac activity as a physiological associate of task-related motivation. Relative to the documentary-viewing, ToT was associated with an elevated level of subjective fatigue, decreased heart rate, and increased HRV, particularly in the vagal-mediated components. Based on fatigued participants’ post-error cardiac slowing, and post-error reaction time analyses, we found no evidence for motivation deficits. The present findings suggest that the parasympathetic branch of the autonomous nervous system functioning as a relaxation system tends to be activated under increasing mental fatigue. In addition, the study shows that many HRV indices also seem to change when individuals are engaged in a prolonged, less fatiguing activity (e.g. documentary viewing). This finding emphasizes the relevance of comparisons/control conditions in ToT experiments.

Low Physiological Arousal in Mental Fatigue: Analysis of Heart Rate Variability during Time-on-task, Recovery, and Reactivity

Heart Rate Variability (HRV) has been suggested as a useful tool to assess fatigue-sensitive psychological operations. The present study uses between and within-subject design to examine the temporal profile of HRV including the changes related to reactivity, time-on-task (ToT), and recovery on a cognitively demanding task. In the fatigue group, participants worked on a bimodal 2-back task with a game-like character (the gatekeeper task) for about 1.5 hours, followed by a 12-minute break, and a post-break block of performance (about 18 min). In the control group, participants watched documentaries. We hypothesized that mental fatigue is associated with low physiological arousal and increasing vagal-mediated HRV as a function of ToT. We also analysed the trial-based post-response cardiac activity as a physiological indicator of task-related motivation. Relative to the control, ToT was associated with an elevated level of subjective fatigue, decreased heart rate, and increased HRV most robustly in the vagal-mediated components. Based on fatigued participants’ post-error cardiac slowing, and post-error reaction time analyses, we found no evidence for motivation deficit in association with increasing HRV and ToT. The present findings support the low arousal state of mental fatigue and suggest that primarily the vagal components of the HRV spectrum are indicative of fatigue. In addition, the study provides evidence that many HRV indices might be changed not only in a fatiguing condition but also if individuals are engaged in a prolonged non-fatiguing activity. This finding emphasizes the relevance of control conditions in ToT experiments.

Cardiac and Electrophysiological Responses to Valid and Invalid Feedback in a Time-Estimation Task

This study investigated the cardiac and electrophysiological responses to feedback in a time-estimation task in which feedback-validity was manipulated. Participants across a wide age range had to produce 1 s intervals followed by positive and negative feedback that was valid or invalid (i.e., related or unrelated to the preceding time estimate). Performance results showed that they processed the information provided by the feedback. Negative feedback was associated with a transient cardiac slowing only when feedback was valid. Correct adjustments after valid negative feedback were associated with a more pronounced cardiac slowing. Validity did not affect the feedback-related negativity (FRN), except when remedial action was taken into account. The FRN and cardiac response to feedback decreased with advancing age, but performance did not. The current pattern of findings was interpreted to suggest that the FRN and cardiac response signal “alert” and that the cardiac response, but not the FRN, is implicated in the mechanisms invoked in remedial action.