Depersonalisation /Derealisation (DP/DR) has been an object of interest in clinical psychology for many years, with its exact causes still uncertain and debated. As part of a pilot study for a...Show moreDepersonalisation /Derealisation (DP/DR) has been an object of interest in clinical psychology for many years, with its exact causes still uncertain and debated. As part of a pilot study for a larger study, this paper attempts to integrate information from previous studies to link DP/DR to disrupted interoceptive processes, indicated through a disruption in the sense of presence in the real world and decreased heart rate variability (HRV). By using a virtual reality (VR) experience to induce an altered state of consciousness, data from questionnaires and electrocardiogram (ECG) measures were used to determine the relations between the sense of presence and HRV, depending on whether attention was directed, or the participant was allowed to fully immerse themselves in the experience. While no significant results were found, the limitation of a small sample size does not necessarily imply the rejection of the theoretical assumptions shaping the proposed hypothesis, and trends in the data may reflect the theoretical background.Show less
Worry and anxiety are associated with an increase in absolute heart rate, while heart rate variability decreases. Low heart rate variability is associated with an active anterior insula. A...Show moreWorry and anxiety are associated with an increase in absolute heart rate, while heart rate variability decreases. Low heart rate variability is associated with an active anterior insula. A hyperactive anterior insula is observed in individuals with anxiety disorders. However, it is not yet known whether a hyperactive anterior insula makes a person vulnerable to developing anxiety disorders or whether the anterior insula becomes hyperactive as a result of the disorder. Therefore, this study aims to investigate these associations in healthy participants. The following research questions were asked, "Is there a correlation between absolute heart rate and trait worry?" and "Is trait worry associated with low heart rate variability?" the same questions are posed in the context of anxiety. Finally, the question "Is trait anxiety associated with a hyperactive insula?" is asked. To examine this, data from the HADS, PSWQ, vectorcardiogram measures of heart rate and the heart rate variability, and the functional connectivity of the salience network from the 30 female participants were used. Results show no significant relationship between absolute heart rate, heart rate variability, and trait worry and anxiety in healthy participants. A significant relationship between the functional connectivity in the anterior insula and trait anxiety was found in our sample (r = .42, p = <.05). The effects of worry and anxiety on cardiac activity are mainly seen in clinically diagnosed individuals under an unpredictable and uncontrollable stressful environment. Our sample were healthy individuals, so symptoms were apparently not severe enough. The effects of trait anxiety are directly reflected in brain connectivity in the anterior insula observed in our analysis. The results can be applied to treatments reducing anxiety and worry.Show less
Research master thesis | Psychology (research) (MSc)
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Introduction: The default mode network (DMN) is a large intrinsic network in the brain, which seems to be affected in depressed patients. Also, aberrant heart rate variability (HRV) is often found...Show moreIntroduction: The default mode network (DMN) is a large intrinsic network in the brain, which seems to be affected in depressed patients. Also, aberrant heart rate variability (HRV) is often found in this population. Ketamine is thought to be a fast-acting antidepressant and has shown to have an effect on HRV and intrinsic brain connectivity. In this study, the effect of HRV on resting-state functional connectivity of the DMN and brain activity of areas within the DMN that were significantly correlated with HRV was examined. Also, it was investigated whether ketamine moderated this relationship. Method: Twelve healthy men received an intravenous ketamine or placebo infusion on two occasions. Resting-state functional connectivity and HRV were measured before, during, and after infusion. Dual-regression was used to obtain DMN connectivity scores, while a whole brain analysis was done to determine which brain areas were correlated with HRV. Raw digitized electrocardiogram (EKG), obtained with a pulse oximeter, was analyzed in order to extract HRV data. Multilevel analysis was used to determine the effect of HRV and ketamine on resting-state functional connectivity in the DMN and brain activity in the subgenual anterior cingulate cortex (sgACC), right dorsolateral prefrontal cortex (dlPFC), and the left postcentral gyrus. Results: DMN connectivity strength was negatively related to HRV, but positively related to activity of the right dlPFC and the left postcentral gyrus for the placebo condition. Ketamine was associated with a more profound effect of HRV on DMN connectivity and brain activity within the postcentral gyrus. Discussion: The present results complement recent studies that show that HRV is associated with connectivity strength in the DMN. Implications for the relevance of using ketamine in depressed patients are discussed. Initial increases of DMN connectivity are followed by a decrease in the DMN, which may be beneficial for depressed patients who generally show hyperconnectivity within the DMN. Results thus imply that ketamine has a moderating role in this.Show less
