Investigating Individual Differences in Acute Psychosocial Stress Reactivity and Evaluation of Wearable Devices for Heart Rate Variability Measurement

The stress response has been demonstrated to vary considerably between individuals, with maladaptive responses found to put people at increased risk for development of psychiatric disorders. The personality organisation of schizotypy and the rs1006737 (A/G) single nucleotide polymorphism within the CACNA1C genotype have been strongly implicated in mental health vulnerability. This research aimed to investigate the interaction between the gene variant and schizotypy with stress response and recovery, utilising physiological and self-report measures. The use of wearable devices to measure heart rate variability was introduced, keeping up with recent research. As the use of wearable devices is a recent development, a second study aimed to investigate the reliability of wearable devices for heart rate variability measurement, directly exploring the influence of movement. Salivary cortisol, heart rate variability, electrodermal activity and self-reported stress, anxiety and insecurity were recorded in 22 females during a laboratory based acute psychosocial stressor. In the second study, 12 participants completed a series of movements at varying levels of intensity whilst wearing the Empatica E4 and Polar H10. High level schizotypy individuals were found to report increased perceived stress both leading up to the experiment and at multiple points during it. In the second study, the Empatica E4 was consistently associated with increased movement artefacts, in a range of movement intensities. This study provides evidence for the influence of schizotypy on perceived and subjective stress on individuals. Results from the rs1006737 single nucleotide polymorphism suggested a potential influence of rs1006737 on cortisol release pattern, warranting future studies to further investigate this.