Acute Stress

The purpose of this study is to evaluate the acute psychological and physiological effects of a single-session structured horticultural therapy program on patients undergoing routine hemodialysis. The study is designed as a two-arm, parallel, pretest-posttest randomized controlled trial conducted at Bingöl State Hospital. Participants are randomized (1:1) to either an experimental group receiving a 45-60 minute individual horticultural therapy session (e.g., planting and caring for Tagetes erecta, Celosia cristata, and Petunia grandiflora) or a control group maintaining standard waiting conditions for the same duration during non-dialysis days. Primary outcomes evaluate acute changes in state anxiety (measured via STAI-1) and physiological stress response (measured via salivary cortisol concentration) before and immediately after the intervention.

This study aims to investigate neurophysiological, autonomic, and subjective responses to different acute physical and emotional stress-inducing conditions using a within-subject repeated-measures design. Participants will complete four experimental conditions: a resting-state baseline, a Cold Pressor Test, a negative autobiographical memory recall task, and an affective picture-viewing task using stimuli selected from the Nencki Affective Picture System (NAPS). The order of the experimental stress conditions will be randomized or counterbalanced to minimize potential order and carry-over effects. Electroencephalographic (EEG) and autonomic activity will be recorded throughout the experimental session. Autonomic measures will include heart rate (HR), heart rate variability (HRV), electrodermal activity (EDA), and skin conductance responses (SCR). Subjective levels of stress, anxiety, and pain will be assessed using visual analogue scales (VAS). Participants will also complete validated psychological measures assessing resilience, perceived stress, and state and trait anxiety, together with the Tower of London task as a behavioral measure of executive planning. The primary objective is to characterize the modulation of EEG alpha-band activity during acute physical stress, with the main comparison focusing on the Cold Pressor Test relative to resting-state baseline. Secondary and exploratory objectives include comparing cortical, autonomic, and subjective responses across experimental conditions and investigating whether individual psychological characteristics and executive functioning are associated with differences in psychophysiological stress responses.

The goal of this study is to find out whether an open-label placebo nasal spray can reduce stress among individuals engaging in a high-stress canyon swing. The main questions the study aims to answer are: 1) Does an open-label placebo increase likelihood of participants completing another jump? 2) Does the placebo affect how long it takes participants to jump, reduce the reported stress levels before the jump 3) Does the placebo change how enjoyable participants find the jump? Researchers will compare participants who receive an open-label placebo nasal spray (a spray that contains no active medication and is clearly described as a placebo) with participants who receive no treatment (control). The aim is to see whether the placebo nasal spray can increase likelihood of participants completing another jump, reduce reported stress and improve participants overall enjoyment of the jump. Participants will: * Complete a short questionnaire before they jump * Either self administer a placebo nasal spray (one spray in each nostril) right before stepping through the gate to jump, or receive no treatment (control). * Complete a short questionnaire after completing the jump * Whether they complete another jump will be noted