Physiological Explicit Of Delayed Psychological Stress Response Induced By Extra Neural Regulation

Acute stress may lead to a series of cardiovascular diseases and has become a serious issue in our daily lives.Stressors can be divided into exteroceptive stimuli and interoceptive stimuli,which corresponding to acute physical stress and acute psychological stress,respectively.Neurological studies have shown that acute psychological stress is conducted along a different neural pathway from acute physical stress in the human body.In particular,there exists a conduction delay during the psychological stress response.This conduction delay is reflected in the central nervous system(CNS)as an evaluation process that allows the body to respond optimally to stressors based on previous experience.However,how this conduction delay is manifested in the autonomic nervous system(ANS)and heart rate variability(HRV)remains to be studied.In this thesis,Cold stress test(CPT)and Stroop color test(SCWT)were used as acute physical and psychological stressors.ECG of twenty-six subjects under two kinds of stress and baseline stages were collected and the original ECG data was pre-processed using wavelet transform,followed by R-peak detection.Then nine HRV time domain,frequency domain and nonlinear features were extracted and a feature dimensional reduction was performed.Finally,the variation of the features after dimensional reduction was analyzed.The results show that due to the delayed conduction of psychological stress response,the variation in HRV features under psychological stress has a delayed and enhanced performance compared with acute physical stress.In particular,the HRV features began to change significantly in the later stage of psychological stress,and these features have a linear variation during the later stage of psychological stress.In addition,during the later stage of stress,four HRV features can distinguish between baseline and acute psychological stress,but these features do not have significant differences during acute physical stress.