The Relationship Between Neuroticism And The Pattern Of Cardiovascular Response To Acute Psychological Stress: The Effect Of Stress Type And Intensity

Neuroticism is a personality trait characterized by susceptibility to stress and a high risk predictor of cardiovascular disease.To investigate the relationship between neuroticism and acute stress cardiovascular response pattern is helpful to reveal the intermal physiological mechanism of neuroticism leading to cardiovascular diseases.However,previous studies have examined the relationship between neuroticism and the cardiovascular response to stress,ignoring the role of the nature(type and intensity)of the stress situation,and fail to connect the personality traits with the characteristics of the stress situation.Social stress(speech)and cognitive stress(mental arithmetic)are both high-demand stress types requiring individuals to mobilize their own resources to deal with,but neurotic personality is more sensitive to interpersonal social cues,so individuals with higher neuroticism scores may show different cardiovascular response pattern in social stress eompared with other types of stress.In addition,previous laboratory researches have mainly created low or moderate-intensity stress tasks,while in reality individuals may face more intense stress.Among the different types and different intensities of stressors,the relationship between neuroticism and cardiovascular response pattern is still unclear and needs to be explored.This study will help reveal the deep physiological mechanisms of neuroticism affecting stress health,enrich and improve the basic research of neurophysiology of personality,at the same time provide important guidance for clinical intervention and treatment,so as to promote and enhance the health level of individuals.In this study,two independent experiments were conducted to investigate the relationship between neuroticism and stress cardiovascular response pattern in social stress of different intensities(moderate and high intensity)and cognitive stress of different intensities(moderate and high intensity).Both experiments were carried out using a 2×3 mixed-factorial design,with stress intensity as a between-subject variable,experimental phase(baseline,stress period,recovery period)as a within-subject variable.Neurotic score of the Big Five Personality as a continuous independent variable,and cardiovascular(heart rate,systolic blood pressure,diastolic blood pressure)reactivity(the difference between the stress period value and the baseline value)and the recovery(the difference between the recovery period value and the baseline value)as dependent variables.Experiment 1 explored the relationship between neuroticism and cardiovascular response pattern in the social stress by adding negative feedback evaluation to the speech task to create moderate-and high-intensity social stress,and Experiment 2 explored the relationship between neuroticism and cardiovascular response pattern in the cognitive stress by manipulated the difficulty of mental arithmetic task to produce moderate,and high-intensity cognitive stress.In this study,correlation and hierarchical regression were used to analyze the relationship between neuroticism and cardiovascular response pattern(reactivity and recovery),and the results were as follows:(1)The results of Experiment 1 showed that after controlling for gender and age,neuroticism significantly negatively predicted systolic blood pressure reactivity and diastolic blood pressure reactivity in moderate-intensity social stress.When the corresponding cardiovascular reactivity was further controlled,neuroticism significantly positively predicted heart rate recovery,indicating that in moderate-intensity social stress,the higher the neurotic level of individual,the passivated the blood pressure reactivity,and the worse the heart rate recovery after stress(the greater the difference between the recovery period value and the baseline value,the worse the recovery).In high-intensity social stress,neuroticism significantly negatively predicted heart rate reactivity,systolic blood pressure reactivity,diastolic blood pressure reactivity,and significantly positively predicted heart rate recovery,systolic blood pressure recovery,and diastolic blood pressure recovery,displaying neuroticism was still associated with blunted stress cardiovascular reactivity and poor cardiovascular recovery in high-intensity social stress,but compared with moderate intensity,the correlation was stronger.(2)The results of Experiment 2 showed that after controlling for variables such as gender and age,no significant predictive effect of neuroticism on any indicator was found in moderate-intensity cognitive stress.In high-intensity cognitive stress,neuroticism significantly negatively predicted diastolic blood pressure reactivity,but had no predictive effect on recovery,suggesting that although neuroticism had no significant effect on stress cardiovascular response pattern in moderate-intensity cognitive stress,high neurotic level was still associated with blunted diastolic blood pressure reactivity in high-intensity cognitive stress.The above results indicate that regardless of the type and intensity of the stress situation,individuals with higher neuroticism scores always exhibit blunted cardiovascular reactivity to stress and poor cardiovascular recovery after stress.The cardiovascular response pattern of neuroticism that does not adjust with the changes in the demands of the stress situation,reflectes the lack of physiological flexibility of individuals with higher neuroticism scores in coping with environmental challenges,which may constitute the intrinsic mechanism for neuroticism to increase the risk of individual diseases.