Behavioral assessments of the aversive quality of pain in animals

Animals and humans share similar mechanisms of pain detection and similar brain areas involved in pain processing.Also,they show similar pain behaviors,such as reflexed sensation to nociceptive stimuli.Pain is often described in sensory discrimination （algosity） and affective motivation （unpleasantness） dimensions.Both basic and clinical findings indicate that individuals with chronic pain usually suffer more from pain-associated affective disturbances than from the actual pain sensations per se.Although the neural systems responsible for the sensory component of pain have been studied extensively,the neural mechanisms underlying negative affective component are not well understood.This is partly due to the relative paucity of animal paradigms for reliable examination of each component of pain.In humans,the experience of pain and suffering can be reported by language,while in animals,pain can only be inferred through physical and behavioral reactions.Animal behaviors,cognitive psychology and functional brain imaging have made it possible to assess pain affection and pain memory in animals.Animals subjected to either neuropathic injury or inflammatory insult display significant conditioned place aversion to a pain-paired environment in behaviors.The present review aims to summarize the common methods of affective unpleasantness assessment in rats.

Paying less but harvesting more:the effect of unconscious acceptance in regulating frustrating emotion

Previous studies indicate that emotion regulation may occur unconsciously, without the cost of cognitive effort, while conscious acceptance may enhance negative experiences despite having potential long-term health benefits. Thus, it is important to overcome this weakness to boost the efficacy of the acceptance strategy in negative emotion regulation. As unconscious regulation occurs with little cost of cognitive resources, the current study hypothesizes that unconscious acceptance regulates the emotional consequence of negative events more effectively than does conscious acceptance. Subjects were randomly assigned to conscious acceptance, unconscious acceptance and no-regulation conditions. A frustrating arithmetic task was used to induce negative emotion. Emotional experiences were assessed on the Positive Affect and Negative Affect Scale while emotion-related physiological activation was assessed by heart-rate reactivity. Results showed that conscious acceptance had a significant negative affective consequence, which was absent during unconscious acceptance. That is, unconscious acceptance was linked with little reduction of positive affect during the experience of frustration, while this reduction was prominent in the control and conscious acceptance groups. Instructed, conscious acceptance resulted in a greater reduction of positive affect than found for the control group. In addition, both conscious and unconscious acceptance strategies significantly decreased emotion-related heart-rate activity(to a similar extent) in comparison with the control condition. Moreover, heart-rate reactivity was positively correlated with negative affect and negatively correlated with positive affect during the frustration phase relative to the baseline phase, in both the control and unconscious acceptance groups. Thus, unconscious acceptance not only reduces emotion-related physiological activity but also better protects mood stability compared with conscious acceptance. This suggests that the clinical practice of acceptance therapy may need to consider using the unconscious priming of an accepting attitude, instead of intentionally instructing people to implement such a strategy, to boost the efficacy of acceptance in emotion regulation.

Subjective well-being and mortality among the older people in China

The present study investigates the effects of subjective well-being(SWB)on mortality risk using a large sample from the Chinese Longitudinal Healthy Longevity Study conducted in 1998,2000,2002,2005,2008,2011 and 2014.SWB is measured by life satisfaction,positive affect and negative affect.We found that positive affect,negative affect,life satisfaction and the change of life satisfaction significantly have predicted mortality risks of the older people with control of social demographic characteristics,physical health,social support,cognitive ability,and social participation.The higher the positive affect,the lower the negative affect,the improvement the life satisfaction,the lower the mortality risk.Marital status plays a decisive role in the influence of life satisfaction on the mortality risk.The married persons have lower mortality risk even if they rate their life bad.In further analyses,we found that the effects of SWB on mortality risk were underestimated in short-term study compared with those in long-term study.SWB is essentially a time-dependent variable and changes with age,so treating SWB as time-independent variable underestimated its impact on mortality risk.