Abstract:

Increasing evidence shows that pain interacts with inhibition function, and this relationship may be an important reason for the development of chronic pain. However, the cognitive mechanism of the interaction between pain and inhibition function remains unclear. This study attempts to clarify how pain affects inhibition function and how inhibition function regulates pain. Pain significantly activates the dorsolateral prefrontal cortex (DLPFC). The structure and function of the DLPFC change with the development and healing of pain, and the DLPFC plays an important role in the pain farther down the inhibition system. At the same time, the DLPFC is also a key brain area that reflects inhibition function. The overlap of pain and inhibition function in the DLPFC provides physiological evidence for the interaction between pain and inhibition function. Both laboratory pain and chronic pain damages the inhibition function. As a prominent sensory stimulus threatening human survival, pain will automatically induce the individual's self-defence mechanism to control pain from top to bottom. Inhibition is also a top-down control of conflicting information and superior response. According to the theory of cognitive resources, the control of pain will occupy the cognitive resources of the inhibition function and impair the inhibition function. However, the pain-influencing inhibition function is not unidirectional. In turn, inhibition function can predict the incidence of chronic pain and regulate the pain experience. Although the relationship between inhibition function and pain sensitivity is controversial, in the study of distracted analgesia, inhibition function was significantly positively correlated with the performance of distracted tasks, showing consistency across studies. The performance profile of distracted tasks reflects the degree of pain interference by individuals, and individuals with high inhibition function are less affected by pain than individuals with low inhibition function. For individuals with low inhibition function, pain brings more interference and increases the individual’s pain fear and pain catastrophe. This process updates the psychological meaning of pain to the individual and further increases the individual’s negative expectations for the next occurrence of pain. Conversely, individuals with high inhibition function reduce their negative expectations for the next occurrence of pain. The daily activities of patients with chronic pain are interrupted long-term by pain, and the patients' stronger inhibition function helps to reduce pain interference and negative expectations of pain. When patients have more positive expectations than negative expectations for pain relief, the effect of pain treatment is significantly increased. Unfortunately, research on the effect of inhibition function on pain is mainly based on a relevant design, because inhibition function as a personal characteristic is difficult to control in the laboratory. Future research should use more longitudinal designs and methods to control inhibition function (short-term cognitive training) to further clarify the causal relationship between inhibition function and the pain experience. Pain can impair inhibition function, and poor inhibition function is not conducive to pain relief. The interaction between pain and inhibition function highlights the importance and urgency of inhibition function in the treatment of pain by psychological factors. Especially for elderly individuals with poor inhibition function and patients with mild chronic pain, early inhibition function intervention can help reverse the development of chronic pain. According to the existing research results, in-depth exploration of the cognitive mechanism of the interaction between pain and inhibition function is conducive to perfecting the related theories of pain psychobehavioural therapy and further guiding the inhibition function to target pain.

Key words: pain, chronic pain, inhibition function, DLPFC