Memory for pain: neural processing and cognitive intervention strategies

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Pain is a sensory and emotional experience that is important for learning, but, few studies have explored our ability to remember painful experiences as an objective in its own right. Understanding the mechanisms underlying memory for pain could help us understand and intervene in pain-related disorders. Some of these disorders, indeed, have been recently characterised as stemming from maladaptive pain.I am proposing a series of studies committed to this line of investigation. These studies will be guided by two main aims. The first is to investigate the neural processes involved inworking memory for pain (i.e. short-term storage of a pain memory). This will allow me to understand the early stages of pain memory consolidation-the process by which short-term memory is stabilised into long-term memory. Using psychophysical, electrophysiological and brain stimulation methods, I will investigate the neural mechanisms involved in holding pain in working memory, and the extent to which they overlap with working memory for non-painful touch. I will compare participants' performance on painful and non-painful stimulus discrimination tasks requiring them to hold one stimulus in memory and compare it with another, whilst transiently disrupting brain regions known to be involved in tactile working memory.My second aim is to use a well-grounded and rapidly advancing paradigm of memory research called reconsolidation interference to assess how we can interfere with associative pain memories that have already been stabilised into long-term memory. According to this theory, reactivation of a memory trace initiates a window of vulnerability to memory interference. Specifically, it may be possible to use a dual-load paradigm in which neural processes recruited by a cognitive/behavioural task interfere with those required to reconsolidate the memory, destabilising the memory trace. This offers a potential mechanism to erase maladaptive pain memories. To test this possibility, I will use transient, experimentally induced pain in healthy volunteers during a cue conditioning procedure. During a reactivation phase, participants will perform a working memory task that targets either sensory or emotional processing, since those two processes are fundamental to pain experiences. In the final phase, I will measure arousal responses to the visual cues previously paired with pain to determine whether the interference procedure was effective. These studies will determine whether sensory or emotional processing is more important for consolidating pain memories, and therefore more successful at interfering with their reconsolidation. Additionally, in the long term, I would like to apply the successful interventions to spontaneous clinical pain. This will provide insight into the nature of memory for pain in clinical pain samples and direct potential intervention strategies in these populations.The research I am proposing will contribute to our theoretical understanding of memory for pain. Importantly, it will show how working memory for pain differs from or overlaps with tactile working memory, and whether sensory or emotional representations of pain are more predominant in pain memories. In particular, it could shed light on the contributions of somatosensory pathways and affective brain networks to pain memories in conditions of persistent, non-resolving pain. Understanding these processes can provide insight into the nature of pain memory traces and why they may show resistance to erasure. Alongside significant theoretical contributions, my research would have important implications for pain-management strategies and non-pharmacological clinical interventions.