Pain experienced in everyday life may impact one’s memory

Anew study has found that higher pain intensity is linked to reductions in working memory ability and increased activity in the ventromedial prefrontal cortex.

The findings of the study were published in the journal ‘Neuropsychologia’.

Prior research suggested that pain-related impairments in working memory depend on an individual’s level of emotional distress. Yet the specific brain and psychological factors underlying the role of emotional distress in contributing to this relationship are not well understood.

However, this study suggested that healthy individuals in pain also show deficits in working memory or the cognitive process of holding and manipulating information over short periods of time.

The study was authored by recent University of Miami psychology Ph.D. graduate students Steven Anderson, Joanna Witkin, and Taylor Bolt and their advisors Elizabeth Losin, director of the Social and Cultural Neuroscience Laboratory at the University of Miami; Maria Llabre, professor and associate chair of the Department of Psychology; and Claire Ashton-James, senior lecturer at the University of Sydney.

The study used publicly available brain imaging and self-report data from the Human Connectome Project (HCP), a large-scale project sponsored by the National Institutes of Health (NIH) which aims to construct a map of the complete structural and functional connections in the healthy human brain.

In the 228 participants who reported experiencing some level of pain in the seven days prior to the study, the authors found that higher pain intensity was directly associated with worse performance a commonly used test of working memory, the nback task. In the n-back task, participants are shown a series of letters and asked whether the letter they are seeing appeared on some number of screens previously. The more screens back in the sequence participants are asked to recall, the more working memory is required.

In addition, the authors found that higher pain intensity was indirectly associated with worse working memory performance through increased activity in a particular region in the center of the frontal cortex during the n-back task, the ventromedial prefrontal cortex (vmPFC). The vmPFC is a brain region involved in pain, affective distress, and cognition. Interestingly, the relationship between everyday pain and vmPFC brain activity in this study is similar to prior findings in patients with chronic pain.