Chennai: Researchers during a recent study have found that reduced working memory ability and increased activity in the ventromedial prefrontal cortex are linked to higher pain intensity in daily life.
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 titled ‘Modeling neural and self-reported factors of affective distress in the relationship between pain and working memory in healthy individuals’, sought to address this gap in the literature.
The study was authored by recent University of Miami psychology PhD 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.
Brain imaging and self-report data from 416 HCP participants were analysed using structural equation modelling (SEM), a statistical technique for modelling complex relationships between multiple variables.
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.
‘We found that healthy participants with even low levels of reported pain had different levels of activity in the vmPFC during the n-back task compared to healthy participants who didn’t report pain. Surprisingly, this pattern of activity was more similar to patients with chronic pain than healthy patients who are exposed to pain manipulations in a laboratory’, said Witkin.
In contrast, the authors found that certain aspects of emotional distress reported by participants, such as anger, fear, and perceived stress, were not associated with working memory performance.
‘Studies looking at the relationship between pain and cognition have typically focused on patients with chronic pain or research participants given experimentally-induced pain’, noted Anderson.
‘Even though pain is a common experience for many people, we know surprisingly little about how the everyday experience of pain impacts cognition’, Anderson added.