Photo Credit: Alexey Yaremenko
The following is a summary of “How the magnitude and precision of pain predictions shape pain experiences,” published in the December 2024 issue of Pain by Derksen et al.
Bayesian models, including predictive processing, suggest that the magnitude and precision of pain expectancies were the essential factors in pain perception, but few studies have directly tested this, with inconclusive results.
Researchers conducted a retrospective study to examine the effects of expectancy on pain experiences and related affective responses.
They performed 2 studies with healthy participants (n = 30 in each). In Study 1, painful electrical stimuli were administered with varying pain predictions and intensities. In Study 2, the magnitude and precision of pain predictions were altered, while pain intensity remained constant. The primary outcome in both studies was the intensity of pain experienced.
The results showed that pain experiences tended to align with both under- and overpredictions of pain. In Study 1, effects were minimal, if present, for non-painful stimuli, and larger predictions did not necessarily lead to greater effects. In Study 2, pain experiences were assimilated regardless of prediction precision, and no significant effects on electromyography (EMG) eyeblink startle responses were found. Additionally, underpredictions led to disappointment and overpredictions to relief, with precise predictions causing more disappointment than imprecise ones.
Investigators concluded the impact of pain predictions on actual pain experiences was more intricate than anticipated by existing theoretical models, with no consistent pattern of pain experiences aligning perfectly with more accurate predictions.
Source: onlinelibrary.wiley.com/doi/full/10.1002/ejp.4769
