Background & Aims

The impact of pain on cognition can be studied with the cognitive-branching task1,2, a working memory and selective attention task that requires a participant to hold their place in a primary sequence in mind while performing a secondary sequence to later return to the primary sequence. Using this task, we previously demonstrated that pain impacts performance in a value-based manner, affecting low-reward trials ($0.05/correct response), but not the high-reward trials ($1/correct response). Given that the priority of tasks depends on perceived value1, we aimed to determine whether task priority could be modulated based on different monetary value of task trials—i.e., does the value of the trial determine the extent of pain interference on task performance. We hypothesized that there would be a parametric relationship between task performance and monetary value attributed to trials. We further explored whether there were sex differences in this relationship.

Methods

In an interim analysis of reward modulation of the cognitive-branching task, the value of the low-reward secondary sequence trials was increased parametrically, given that pain interferes with performance selectively on these trials. Values pseudorandomly changed between low ($0.05), mid ($0.50), and high ($1) reward per correct response. Thirty participants performed the task at baseline (without sensory stimulation). Next, participants repeated the task while experiencing a tonic chemical-heat pain (elicited with the capsaicin-heat pain model3). To control for learning effects, an independent cohort of thirty participants performed the same experiment without any stimulation to test whether task performance in the absence of a noxious stimulus was affected by the reward levels of the secondary sequence trials. Reaction times and error rates were analyzed using linear mixed models within each group along with sex disaggregated analyses in each group. Significance was set at p<0.05.

Results

In this interim analysis, 30 healthy participants (15 female) performed faster while experiencing pain across all task trials compared to baseline (p<0.05), unlike previous findings. Parametrically increasing the value of the low-reward trials while experiencing pain did not significantly improve performance (p>0.05): more errors were made when the trials were worth a high reward and this effect was observed in males but not females (p<0.05). The independent cohort also performed faster over time and more errors were made when low-reward trials were worth a high reward in both males and females (p<0.05).

Conclusions

While the interference of pain on cognitive task performance is not modulated by increases in monetary task reward, our findings provide insight on sex differences influencing pain-cognition interactions.

References

  1. Charron, S. & Koechlin, E. Divided representation of concurrent goals in the human frontal lobes. Science (80-. ). (2010)
  2. Nee, D. E. & D’Esposito, M. The hierarchical organization of the lateral prefrontal cortex. Elife (2016)
  3. Furman, A. J. et al. Cerebral peak alpha frequency predicts individual differences in pain sensitivity. Neuroimage (2018)

Presenting Author

Georgia Hadjis

Poster Authors

Georgia Hadjis

BSc

University of Toronto

Lead Author

Topics

  • Models: Acute Pain