Background & Aims
The memory of past pain experiences impacts subsequent pain experiences. It has been recently suggested that chronic pain may be related to the inability to extinguish pain memories and difficulties in learning that pain is no longer associated with conditioned stimulus after lesion recovery. Cognition (e.g., working memory) and individual characteristics (e.g., anxiety) play a role in how patients encode and recall pain memories1. A thorough investigation is being done in the field of conditioned learning and factors influencing these processes2. Pain memory, however, remains understudied mainly due to the inherent challenges of confounding reciprocal influences of pain impacting cognitive resources and vice-versa, commonly altered in chronic pain patients.
This exploratory study aimed to investigate the cognitive and psychological factors contributing to the recall of an episode of induced pain in healthy individuals.
Methods
Healthy volunteers were invited to two laboratory visits. In the first session, participants completed a set of questionnaires concerning demographic and psychological characteristics – State-Trait Anxiety Inventory, Pain Catastrophizing Scale, and Life Orientation Test-R. Subsequently, they underwent the Cold Pressor Test (CPT), where they were requested to report pain on a 0-100 VAS every 30 seconds until during 4 minutes. After a two-week interval, participants were contacted via telephone to record their maximum memory for pain experienced during the CPT, using a 0-100NRS. Additionally, they were asked to predict expected pain for the upcoming session if the CPT was performed. Throughout the second visit, approximately 4-weeks after the initial visit, participants underwent neuropsychological assessment, including digit-span and California Verbal Learning test. The session finished with a repetition of the CPT task followed by the CVLT long-term evocation.
Results
Sixty-four healthy volunteers took part in the study. Significant differences were found between the maximum intensity of pain felt in the CPT and the recall of that pain. While pain sensitivity correlated with the scores on the anxiety, optimism, and catastrophizing questionnaires, the memory of pain correlated specifically with the results of the neuropsychological memory tests. There was a correlation between recall of the pain episode and reverse-order digit memory, suggesting that better recall of CPT was associated with poorer performance in working memory. Moreover, individuals with more accurate memory had better performance in retaining long-term information.
Conclusions
This exploratory study sheds light on the factors potentially influencing the ability to recall painful events, revealing associations between working and long-term memory and the accuracy of memory of a previous pain event, the Cold Pressor Test (CPT). Despite the significance of prior pain memories for future experiences, research on experimental-induced pain in non-clinical populations remains limited. Future investigations should delve deeper into the interplay between verbal memory skills and the recall of painful events.
References
1.Phelps CE, Navratilova E, Porreca F. Cognition in the Chronic Pain Experience: Preclinical Insights. Trends Cogn Sci. 2021;25(5):365-376. doi:10.1016/j.tics.2021.01.001
2.Colloca L, Akintola T, Haycock NR, et al. Prior Therapeutic Experiences, Not Expectation Ratings, Predict Placebo Effects: An Experimental Study in Chronic Pain and Healthy Participants. Psychother Psychosom. 2020;89(6):371-378. doi:10.1159/000507400
Presenting Author
Mariana Agostinho
Poster Authors
Mariana Agostinho
Master
University of Haifa & Universidade Católica Portuguesa
Lead Author
Miguel Réfega
Institute of Health Sciences, Universidade Católica Portuguesa
Lead Author
Duarte Santos
Institute of Health Sciences, Universidade Católica Portuguesa
Lead Author
Rita Canaipa
Centre for Interdisciplinary Health Research, ICS, Universidade Católica Portuguesa
Lead Author
Topics
- Mechanisms: Psychosocial and Biopsychosocial