title: The influence of working memory capacity on experimental heat pain.
abstract: Pain processing and attention have a bidirectional interaction that depends upon one's relative ability to use limited-capacity resources. However, correlations between the size of limited-capacity resources and pain have not been evaluated. Working memory capacity, which is a cognitive resource, can be measured using the reading span task (RST). In this study, we hypothesized that an individual's potential working memory capacity and subjective pain intensity are related. To test this hypothesis, we evaluated 31 healthy participants' potential working memory capacity using the RST, and then applied continuous experimental heat stimulation using the listening span test (LST), which is a modified version of the RST. Subjective pain intensities were significantly lower during the challenging parts of the RST. The pain intensity under conditions where memorizing tasks were performed was compared with that under the control condition, and it showed a correlation with potential working memory capacity. These results indicate that working memory capacity reflects the ability to process information, including precise evaluations of changes in pain perception.
  
  
  CONCLUSIONS
  In this work, we present data suggesting that changes in subjective pain intensity are related, depending upon individual potential working memory capacities. Individual working memory capacity may be a phenotype that reflects sensitivity to changes in pain perception.
authors.affiliation: Department of Anesthesiology & Intensive Care, Osaka University Graduate School of Medicine, Osaka, Japan. Electronic address: anakae@anes.med.osaka-u.ac.jp.
authors.forename: Aya
authors.initials: A
authors.lastname: Nakae
authors.forename: Kaori
authors.initials: K
authors.lastname: Endo
authors.forename: Tomonori
authors.initials: T
authors.lastname: Adachi
authors.forename: Takashi
authors.initials: T
authors.lastname: Ikeda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hagihira
authors.forename: Takashi
authors.initials: T
authors.lastname: Mashimo
authors.forename: Mariko
authors.initials: M
authors.lastname: Osaka
mesh_terms: D000293:Adolescent; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007206:Individuality; D008297:Male; D008570:Memory, Short-Term; D009483:Neuropsychological Tests; D010146:Pain / Q000209:etiology / Q000523:psychology*; D010147:Pain Measurement / Q000523:psychology; D011597:Psychomotor Performance; D013696:Temperature; D055815:Young Adult
keywords: Working memory capacity; heat pain; individual difference; listening span test; reading span test