title: Reduced pain inhibition is associated with reduced cognitive inhibition in healthy aging.
abstract: The analgesic effect of heterotopic noxious counter-stimulation (HNCS; "pain inhibits pain") has been shown to decrease in older persons, while some neuropsychological studies have suggested a reduction in cognitive inhibition with normal aging. Taken together, these findings may reflect a generalized reduction in inhibitory processes. The present study assessed whether the decline in the efficacy of pain inhibition processes is associated with decreased cognitive inhibition in older persons. Healthy young (18-46 years old; n=21) and older (56-75 years old; n=23) adult volunteers participated in one experimental session to assess the effect of HNCS (cold pain applied on the left forearm) on shock pain and RIII reflex induced by transcutaneous electrical stimulation of the right sural nerve. In the same session, participants also performed a modified Stroop task, including a target condition requiring the frequent switching between inhibition and no inhibition of the meaning of color words. The analgesic effect induced by HCNS was significantly smaller in older participants for both shock-pain ratings (P<0.001) and RIII-reflex amplitude (P<0.05). The Stroop effect was significantly larger in elderly participants in the inhibition trials of the switching condition. Increased cognitive interference (ie, larger Stroop effect) correlated with smaller inhibition of the RIII reflex by HNCS across groups (r=-.34, P=0.025). This association was independent from the age-related slowing observed in control reading and naming tasks. These results suggest a generalized age-related reduction in inhibitory processes affecting both executive functions and cerebrospinal processes involved in the regulation of pain-related responses induced by competing nociceptive threats.
authors.affiliation: Department of Neuroscience, Université de Montréal, Montréal, QC H3T 1J4, Canada Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Université de Montréal, Montreal, QC H3T 1J4, Canada Department of Stomatology, Université de Montréal, Montréal, QC H3T 1J4, Canada Department of Psychology, Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada PERFORM Centre and Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada Centre de recherche en neuropsychologie et cognition (CERNEC), Université de Montréal, Montréal, QC H3T 1J4, Canada Department of Chiropractic, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada Groupe de recherche sur le système nerveux central (GRSNC), Université de Montréal, Montréal, QC H3T 1J4, Canada.
authors.forename: Rafik
authors.initials: R
authors.lastname: Marouf
authors.forename: Stéphane
authors.initials: S
authors.lastname: Caron
authors.forename: Maxime
authors.initials: M
authors.lastname: Lussier
authors.forename: Louis
authors.initials: L
authors.lastname: Bherer
authors.forename: Mathieu
authors.initials: M
authors.lastname: Piché
authors.forename: Pierre
authors.initials: P
authors.lastname: Rainville
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology* / Q000523:psychology; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D010147:Pain Measurement / Q000379:methods*; D055815:Young Adult
keywords: Aging; Cognitive inhibition; DNIC; Pain; RIII reflex