The Impact of Chronic Musculoskeletal Pain on Traditional and Modified Pain Stroop Task Performance in Older Adults

Abstract

Aging studies that have employed the Stroop Color and Word Test have identified several factors that influence the effect of age on inhibitory control, cognitive facilitation, and selective attention. An understudied factor that may influence, and further qualify, this relationship is chronic musculoskeletal pain. Therefore, the purpose of this study was to determine how chronic musculoskeletal pain impacts traditional and modified pain Stroop performance in older adults with chronic pain. Participants completed a computerized traditional and modified pain Stroop task. A series of mixed ANOVAs were used to compare reaction times, accuracy rates, interference scores, and facilitation scores between ‘Younger Adults without Chronic Pain' (n = 19), ‘Older Adults without Chronic Pain (n = 23), and ‘Older Adults with Chronic Pain' (n = 36) for each Stroop condition. A mediation analysis using the product-of-the-coefficients method with bootstrapping (5,000 samples) was also run to assess the indirect effect of aging on Stroop performance through the mediator of pain severity. (Preacher & Hayes, 2004; Preacher et al., 2007). No differences were found between older adults with and without chronic pain for any Stroop performance measure. On average, the ‘Younger Adults without Chronic Pain' had significantly faster reaction times than both older adult groups for the traditional and modified pain Stroop tasks (p < 0.001). Pain severity partially mediated the relationship between aging and traditional Stroop congruent condition reaction time and fully mediated the relationship between aging and traditional Stroop interference and facilitation. Mild levels of chronic pain were not enough to elicit differences in inhibitory control, cognitive facilitation, or selective attention between older adults with and without chronic pain. Pain severity, however, mediates the relationship between age and traditional Stroop performance, which suggests cognitive declines associated with chronic pain may contribute to age-related differences in Stroop performance. Grant support from NIA grants K01AG048259, R01AG059809, R01AG067757 to YCA; University of Florida Claude D. Pepper Center (P30AG028740) to YCA.