Intact pain modulation through manipulation of controllability and expectations in aging.

Abstract

Pain expectation and controllability can modulate pain processing. However, little is known about age-related effects on these cognitive factors involved in pain control. This study assessed age-related brain changes associated with pain expectation and controllability. 17 healthy older adults (9 men; 65.65±4.34years) and 18 healthy younger adults (8 men; 20.56±5.56years) participated in the study. Pain evoked potentials and pain ratings were recorded while participants received painful electrical stimuli under two different conditions of pain controllability over the intensity of the stimulation (self-controlled vs. computer controlled) and two conditions of pain expectations (high vs. low pain). Although the intensity of the painful stimulation was kept constant, all participants showed reduced pain perception in the controllable and low pain expectancy conditions. However, older participants showed reduced amplitudes of pain evoked potentials in the time window between 150 and 500ms after stimulus onset as compared to younger participants. Moreover, younger participants showed greater negative amplitudes from 80 to 150ms after stimulus onset for uncontrollable versus controllable pain. These results suggest that although cognitive pain modulation is preserved during ageing, neural processing of pain is reduced in older adults. This research describes the impact of age on cognitive pain modulation evoked by the manipulation of pain controllability and pain expectations. Our findings constitute a first step in the understanding of the greater vulnerability of older individuals to chronic pain. Moreover, we show that older adults can benefit from cognitive pain control mechanisms to increase the efficacy of pain treatments.