How Age and Acute Stress Affect Cognitive Modulation of Pain by Attention

Distraction from pain via cognitive engagement is known as an effective pain modulation strategy. While inhibition of pain relies on the prefrontal cortex, a structure that is affected by age, little is known how cognitive distraction from pain is influenced by age and age-related cognitive decline. In addition, age has been shown to alter the stress response, which itself is assumed to have a negative impact on cognitive modulation of pain.
To investigate the impact of age and acute stress on distraction from pain, healthy young and older participants (60+ years) underwent the Trier Social Stress Test (TSST) and a respective control condition in a two-session design. Before and afterwards, they performed a pain distraction task, a n-Back working memory task with low and high cognitive load, during which participants received individually adjusted transdermal electrical pulse trains in non-painful and moderately painful intensities to the inner forearm. Participants rated them regarding their intensity and unpleasantness. Pain-related evoked potentials were recorded with a 64-channel EEG and saliva was collected for cortisol analysis.
Preliminary behavioral and electrophysiological results revealed a pain relief by distraction irrespectively of the cognitive load and age. While older and younger participants were equally stressed by the TSST, showing similar elevated cortisol levels, young participants tend to be more affected by acute stress in their pain-relief than older participants.
The findings suggest that healthy older adults showing only a mild age-appropriate cognitive decline benefit from psychological strategies to reduce pain and acute stress does not diminish its efficacy.