Mental imagery-induced attention modulates pain perception and cortical excitability

Abstract

BackgroundMental imagery is a powerful method of altering brain activity and behavioral outcomes, such as performance of cognition and motor skills. Further, attention and distraction can modulate pain-related neuronal networks and the perception of pain. This exploratory study examined the effects of mental imagery-induced attention on pressure pain threshold and cortical plasticity using transcranial magnetic stimulation (TMS). This blinded, randomized, and parallel-design trial comprised 30 healthy right-handed male subjects. Exploratory statistical analyses were performed using ANOVA and t-tests for pain and TMS assessments. Pearson’s correlation was used to analyze the association between changes in pain threshold and cortical excitability.ResultsIn the analysis of pain outcomes, there was no significant interaction effect on pain between group versus time. In an exploratory analysis, we only observed a significant effect of group for the targeted left hand (ANOVA with pain threshold as the dependent variable and time and group as independent variables). Although there was only a within-group effect of mental imagery on pain, further analyses showed a significant positive correlation of changes in pain threshold and cortical excitability (motor-evoked potentials via TMS).ConclusionsMental imagery has a minor effect on pain modulation in healthy subjects. Its effects appear to differ compared with chronic pain, leading to a small decrease in pain threshold. Assessments of cortical excitability confirmed that these effects are related to the modulation of pain-related cortical circuits. These exploratory findings suggest that neuronal plasticity is influenced by pain and that the mental imagery effects on pain depend on the state of central sensitization.

Online and Offline Performance Gains Following Motor Imagery Practice: A Comprehensive Review of Behavioral and Neuroimaging Studies

“…In this vein, recent approaches attempted to evaluate a priori the clinical efficacy of MIP (and their neurophysiological basis) from data measured in healthy participants. Particularly, Volz et al ( 2015 ) studied whether a single session of MIP (20 min of finger-to-thumb oppositions) decreased the pain threshold evoked by thenar pressure (see Einsiedel et al, 2011 ; Frenkel et al, 2014 for a similar approach in a clinical model of joint immobilization). The authors measured reduced pain threshold in the MIP group, but not in control subjects.…”

Cognitive effects of transcranial direct current stimulation combined with working memory training in fibromyalgia: a randomized clinical trial

“…Fibromyalgia (FM) is a chronic pain condition with 2 to 5% prevalence in general population, being more frequent in women 1 , 2 . It comprises widespread chronic pain, fatigue, depression, anxiety, disrupted sleep and other somatic complaints, as well as impaired cognition 3 . In general, the most frequent complains related to cognitive aspects include a poorer recall, difficulty with concentration and attention.…”

Distraction by a cognitive task has a higher impact on electrophysiological measures compared with conditioned pain modulation

“…Although CPM has been extensively studied both in animals 16,17 and humans using psychophysiological and electrophysiological methods [18][19][20][21][22][23][24] , it is still under debate whether the pain reduction during CS results solely from the descending noxious inhibitory pathways. Pain modulation can be achieved also by cognitive factors like attention and distraction [25][26][27] . Postsurgical pain is reported as more intense when patients are attending to it 28 ; in contrast, listening to music [29][30][31] , therapeutic play interventions 32 and animal-assisted treatments 33 for children can reduce postoperative pain intensity, presumably by distraction.…”