The effect of local vs remote experimental pain on motor learning and sensorimotor integration using a complex typing task

Abstract

Recent work demonstrated that capsaicin-induced acute pain improved motor learning performance; however, baseline accuracy was very high, making it impossible to discern the impact of acute pain on motor learning and retention. In addition, the effects of the spatial location of capsaicin application were not explored. Two experiments were conducted to determine the interactive effects of acute pain vs control (experiment 1) and local vs remote acute pain (experiment 2) on motor learning and sensorimotor processing. For both experiments, somatosensory evoked potential (SEP) amplitudes and motor learning acquisition and retention (accuracy and response time) data were collected at baseline, after application, and after motor learning. Experiment 1: N11 (P < 0.05), N13 (P < 0.05), and N30 (P < 0.05) SEP peak amplitudes increased after motor learning in both groups, whereas the N20 SEP peak increased in the control group (P < 0.05). At baseline, the intervention group outperformed the control group in accuracy (P < 0.001). Response time improved after motor learning (P < 0.001) and at retention (P < 0.001). Experiment 2: The P25 SEP peak decreased in the local group after application of capsaicin cream (P < 0.01), whereas the N30 SEP peaks increased after motor learning in both groups (P < 0.05). Accuracy improved in the local group at retention (P < 0.005), and response time improved after motor learning (P < 0.005) and at retention (P < 0.001). This study suggests that acute pain may increase focal attention to the body part used in motor learning, contributing to our understanding of how the location of pain impacts somatosensory processing and the associated motor learning.

Interactive effect of acute pain and motor learning acquisition on sensorimotor integration and motor learning outcomes

“…Typically, motor deficits are regarded as a consequence of movement-related pain; however, there is evidence that pain affects motor control and has the ability to negatively influence the neuroplasticity associated with motor output (Bank et al 2013;Hodges and Tucker 2011;Mercier and Leonard 2011). While the presence of acute pain during motor learning may interfere with skill acquisition (Boudreau et al 2007;Flor 2003;Schweinhardt et al 2006), our recent studies (Dancey et al 2014(Dancey et al , 2016 demonstrated that motor learning acquisition improved in the presence of acute pain. A limitation of previous work (Andrew et al 2015;Dancey et al 2014Dancey et al , 2016 is that learning saturation occurred with these typing tasks as baseline accuracy was high.…”

“…While the presence of acute pain during motor learning may interfere with skill acquisition (Boudreau et al 2007;Flor 2003;Schweinhardt et al 2006), our recent studies (Dancey et al 2014(Dancey et al , 2016 demonstrated that motor learning acquisition improved in the presence of acute pain. A limitation of previous work (Andrew et al 2015;Dancey et al 2014Dancey et al , 2016 is that learning saturation occurred with these typing tasks as baseline accuracy was high. If the learning task difficulty is not high enough, differences between groups may not be observed and a type II error may be likely (Dancey et al 2014(Dancey et al , 2016.…”

“…A limitation of previous work (Andrew et al 2015;Dancey et al 2014Dancey et al , 2016 is that learning saturation occurred with these typing tasks as baseline accuracy was high. If the learning task difficulty is not high enough, differences between groups may not be observed and a type II error may be likely (Dancey et al 2014(Dancey et al , 2016. To address this we developed and validated a more difficult motor tracing task.…”

“…SEPs offer the highest temporal resolution available in noninvasive investigation (Walsh and Cowey 2000) and include peripheral (N9), spinal (N11, N13), subcortical (N18), and cortical (N20, P25, N24, N30) components for the upper limb. Recent work has found significant changes in spinal (N13) and cortical (N20, N24, P25, N30) SEP peaks after tracing (Andrew et al 2015) and typing (Dancey et al 2016) tasks. Studies using experimental muscle pain (Rossi et al 2003;Schabrun et al 2013) and acute cutaneous pain (Dancey et al 2016) have found decreases in early SEP amplitudes in healthy individuals.…”

Effect of Experimental Cutaneous Hand Pain on Corticospinal Excitability and Short Afferent Inhibition

“…It would be of interest in further studies to assess both pain-induced modulation in S1 excitability and SAI given the results of recent studies showing that a decrease in S1 excitability induced by non-invasive stimulation results in a reduction of the amount of SAI. At this stage, the impact of nociceptive stimuli on S1 excitability (as measured by the short latency components of somatosensory evoked potentials) remains unclear, especially for cutaneous nociceptive modalities [30,31,40,41,42,43,44,45]. One also needs to consider that the nociceptive modality and the location of the nociceptive stimuli with respect to the tested muscle might influence the results.…”