Extensive sensorimotor training enhances nociceptive cortical responses in healthy individuals

Association Between Interoceptive Accuracy and Pain Perception: Insights From Trained Musicians and Athletes

BACKGROUND

The integration of concurrent endogenous and exogenous multisensory information throughout years of dedicated sensorimotor training is associated with enhanced interoceptive accuracy and altered pain perception in healthy individuals. However, this relationship remains inconclusive, with outcomes varying by training modality and pain stimulus. This study examines associations between distinct forms of sensorimotor training, interoception and pain perception.

METHODS

Two groups of individuals performing extensive sensorimotor training, 17 musicians and 15 athletes, and 14 non-musicians/athletes were recruited. Participants completed a cardiac interoceptive accuracy (IAcc) task and quantitative sensory tests, including mechanical and electrical detection thresholds (MDTs and EDTs), pressure and heat pain thresholds (PPTs and HPTs), as well as music-related perceptual discrimination and self-reported physical activity assessments.

RESULTS

Results revealed superior IAcc and PPTs in athletes compared to controls. Musicians exhibited increased heat pain sensitivity. While IAcc in musicians did not reach significance, training duration significantly predicted IAcc across both groups. PPTs correlated positively with both IAcc and accumulated training, but mediation analyses revealed that training effects on PPTs occurred independently of IAcc, suggesting distinct pathways for interoception and pain modulation. Additionally, physical activity levels correlated positively with both IAcc and PPTs across participants.

CONCLUSIONS

These findings support the emerging view that individuals engaging in sensorimotor training routines, which require embodied multisensory integration for optimal performance, enhance interoceptive accuracy. They also confirm that pain processing varies by training modality. Furthermore, they suggest that the type of acute pain stimulus may explain inconsistencies in the interoception-pain relationship in healthy populations.

SIGNIFICANCE STATEMENT

This study advances our understanding of the interoception-pain-training nexus by revealing two distinct pathways: one linking sensorimotor training, interoceptive accuracy and pressure pain perception and another showing that accumulated sensorimotor training independently elevates pain thresholds. By differentiating between pain modalities, the findings contribute to resolving previous contradictory results, refine our insights into interoception in healthy populations and inform about potential clinical interventions.

Mild hypohydration in healthy older adults increases pain-related brain activity without affecting pain perception: a single-blind study

Understanding how hydration status influences pain perception is particularly important in older adults, as both dehydration and pain are prevalent in this population. Ten individuals (70 ± 4 yr) completed two randomized and counterbalanced trials. They were exposed to passive heat until they lost 1% body mass through sweat and urine (∼100 min), with the loss either unreplaced (sham infusion, HYPO) or fully replaced via 0.45% saline infusion (EUH). Nociceptive electrical stimulation was applied to the sural nerve 1) before heat exposure (baseline), 2) 60 min following hydration manipulation (R60, ∼160 min after baseline), 3) after mouth rinsing with water (MR, ∼170 min after baseline), and 4) following water ingestion (ING, ∼185 min after baseline). Pain-related event-related potentials were assessed using electroencephalography (EEG) at R60, MR, and ING. After hydration manipulation, body mass loss and plasma osmolality were greater, and plasma volumes were lower in HYPO than in EUH, although thirst did not differ between the conditions. There were no differences between the two conditions regarding pain intensity and unpleasantness. Still, EEG analyses revealed that the peak-to-peak amplitude of the pain-related N200-P300 potential (∼136-310 ms) was significantly greater in HYPO than in EUH (P = 0.036) and significantly greater in R60 compared with both MR (P = 0.01) and ING (P = 0.03), either with HYPO and EUH. These results suggest that mild hypohydration in healthy older adults may influence some neurophysiological processes related to nociception without significantly affecting pain perception.NEW & NOTEWORTHY This study reveals, for the first time, that mild hypohydration equivalent to ∼1% of body mass does not alter pain perception in healthy older adults when they are blinded to their hydration status, despite electroencephalography signals showing modulation of pain-related brain responses.

Impact of Chronic Pain on Use-Dependent Plasticity: Corticomotor Excitability and Motor Representation in Musicians With and Without Pain

Long-term musical training induces adaptive changes in the functional representation of the motor cortex. It is unknown if the maladaptive plasticity associated with chronic pain, frequently affecting trained musicians, may alter the use-dependent plasticity in the motor cortex. This study investigated the interaction between adaptive and maladaptive plasticity in the motor pathways, in particular how chronic pain influences long-term use-dependent plasticity. Using transcranial magnetic stimulation (TMS), corticospinal excitability was assessed by measuring the amplitude of the motor-evoked potential (MEP), area of the motor map, volume, and center of gravity of the first dorsal interosseous muscle in 19 pain-free musicians, 17 upper limb/neck pain chronic pain musicians, and 19 pain-free non-musicians as controls. Motor map volume and MEP amplitude were smaller for both pain-free and chronic pain musicians compared to pain-free controls (P < 0.011). No significant differences were found between musicians with and without chronic pain. These findings confirm that long-term musical training can lead to focalized and specialized functional organization of the primary motor cortex. Moreover, the adaptive use-dependent plasticity acquired through fine-motor skill acquisition is not significantly compromised by the maladaptive plasticity typically associated with chronic pain, highlighting the potential of long-term sensorimotor training to counteract the effects of chronic pain in the motor system.

The relationship between musicianship and pain. Is chronic pain and its management a problem for student musicians only?

Introduction

The neuro-biological side of chronic pain research has presented reliable evidence of distinct cortical and spinal alteration compared to healthy individuals. Furthermore, research suggests that musicians are especially vulnerable to pain, and recent neurological investigations into musicians' brain plasticity support this hypothesis. However, chronic pain is not acute pain plus time, but a separate condition, and little is known about musicians' chronic pain-related emotions and behaviors. This knowledge, however, is a crucial step in understanding how chronic pain is processed by musicians.

Methods

This study investigated pain catastrophizing as a critical pain-related behavior and emotional concept alongside six complementary variables: anxiety, depression, depersonalisation, burnout, coping strategies and professional identity.

Results

103 under- and postgraduate students from various higher education institutions participated in an online survey. Students were allocated into three groups according to their main study subject and type of institution: music college musicians, university musicians and university non-musicians. A tree model confirmed the current chronic pain multifactorial model, suggesting a combination of several variables before catastrophizing pain. Group testing, however, showed that university non-musicians' pain catastrophizing was significantly worse especially when compared to music college musicians. Music college musicians and university musicians were less prone to maladaptive pain processes, despite perceiving pain for significantly longer.

Discussion

This novel finding indicates that chronic pain does not inevitably lead to dysfunctional pain processing for musicians and should be reflected accordingly to optimize pain-control. The biopsychosocio model of chronic pain provides a robust framework for future research in this population.