David L. Wright

The field of motor learning faces a critical gap between foundational theory and real-world application. This editorial synthesizes expert discussions from the First Theoretical and Applied Advances in Motor Learning Conference to address key issues impeding further progress. We are hampered by the science of “averages,” characterized by an overreliance on data from homogenous, Western, educated, industrialized, rich, and democratic populations and a flawed assumption of cognitive uniformity. This approach masks critical individual differences, limiting the translational potential of our science and leading to one-size-fits-all enhancement strategies. We propose a multitiered roadmap for the maturation of our field. The foundational priorities are structural: embracing co-creation with diverse communities; moving beyond Western, Educated, Industrialized, Rich, and Democratic science; and implementing structured mentorship and active sponsorship to empower a new generation of scholars. Building on this, we advocate for technology-driven individualization like using advanced Mobile Brain/Body Imaging techniques for the development of neurophenotypes, to fulfill the potential of Brain–Computer Interfaces. Finally, we call for a precision-enhancement framework, shifting from “learning boosters” to a diagnostic-to-prescriptive model that targets specific, identified bottlenecks. This roadmap allows our field to build upon its foundational principles to create a more effective, accessible, and equitable motor learning science for all.

Dual-coil paired-pulse transcranial magnetic stimulation (ppTMS) has garnered interest for its potential in elucidating neural circuit dynamics. In this study, the dual-coil ppTMS was utilized to assess the effective connectivity between the supplementary motor complex (SMC) and the primary motor cortex (M1) in humans. A robust facilitatory connection between the SMC and M1 was observed, manifested as a 19% increase in mean peak-to-peak motor-evoked potentials following conditioning of SMC 7 ms prior to M1 stimulation. Importantly, the facilitatory influence of SMC was found in subjects who received conditioning stimulation 4 cm anterior to Cz, but not in those stimulated at 5 cm, 6 cm, or 7 cm. While previous work has focused on demonstrating important temporal dynamics for SMC-M1 plasticity, the present findings highlight a critical contribution of spatial specificity for the modulation of SMC-M1 circuitry.

In recent years, dual-coil paired-pulse transcranial magnetic stimulation (ppTMS) has garnered interest for its potential in elucidating neural circuit dynamics. In this study, the dual-coil ppTMS was utilized to assess the effective connectivity between the supplementary motor complex (SMC) and the primary motor cortex (M1) in humans. A robust facilitatory connection between the SMC and M1 was observed, manifested as a 19% increase in mean peak-to-peak motor-evoked potentials following preconditioning of SMC 7 ms prior to M1 stimulation. Importantly, the facilitatory influence of SMC only occurred when the preconditioning stimulation was administered 4 cm anterior to Cz but not when applied at 5-cm, 6-cm, or 7-cm distance. While previous work has focused on demonstrating important temporal dynamics for SMC-M1 plasticity, the present findings highlight a critical contribution of spatial specificity for modulation of SMC-M1 circuitry. Highlights The conditioned stimulus induced larger MEPs compared to the unconditioned stimulus The connectivity between SMC and M1 diminished when the SMC coil was moved forward Findings highlight the importance of spatial specificity for modulation of SMC-M1 circuitry

Caffeine is consumed in various beverages, such as coffee, energy drinks, soda, and tea. The effects of caffeine have been shown to manifest in various ways across different studies. Some studies suggest that caffeine can enhance motor performance. Despite this, numerous motor learning studies do not control for participants' caffeine intake or do not record whether participants consumed caffeine. The purpose of this study was to compare the motor learning performance (i.e., online improvement) of individuals who consumed caffeine and those who did not before practice with a novel motor sequence task. Sixty-five right-handed healthy undergraduate students participated in this study. Individuals reported their caffeine consumption through a pre-experiment questionnaire prior to performing an eight-item serial reaction time task. The participants who consumed caffeine reported drinking one cup of coffee on average 158.8 minutes before performing the sequential task. The motor performance of individuals who consumed caffeine was compared to those who did not, with the caffeine-consuming group (n = 13) exhibiting faster response times during online learning than the non-caffeine group (n = 52). The findings of this study suggest that caffeine should be controlled for in future motor learning research.

Drugs that modulate N-methyl-D-aspartate (NMDA) or γ-Aminobutyric acid type A (GABA _A ) receptors can shed light on their role in synaptic plasticity mechanisms underlying the effects of non-invasive brain stimulation. However, research on the combined effects of these drugs and exogenous stimulation on motor learning is limited. This study aimed to investigate the effects of pharmacological interventions combined with intermittent theta-burst stimulation (iTBS) on human motor learning. Nine right-handed healthy subjects (mean age ± SD: 31.56 ± 12.96 years; 6 females) participated in this double-blind crossover study. All participants were assigned to four drug conditions in a randomized order: (1) D-cycloserine (partial NMDA receptor agonist), (2) D-cycloserine + dextromethorphan (NMDA receptor agonist + antagonist), (3) lorazepam (GABA _A receptor agonist), and (4) placebo (identical microcrystalline cellulose capsule). After drug intake, participants practiced the 12-item keyboard sequential task as a baseline measure. Two hours after drug intake, iTBS was administered at the primary motor cortex. Following iTBS, the retention test was performed in the same manner as the baseline measure. Our findings revealed that lorazepam combined with iTBS impaired motor learning during the retention test. Future studies are still needed for a better understanding of the mechanisms through which TMS may influence human motor learning.

Primary motor cortex (M1) plays a major role in motor memory acquisition and retention in humans, but its role in interleaved practice (as opposed to repetitive practice) remains unknown. We anticipated that the improved retention typically associated with interleaved practice depends on M1, and thus cathodal transcranial direct current (ctDCS) stimulation to M1 during training would disrupt this improved retention. The benefits of interleaved practice have been reported to occur from more effective consolidation, manifested as rapid skill memory stabilization followed by more long-term enhancement. While we observed the expected decline in retention performance following interleaved practice paired with ctDCS, this reduced retention resulted from more modest encoding of novel skill memory during acquisition rather than from disruption of offline consolidation processes. These data highlight the broad role played by motor cortex for both encoding and retention of novel skill memory.

Posttraining meditation has been shown to promote wakeful memory stabilization of explicit motor sequence information in learners who are experienced meditators. We investigated the effect of single-session mindfulness meditation on wakeful and sleep-dependent forms of implicit motor memory consolidation in meditation naïve adults. Immediately after training with a target implicit motor sequence, participants (N = 20, eight females, 23.9 ± 3.3 years) completed either a 10-min mindfulness meditation (N = 10) or a control listening task before exposure to task interference induced by training with a novel implicit sequence. Target sequence performance was tested following 5-hr wakeful and 15-hr postsleep periods. Bayesian inference was applied to group comparisons of mean reaction time (RT) changes across training, interference, wakeful, and postsleep timepoints. Relative to control conditions, posttraining meditation reduced RT slowing between target sequence training and interference sequence introduction (BF₁₀ [Bayes factors] = 6.61) and supported RT performance gains over the wakeful period (BF₁₀ = 8.34). No group differences in postsleep RT performance were evident (BF₁₀ = 0.38). These findings illustrate that posttraining mindfulness meditation expedites wakeful, but not sleep-dependent, offline learning with implicit motor sequences. Previous meditation experience is not required to obtain wakeful consolidation gains from posttraining mindfulness meditation.

The C3 region in the international 10-20 system for electroencephalography (EEG) recording is assumed to represent the right motor hand area. Therefore, in the absence of transcranial magnetic stimulation (TMS) or a neuronavigational system, neuromodulation methods, such as transcranial direct current stimulation, target C3 or C4, based on the international 10-20 system, to influence the cortical excitability of the right and left hand, respectively. The purpose of this study is to compare the peak-to-peak motor evoked potential (MEP) amplitudes of the right first dorsal interosseus (FDI) muscle after single-pulse TMS at C3, C3h, and C1. Using an intensity of 110% of the resting motor threshold, 15 individual MEPs from each of C3, C3h, C1, and hotspots were randomly recorded from FDI for sixteen right-handed undergraduate students. Average MEPs were greatest at C3h and C1, with both being larger than those recorded at C3. These data are congruent with recent findings using topographic analysis of individual MRIs that revealed poor correspondence between C3/C4 and the respective hand knob. Implications for the use of scalp locations determined using the 10-20 system for localizing the hand area are highlighted. Highlights MEPs recorded at C3h and C1 were larger than those recorded at C3. Scalp locations other than C3 offer a more accurate estimation of human hand area.

Administering anodal tDCS at the primary motor cortex (M1) at various temporal loci relative to motor training is reported to affect subsequent performance gains. Stimulation administered in conjunction with motor training appears to offer the most robust benefit that emerges during offline epochs. This conclusion is made, however, based on between-experiment comparisons that involved varied methodologies. The present experiment addressed this shortcoming by administering the same 15-minute dose of anodal tDCS at M1 before, during, or after practice of a serial reaction time task (SRTT). It was anticipated that exogenous stimulation during practice with a novel SRTT would facilitate offline gains. Ninety participants were randomly assigned to one of four groups: tDCS before practice, tDCS during practice, tDCS after practice, or no tDCS. Each participant was exposed to 15 minutes of 2 mA of tDCS and motor training of an eight-element SRTT. The anode was placed at right M1 with the cathode at left M1, and the left hand was used to execute the SRTT. Test blocks were administered 1 and 24 hours after practice concluded. The results revealed significant offline gain for all conditions at the 1-hour and 24-hour test blocks. Importantly, exposure to anodal tDCS at M1 at any point before, during, or after motor training failed to change the trajectory of skill development as compared to the no stimulation control condition. These data add to the growing body of evidence questioning the efficacy of exogenous stimulation as an adjunct to motor training for fostering skill learning. Highlights Time-dependent consolidation of a novel motor skill occurred within 1 hour after the first practice block Further consolidation of this memory still occurred 24 hours after practice tDCS at M1 before, during, or after the initial bout of practice did not modify online or offline performance gains