Biology subjects

Neva, J. L.

Publications and source records attributed to Neva, J. L..

10 recordsLinked to original sources

bioRxiv2026

Dorsal and ventral premotor cortices differentially influence contralateral motor cortex excitability

Dorsal (PMd) and ventral (PMv) premotor cortices can modulate contralateral primary motor cortex (M1) excitability, but their distinct interhemispheric influence via transcranial magnetic stimulation (TMS) remains unclear. Single-pulse TMS over PMd, PMv and M1 assessed transcallosal inhibition via the ipsilateral silent period (iSP). Dual-site TMS examined short-(10 ms inter-stimulus interval [ISI]), long-(50 ms ISI) and non-callosal-(0 ms ISI) interhemispheric inhibition (IHI). An iSP was elicited from PMd, PMv, and M1, with distinctly evoked iSP parameters. The iSP magnitude was greatest from M1, followed by PMd and then PMv, while iSP duration was greatest for M1 and showed no differences between PMd and PMv. Dual-site TMS revealed that PMd and M1 inhibited contralateral M1 excitability across all ISIs, while PMv showed inhibition at 0-and 50-ms ISIs. PMd and M1 demonstrated greater short-IHI compared to PMv, all demonstrating similar long-IHI, and PMd demonstrating greater non-callosal-IHI than M1. PMv displayed distinct IHI across ISIs, PMd showed differences across most ISIs and M1 demonstrated the fewest differences across ISIs. Longer iSP duration related to greater long-IHI magnitude elicited from PMd and PMv. Our findings demonstrate differential IHI from PMd and PMv on contralateral M1, which may inform neuromodulation strategies in rehabilitation contexts.

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bioRxiv2025

Aerobic Exercise Intensity: A Dose-Response Effect on Motor Adaptation and Learning

Acute aerobic exercise (AEX) can enhance motor learning. While AEX intensity likely plays a key role, there is mixed evidence for AEX-enhanced motor skill acquisition and learning across a spectrum of exercise intensities. This may stem, in part, from inconsistent AEX parameters (i.e., intensity, structure, and duration) employed within and across studies. Additionally, evidence suggests that AEX can enhance a specific form of motor learning, namely motor adaptation. Moderate- and high-intensity AEX can increase motor adaptation, but evidence remains limited and inconsistent. Hence, the impact of AEX intensity on motor adaptation remains unclear. Here, we investigated the influence of AEX intensity on motor adaptation, while controlling for AEX structure and duration. Eighty young adults were assigned to four cycling AEX/Rest groups (n=20/group): 20 min of light (LIIT), moderate (MIIT), or high (HIIT) intensity interval training, or Rest (control). AEX consisted of four 3-min cycling intervals (LIIT, 35% heart rate reserve [HRR]; MIIT, 55%HRR; HIIT, 80%HRR) and 2-min active recovery (25%HRR). Participants practiced a visuomotor rotation task immediately after AEX/Rest (adaptation) and at a no-AEX 24 h retention test (motor learning). We found that: (1) all AEX intensities enhanced motor learning compared to Rest, and (2) HIIT enhanced motor adaptation and learning to the greatest extent, followed by MIIT then LIIT. This is the first study to demonstrate a dose-response effect of AEX intensity on motor adaptation and learning. Our results highlight the importance of considering intensity when prescribing AEX in sports and clinical contexts to promote motor learning.

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bioRxiv2025

Effects of experimentally induced fatigue on motor learning: A scoping review

The literature on the effect of fatigue on motor learning is limited and marked by inconsistent findings. This scoping review aimed to explore the available knowledge on the effects of fatigue induced by physical and cognitive exertion on motor learning, and to compile and understand how it is studied. A comprehensive search strategy using relevant index terms and keywords was conducted across MEDLINE, EMBASE, SPORTDiscus, Web of Science, PsycINFO, CINAHL, ERIC, and Dissertations & Theses Global. Twenty-five studies met the inclusion criteria. The findings revealed considerable inconsistencies in how fatigue and motor learning were defined and measured. None of the studies examined the effect of fatigue induced by combined physical and cognitive exertion, and only 7 studies investigated fatigue induced by cognitive exertion. Acuity tasks were the most frequently used to assess motor learning, employed in 14 studies. Notably, all participants were between 16.5 and 31 years of age, and reporting of key demographic and physiological characteristics such as sex, gender, physical activity level, and body mass index was inconsistent or absent. This review highlights the need for comprehensive definitions of both fatigue and motor learning to improve consistency and reproducibility across studies. Given the limited research on the effects of fatigue induced by cognitive and combined physical and cognitive exertion, future studies should prioritize using these experimental manipulations. Also, future studies should diversify the motor learning tasks used in research to allow both direct and conceptual replication. Additionally, broader age ranges and comprehensive participant profiling should be prioritized.

neuroscience↗

bioRxiv2025

Distinct Motor Cortex Interneuron Plasticity and Its Association with Prefrontal Brain Volume in Parkinson's Disease

Parkinsons disease (PD) is characterized by motor and cognitive deficits, including abnormal primary motor cortex (M1) excitability and diminished sensorimotor neuroplasticity. While paired associative stimulation (PAS) can induce M1 plasticity, people with PD (PwPD) demonstrate variability that cannot be accounted for by disease progression or medication status. Distinct M1 interneuron populations and attention-related brain structures may influence the reduced PAS- induced neuroplasticity. We aimed to characterize M1 interneuron plasticity in PwPD using attention-modulated PAS and identify neurostructural correlates. PwPD underwent MRI, then a PAS protocol with task-relevant attention. Transcranial magnetic stimulation (TMS) assessments of corticospinal excitability using posterior-to-anterior (PA) and anterior-to-posterior (AP) current directions were employed before and three post-PAS time-points. PAS induced distinct time- dependent M1 interneuron excitability changes. PA TMS showed increased corticospinal excitability at all post-PAS time-points; AP TMS increased only at 30 minutes. Rostral middle frontal gyrus volume uniquely explained variance in PA-sensitive M1 interneuron plasticity. In contrast, AP-sensitive plasticity was associated with baseline AP TMS excitability and age. These findings highlight that M1 interneuron circuits show unique neuroplasticity patterns in PwPD and relate to prefrontal brain volume. Our results suggest a complex interplay between motor and cognition-related deficits as interrelated pathophysiological features in PD.

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bioRxiv2025

Physical exercise and motor learning: A scoping review

Physical exercise can enhance motor learning by inducing neurophysiological changes that facilitate this process. This preregistered scoping review aimed to map current knowledge on the effects of physical exercise on motor learning. Experimental studies and review articles examining any form of physical exercise in healthy or clinical populations were included, with outcomes assessing motor skill acquisition and/or retention. A systematic search across eight databases (e.g., MEDLINE, EMBASE, PsychINFO) identified 66 sources, including 62 experimental studies and 4 reviews. Two researchers independently reviewed articles and extracted data using a pretested data extraction table; disagreements at the study selection or data extraction stages were resolved through discussion with a third researcher. Most studies involved healthy populations (83%), with clinical populations underrepresented (17%). Aerobic exercise was most commonly investigated, particularly lower-limb cycling (73%), while resistance exercise was rarely examined (0.6%). Exercise intensity was predominantly high, although 6% of studies reported intensity not reflecting the prescribed method. Motor learning outcomes varied: 55% assessed both skill acquisition and retention, while 45% relied on retention tests alone at short-term or delayed time points, or both. Infrequent use of long-term retention tests limits understanding of lasting effects. Overall, this review highlights gaps in the literature, including the underrepresentation of clinical populations, inconsistent reporting of exercise intensity, scarce research on resistance exercise, and limited assessment of long-term retention, which may affect interpretation of exercises impact on motor learning. HighlightsO_LIClinical populations were underrepresented in the exercise and motor learning field. C_LIO_LIHigh-intensity lower-limb cycling was the most common exercise studied. C_LIO_LIResistance exercise was underrepresented in the field. C_LIO_LIAccurate prescription of exercise intensity is essential to ensure reliable results. C_LIO_LIFuture research should more frequently use longer-term retention tests. C_LI

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bioRxiv2025

Eccentric cycling enhances primary motor cortex excitability

Acute aerobic exercise (AAE) can modulate primary motor cortex (M1) excitability. To date, studies evaluating its effects have focused almost exclusively on concentric cycling. Critically, we found that eccentric AAE enhances motor learning more than concentric AAE, possibly explained by enhanced frontal-parietal brain activation during eccentric cycling. Yet, M1 excitability mechanisms underlying this eccentric AAE-enhanced motor learning remain unknown. Thus, this study aimed to evaluate the effect of eccentric cycling AAE on M1 excitability using transcranial magnetic stimulation (TMS). Thirty adults performed three 20 min-conditions: i) eccentric cycling AAE, ii) concentric cycling AAE, and iii) rest. Cycling AAE was carried out at a workload corresponding to 70% of peak heart rate (%HRpeak) measured during concentric incremental cycling exercise. TMS assessments were conducted before (Pre), immediately (Post0) and 20 minutes after (Post20) AAE/rest to evaluate changes in corticospinal excitability (CSE) and short-interval intracortical inhibition (SICI). Overall, we found CSE increased and intracortical inhibition (SICI) was reduced at Post20 to a comparable extent following eccentric and concentric cycling AAE compared to rest. Also, %HRpeak, muscle pain and perceived effort were lower during eccentric cycling AAE compared to concentric cycling AAE. Our results showed that eccentric cycling impacted M1 excitability change to a comparable degree as concentric cycling, while requiring less cardiovascular response, eliciting less muscle pain and lower perceived effort. Taken together, our results suggest that eccentric cycling AAE may be a valuable intervention to modulate M1 excitability for populations with limited cardiovascular capacity and may have potential implications in clinical and sports-related contexts.

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bioRxiv2025

Eccentric cycling improves motor learning more than concentric cycling

An acute bout of aerobic exercise (AAE) performed before practicing a motor task can enhance skill acquisition and motor learning. To date, research on the effects of AAE on motor learning has focused exclusively on concentric cycling, leaving the impact of eccentric cycling unexplored. Unlike concentric cycling, eccentric cycling involves muscle lengthening while resisting the reverse movement of the pedals and is characterized by greater force production with lower cardiovascular and metabolic cost. Regarding neuroplasticity changes, eccentric contractions induced a prolonged decrease in intracortical inhibition compared to concentric contractions. Eccentric cycling AAE also increases activation in cognitive-related regions. Given the involvement of these regions and motor cortex excitability in motor learning, we hypothesized that eccentric cycling AAE would enhance motor learning to a greater extent than concentric AAE. A total of 60 young healthy individuals were allocated to one of three groups that performed 20 min of: i) eccentric cycling; ii) concentric cycling; or iii) seated rest. Both cycling AAE conditions were performed at a power equivalent to 70% peak heart rate (i.e., moderate intensity). A continuous tracking task was used to assess motor skill acquisition (immediately after the intervention) and motor learning (48 h retention test). For both acquisition and retention, the eccentric group outperformed both the concentric and rest groups, while the concentric group also showed a better performance compared to the rest group at retention. Thus, we demonstrated that eccentric cycling AAE enhances motor learning to a greater extent than concentric cycling AAE, while also confirming previous work that showed enhanced motor learning following concentric cycling AAE compared to rest. Our findings suggest that eccentric cycling AAE may have important implications for exercise protocols prescribed in sports-related and clinical contexts. HighlightsO_LIEccentric cycling enhanced motor learning to a greater extent than concentric cycling C_LIO_LIEccentric and concentric cycling enhanced motor learning more than rest C_LIO_LIEnhanced skill acquisition occurred after eccentric cycling, along with lower heart rate response and perceived effort. C_LIO_LIEccentric cycling may have important implications in sports-related and clinical contexts C_LI

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bioRxiv2023

Improved cognitive-motor processing speed and decreased functional connectivity after high intensity aerobic exercise in individuals with chronic stroke

After stroke, impaired motor performance is linked to an increased demand for cognitive resources. Aerobic exercise improves cognitive function in healthy populations and may be effective in altering cognitive function post-stroke. We sought to determine if high intensity aerobic exercise paired with motor training in individuals with chronic stroke alters cognitive-motor function and functional connectivity between the dorsolateral prefrontal cortex (DLPFC), a key region for cognitive-motor processes, and the sensorimotor network. Twenty-five participants with chronic stroke were randomly assigned to exercise (n = 14; 66 {+/-} 11 years; 4 females), or control (n = 11; 68 {+/-} 8 years; 2 females) groups. Both groups performed five-days of paretic upper limb motor training after either high intensity aerobic exercise (3 intervals of 3 minutes each, total exercise duration of 23-minutes) or watching a documentary (control). Resting-state fMRI, and TMT-A and B were recorded pre- and post-intervention. Both groups showed implicit motor sequence learning (p < .001), but there was no added benefit of exercise (p = .738). Regardless of group, the changes in task score (p = .025), and dwell time (p = .043) were correlated with a decrease in DLPFC-sensorimotor network functional connectivity (p = .024), which is thought to reflect a reduction in the cognitive demand and increased automaticity. The exercise group experienced greater overall cognitive-motor improvements measured with the trail making test part A (TMT-A: task score: p = .012; dwell time: p = .024; movement time: p = .567). Aerobic exercise may improve cognitive-motor processing speed post-stroke. Significance statementAfter stroke, impaired motor performance is linked to an increased demand for cognitive resources. In our work we show that high intensity aerobic exercise paired with an implicit motor learning task improves cognitive-motor processing speed and reduces resting-state functional connectivity between the dorsolateral prefrontal cortex and the sensorimotor network in individuals living with chronic stroke. These data likely reflect a reduction in cognitive resource dependence during a cognitive-motor task after stroke and a shift towards cognitive-motor automaticity.

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bioRxiv2021

Multiple bouts of high-intensity interval exercise reverse age-related functional connectivity disruptions without affecting motor learning in older adults

Exercise has emerged as an intervention that may mitigate age-related resting state functional connectivity and sensorimotor declines. Here, 42 healthy older adults rested or completed 3 sets of high-intensity interval exercise for a total of 23 minutes, then immediately practiced an implicit motor task with their non-dominant hand across five separate sessions. Participants completed resting stage functional MRI before the first and after the fifth day of practice; they also returned 24-hours and 35-days later to complete short- and long-term retention. Independent component analysis of resting state functional MRI revealed increased connectivity in the frontoparietal, the dorsal attentional, and cerebellar networks and group. seed-based analysis showed strengthened connectivity between the limbic system and right cerebellum, and between the right cerebellum and bilateral middle temporal gyri in the exercise group. There was no motor learning advantage for the exercise group. Our data suggest that exercise paired with an implicit motor learning task in older adults can augment resting state functional connectivity without enhancing behaviour beyond that stimulated by skilled motor practice. Impact statementFive separate bouts of exercise paired with skilled motor practice strengthens resting state networks in brain regions that are susceptible to declines in older adults without affecting motor acquisition or learning.

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bioRxiv2017

Reward and automatic processes in exercise behavior: A new approach and a systematic review

BackgroundIn a time of physical inactivity pandemic, attempts to better understand the factors underlying the regulation of exercise behavior is important. The dominant neuropsychological approach to exercise behavior explains physical activity as a reward. However, the opposite of physical exertion -- behaviors minimizing energy cost -- may also be a reward, which activates automatic reactions favoring the engagement in behaviors associated with lower energetic costs.\n\nObjectiveOur objective was to systematically review studies testing the automatic reactions triggered by stimuli associated with different types of exercise behavior (e.g., physical activity, sedentary behaviors) and energetic cost variations (e.g., behaviors minimizing energetic cost).\n\nMethodsTwo authors systematically searched, screened, extracted, and analyzed data from articles in the MEDLINE database.\n\nResultsWe included 26 studies. Three types of automatic processes were tested: Affective reactions, attentional capture, and approach tendencies. Results show that automatic reactions toward stimuli depicting exercise behaviors explained individuals level of physical activity. Brain imaging results show that stimuli associated with exercise behavior activate regions associated with reward, but these studies were scarce.\n\nConclusionReward is an important factor of exercise behavior. There is strong evidence showing that physical activity is a reward. While brain imaging results suggest that sedentary behaviors are also a reward, behaviors minimizing energetic cost have not been investigated so far. Additional studies are required to establish a strong and complete framework of reward in exercise behavior.\n\nKey points- Behavioral and brain imaging studies using different types of automatic behavior show that physical activity is a reward\n- Behaviors minimizing energetic cost have been essential to evolutionary survival and are likely to be a reward. However, experimental evidence remains scarce\n- The dominant neuropsychological approaches to exercise behavior may be incomplete, which may partly explain our current inability to counteract the pandemic of physical inactivity

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