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1.
Exp Brain Res ; 242(4): 921-935, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38329516

RESUMO

In rapid manual aiming, traditional wisdom would have it that two components manifest from feedback-based processes, where error accumulated within the primary submovement can be corrected within the secondary submovement courtesy of online sensory feedback. In some aiming contexts, there are more type 1 submovements (overshooting) compared to types 2 and 3 submovements (undershooting), particularly for more rapid movements. These particular submovements have also been attributed to a mechanical artefact involving movement termination and stabilisation. Hence, the goal of our study was to more closely examine the function of type 1 submovements by revisiting some of our previous datasets. We categorised these submovements according to whether the secondary submovement moved the limb closer (functional), or not (non-functional), to the target. Overall, there were both functional and non-functional submovements with a significantly higher proportion for the former. The displacement at the primary and secondary submovements, and negative velocity peak were significantly greater in the functional compared to non-functional. The influence of submovement type on other movement characteristics, including movement time, was somewhat less clear. These findings indicate that the majority of type 1 submovements are related to intended feedforward- and/or feedback-based processes, although there are a portion that can be attributed an indirect manifestation of a mechanical artefact. As a result, we suggest that submovements should be further categorised by their error-reducing function.


Assuntos
Movimento , Desempenho Psicomotor , Humanos , Extremidades
2.
Exp Brain Res ; 240(7-8): 1911-1919, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35596073

RESUMO

Subclinical neck pain (SCNP) refers to recurrent neck pain and/or stiffness for which individuals have not yet sought treatment. Prior studies have shown that individuals with SCNP have altered cerebellar processing that exhibits an altered body schema. The cerebellum also plays a vital role in upper limb reaching movements through refining internal models and integrating sensorimotor information. However, the impact of SCNP on these processes has yet to be examined in the context of a rapid goal-directed aiming response that relies on feedforward and feedback processes to guide the limb to the target. To address this, SCNP and control participants performed goal-directed upper limb movements with the dominant and non-dominant hands using light and heavy styli in the horizontal plane. The results show greater peak accelerations in SCNP participants using the heavy stylus. However, there were no other group differences seen, possibly due to the fact that reaching behavior predominantly relies on vision such that any proprioceptive deficits seen in those with SCNP can be compensated. This study illustrates the robust compensatory nature of the CNS when performing end-effector reaching tasks, suggesting studies altering visual feedback may be needed to see the full impact of SCNP on upper limb aiming.


Assuntos
Cervicalgia , Desempenho Psicomotor , Objetivos , Humanos , Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Extremidade Superior
3.
Exp Brain Res ; 238(12): 2685-2699, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33079207

RESUMO

Several years ago, our research group forwarded a model of goal-directed reaching and aiming that describes the processes involved in the optimization of speed, accuracy, and energy expenditure Elliott et al. (Psychol Bull 136:1023-1044, 2010). One of the main features of the model is the distinction between early impulse control, which is based on a comparison of expected to perceived sensory consequences, and late limb-target control that involves a spatial comparison of limb and target position. Our model also emphasizes the importance of strategic behaviors that limit the opportunity for worst-case or inefficient outcomes. In the 2010 paper, we included a section on how our model can be used to understand atypical aiming/reaching movements in a number of special populations. In light of a recent empirical and theoretical update of our model Elliott et al. (Neurosci Biobehav Rev 72:95-110, 2017), here we consider contemporary motor control work involving typical aging, Down syndrome, autism spectrum disorder, and tetraplegia with tendon-transfer surgery. We outline how atypical limb control can be viewed within the context of the multiple-process model of goal-directed reaching and aiming, and discuss the underlying perceptual-motor impairment that results in the adaptive solution developed by the specific group.


Assuntos
Transtorno do Espectro Autista , Objetivos , Extremidades , Humanos , Movimento , Resolução de Problemas , Desempenho Psicomotor
4.
Exp Brain Res ; 233(4): 1097-107, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25567091

RESUMO

Goal-directed aiming movements are planned and executed so that they optimize speed, accuracy and energy expenditure. In particular, the primary submovements involved in manual aiming attempts typically undershoot targets in order to avoid costly time and energy overshoot errors. Furthermore, in aiming movements performed over a series of trials, the movement planning process considers the sensory information associated with the most recent aiming attempt. The goal of the current study was to gain further insight into how the sensory consequences associated with the recent and forthcoming aiming attempts impact performance. We first examined whether performers are more conservative in their aiming movements with a heavy, as opposed to a light, stylus by determining whether primary submovements undershot the target to a greater extent in the former due to an anticipated increase in spatial variability. Our results show that movements with the heavy stylus demonstrated greater undershoot biases in the primary submovements, as well as greater trial-to-trial spatial variability at specific trajectory kinematic landmarks. In addition, we also sought to determine whether the sensory information experienced on a previous aiming movement affected movement planning and/or online control on the subsequent aiming attempt. To vary the type sensory consequences experienced on a trial-to-trial basis, participants performed aiming movements with light and heavy styli in either blocked or random orderings of trials. In the random-order conditions, some participants were provided advance information about stylus mass for the upcoming trial, while others were not. The blocked and random trial orders had minimal impacts on end point aiming performance. Furthermore, similarities in the times to key kinematic landmarks in the trajectories of the random-order groups suggest that recent trial experience had a greater effect on the upcoming aiming movement compared with advance task knowledge.


Assuntos
Fenômenos Biomecânicos/fisiologia , Retroalimentação Sensorial , Objetivos , Movimento/fisiologia , Sistemas On-Line , Desempenho Psicomotor/fisiologia , Adulto , Feminino , Mãos/inervação , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
5.
Exp Brain Res ; 229(4): 525-32, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23793508

RESUMO

The online visual control of movement involves contributions from 2 processes: a process early in the trajectory concerned with comparisons between actual and expected sensory consequences and another process late in the trajectory that reduces the discrepancy between the position of the hand and the target. This experiment was designed to determine how early and late visual controls are impacted by the illusory characteristics of the target in a rapid reaching task. Participants performed 500 ms movements to the vertices of Müller-Lyer figures with the availability of full vision on the majority of trials. However, on a fraction of the trials, movements to the targets were performed with either early vision (first 200 ms of movement), late vision (last 200 ms of movement) or no vision. Although participants undershoot the targets under all target and visual conditions, the impact of the target configuration was greatest when vision was available during only the final portion of the movement trajectory and least when only early vision was available for limb regulation. Aiming bias under full-vision and no-vision conditions was intermediate. These findings indicate that visual context has a greater impact on late discrete limb regulation than on early dynamic control of the limb trajectory.


Assuntos
Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Visão Ocular/fisiologia , Adulto , Feminino , Objetivos , Mãos/fisiologia , Humanos , Masculino , Tempo de Reação , Adulto Jovem
6.
J Mot Behav ; 54(4): 503-514, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34906031

RESUMO

For manual aiming, the optimized submovement model predicts a tendency toward target-center of primary movement endpoints (probabilistic strategy), while the minimization model predicts target undershooting ("play-it-safe" strategy). The spatial variability of primary movement endpoints directed toward a cross-hair (400-500 ms) (Session 1) were scaled by a multiplicative factor (x1 - 4) to form circular targets of different sizes (Session 2). In recognition of both models, it was predicted that the more that inherent variability exceeded the target size, the greater the tendency to shift from target-center aiming to target undershooting. The central tendency of primary movement endpoints was not influenced by the targets, while it neared target-center. These findings concur with a probabilistic strategy, although we speculate on factors that might otherwise foster a "play-it-safe" strategy.


Assuntos
Movimento , Desempenho Psicomotor , Humanos
7.
J Mot Behav ; 52(2): 145-166, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30982465

RESUMO

The continuous pointing task uses target-directed pointing responses to determine how perceived distance traveled is estimated during forward linear walking movements. To more precisely examine the regulation of this online process, the current study measured upper extremity joint angles and step-cycle kinematics in full vision and no-vision continuous pointing movements. Results show perceptual under-estimation of traveled distance in no-vision trials compared to full vision trials. Additionally, parsing of the shoulder plane of elevation trajectories revealed discontinuities that reflected this perceptual under-estimation and that were most frequently coupled with the early portion of the right foot swing phase of the step-cycle. This suggests that spatial updating may be composed of discrete iterations that are associated with gait parameters.


Assuntos
Braço/fisiologia , Cotovelo/fisiologia , Movimento/fisiologia , Percepção Espacial/fisiologia , Caminhada/fisiologia , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Ombro/fisiologia , Percepção Visual/fisiologia , Adulto Jovem
8.
Multisens Res ; 33(6): 599-623, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31899870

RESUMO

Multisensory integration is a fundamental form of sensory processing that is involved in many everyday tasks. Those with Attention-Deficit/Hyperactivity Disorder (ADHD) have characteristic alterations to various brain regions that may influence multisensory processing. The overall aim of this work was to assess how adults with ADHD process audiovisual multisensory stimuli during a complex response time task. The paradigm used was a two-alternative forced-choice discrimination task paired with continuous 64-electrode electroencephalography, allowing for the measurement of response time and accuracy to auditory, visual, and audiovisual multisensory conditions. Analysis revealed that those with ADHD ( n = 10) respond faster than neurotypical controls ( n = 12) when presented with auditory, visual, and audiovisual multisensory conditions, while also having race model violation in early response latency quantiles. Adults with ADHD also had more prominent multisensory processing over parietal-occipital brain regions at early post-stimulus latencies, indicating that altered brain structure may have important outcomes for audiovisual multisensory processing. The present study is the first to assess how those with ADHD respond to multisensory conditions during a complex response time task, and demonstrates that adults with ADHD have unique multisensory processing when assessing both behavioral response time measures and neurological measures.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Percepção Auditiva/fisiologia , Lobo Occipital/fisiopatologia , Lobo Parietal/fisiopatologia , Tempo de Reação/fisiologia , Percepção Visual/fisiologia , Estimulação Acústica , Adolescente , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Eletroencefalografia , Feminino , Humanos , Masculino , Estimulação Luminosa , Adulto Jovem
9.
Brain Sci ; 9(12)2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31818030

RESUMO

Multisensory integration (MSI) is necessary for the efficient execution of many everyday tasks. Alterations in sensorimotor integration (SMI) have been observed in individuals with subclinical neck pain (SCNP). Altered audiovisual MSI has previously been demonstrated in this population using performance measures, such as reaction time. However, neurophysiological techniques have not been combined with performance measures in the SCNP population to determine differences in neural processing that may contribute to these behavioral characteristics. Electroencephalography (EEG) event-related potentials (ERPs) have been successfully used in recent MSI studies to show differences in neural processing between different clinical populations. This study combined behavioral and ERP measures to characterize MSI differences between healthy and SCNP groups. EEG was recorded as 24 participants performed 8 blocks of a simple reaction time (RT) MSI task, with each block consisting of 34 auditory (A), visual (V), and audiovisual (AV) trials. Participants responded to the stimuli by pressing a response key. Both groups responded fastest to the AV condition. The healthy group demonstrated significantly faster RTs for the AV and V conditions. There were significant group differences in neural activity from 100-140 ms post-stimulus onset, with the control group demonstrating greater MSI. Differences in brain activity and RT between individuals with SCNP and a control group indicate neurophysiological alterations in how individuals with SCNP process audiovisual stimuli. This suggests that SCNP alters MSI. This study presents novel EEG findings that demonstrate MSI differences in a group of individuals with SCNP.

10.
Front Hum Neurosci ; 13: 95, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30941026

RESUMO

The purpose of this study was to assess how young adults with attention-deficit/hyperactivity disorder (ADHD) process audiovisual (AV) multisensory stimuli using behavioral and neurological measures. Adults with a clinical diagnosis of ADHD (n = 10) and neurotypical controls (n = 11) completed a simple response time task, consisting of auditory, visual, and AV multisensory conditions. Continuous 64-electrode electroencephalography (EEG) was collected to assess neurological responses to each condition. The AV multisensory condition resulted in the shortest response times for both populations. Analysis using the race model (Miller, 1982) demonstrated that those with ADHD had violation of the race model earlier in the response, which may be a marker for impulsivity. EEG analysis revealed that both groups had early multisensory integration (MSI) occur following multisensory stimulus onset. There were also significant group differences in event-related potentials (ERPs) in frontal, parietal, and occipital brain regions, which are regions reported to be altered in those with ADHD. This study presents results examining multisensory processing in the population of adults with ADHD, and can be used as a foundation for future ADHD research using developmental research designs as well as the development of novel technological supports.

11.
J Mot Behav ; 49(2): 129-140, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28327058

RESUMO

Energy optimization in goal-directed aiming has been demonstrated as an undershoot bias in primary movement endpoint locations, especially in conditions where corrections to target overshoots must be made against gravity. Two-component models of upper limb movement have not yet considered how joint angles are organized to deal with the energy constraints associated with moving the upper limb in goal-directed aiming tasks. To address this limitation, participants performed aiming movements to targets in the up and down directions with the index finger and two types of rod extensions attached to the index finger. The rod extensions were expected to invoke different energy optimizing strategies in the up and down directions by allowing the distal joints the opportunity to contribute to end effector displacement. Primary movements undershot the farthest target to a greater extent in the downward direction compared to the upward direction, showing that movement kinematics optimize energy expenditure in consideration of the effects of gravity. As rod length increased, shoulder elevation was optimized in movements to the far-up target and elbow flexion was optimally minimized in movements to the far-down target. The results suggest energy optimization in the control of joint angles independent of the force of gravity.


Assuntos
Fenômenos Biomecânicos/fisiologia , Metabolismo Energético/fisiologia , Objetivos , Articulações/fisiologia , Movimento/fisiologia , Extremidade Superior/fisiologia , Feminino , Gravitação , Humanos , Masculino , Distribuição Aleatória , Adulto Jovem
12.
Neurosci Biobehav Rev ; 72: 95-110, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27894830

RESUMO

Recently our group forwarded a model of speed-accuracy relations in goal-directed reaching. A fundamental feature of our multiple process model was the distinction between two types of online regulation: impulse control and limb-target control. Impulse control begins during the initial stages of the movement trajectory and involves a comparison of actual limb velocity and direction to an internal representation of expectations about the limb trajectory. Limb-target control involves discrete error-reduction based on the relative positions of the limb and the target late in the movement. Our model also considers the role of eye movements, practice, energy optimization and strategic behavior in limb control. Here, we review recent work conducted to test specific aspects of our model. As well, we consider research not fully incorporated into our earlier contribution. We conclude that a slightly modified and expanded version of our model, that includes crosstalk between the two forms of online regulation, does an excellent job of explaining speed, accuracy, and energy optimization in goal-directed reaching.


Assuntos
Objetivos , Humanos , Movimento
13.
J Mot Behav ; 48(6): 542-551, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27362494

RESUMO

During rapid aiming, movements are planned and executed to avoid worst-case outcomes that require time and energy to correct. As such, downward movements initially undershoot the target to avoid corrections against gravity. Illusory target context can also impact aiming bias. Here, the authors sought to determine how strategic biases mediate illusory biases. Participants aimed to Müller-Lyer figures in different directions (forward, backward, up, down). Downward biases emerged late in the movement and illusory biases emerged from peak velocity. The illusory effects were greater for downward movements at terminal endpoint. These results indicate that strategic biases interact with the limb-target control processes associated with illusory biases. Thus, multiple control processes during rapid aiming may combine and later affect endpoint accuracy (D. Elliott et al., 2010 ).


Assuntos
Ilusões/fisiologia , Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Objetivos , Humanos , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Adulto Jovem
14.
J Mot Behav ; 46(6): 433-43, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25204201

RESUMO

Two experiments were conducted to examine time and energy optimization strategies for movements made with and against gravity. In Experiment 1, the authors manipulated concurrent visual feedback, and knowledge about feedback. When vision was eliminated upon movement initiation, participants exhibited greater undershooting, both with their primary submovement and their final endpoint, than when vision was available. When aiming downward, participants were more likely to terminate their aiming following the primary submovement or complete a lower amplitude corrective submovement. This strategy reduced the frequency of energy-consuming corrections against gravity. In Experiment 2, the authors eliminated vision of the hand and the target at the end of the movement. This procedure was expected to have its greatest impact under no-vision conditions where no visual feedback was available for subsequent planning. As anticipated, direction and concurrent visual feedback had a profound impact on endpoint bias. Participants exhibited pronounced undershooting when aiming downward and without vision. Differences in undershooting between vision and no vision were greater under blocked feedback conditions. When performers were uncertain about the impending feedback, they planned their movements for the worst-case scenario. Thus movement planning considers the variability in execution, and avoids outcomes that require time and energy to correct.


Assuntos
Retroalimentação Sensorial/fisiologia , Movimento/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos/fisiologia , Feminino , Sensação Gravitacional , Humanos , Masculino , Desempenho Psicomotor/fisiologia , Adulto Jovem
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