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Oda H, Tsujinaka R, Fukuda S, Hamada N, Matsuoka M, Hiraoka K. Descending motor command to prime mover of dependent finger induces tactile gating in target and distant non-target finger. Somatosens Mot Res 2024:1-8. [PMID: 38785341 DOI: 10.1080/08990220.2024.2358298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 05/16/2024] [Indexed: 05/25/2024]
Abstract
This study examined whether tactile gating induced by the descending motor command to one finger spreads out to the other fingers to which the command is not delivered and whether this gating is dependent on the target finger to which the command is delivered. The change in perceptual threshold to the digital nerve stimulation of one finger induced by tonic contraction of the first dorsal interosseous or abductor digiti minimi muscle was examined. The perceptual threshold to the digital nerve stimulation of the thumb or little finger was increased by tonic contraction of the abductor digiti minimi muscle. This finding indicates that the descending motor command to the prime mover of the little finger abduction induces tactile gating not only in the finger to which the command is delivered but also in the other finger to which the command is not delivered. Tonic contraction of the first dorsal interosseous muscle did not change the perceptual threshold to the digital nerve stimulation in any finger. This finding means that tactile gating occurs particularly when the descending motor command is delivered to the dependent finger. Spreading out of tactile gating of one finger, to which the descending motor command is not delivered, is likely mediated by surround inhibition.
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Affiliation(s)
- Hitoshi Oda
- Graduate School of Rehabilitation Science, Osaka Metropolitan University, Habikino City, Japan
| | - Ryo Tsujinaka
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Sakai, Japan
| | - Shiho Fukuda
- Graduate School of Rehabilitation Science, Osaka Metropolitan University, Habikino City, Japan
| | - Naoki Hamada
- Graduate School of Rehabilitation Science, Osaka Metropolitan University, Habikino City, Japan
| | - Masakazu Matsuoka
- Graduate School of Rehabilitation Science, Osaka Metropolitan University, Habikino City, Japan
| | - Koichi Hiraoka
- School of Medicine, Osaka Metropolitan University, Habikino City, Japan
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Oda H, Tsujinaka R, Fukuda S, Sawaguchi Y, Hiraoka K. Tactile perception of right middle fingertip suppresses excitability of motor cortex supplying right first dorsal interosseous muscle. Neuroscience 2022; 494:82-93. [PMID: 35588919 DOI: 10.1016/j.neuroscience.2022.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/08/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022]
Abstract
The present study examined whether tactile perception of the fingertip modulates excitability of the motor cortex supplying the intrinsic hand muscle and whether this modulation is specific to the fingertip stimulated and the muscle and hand tested. Tactile stimulation was given to one of the five fingertips in the left or right hand, and transcranial magnetic stimulation eliciting motor evoked potential in the first dorsal interosseous muscle (FDI) or abductor digiti minimi was given 200 ms after the onset of tactile stimulation. The corticospinal excitability of the FDI at rest was suppressed by the tactile stimulation of the right middle fingertip, but such suppression was absent for the other fingers stimulated and for the other muscle or hand tested. The persistence and amplitude of the F-wave was not significantly influenced by tactile stimulation of the fingertip in the right hand. These findings indicate that tactile perception of the right middle fingertip suppresses excitability of the motor cortex supplying the right FDI at rest. The suppression of corticospinal excitability was absent during tonic contraction of the right FDI, indicating that the motor execution process interrupts the tactile perception-induced suppression of motor cortical excitability supplying the right FDI. These findings are in line with a view that the tactile perception of the right middle finger induces surround inhibition of the motor cortex supplying the prime mover of the finger neighboring the stimulated finger.
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Affiliation(s)
- Hitoshi Oda
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Ryo Tsujinaka
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Shiho Fukuda
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Yasushi Sawaguchi
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Koichi Hiraoka
- College of Health and Human Sciences, Osaka Prefecture University, Habikino city, Osaka, Japan.
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3
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The Nature of Finger Enslaving: New Results and Their Implications. Motor Control 2021; 25:680-703. [PMID: 34530403 DOI: 10.1123/mc.2021-0044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/01/2021] [Accepted: 07/25/2021] [Indexed: 11/18/2022]
Abstract
We present a review on the phenomenon of unintentional finger action seen when other fingers of the hand act intentionally. This phenomenon (enslaving) has been viewed as a consequence of both peripheral (e.g., connective tissue links and multifinger muscles) and neural (e.g., projections of corticospinal pathways) factors. Recent studies have shown relatively large and fast drifts in enslaving toward higher magnitudes, which are not perceived by subjects. These and other results emphasize the defining role of neural factors in enslaving. We analyze enslaving within the framework of the theory of motor control with spatial referent coordinates. This analysis suggests that unintentional finger force changes result from drifts of referent coordinates, possibly reflecting the spread of cortical excitation.
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Common Motor Drive Triggers Response of Prime Movers When Two Fingers Simultaneously Respond to a Cue. Brain Sci 2021; 11:brainsci11060700. [PMID: 34073345 PMCID: PMC8227196 DOI: 10.3390/brainsci11060700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/16/2021] [Accepted: 05/24/2021] [Indexed: 12/05/2022] Open
Abstract
This study investigated whether the motor execution process of one finger movement in response to a start cue is influenced by the participation of another finger movement and whether the process of the finger movement is dependent on the movement direction. The participants performed a simple reaction time (RT) task, the abduction or flexion of one (index or little finger) or two fingers (index and little fingers). The RT of the prime mover for the finger abduction was significantly longer than that for the flexion, indicating that the time taken for the motor execution of the finger response is dependent on the movement direction. The RT of the prime mover was prolonged when the abduction of another finger, whose RT was longer than the flexion, was added. This caused closer RTs between the prime movers for a two-finger response compared with the RTs for a one finger response. The absolute difference in the RT between the index and little finger responses became smaller when two fingers responded together compared with one finger response. Those results are well explained by a view that the common motor drive triggers the prime movers when two fingers move together in response to a start cue.
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Long-term practice of isolated finger movements reduces enslaved response of tonically contracting little finger abductor to tonic index finger abduction. Exp Brain Res 2020; 238:499-512. [PMID: 31960102 DOI: 10.1007/s00221-020-05731-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/08/2020] [Indexed: 10/25/2022]
Abstract
The purpose of this study was to elucidate whether the long-term practice of isolated finger movements reduces the enslaved response of the little finger abductor to the index finger abduction. The right-handed participants tonically or phasically abducted the index finger, while they maintained at rest or tonic abduction of the little finger. The enslaved response of the tonically contracting little finger abductor to the tonic abduction of the index finger was greater than the response of the same muscle at rest in the nonpianists. This indicates that the tonic contraction of the little finger abductor enhances the enslaving drive from the tonically contracting index finger abductor to the little finger abductor. The enslaved response of the tonically contracting little finger abductor to the tonic abduction of the index finger in the pianists was significantly smaller than that in the nonpianists, but such a significant group difference was absent when the little finger abductor was at rest. This indicates that the inhibitory process on the enslaving drive from the tonically contracting index finger abductor to the tonically active little finger abductor is unmasked through the long-term practice.
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Aoyama T, Kaneko F, Ohashi Y, Kohno Y. Neural mechanism of selective finger movement independent of synergistic movement. Exp Brain Res 2019; 237:3485-3492. [PMID: 31741000 DOI: 10.1007/s00221-019-05693-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/13/2019] [Indexed: 10/25/2022]
Abstract
Muscle synergy is important for simplifying functional movement, which constitutes spatiotemporal patterns of activity across muscles. To execute selective finger movements that are independent of synergistic movement patterns, we hypothesized that inhibitory neural activity is necessary to suppress enslaved finger movement caused by synergist muscles. To test this hypothesis, we focused on a pair of synergist muscles used in the hand opening movement, namely the index finger abductor and little finger abductor (abductor digiti minimi; ADM), and examined whether inhibitory neural activity in ADM occurs during selective index finger abduction/adduction movements and/or its imagery using transcranial magnetic stimulation and F-wave analysis. During the index finger adduction movement, background EMG activity, F-wave persistence, and motor evoked potential (MEP) amplitude in ADM were elevated. However, during the index finger abduction movement, ADM MEP amplitude remained unchanged despite increased background EMG activity and F-wave persistence. These results suggest that increased spinal excitability in ADM is counterbalanced by cortical-mediated inhibition only during selective index finger abduction movement. This assumption was further supported by the results of motor imagery experiments. Although F-wave persistence in ADM increased only during motor imagery of index finger abduction, ADM MEP amplitude during motor imagery of index finger abduction was significantly lower than that during adduction. Overall, our findings indicate that cortical-mediated inhibition contributes to the execution of selective finger movements that are independent of synergistic hand movement patterns.
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Affiliation(s)
- Toshiyuki Aoyama
- Department of Physical Therapy, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-Machi, Inashiki-gun, Ibaraki, Japan.
| | - Fuminari Kaneko
- Department of Rehabilitation Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Yukari Ohashi
- Department of Physical Therapy, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-Machi, Inashiki-gun, Ibaraki, Japan
| | - Yutaka Kohno
- Center for Medical Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-Machi, Inashiki-gun, Ibaraki, Japan
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Jono Y, Iwata Y, Mizusawa H, Hiraoka K. Change in Excitability of Corticospinal Pathway and GABA-Mediated Inhibitory Circuits of Primary Motor Cortex Induced by Contraction of Adjacent Hand Muscle. Brain Topogr 2016; 29:834-846. [PMID: 27251710 DOI: 10.1007/s10548-016-0499-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 05/24/2016] [Indexed: 11/29/2022]
Abstract
The present study examined whether the excitability of the corticospinal pathway and the GABA-mediated inhibitory circuits of the primary motor cortex that project onto the corticospinal neurons in the tonically contracting hand muscle are changed by tonic contraction of the adjacent hand muscle. The motor evoked potential (MEP) and cortical silent period (CSP) in the tonically contracting hand muscle were obtained while the adjacent hand muscle was either tonically contracting or at rest. The MEP and CSP of the first dorsal interosseous (FDI) muscle elicited across the scalp sites where the MEP is predominantly elicited in the FDI muscle were decreased by tonic contraction of the abductor digiti minimi (ADM) muscle. The centers of the area of the MEP and the duration of the CSP in the FDI muscle elicited across the sites where the MEP is predominantly elicited in the FDI muscle were lateral to those in the FDI muscle elicited across the sites where the MEP is elicited in both the FDI and ADM muscles. They were also lateral to those in the ADM muscle elicited either across the sites where the MEP is predominantly elicited in the ADM muscle, or across the sites where the MEP is elicited in both the FDI and ADM muscles. The decrease in the corticospinal excitability and the excitability of the GABA-mediated inhibitory circuits of the primary motor cortex that project onto the corticospinal neurons in the FDI muscle may be due either to (1) the interaction between the activity of the lateral area of the FDI representation and the descending drive to the ADM muscle, or (2) the decreased susceptibility of the primary motor area that predominantly projects onto the corticospinal neurons in the FDI muscle, which also plays a role in independent finger movement when both the FDI and ADM muscles act together as synergists.
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Affiliation(s)
- Yasutomo Jono
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, 3-7-30 Habikino, Habikino, Osaka, 583-8555, Japan
| | - Yasuyuki Iwata
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, 3-7-30 Habikino, Habikino, Osaka, 583-8555, Japan
| | - Hiroki Mizusawa
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, 3-7-30 Habikino, Habikino, Osaka, 583-8555, Japan
| | - Koichi Hiraoka
- College of Health and Human Sciences, Osaka Prefecture University, Habikino, Osaka, Japan.
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Wilhelm LA, Martin JR, Latash ML, Zatsiorsky VM. Finger enslaving in the dominant and non-dominant hand. Hum Mov Sci 2013; 33:185-93. [PMID: 24360253 DOI: 10.1016/j.humov.2013.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/28/2013] [Accepted: 10/19/2013] [Indexed: 11/27/2022]
Abstract
During single-finger force production, the non-instructed fingers unintentionally produce force (finger enslaving). In this study, enslaving effects were compared between the dominant and non-dominant hands. The test consisted of a series of maximum voluntary contractions with different finger combinations. Enslaving matrices were calculated by means of training an artificial neural network. The dominant hand was found to be stronger, but there was found to be no difference between the overall enslaving effects in the dominant and non-dominant hands. There was no correlation between the magnitude of finger enslaving and the performance in such tests as the Edinburgh Handedness Inventory, the Grooved Pegboard test, and the Jebsen-Taylor Hand Function test. Each one of those three tests showed a significant difference between the dominant and non-dominant hand performances. Eleven subjects were retested after two months, and it was found that enslaving effects did not fluctuate significantly between the two testing sessions. While the dominant and non-dominant hands are involved differently in everyday tasks, e.g. in writing or eating, this practice does not cause significant differences in enslaving between the hands.
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Affiliation(s)
- Luke A Wilhelm
- The Biomechanics Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA.
| | - Joel R Martin
- School of Recreation, Health, and Tourism, George Mason University, 10900 University Blvd, Manassas, VA 20110, USA.
| | - Mark L Latash
- The Biomechanics Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA.
| | - Vladimir M Zatsiorsky
- The Biomechanics Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA.
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Guan CQ, Meng W, Yao R, Glenberg AM. The motor system contributes to comprehension of abstract language. PLoS One 2013; 8:e75183. [PMID: 24086463 PMCID: PMC3784420 DOI: 10.1371/journal.pone.0075183] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 08/10/2013] [Indexed: 11/18/2022] Open
Abstract
If language comprehension requires a sensorimotor simulation, how can abstract language be comprehended? We show that preparation to respond in an upward or downward direction affects comprehension of the abstract quantifiers "more and more" and "less and less" as indexed by an N400-like component. Conversely, the semantic content of the sentence affects the motor potential measured immediately before the upward or downward action is initiated. We propose that this bidirectional link between motor system and language arises because the motor system implements forward models that predict the sensory consequences of actions. Because the same movement (e.g., raising the arm) can have multiple forward models for different contexts, the models can make different predictions depending on whether the arm is raised, for example, to place an object or raised as a threat. Thus, different linguistic contexts invoke different forward models, and the predictions constitute different understandings of the language.
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Affiliation(s)
- Connie Qun Guan
- University of Science and Technology, Beijing, China
- Florida State University and Florida Center for Reading Research, Tallahassee, Florida, United States of America
| | - Wanjin Meng
- Florida State University and Florida Center for Reading Research, Tallahassee, Florida, United States of America
- National Institute of Education Sciences, Beijing, China
| | - Ru Yao
- National Institute of Education Sciences, Beijing, China
| | - Arthur M. Glenberg
- Arizona State University, Tempe, Arizona, United States of America
- University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
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Hou W, Shen S, Sterr A. An MRI compatible visual force-feedback system for the study of force control mechanics. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2012; 2005:3687-90. [PMID: 17281027 DOI: 10.1109/iembs.2005.1617282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Motor task experiments play an essential role in exploring the brain mechanisms of movement control, and visual force-feedback is an important factor in these motor experiments. In this paper, the authors proposed a visual forcefeedback system suitable for neuroscience experiment. With this system, the force output produced by participants can be detected and recorded in real time, while force output was visually displayed as a feedback cue to the participants simultaneously. Furthermore, this force feedback system is MRI compatible, and can be used both in fMRI and ERP experiments. The proposed system has been applied in handgrip tasks and finger movement experiments, which were designed to explore the relationship between force output and brain activation mode in normal subject and stroke patient. The results demonstrated that various force levels were well detected and visual feedback signals enabled the accomplishment of experiments with both fixed and variable target force levels.
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Affiliation(s)
- Wensheng Hou
- Biomedical Department of Chongqing University, 174 Shazheng Street, Chongqing 400044, China; Psychology Department, School of Human Science, University of Surrey, Guildford, Surrey, Gu2 7XH, UK
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Ibáñez A, Cardona JF, Dos Santos YV, Blenkmann A, Aravena P, Roca M, Hurtado E, Nerguizian M, Amoruso L, Gómez-Arévalo G, Chade A, Dubrovsky A, Gershanik O, Kochen S, Glenberg A, Manes F, Bekinschtein T. Motor-language coupling: direct evidence from early Parkinson's disease and intracranial cortical recordings. Cortex 2012; 49:968-84. [PMID: 22482695 DOI: 10.1016/j.cortex.2012.02.014] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Revised: 02/28/2012] [Accepted: 02/28/2012] [Indexed: 11/24/2022]
Abstract
Language and action systems are functionally coupled in the brain as demonstrated by converging evidence using Functional magnetic resonance imaging (fMRI), electroencephalography (EEG), transcranial magnetic stimulation (TMS), and lesion studies. In particular, this coupling has been demonstrated using the action-sentence compatibility effect (ACE) in which motor activity and language interact. The ACE task requires participants to listen to sentences that described actions typically performed with an open hand (e.g., clapping), a closed hand (e.g., hammering), or without any hand action (neutral); and to press a large button with either an open hand position or closed hand position immediately upon comprehending each sentence. The ACE is defined as a longer reaction time (RT) in the action-sentence incompatible conditions than in the compatible conditions. Here we investigated direct motor-language coupling in two novel and uniquely informative ways. First, we measured the behavioural ACE in patients with motor impairment (early Parkinson's disease - EPD), and second, in epileptic patients with direct electrocorticography (ECoG) recordings. In experiment 1, EPD participants with preserved general cognitive repertoire, showed a much diminished ACE relative to non-EPD volunteers. Moreover, a correlation between ACE performance and action-verb processing (kissing and dancing test - KDT) was observed. Direct cortical recordings (ECoG) in motor and language areas (experiment 2) demonstrated simultaneous bidirectional effects: motor preparation affected language processing (N400 at left inferior frontal gyrus and middle/superior temporal gyrus), and language processing affected activity in movement-related areas (motor potential at premotor and M1). Our findings show that the ACE paradigm requires ongoing integration of preserved motor and language coupling (abolished in EPD) and engages motor-temporal cortices in a bidirectional way. In addition, both experiments suggest the presence of a motor-language network which is not restricted to somatotopically defined brain areas. These results open new pathways in the fields of motor diseases, theoretical approaches to language understanding, and models of action-perception coupling.
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Affiliation(s)
- Agustín Ibáñez
- Laboratory of Experimental Psychology and Neuroscience (LPEN), Institute of Cognitive Neurology (INECO); Favaloro University, Buenos Aires, Argentina.
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Shim JK, Karol S, Kim YS, Seo NJ, Kim YH, Kim Y, Yoon BC. Tactile feedback plays a critical role in maximum finger force production. J Biomech 2012; 45:415-20. [DOI: 10.1016/j.jbiomech.2011.12.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Revised: 12/02/2011] [Accepted: 12/02/2011] [Indexed: 11/29/2022]
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A novel device for the study of somatosensory information processing. J Neurosci Methods 2011; 204:215-20. [PMID: 22155443 DOI: 10.1016/j.jneumeth.2011.11.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 11/01/2011] [Accepted: 11/04/2011] [Indexed: 11/22/2022]
Abstract
Current methods for applying multi-site vibratory stimuli to the skin typically involve the use of multiple, individual vibrotactile stimulators. Limitations of such an arrangement include difficulty with both positioning the stimuli as well as ensuring that stimuli are delivered in a synchronized and deliberate manner. Previously, we reported a two-site tactile stimulator that was developed in order to solve these problems (Tannan et al., 2007a). Due to both the success of that novel stimulator and the limitations that were inherent in that device, we designed and fabricated a four-site stimulator that provides a number of advantages over the previous version. First, the device can stimulate four independent skin sites and is primarily designed for stimulating the digit tips. Second, the positioning of the probe tips has been re-designed to provide better ergonomic hand placement. Third, the device is much more portable than the previously reported stimulator. Fourth, the stimulator head has a much smaller footprint on the table or surface where it resides. To demonstrate the capacity of the device for delivering tactile stimulation at four independent sites, a finger agnosia protocol, in the presence and absence of conditioning stimuli, was conducted on seventeen healthy control subjects. The study demonstrated that with increasing amplitudes of vibrotactile conditioning stimuli concurrent with the agnosia test, inaccuracies of digit identification increased, particularly at digits D3 and D4. The results are consistent with prior studies that implicated synchronization of adjacent and near-adjacent cortical ensembles with conditioning stimuli in impacting TOJ performance (Tommerdahl et al., 2007a,b).
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Abstract
Surround inhibition is a physiological mechanism to focus neuronal activity in the central nervous system. This so-called center-surround organization is well known in sensory systems, where central signals are facilitated and eccentric signals are inhibited in order to sharpen the contrast between them. There is evidence that this mechanism is relevant to skilled motor behavior, and it is deficient, for example, in the affected primary motor cortex of patients with focal hand dystonia (FHD). While it is still not fully elucidated how surround inhibition is generated in healthy subjects, the process is enhanced with handedness and task difficulty indicating that it may be an important mechanism for the performance of individuated finger movements. In FHD, where involuntary overactivation of muscles interferes with precise finger movements, a loss of intracortical inhibition likely contributes to the loss of surround inhibition. Several intracortical inhibitory networks are modulated differently in FHD compared with healthy subjects, and these may contribute to the loss of surround inhibition. Surround inhibition can be observed and assessed in the primary motor cortex. It remains unclear, however, if the effects are created in the cortex or if they are derived from, or supported by, motor signals that come from the basal ganglia.
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Aravena P, Hurtado E, Riveros R, Cardona JF, Manes F, Ibáñez A. Applauding with closed hands: neural signature of action-sentence compatibility effects. PLoS One 2010; 5:e11751. [PMID: 20676367 PMCID: PMC2911376 DOI: 10.1371/journal.pone.0011751] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2010] [Accepted: 06/25/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Behavioral studies have provided evidence for an action-sentence compatibility effect (ACE) that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes. METHODOLOGY/PRINCIPAL FINDINGS Participants listened to sentences describing an action that involved an open hand, a closed hand, or no manual action. Each participant was asked to press a button to indicate his/her understanding of the sentence. Each participant was assigned a hand-shape, either closed or open, which had to be used to activate the button. There were two groups (depending on the assigned hand-shape) and three categories (compatible, incompatible and neutral) defined according to the compatibility between the response and the sentence. ACEs were found in both groups. Brain markers of semantic processing exhibited an N400-like component around the Cz electrode position. This component distinguishes between compatible and incompatible, with a greater negative deflection for incompatible. Motor response elicited a motor potential (MP) and a re-afferent potential (RAP), which are both enhanced in the compatible condition. CONCLUSIONS/SIGNIFICANCE The present findings provide the first ACE cortical measurements of semantic processing and the motor response. N400-like effects suggest that incompatibility with motor processes interferes in sentence comprehension in a semantic fashion. Modulation of motor potentials (MP and RAP) revealed a multimodal semantic facilitation of the motor response. Both results provide neural evidence of an action-sentence bidirectional relationship. Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process. In contrast, motor-language integration occurring during the verb onset supports a genuine and ongoing brain motor-language interaction.
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Affiliation(s)
- Pia Aravena
- Laboratory of Experimental Psychology & Neuroscience, Institute of Cognitive Neurology (INECO), Buenos Aires, Capital Federal, Argentina
- Laboratory of Cognitive Neuroscience, Universidad Diego Portales, Santiago, Chile
| | - Esteban Hurtado
- Doctoral Program, Psychology School, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rodrigo Riveros
- Laboratory of Cognitive Neuroscience, Universidad Diego Portales, Santiago, Chile
| | - Juan Felipe Cardona
- Laboratory of Experimental Psychology & Neuroscience, Institute of Cognitive Neurology (INECO), Buenos Aires, Capital Federal, Argentina
| | - Facundo Manes
- Laboratory of Experimental Psychology & Neuroscience, Institute of Cognitive Neurology (INECO), Buenos Aires, Capital Federal, Argentina
- Institute of Neuroscience, Favaloro University, Buenos Aires, Capital Federal, Argentina
| | - Agustín Ibáñez
- Laboratory of Experimental Psychology & Neuroscience, Institute of Cognitive Neurology (INECO), Buenos Aires, Capital Federal, Argentina
- Laboratory of Cognitive Neuroscience, Universidad Diego Portales, Santiago, Chile
- Institute of Neuroscience, Favaloro University, Buenos Aires, Capital Federal, Argentina
- National Scientific and Technical Research Council (CONICET), Buenos Aires, Capital Federal, Argentina
- * E-mail:
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Beck S, Schubert M, Richardson SP, Hallett M. Surround inhibition depends on the force exerted and is abnormal in focal hand dystonia. J Appl Physiol (1985) 2009; 107:1513-8. [PMID: 19713426 DOI: 10.1152/japplphysiol.91580.2008] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
There is evidence that surround inhibition (SI), a neural mechanism to enhance contrast between signals, may play a role in primary motor cortex during movement initiation, while it is deficient in patients with focal hand dystonia (FHD). To further characterize SI with respect to different force levels, single- and paired-pulse transcranial magnetic stimulation was applied at rest and during index finger movement to evoke potentials in the nonsynergistic, abductor policis muscle. In Experiment 1, in 19 healthy volunteers, SI was tested using single-pulse transcranial magnetic stimulation. Motor-evoked potentials at rest were compared with those during contraction using four different force levels [5, 10, 20, and 40% of maximum force (F(max))]. In Experiments 2 and 3, SI and short intracortical inhibition (SICI) were tested, respectively, in 16 patients with FHD and 20 age-matched controls for the 10% and 20% F(max) levels. SI was most pronounced for 10% F(max) and abolished for the 40% F(max) level in controls, whereas FHD patients had no SI at all. In contrast, a loss of SICI was observed in FHD patients, which was more pronounced for 10% F(max) than for 20% F(max). Our results suggest that SI is involved in the generation of fine finger movements with low-force levels. The greater loss of SICI for the 10% F(max) level in patients with FHD than for the 20% F(max) level indicates that this inhibitory mechanism is more abnormal at lower levels of force.
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Affiliation(s)
- S Beck
- Human Motor Control Section, NINDS, National Institutes of Health, Bldg. 10/5N240, 10 Center Drive, Bethesda, MD 20892-1428, USA.
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Louvel J, Turak B, Buser P. Comparing ERP concomitant with stimulus-induced and self-paced movements: Intracerebral recordings at various cortical sites. Neurophysiol Clin 2009; 39:149-58. [DOI: 10.1016/j.neucli.2009.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Revised: 04/14/2009] [Accepted: 06/20/2009] [Indexed: 11/15/2022] Open
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Short intracortical and surround inhibition are selectively reduced during movement initiation in focal hand dystonia. J Neurosci 2008; 28:10363-9. [PMID: 18842895 DOI: 10.1523/jneurosci.3564-08.2008] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In patients with focal hand dystonia (FHD), pathological overflow activation occurs in muscles not involved in the movement. Surround inhibition is a neural mechanism that can sharpen desired movement by inhibiting unwanted movement in adjacent muscles. To further establish the phenomenon of surround inhibition and to determine whether short intracortical inhibition (SICI) reflecting inhibition from the local interneurons in primary motor cortex (M1), might play a role in its genesis, single- and paired-pulse transcranial magnetic stimulation (TMS), and Hoffmann reflex testing were applied to evaluate the excitability of the relaxed abductor pollicis brevis muscle (APB) at various intervals during a movement of the index finger in 16 patients with FHD and 20 controls. Whereas controls showed inhibition of APB motor-evoked potential (MEP) size during movement initiation and facilitation of APB MEP size during the maintenance phase, FHD patients did not modulate APB MEP size. In contrast, SICI remained constant in controls, but FHD patients showed reduced SICI during movement initiation. The H(max)/M(max) ratio in control subjects increased during movement initiation. The results provide additional evidence for the presence of surround inhibition in M1, where it occurs only during movement initiation, indicating that different mechanisms underlie movement initiation and maintenance. Thus, surround inhibition is sculpted both in time and space and may be an important neural mechanism during movement initiation to counteract increased spinal excitability. SICI may contribute to its generation, because in patients with FHD, the lack of depression of APB MEP size is accompanied by a reduction in SICI.
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Kim SW, Shim JK, Zatsiorsky VM, Latash ML. Finger inter-dependence: linking the kinetic and kinematic variables. Hum Mov Sci 2008; 27:408-22. [PMID: 18255182 DOI: 10.1016/j.humov.2007.08.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Revised: 08/24/2007] [Accepted: 08/28/2007] [Indexed: 11/28/2022]
Abstract
We studied the dependence between voluntary motion of a finger and pressing forces produced by the tips of other fingers of the hand. Participants moved one of the fingers (task finger) of the right hand trying to follow a cyclic, ramp-like flexion-extension template at different frequencies. The other fingers (slave fingers) were restricted from moving; their flexion forces were recorded and analyzed. Index finger motion caused the smallest force production by the slave fingers. Larger forces were produced by the neighbors of the task finger; these forces showed strong modulation over the range of motion of the task finger. The enslaved forces were higher during the flexion phase of the movement cycle as compared to the extension phase. The index of enslaving expressed in N/rad was higher when the task finger moved through the more flexed postures. The dependence of enslaving on both range and direction of task finger motion poses problems for methods of analysis of finger coordination based on an assumption of universal matrices of finger interdependence.
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Affiliation(s)
- Sun Wook Kim
- Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, United States
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20
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Gorniak SL, Zatsiorsky VM, Latash ML. Hierarchies of synergies: an example of two-hand, multi-finger tasks. Exp Brain Res 2006; 179:167-80. [PMID: 17103206 PMCID: PMC1859846 DOI: 10.1007/s00221-006-0777-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Accepted: 10/24/2006] [Indexed: 11/27/2022]
Abstract
We explored the ability of the central nervous system (CNS) to assemble synergies stabilizing the output of sets of effectors at two levels of a control hierarchy. Specifically, we asked a question: can the CNS organize both two-hand and within-a-hand force stabilizing synergies in a simple two-hand force production task that involves two fingers per hand? Intuitively, one could expect a positive answer; that is, forces produced by each hand are expected to co-vary negatively across trials to bring down the total force variability, while forces produced by each finger within-a-hand are expected to co-vary negatively to reduce the variability of that hand's contribution to the total force. The subjects were instructed to follow a trapezoidal time profile with the signal corresponding to the force produced by a set of instructed fingers in one-hand tasks with two-finger force production and in two-hand tasks with involvement of both symmetrical and asymmetrical finger pairs in the two hands. Finger force co-variation across trials was quantified and used as an index of stabilization of the force produced by all the instructed fingers, and of the force produced by finger pairs within-a-hand. No major differences were seen between the dominant and the non-dominant hand and between the two-hand tasks with symmetrical and asymmetrical finger involvement. Stronger synergies were seen in the index-middle finger pair as compared to the ring-little finger pair. The main result of the study is the significantly weaker or even lacking two-finger force stabilizing synergies within-a-hand during two-hand tasks while such synergies were present in one-hand tasks. This observation points at a potential limitation in the ability of the CNS to organize synergies at two levels of a control hierarchy simultaneously. It also allows suggesting a hypothesis on two types of synergies in the human motor repertoire, well-practiced synergies that form a library serving as the foundation for all novel actions, and freshly assembled synergies.
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Slobounov S, Hallett M, Newell KM. Perceived effort in force production as reflected in motor-related cortical potentials. Clin Neurophysiol 2004; 115:2391-402. [PMID: 15351382 DOI: 10.1016/j.clinph.2004.05.021] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/12/2004] [Indexed: 11/23/2022]
Abstract
OBJECTIVE The perceived effort in force production was investigated in a series of experiments where subjects performed isometric force tasks with the index finger while the nominal force, the rate of force development and signal gain were controlled and rating of effort for each task was obtained. The hypotheses tested were that: (1) force-related perceived effort may selectively influence the amplitude of motor-related cortical potentials (MRCP); and (2) the MRCP may directly reflect the intensity of perceived effort associated with force production. METHODS The force trace was displayed on a computer monitor using various control-gains so that the perceived effort matched or was at odds with actual muscular effort applied to the load cell to accomplish the task. The MRCP were extracted from continuous EEG records using averaging techniques. RESULTS The findings showed that: (1) perceived effort proportionally increased with the increment of rate of force development and force error, but not with the actual force level; (2) the amplitude of the MRCP increased when a large amount of force was accompanied by an increased rate of force development; (3) the amplitude of early components of MRCP preceding the force initiation (MP-100 to 0) increased as a function of anticipated effort, whereas, the amplitude movement-monitoring potentials (MMP) accompanying the force production increased as a function of actual force level. CONCLUSIONS The findings from this study provide additional insight clarifying the distinct patterns of EEG activity exhibited under various degrees of perceived effort associated with force output. The findings support the hypothesis that the early components of MRCP may reflect the perceived effort associated with achieving the required force level. SIGNIFICANCE The results from this study may be considered in the larger context of physical activity in terms of importance of perceived effort during prescribed exercise in rehabilitation programs.
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Affiliation(s)
- Semyon Slobounov
- Department of Kinesiology, Pennsylvania State University, University Park, PA, USA.
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Chiang H, Slobounov SM, Ray W. Practice-related modulations of force enslaving and cortical activity as revealed by EEG. Clin Neurophysiol 2004; 115:1033-43. [PMID: 15066527 DOI: 10.1016/j.clinph.2003.12.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/03/2003] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To examine the role of practice in the modification of force enslaving and motor-related cortical potentials using finger force production tasks. This study follows-up previous studies in our laboratory using experienced piano players. METHODS Two experiments were performed. In Expt. 1, 6 subjects participated in a pre and post EEG session separated by 12 practice sessions which were conducted 3 days a week for 4 weeks. With visual feedback regarding the accuracy of force output, subjects produced one of two force levels with either their ring or index finger. Experiment 2 followed a similar procedure to that of Expt. 1 with additional visual feedback to the degree of finger independency. Both behavioral (isometric force output) and EEG data preceding and accompanying force responses were measured. RESULTS In Expt. 1 we found that forced enslaving increased along with improved accuracy following 4 weeks of practice. We found a reduction of motor potential (MP) amplitude for the index but not the ring finger following practice. Experiment 2 showed an increase in accuracy and reduction in force enslaving after practice with adequate feedback. The amplitude of MP for the index finger also decreased after practice as in Expt. 1. In contrast, the amplitude of MP for the ring finger increased after practice. CONCLUSIONS The present study extends our earlier work with piano players and shows the role of practice in modifying behavioral and cortical measures. The concluding theme emergent from our studies is that individuated finger control is not hard-wired, but rather plastic and greatly influenced by deliberate practice. SIGNIFICANCE This research supports the idea that experience and practice are associated with changes in behavioral and EEG correlates of task performance and have clinical implications in disorders such as stroke or dystonia. Practice-related procedures offer useful approaches to rehabilitation strategies.
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Affiliation(s)
- H Chiang
- Department of Kinesiology, The Pennsylvania State University, 19 Recreation Building, University Park, PA 16802-5702, USA
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Carson RG, Kelso JAS. Governing coordination: behavioural principles and neural correlates. Exp Brain Res 2003; 154:267-74. [PMID: 14608455 DOI: 10.1007/s00221-003-1726-8] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2002] [Accepted: 09/16/2003] [Indexed: 01/11/2023]
Abstract
The coordination of movement is governed by a coalition of constraints. The expression of these constraints ranges from the concrete--the restricted range of motion offered by the mechanical configuration of our muscles and joints; to the abstract--the difficulty that we experience in combining simple movements into complex rhythms. We seek to illustrate that the various constraints on coordination are complementary and inclusive, and the means by which their expression and interaction are mediated systematically by the integrative action of the central nervous system (CNS). Beyond identifying the general principles at the behavioural level that govern the mutual interplay of constraints, we attempt to demonstrate that these principles have as their foundation specific functional properties of the cortical motor systems. We propose that regions of the brain upstream of the motor cortex may play a significant role in mediating interactions between the functional representations of muscles engaged in sensorimotor coordination tasks. We also argue that activity in these "supramotor" regions may mediate the stabilising role of augmented sensory feedback.
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Affiliation(s)
- R G Carson
- Perception and Motor Systems Laboratory, School of Human Movement Studies, The University of Queensland, 4072 Brisbane, Queensland, Australia.
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Murphy BA, Haavik Taylor H, Wilson SA, Oliphant G, Mathers KM. Rapid reversible changes to multiple levels of the human somatosensory system following the cessation of repetitive contractions: a somatosensory evoked potential study. Clin Neurophysiol 2003; 114:1531-7. [PMID: 12888037 DOI: 10.1016/s1388-2457(03)00127-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Numerous somatosensory evoked potential (SEP) studies have provided clear evidence that during repetitive voluntary movement, the transmission of somatosensory afferent information is attenuated. The objective of this work was to determine if this gating phenomenon could persist beyond the period of repetitive movement. METHODS We recorded spinal, brainstem, and cortical SEPs to median nerve stimulation before and immediately after a modified 20 min repetitive typing task that did not involve the thenar muscles. RESULTS There were significant decreases in pre-central cortical and subcortical SEP amplitudes for several minutes following task cessation. CONCLUSIONS These results demonstrate the persistence of the gating phenomenon beyond the cessation of the actual repetitive movement. They also indicate that plastic changes do occur in cortical and subcortical components of the somatosensory system, following voluntary repetitive contractions. SIGNIFICANCE The persistence of changes in somatosensory processing beyond the period of repetitive activity may be relevant to the initiation of overuse injuries.
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Affiliation(s)
- B A Murphy
- Department of Sport and Exercise Science, Tamaki Campus, University of Auckland, Private Bag 92019, Auckland, New Zealand.
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Slobounov S, Chiang H, Johnston J, Ray W. Modulated cortical control of individual fingers in experienced musicians: an EEG study. Electroencephalographic study. Clin Neurophysiol 2002; 113:2013-24. [PMID: 12464342 DOI: 10.1016/s1388-2457(02)00298-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The present research was designed to address the nature of interdependency between fingers during force production tasks in subjects with varying experience in performing independent finger manipulation. Specifically, behavioral and electroencephalographic (EEG) measures associated with controllability of the most enslaved (ring) and the least enslaved (index) fingers was examined in musicians and non-musicians. METHODS Six piano players and 6 age-matched control subjects performed a series of isometric force production tasks with the index and ring fingers. Subjects produced 3 different force levels with either their index or ring fingers. We measured the isometric force output produced by all 4 fingers (index, ring, middle and little), including both ramp and static phases of force production. We applied time-domain averaging of EEG single trials in order to extract 4 components of the movement-related cortical potentials (MRCP) preceding and accompanying force responses. RESULTS Three behavioral findings were observed. First, musicians were more accurate than non-musicians at reaching the desired force level. Second, musicians showed less enslaving as compared to non-musicians. And third, the amount of enslaving increased with the increment of nominal force levels regardless of whether the index or ring finger was used as the master finger. In terms of EEG measures, we found differences between tasks performed with the index and ring fingers in non-musicians. For musicians, we found larger MRCP amplitudes at most electrode sites for the ring finger. CONCLUSIONS Our data extends previous enslaving research and suggest an important role for previous experience in terms of the independent use of the fingers. Given that a variety of previous work has shown finger independence to be reflected in cortical representation in the brain and our findings of MRCP amplitude associated with greater independence of fingers in musicians, this suggests that what has been considered to be stable constraints in terms of finger movements can be modulated by experience. SIGNIFICANCE This work supports the idea that experience is associated with changes in behavioral and EEG correlates of task performance and may have clinical implications in disorders such as stroke or focal hand dystonia. Practice-related procedures offer useful approaches to rehabilitation strategies.
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Affiliation(s)
- S Slobounov
- Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802-5702, USA.
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