Perspectives and problems in motor learning

Wolpert, Daniel M.; Ghahramani, Zoubin; Flanagan, J. Randall

doi:10.1016/s1364-6613(00)01773-3

Cited by 573 publications

(396 citation statements)

References 56 publications

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“…[55,73]). Conceivably, when a secondary cognitive task sufficiently or overly strains the individual's attentional capacity, covert motor preparatory attention that is part of the automatized process of postural control may be affected as well.…”

Section: Cognitive Demands Of the Secondary Taskmentioning

confidence: 99%

“…A well-established view suggests that the brain utilizes internal representations of forward motor commands and multi-sensory feedbacks to monitor, update, calibrate, and maintain the body's position (e.g., [37,72,74]). Findings derived from spatial-neglect patients who suffer from postural instability suggest in particular the involvement of parietal cortical functions in postural control probably implicating internal body representations [27,38,44,65,66,73,75]. In addition to maintaining the internal body representation in 3D space, parietal lobe functions may also underlie covert preparatory motor attention [55,56], somewhat analogous to their roles in covert orienting of visual attention [46].…”

Section: Introductionmentioning

confidence: 99%

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Dual-tasking postural control: Aging and the effects of cognitive demand in conjunction with focus of attention

Huxhold

Schmiedek

et al. 2006

Brain Research Bulletin

506

379

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Postural control in everyday life is generally accompanied by posture-unrelated cognitive activity. Thus, mild forms of dual-tasking postural control are the norm rather than the exception. Based on this consideration and available evidence, we propose and empirically examined, in young and old adults, a non-monotonic, U-shaped relation between the efficacy of postural control and concurrent cognitive demands that reflect opposing trends of the effects of attention focus and attentional resource competition. When instructed to perform an easy cognitive task that presumably shifted the focus of attention away from posture control, the center of body pressure (COP) excursions decreased both in young and older adults relative to a single-task baseline where the focus of attention was explicitly directed towards the postural control task itself. However, when performing more demanding cognitive tasks, older adults showed increased COP displacements, in line with the predicted Ushape function, whereas young adults did not. We outline mechanisms linking postural control to cognitive demand and suggest routes for future investigation.

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Section: Cognitive Demands Of the Secondary Taskmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dual-tasking postural control: Aging and the effects of cognitive demand in conjunction with focus of attention

Huxhold

Schmiedek

et al. 2006

Brain Research Bulletin

506

379

View full text Add to dashboard Cite

show abstract

“…Sensory attenuation refers to the decreased salience of self-generated sensations with respect to that of externally generated sensations. In the somatosensory domain, this is reflected in the fact that when one actively touches his/her own body (self-touch), the touch feels less intense (and less ticklish) compared with an identical touch applied by another person or a machine (16)(17)(18)(19). Somatosensory attenuation can be effectively studied using the classical force-matching paradigm, which allows a psychophysical quantification of the degree of attenuation introduced by a simulated self-touch between the index fingers by means of a motor (20)(21)(22)(23).…”

mentioning

confidence: 99%

Body ownership determines the attenuation of self-generated tactile sensations

Kilteni

Ehrsson

2017

Proc. Natl. Acad. Sci. U.S.A.

131

132

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Self-perception depends on the brain's abilities to differentiate our body from the environment and to distinguish between the sensations generated as a consequence of voluntary movement and those arising from events in the external world. The first process refers to the sense of ownership of our body and relies on the dynamic integration of multisensory (afferent) signals. The second process depends on internal forward models that use (efferent) information from our motor commands to predict and attenuate the sensory consequences of our movements. However, the relationship between body ownership and sensory attenuation driven by the forward models remains unknown. To address this issue, we combined the rubber hand illusion, which allows experimental manipulation of body ownership, and the force-matching paradigm, which allows psychophysical quantification of somatosensory attenuation. We found that a rubber right hand pressing on the left index finger produced somatosensory attenuation but only when the model hand felt like one's own (illusory selftouch); reversely, the attenuation that was expected to occur during actual self-touch with the real hands was reduced when the participants simultaneously experienced ownership of a rubber right hand that was placed at a distance from their left hand. These results demonstrate that the sense of body ownership determines somatosensory attenuation. From a theoretical perspective, our results are important because they suggest that body ownership updates the internal representation of body state that provides the input to the forward model generating sensory predictions during voluntary action.sensory attenuation | body ownership | forward models | state estimation | predictive motor control T he distinction between self and nonself is fundamental for all biological organisms. External signals constitute potential threats and must be clearly distinguished from self-related signals. Imagine, for example, how dangerous it would be if you could not distinguish between a spider crawling up your neck and your own fingers scratching the same part of the skin. The central nervous system has therefore developed mechanisms to distinguish between self-related signals and non-self-related signals. Two neural mechanisms are considered particularly important for this differentiation. First, the integration of signals from different sensory modalities (e.g., vision, touch, proprioception; multisensory integration) leads to the formation of a central representation of one's own body in space (1, 2). Sensory information attributed to this representation is experienced as originating from one's own body (sense of body ownership). Second, when we actively move our body, the brain predicts the sensory consequences of the movements by using internal copies of the voluntary motor commands (efference copy) (3-5). This allows the central nervous system to disambiguate self-produced sensations from sensations arising from external causes. However, the relationship between these two basic self-...

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“…Thus, motor re-learning could be viewed as the process of acquiring both forward and inverse internal models, appropriate for different tasks [59]. The process of acquiring and retaining the internal models is a computational approach aimed at adapting to different situations quickly [60].…”

Section: Computational Approaches To the Motor Systemmentioning

confidence: 99%

“…Several concepts of internal models have been presented in neuroscience and most of them have been supported by neurophysiological and neuroimaging studies [53,55,59,60]. The internal model paradigm has its origin in control theory, and robotics and was studied in the sensory system for processes other than motor control.…”

Section: Computational Approaches To the Motor Systemmentioning

confidence: 99%