scholarly journals Differential contributions of implicit and explicit learning mechanisms to various contextual cues in dual adaptation

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253948
Author(s):  
Maria N. Ayala ◽  
Denise Y. P. Henriques
Keyword(s):  
Motor System ◽  
Visual Cues ◽  
Passive Movement ◽  
Contextual Cues ◽  
Learning Mechanisms ◽  
Experimental Conditions ◽  
Dual Adaptation ◽  
Human Motor ◽  
Implicit And Explicit ◽  
Implicit And Explicit Learning

The ability to switch between different visuomotor maps accurately and efficiently is an invaluable feature to a flexible and adaptive human motor system. This can be examined in dual adaptation paradigms where the motor system is challenged to perform under randomly switching, opposing perturbations. Typically, dual adaptation doesn’t proceed unless each mapping is trained in association with a predictive cue. To investigate this, we first explored whether dual adaptation occurs under a variety of contextual cues including active follow-through movements, passive follow-through movements, active lead-in movements, and static visual cues. In the second experiment, we provided one group with a compensatory strategy about the perturbations (30° CW and 30° CCW rotations) and their relationships to each context (static visual cues). We found that active, but not passive, movement cues elicited dual adaptation. Expectedly, we didn’t find evidence for dual adaptation using static visual cues, but those in the Instruction group compensated by implementing aiming strategies. Then, across all experimental conditions, we explored the extent by which dual learning is supported by both implicit and explicit mechanisms, regardless of whether they elicited dual adaptation across all the various cues. To this end, following perturbed training, participants from all experiments were asked to either use or ignore the strategy as they reached without visual feedback. This Process Dissociation Procedure teased apart the implicit and explicit contributions to dual adaptation. Critically, we didn’t find evidence for implicit learning for those given instructions, suggesting that when explicit aiming strategies are implemented in dual adaptation, implicit mechanisms are likely not involved. Thus, by implementing conscious strategies, dual adaptation can be easily facilitated even in cases where learning would not occur otherwise.

scholarly journals Differential contributions of implicit and explicit learning mechanisms to various contextual cues in dual adaptation

2020 ◽  
Author(s):  
Maria Nadine Ayala ◽  
Denise Henriques
Keyword(s):  
Motor System ◽  
Visual Cues ◽  
Active Movement ◽  
Contextual Cues ◽  
Learning Mechanisms ◽  
Dual Adaptation ◽  
Instruction Group ◽  
Human Motor ◽  
Implicit And Explicit ◽  
Implicit And Explicit Learning

The ability to switch between different tasks accurately and efficiently is an invaluable feature to a flexible and adaptive human motor system. This can be examined in dual adaptation paradigms where the motor system is challenged to perform under randomly switching, opposing perturbations. Typically, dual adaptation doesn’t proceed unless each mapping is trained in association with a predictive cue. To investigate this, we first explored whether dual adaptation occurs under a variety of contextual cues including active follow-through movements, passive follow-through movements, active three-part lead-in movements, and static visual cues. In a final intervention, we provided our Instructed group with a compensatory strategy about the perturbations (30° CW/CCW rotations) and their relationships to each context (static visual cues). This allowed us to explore the extent by which dual learning is supported by both implicit and explicit mechanisms, regardless of whether or not they elicited dual adaptation across all the various cues. To this end, following perturbed training, participants from all experiments were asked to either use or ignore the strategy as they reached without visual feedback. This Process Dissociation Procedure teased apart the implicit and explicit contributions to dual adaptation. We found that active movement cues, but not passive ones, elicited dual adaptation. Expectedly, static visual cues didn’t elicit dual adaptation, but those in the Instruction group compensated by implementing aiming strategies. Critically, we found no implicit contributions in this Instruction group, but an effect of instruction, suggesting that explicit aiming strategies inhibit implicit mechanisms in dual adaptation. Thus, by implementing conscious strategies, dual adaptation can be easily facilitated even in cases where learning would not occur otherwise.

scholarly journals Task-dependent switching of feedback controllers

2021 ◽  
Author(s):  
Justinas Česonis ◽  
David W. Franklin
Keyword(s):  
Motor Control ◽  
Feedback Control ◽  
Motor System ◽  
The Other ◽  
Contextual Cues ◽  
Feedback Controllers ◽  
Human Motor Control ◽  
Mixed Schedule ◽  
Human Motor ◽  
Human Participants

AbstractThe separation of distinct motor memories by contextual cues is a well known and well studied phenomenon of feedforward human motor control. However, there is no clear evidence of such context-induced separation in feedback control. Here we test both experimentally and computationally if context-dependent switching of feedback controllers is possible in the human motor system. Specifically, we probe visuomotor feedback responses of our human participants in two different tasks – stop and hit – and under two different schedules. The first, blocked schedule, is used to measure the behaviour of stop and hit controllers in isolation, showing that it can only be described by two independent controllers with two different sets of control gains. The second, mixed schedule, is then used to compare how such behaviour evolves when participants regularly switch from one task to the other. Our results support our hypothesis that there is contextual switching of feedback controllers, further extending the accumulating evidence of shared features between feedforward and feedback control.

Higher-order representations of newly learnt action sounds in the human motor system

2011 ◽  
Author(s):  
F. Waszak ◽  
S. Schuetz-Bosbach ◽  
C. Weiss ◽  
L. Ticini
Keyword(s):  
Motor System ◽  
Higher Order ◽  
Human Motor

Electrogenic, K + -dependent chloride transport in locust hindgut

1982 ◽  
Vol 299 (1097) ◽  
pp. 585-595 ◽  
Keyword(s):  
Chloride Transport ◽  
Passive Movement ◽  
Water Reabsorption ◽  
Experimental Conditions ◽  
Cl Transport ◽  
Neuropeptide Hormone ◽  
Flux Measurements ◽  
Ion Sensitive Microelectrodes ◽  
Voltage Clamping ◽  
Electrochemical Potentials

Potassium chloride is the major salt recycled in most insect excretory systems. Ion and water reabsorption occur in the rectum by active transport of Cl- and largely passive movement of K+. Both these processes are stimulated several fold by a neuropeptide hormone acting via cyclic AMP (cAMP). This Cl- transport process was investigated by using intracellular ion-sensitive microelectrodes, radiotracer flux measurements, voltage clamping, ion substitutions and inhibitors. The mucosal entry step for Cl- is energy-requiring and highly selective, and is stimulated directly by cAMP and luminal K +. Under some experimental conditions, measured electrochemical potentials for cations across the mucosal membrane are too small to drive Cl- entry by NaCl or KC1 cotransport mechanisms; moreover, net 36C1- flux is independent of the apical Na+ potential. Similarly no evidence for a HCO 3 -Cl- exchange was obtained. We conclude that Cl- transport in locust gut is different from mechanisms currently proposed for vertebrate tissues.

Crucial Effects of Weightlessness on Human Orientation

1993 ◽  
Vol 3 (3) ◽  
pp. 307-314 ◽  
Author(s):  
H. Mittelstaedt ◽  
S. Glasauer
Keyword(s):  
Visual Cues ◽  
Decisive Role ◽  
Experimental Conditions ◽  
Subjective Vertical ◽  
Independent Components ◽  
Human Orientation ◽  
The Mean ◽  
Trunk Tilt

This contribution examines the consequences of two remarkable experiences of subjects in weightlessness, 1) the missing of sensations of trunk tilt and of the respective concomitant reflexes when the head is tilted with respect to the trunk, and 2) the persistence of a perception of “up” and “down,” that is, of the polarity of the subjective vertical (SV) in the absence of, as well as in contradiction to, visual cues. The first disproves that the necessary head-to-trunk coordinate transformation be achieved by adding representations of the respective angles gained by utricles and neck receptors, but corroborates an extant model of cross-multiplication of utricular, saccular, and neck receptor components. The second indicates the existence of force-independent components in the determination of the SV. Although the number of subjects is still small and experimental conditions are not as homogeneous as desired, measurements and/or reports on the ground, in parabolic, and in space flight point to the decisive role of the saccular z-bias, that is, of a difference of the mean resting discharges of saccular units polarized in the rostrad and the caudad (±z-) direction.

Cholinergic Influences on Use-Dependent Plasticity

2002 ◽  
Vol 87 (1) ◽  
pp. 166-171 ◽  
Author(s):  
L. Sawaki ◽  
B. Boroojerdi ◽  
A. Kaelin-Lang ◽  
A. H. Burstein ◽  
C. M. Bütefisch ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Motor System ◽  
Global Changes ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Corticomotor Excitability ◽  
Dependent Plasticity ◽  
Motor Practice ◽  
Randomized Design ◽  
Human Motor

Motor practice elicits use-dependent plasticity in humans as well as in animals. Given the influence of cholinergic neurotransmission on learning and memory processes, we evaluated the effects of scopolamine (a muscarinic receptor antagonist) on use-dependent plasticity and corticomotor excitability in a double-blind placebo-controlled randomized design study. Use-dependent plasticity was substantially attenuated by scopolamine in the absence of global changes in corticomotor excitability. These results identify a facilitatory role for cholinergic influences in use-dependent plasticity in the human motor system.

Human motor unit recordings: Origins and insight into the integrated motor system

2011 ◽  
Vol 1409 ◽  
pp. 42-61 ◽  
Author(s):  
Jacques Duchateau ◽  
Roger M. Enoka
Keyword(s):  
Motor Unit ◽  
Motor System ◽  
Human Motor ◽  
Insight Into

Conscious and Unconscious Representations of Observed Actions in the Human Motor System

2014 ◽  
Vol 26 (9) ◽  
pp. 2028-2041 ◽  
Author(s):  
Alan D. A. Mattiassi ◽  
Sonia Mele ◽  
Luca F. Ticini ◽  
Cosimo Urgesi
Keyword(s):  
Motor System ◽  
Action Observation ◽  
Single Pulse ◽  
Basic Mechanism ◽  
Perceptual Awareness ◽  
Unconscious Perception ◽  
Motor Resonance ◽  
Specific Increase ◽  
Human Motor ◽  
Hand Action

Action observation activates the observer's motor system. These motor resonance responses are automatic and triggered even when the action is only implied in static snapshots. However, it is largely unknown whether an action needs to be consciously perceived to trigger motor resonance. In this study, we used single-pulse TMS to study the facilitation of corticospinal excitability (a measure of motor resonance) during supraliminal and subliminal presentations of implied action images. We used a forward and backward dynamic masking procedure that successfully prevented the conscious perception of prime stimuli depicting a still hand or an implied abduction movement of the index or little finger. The prime was followed by the supraliminal presentation of a still or implied action probe hand. Our results revealed a muscle-specific increase of motor facilitation following observation of the probe hand actions that were consciously perceived as compared with observation of a still hand. Crucially, unconscious perception of prime hand actions presented before probe still hands did not increase motor facilitation as compared with observation of a still hand, suggesting that motor resonance requires perceptual awareness. However, the presentation of a masked prime depicting an action that was incongruent with the probe hand action suppressed motor resonance to the probe action such that comparable motor facilitation was recorded during observation of implied action and still hand probes. This suppression of motor resonance may reflect the processing of action conflicts in areas upstream of the motor cortex and may subserve a basic mechanism for dealing with the multiple and possibly incongruent actions of other individuals.

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