Decay of inhibition in motor imagery

2020 ◽  
Vol 74 (1) ◽  
pp. 77-94 ◽  
Author(s):  
Victoria KE Bart ◽  
Iring Koch ◽  
Martina Rieger
Keyword(s):  
Motor Imagery ◽  
Mode Switching ◽  
Specific Inhibition ◽  
Sequential Effects ◽  
Action Mode ◽  
Subsequent Trial ◽  
Response Stimulus ◽  
Movement Parameters ◽  
Imagined Movement ◽  
Global Inhibition

During motor imagery, global inhibition and effector-specific inhibition contribute to prevent actual movements. We investigated the decay of inhibition using an action-mode switching paradigm. Participants switched between imagined and executed hand movements. Response–stimulus intervals (RSIs) were varied (200, 700, 1,300, and 2,000 ms). As inhibition (due to imagination) or activation (due to execution) in one trial affects performance in the subsequent trial, we analysed sequential effects. Evidence for the contribution of global inhibition (e.g., switch benefits in execution [E]—imagination [I] sequences compared with I-I sequences) and effector-specific inhibition (e.g., hand repetition costs after an imagination trial) was observed. Sequential effects decreased with increasing RSIs, indicating that both forms of inhibition are subject to decay. However, the decrease of sequential effects was less pronounced for global inhibition than for effector-specific inhibition. This indicates that global inhibition may decay slowly, whereas effector-specific inhibition decays rather quickly. In conclusion, global inhibition may be at least partly implemented in all contexts in which motor imagery has to be performed, whereas effector-specific inhibition may contribute to motor imagery only as soon as the exact movement parameters are known and may decay quickly after the imagined movement has been performed.

scholarly journals Inhibition in motor imagery: a novel action mode switching paradigm

2016 ◽  
Vol 24 (2) ◽  
pp. 459-466 ◽  
Author(s):  
Martina Rieger ◽  
Stephan F. Dahm ◽  
Iring Koch
Keyword(s):  
Motor Imagery ◽  
Mode Switching ◽  
Action Mode

scholarly journals Stopping vs Resting state during motor imagery paradigm

2021 ◽  
Author(s):  
Bastien Orset ◽  
Kyuhwa Lee ◽  
Ricardo Chavarriaga ◽  
Jose del R Millan
Keyword(s):  
Motor Imagery ◽  
Resting State ◽  
Beta Band ◽  
Movement Onset ◽  
Major Drawback ◽  
Non Invasive ◽  
Control Brain ◽  
Motor Actions ◽  
Imagined Movement ◽  
Termination Process

Current non-invasive Brain Machine interfaces commonly rely on the decoding of sustained motor imagery activity (MI). This approach enables a user to control brain-actuated devices by triggering predetermined motor actions. One major drawback of such strategy is that users are not trained to stop their actions. Indeed, the termination process involved in BMI is poorly understood with most of the studies assuming that the end of an MI action is similar to the resting state. Here we hypothesize that the process of stopping MI (MI termination) and resting state are two different processes that should be decoded independently due to the exhibition of different neural pattens. We compared the detection of both states transitions of an imagined movement, i.e. rest-to-movement (onset) and movement-to-rest (offset). Our results shows that both decoders show significant differences in term of performances and latency (N=17 Subjects) with the offset decoder able to detect faster and better MI termination. While studying this difference, we found that the offset decoder is primarily based on the use of features in Beta band which appears earlier. Based on this finding, we also proposed a Random Forrest based decoder which enable to distinguish three classes (MI, MI termination and REST).

Motor imagery helps updating internal models during microgravity exposure

2022 ◽  
Author(s):  
Dylan Rannaud Monany ◽  
Marie Barbiero ◽  
Florent Lebon ◽  
Jan Babič ◽  
Gunnar Blohm ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Normal Gravity ◽  
Parabolic Flight ◽  
Internal Models ◽  
Mere Exposure ◽  
Control Group ◽  
Motor Execution ◽  
Internal Representations ◽  
Before And After ◽  
Imagined Movement

Skilled movements result from a mixture of feedforward and feedback mechanisms conceptualized by internal models. These mechanisms subserve both motor execution and motor imagery. Current research suggests that imagery allows updating feedforward mechanisms, leading to better performance in familiar contexts. Does this still hold in radically new contexts? Here, we test this ability by asking participants to imagine swinging arm movements around shoulder in normal gravity condition and in microgravity in which studies showed that movements slow down. We timed several cycles of actual and imagined arm pendular movements in three groups of subjects during parabolic flight campaign. The first, control, group remained on the ground. The second group was exposed to microgravity but did not imagine movements inflight. The third group was exposed to microgravity and imagined movements inflight. All groups performed and imagined the movements before and after the flight. We predicted that a mere exposure to microgravity would induce changes in imagined movement duration. We found this held true for the group who imagined the movements, suggesting an update of internal representations of gravity. However, we did not find a similar effect in the group exposed to microgravity despite the fact participants lived the same gravitational variations as the first group. Overall, these results suggest that motor imagery contributes to update internal representations of movement in unfamiliar environments, while a mere exposure proved to be insufficient.

INDEPENDENT COMPONENT ANALYSIS SEPARATES SEQUENCE-SENSITIVE ERP COMPONENTS

2004 ◽  
Vol 14 (02) ◽  
pp. 667-678 ◽  
Author(s):  
INES JENTZSCH
Keyword(s):  
Independent Component Analysis ◽  
Human Performance ◽  
Brain Activity ◽  
Component Analysis ◽  
Independent Component ◽  
Sequential Effects ◽  
Stimulus Interval ◽  
Electrical Brain Activity ◽  
Sequence Of Events ◽  
Response Stimulus

Human performance is strongly influenced by the sequence of events. Decreasing the response-stimulus interval (RSI) between events qualitatively changes these so-called sequential effects. Using event-related brain potentials (ERPs) to detect electrical brain activity related to sequential patterns helps to uncover mechanisms underlying the observed performance data. Using a spatial compatible two-choice task ERPs were recorded from 32 electrode sites and Independent Component Analysis (ICA) applied to separate sequence-sensitive ERP components from two experiments, involving different RSIs. Independent Component Analysis was able to separate temporally and spatially overlapping ERP components. Sensitivity to the sequence of preceding events could be revealed in an early subcomponent of the N100 complex. Moreover, and in line with earlier reports sequential effects were also observed in P300 subcomponents.

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