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Inhibition in motor imagery: a novel action mode switchingparadigm

View Article: PubMed Central - PubMed

ABSTRACT

Motor imagery requires that actual movements are prevented (i.e.,inhibited) from execution. To investigate at what level inhibition takes placein motor imagery, we developed a novel action mode switching paradigm.Participants imagined (indicating only start and end) and executed movementsfrom start buttons to target buttons, and we analyzed trial sequence effects.Trial sequences depended on current action mode (imagination or execution),previous action mode (pure blocks/same mode, mixed blocks/same mode, or mixedblocks/other mode), and movement sequence (action repetition, hand repetition,or hand alternation). Results provided evidence for global inhibition (indicatedby switch benefits in execution-imagination (E-I)-sequences in comparison toI-I-sequences), effector-specific inhibition (indicated by hand repetition costsafter an imagination trial), and target inhibition (indicated by targetrepetition benefits in I-I-sequences). No evidence for subthreshold motoractivation or action-specific inhibition (inhibition of the movement of aneffector to a specific target) was obtained. Two (global inhibition andeffector-specific inhibition) of the three observed mechanisms are activeinhibition mechanisms. In conclusion, motor imagery is not simply a weaker formof execution, which often is implied in views focusing on similarities betweenimagination and execution.

No MeSH data available.


Sequence of events in an execution and an imagination trial. A trial started whenparticipants pressed the two start buttons (start position). After an intervalof 500 ms, the stimulus was presented. Upon identification of the target button,participants released the corresponding start button and the stimulusdisappeared. Participants then executed or imagined moving to the target button,pressing and releasing it, and moving back to the start button. Whenparticipants arrived at the start button at the end of the (actual or imagined)movement they pressed it again. Imagination and execution were indicated by thecolor of the filled circle in the stimulus display
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Figure 1: Sequence of events in an execution and an imagination trial. A trial started whenparticipants pressed the two start buttons (start position). After an intervalof 500 ms, the stimulus was presented. Upon identification of the target button,participants released the corresponding start button and the stimulusdisappeared. Participants then executed or imagined moving to the target button,pressing and releasing it, and moving back to the start button. Whenparticipants arrived at the start button at the end of the (actual or imagined)movement they pressed it again. Imagination and execution were indicated by thecolor of the filled circle in the stimulus display

Mentions: In the novel action mode switching paradigm, participants imagined(indicating only start and end) and executed movements from two start buttons (onefor each hand) to one of four possible target buttons (two for each hand) upon thepresentation of a visual signal (Fig. 1).Trials were presented in pure blocks (imagination or execution trials only) andmixed blocks (both imagination and execution trials). Trial sequences differeddepending on current action mode (imagination or execution),previous action mode (pure blocks/same mode, mixed blocks/samemode, or mixed blocks/other mode), and the relationship between movements in twoconsecutive trials (movement sequence; complete repetition:movements with the same hand to the same target, hand repetition: movements with thesame hand to the other target, or hand alternation: movements with the other hand toeither target of that hand).


Inhibition in motor imagery: a novel action mode switchingparadigm
Sequence of events in an execution and an imagination trial. A trial started whenparticipants pressed the two start buttons (start position). After an intervalof 500 ms, the stimulus was presented. Upon identification of the target button,participants released the corresponding start button and the stimulusdisappeared. Participants then executed or imagined moving to the target button,pressing and releasing it, and moving back to the start button. Whenparticipants arrived at the start button at the end of the (actual or imagined)movement they pressed it again. Imagination and execution were indicated by thecolor of the filled circle in the stimulus display
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5120687&req=5

Figure 1: Sequence of events in an execution and an imagination trial. A trial started whenparticipants pressed the two start buttons (start position). After an intervalof 500 ms, the stimulus was presented. Upon identification of the target button,participants released the corresponding start button and the stimulusdisappeared. Participants then executed or imagined moving to the target button,pressing and releasing it, and moving back to the start button. Whenparticipants arrived at the start button at the end of the (actual or imagined)movement they pressed it again. Imagination and execution were indicated by thecolor of the filled circle in the stimulus display
Mentions: In the novel action mode switching paradigm, participants imagined(indicating only start and end) and executed movements from two start buttons (onefor each hand) to one of four possible target buttons (two for each hand) upon thepresentation of a visual signal (Fig. 1).Trials were presented in pure blocks (imagination or execution trials only) andmixed blocks (both imagination and execution trials). Trial sequences differeddepending on current action mode (imagination or execution),previous action mode (pure blocks/same mode, mixed blocks/samemode, or mixed blocks/other mode), and the relationship between movements in twoconsecutive trials (movement sequence; complete repetition:movements with the same hand to the same target, hand repetition: movements with thesame hand to the other target, or hand alternation: movements with the other hand toeither target of that hand).

View Article: PubMed Central - PubMed

ABSTRACT

Motor imagery requires that actual movements are prevented (i.e.,inhibited) from execution. To investigate at what level inhibition takes placein motor imagery, we developed a novel action mode switching paradigm.Participants imagined (indicating only start and end) and executed movementsfrom start buttons to target buttons, and we analyzed trial sequence effects.Trial sequences depended on current action mode (imagination or execution),previous action mode (pure blocks/same mode, mixed blocks/same mode, or mixedblocks/other mode), and movement sequence (action repetition, hand repetition,or hand alternation). Results provided evidence for global inhibition (indicatedby switch benefits in execution-imagination (E-I)-sequences in comparison toI-I-sequences), effector-specific inhibition (indicated by hand repetition costsafter an imagination trial), and target inhibition (indicated by targetrepetition benefits in I-I-sequences). No evidence for subthreshold motoractivation or action-specific inhibition (inhibition of the movement of aneffector to a specific target) was obtained. Two (global inhibition andeffector-specific inhibition) of the three observed mechanisms are activeinhibition mechanisms. In conclusion, motor imagery is not simply a weaker formof execution, which often is implied in views focusing on similarities betweenimagination and execution.

No MeSH data available.