Corticomotor Plasticity Underlying Priming Effects of Motor Imagery on Force Performance

Abstract

The neurophysiological processes underlying the priming effects of motor imagery (MI) on force performance remain poorly understood. Here, we tested whether the priming effects of embedded MI practice involved short-term changes in corticomotor connectivity. In a within-subjects counterbalanced experimental design, participants (n = 20) underwent a series of experimental sessions consisting of successive maximal isometric contractions of elbow flexor muscles. During inter-trial rest periods, we administered MI, action observation (AO), and a control passive recovery condition. We collected electromyograms (EMG) from both agonists and antagonists of the force task, in addition to electroencephalographic (EEG) brain potentials during force trials. Force output was higher during MI compared to AO and control conditions (both p < 0.01), although fatigability was similar across experimental conditions. We also found a weaker relationship between triceps brachii activation and force output during MI and AO compared to the control condition. Imaginary coherence topographies of alpha (8–12 Hz) oscillations revealed increased connectivity between EEG sensors from central scalp regions and EMG signals from agonists during MI, compared to AO and control. Present results suggest that the priming effects of MI on force performance are mediated by a more efficient cortical drive to motor units yielding reduced agonist/antagonist coactivation.

Post-Activation Performance Enhancement and Motor Imagery Are Efficient to Emphasize the Effects of a Standardized Warm-Up on Sprint-Running Performances

“…MI results in activation of brain motor regions [ 35 ], especially if participants have great expertise in sports performance, i.e., if they are high-level athletes [ 36 ], as in the present study. Recently, it has been shown that MI can have an acute effect on force performance, mainly by inducing a more efficient cortical drive to motor units and optimizing agonist/antagonist coactivation [ 37 ]. However, the activation of the motor neural system remains weaker than during voluntary contraction [ 38 ].…”

Enhancing motor imagery detection efficacy using multisensory virtual reality priming

“…Using a paired sample t-test, a statistically significant difference was observed [t(9) = 2.935, p = 0.016] in muscle activity between the audio-visual (M = 8.16, SD = 1.40) and multisensory (M= 9.51, SD= 2.30) priming sessions, as the force feedback gloves were on only in the latter condition. The slight activity observed during the motor imagery tasks are likely indicative of the signal noise floor of the EMG sensors, but could also be an indicator of covert motor function that has been reported during motor imagery (Lebon et al, 2008;Dos Anjos et al, 2022).…”

Mentales Training im Sport

“…In zahlreichen Veröffentlichungen wurde die steigernde Wirkung des mentalen Trainings auf die Muskelkraft dokumentiert. Während die ersten Studien zu diesem Thema die Wirksamkeit an sehr kleinen, im Alltag vergleichsweise selten verwendeten Muskeln untersuchten, konnte dieser Effekt inzwischen auch beispielsweise für die Brust- und Beinmuskulatur bestätigt werden 11 18 .…”

“…Erklärt werden kann die Wirkung damit, dass durch ein Vorstellungstraining neuronale Anpassungsprozesse auf kortikaler Ebene angeregt werden, wodurch es zu einem verbesserten efferenten Output kommt und somit motorische Einheiten effizienter rekrutiert werden können 18 . Für die Anwendung eines Vorstellungstrainings zur Kraftsteigerung ist es wichtig, dass maximale Kontraktionen vorgestellt werden und der Fokus auf den kinästhetischen Wahrnehmungsanteilen liegt 19 .…”