Differences in motor imagery time when predicting task duration in alpine skiers and equestrian riders

Differences in motor imagery abilities in active and sedentary individuals: new insights from backward-walking imagination

Evidence has shown that imagining a complex action, like backward-walking, helps improve the execution of the gesture. Despite this, studies in sport psychology have provided heterogeneous results on the use of motor imagery (MI) to improve performance. We aimed to fill this gap by analyzing how sport experience influences backward-walking MI processes in a sample of young women (n = 41, mean age = 21 ± 2.2) divided into Active and Sedentary. All participants were allocated to two randomized mental chronometric tasks, in which they had first to imagine and then execute forward-walking (FW) and backward-walking (BW). The Isochrony Efficiency measured the difference between imagination and execution times in both conditions (FW and BW). Moreover, we analyzed the ability to vividly imagine FW and BW within various perspectives in both groups through the Vividness of Movement Imagery Questionnaire (VMIQ-2). Findings showed that active individuals performed better in the BW imagery task when compared to sedentary ones (F1,39 = 4.98; p = 0.03*), while there were no differences between groups in the FW imagery task (F1,39 = .10; p = 0.75). Further, VMIQ-2 had evidenced that the ability to imagine backward is influenced by perspective used. Specifically, the use of internal visual imagery (IVI) led to worse Isochrony Efficiency (t32,25 = 2.16; p = 0.04*), while the use of kinesthetic imagery (KIN) led to better Isochrony Efficiency (t32,25 =  - 2.34; p = 0.03*). These results suggest a close relation between motor experience and complex motor imagery processes and open new insights for studying these mental processes.

Fragebögen und Testmethoden der Bewegungsvorstellung

Zusammenfassung. Mentale Vorstellungen werden im Sport vornehmlich in Form von Vorstellungen einer Bewegung eingesetzt. Der Gebrauch von Bewegungsvorstellungen hat sich inzwischen in einer Vielzahl von Sportarten etabliert und der Nutzen systematischer Bewegungsvorstellungen wurde mehrfach belegt. Durch Bewegungsvorstellung soll das Erlernen und Stabilisieren von Bewegungen gefördert und in der Rehabilitation die Rückgewinnung bereits erlernter Fähigkeiten erleichtert werden. Die Qualität der Bewegungsvorstellung hat darauf einen weitreichenden Einfluss. Daher geht diese Übersicht umfassend auf die Quantifizierung der Vorstellungsqualität ein. Möglichkeiten zur Erfassung der Bewegungsvorstellung werden vorgestellt. Bei der Messung anhand von Fragebögen welche die Leichtigkeit (z. B. Movement Imagery Questionnaire), Lebhaftigkeit (z. B. Vividness of Movement Imagery Questionnaire) und den Gebrauch von Bewegungsvorstellungen im Sport (z. B. Sport Imagery Questionnaire) abbilden, spielen verschiedene Sinnesmodalitäten wie visuelle und kinästhetische Repräsentationen aber auch die Perspektive der Vorstellung eine zentrale Rolle. Als Alternative gelten quantitative Messungen der Vorstellungszeit. Sowohl Einsatzmöglichkeiten als auch Grenzen der Messmethoden werden aufgezeigt.

Complexity and familiarity enhance single-trial detectability of imagined movements with electroencephalography

OBJECTIVE

We sought to determine whether the sensorimotor rhythms (SMR) elicited during motor imagery (MI) of complex and familiar actions could be more reliably detected with electroencephalography (EEG), and subsequently classified on a single-trial basis, than those elicited during relatively simpler imagined actions.

METHODS

Groups of healthy volunteers, including experienced pianists and ice hockey players, performed MI of varying complexity and familiarity. Their electroencephalograms were recorded and compared using brain-computer interface (BCI) approaches and spectral analyses.

RESULTS

Relative to simple MI, significantly more participants produced classifiable SMR for complex MI. During MI of performance of a complex musical piece, the EEG of the experienced pianists was classified significantly more accurately than during MI of performance of a simpler musical piece. The accuracy of EEG classification was also significantly more sustained during complex MI.

CONCLUSION

MI of complex actions results in EEG responses that are more reliably classified for more individuals than MI of relatively simpler actions, and familiarity with actions enhances these responses in some cases.

SIGNIFICANCE

The accuracy of SMR-based BCIs in non-communicative patients may be improved by employing familiar and complex actions. Increased sensitivity to MI may also improve diagnostic accuracy for severely brain-injured patients in a vegetative state.

Imagining is Not Doing but Involves Specific Motor Commands: A Review of Experimental Data Related to Motor Inhibition

There is now compelling evidence that motor imagery (MI) and actual movement share common neural substrate. However, the question of how MI inhibits the transmission of motor commands into the efferent pathways in order to prevent any movement is largely unresolved. Similarly, little is known about the nature of the electromyographic activity that is apparent during MI. In addressing these gaps in the literature, the present paper argues that MI includes motor execution commands for muscle contractions which are blocked at some level of the motor system by inhibitory mechanisms. We first assemble data from neuroimaging studies that demonstrate that the neural networks mediating MI and motor performance are not totally overlapping, thereby highlighting potential differences between MI and actual motor execution. We then review MI data indicating the presence of subliminal muscular activity reflecting the intrinsic characteristics of the motor command as well as increased corticomotor excitability. The third section not only considers the inhibitory mechanisms involved during MI but also examines how the brain resolves the problem of issuing the motor command for action while supervising motor inhibition when people engage in voluntary movement during MI. The last part of the paper draws on imagery research in clinical contexts to suggest that some patients move while imagining an action, although they are not aware of such movements. In particular, experimental data from amputees as well as from patients with Parkinson’s disease are discussed. We also review recent studies based on comparing brain activity in tetraplegic patients with that from healthy matched controls that provide insights into inhibitory processes during MI. We conclude by arguing that based on available evidence, a multifactorial explanation of motor inhibition during MI is warranted.