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Movement/*physiology

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Jo, H.-G., Hinterberger, T., Wittmann, M., Borghardt, T. L., & Schmidt, S. (2013). Spontaneous EEG fluctuations determine the readiness potential: is preconscious brain activation a preparation process to move? Experimental Brain Research, 231(4), 495–500. https://doi.org/10.1007/s00221-013-3713-z

It has been repeatedly shown that specific brain activity related to planning movement develops before the conscious intention to act. This empirical finding strongly challenges the notion of free will. Here, we demonstrate that in the Libet experiment, spontaneous fluctuations of the slow electro-cortical potentials (SCPs) account for a significant fraction of the readiness potential (RP). The individual potential shifts preceding self-initiated movements were classified as showing a negative or positive shift. The negative and positive potential shifts were analyzed in a self-initiated movement condition and in a no-movement condition. Comparing the potential shifts between both conditions, we observed no differences in the early part of the potential. This reveals that the apparently negative RP emerges through an unequal ratio of negative and positive potential shifts. These results suggest that ongoing negative shifts of the SCPs facilitate self-initiated movement but are not related to processes underlying preparation or decision to act.
Lorey, B., Naumann, T., Pilgramm, S., Petermann, C., Bischoff, M., Zentgraf, K., Stark, R., Vaitl, D., & Munzert, J. (2013). How equivalent are the action execution, imagery, and observation of intransitive movements? Revisiting the concept of somatotopy during action simulation. Brain and Cognition, 81(1), 139–150. https://doi.org/10.1016/j.bandc.2012.09.011

Jeannerod (2001) hypothesized that action execution, imagery, and observation are functionally equivalent. This led to the major prediction that these motor states are based on the same action-specific and even effector-specific motor representations. The present study examined whether hand and foot movements are represented in a somatotopic manner during action execution, imagery, and action observation. The experiment contained ten conditions: three execution conditions, three imagery conditions, three observation conditions, and one baseline condition. In the nine experimental conditions, participants had to execute, observe, or imagine right-hand extension/flexion movements or right-foot extension/flexion movements. The fMRI results showed a somatotopic organization within the contralateral premotor and primary motor cortex during motor imagery and motor execution. However, there was no clear somatotopic organization of action observation in the given regions of interest within the contralateral hemisphere, although observation of these movements activated these areas significantly.
Lorey, B., Pilgramm, S., Bischoff, M., Stark, R., Vaitl, D., Kindermann, S., Munzert, J., & Zentgraf, K. (2011). Activation of the parieto-premotor network is associated with vivid motor imagery--a parametric FMRI study. PloS One, 6(5), e20368. https://doi.org/10.1371/journal.pone.0020368

The present study examined the neural basis of vivid motor imagery with parametrical functional magnetic resonance imaging. 22 participants performed motor imagery (MI) of six different right-hand movements that differed in terms of pointing accuracy needs and object involvement, i.e., either none, two big or two small squares had to be pointed at in alternation either with or without an object grasped with the fingers. After each imagery trial, they rated the perceived vividness of motor imagery on a 7-point scale. Results showed that increased perceived imagery vividness was parametrically associated with increasing neural activation within the left putamen, the left premotor cortex (PMC), the posterior parietal cortex of the left hemisphere, the left primary motor cortex, the left somatosensory cortex, and the left cerebellum. Within the right hemisphere, activation was found within the right cerebellum, the right putamen, and the right PMC. It is concluded that the perceived vividness of MI is parametrically associated with neural activity within sensorimotor areas. The results corroborate the hypothesis that MI is an outcome of neural computations based on movement representations located within motor areas.
Pilgramm, S., Lorey, B., Stark, R., Munzert, J., Vaitl, D., & Zentgraf, K. (2010). Differential activation of the lateral premotor cortex during action observation. BMC Neuroscience, 11, 89. https://doi.org/10.1186/1471-2202-11-89

BACKGROUND: Action observation leads to neural activation of the human premotor cortex. This study examined how the level of motor expertise (expert vs. novice) in ballroom dancing and the visual viewpoint (internal vs. external viewpoint) influence this activation within different parts of this area of the brain. RESULTS: Sixteen dance experts and 16 novices observed ballroom dance videos from internal or external viewpoints while lying in a functional magnetic resonance imaging scanner. A conjunction analysis of all observation conditions showed that action observation activated distinct networks of premotor, parietal, and cerebellar structures. Experts revealed increased activation in the ventral premotor cortex compared to novices. An internal viewpoint led to higher activation of the dorsal premotor cortex. CONCLUSIONS: The present results suggest that the ventral and dorsal premotor cortex adopt differential roles during action observation depending on the level of motor expertise and the viewpoint.

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Last update from database: 04.06.25, 15:35 (UTC)

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