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Ergebnisse 4 Einträge
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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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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.
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This study addresses the controversy over how motor maps are organized during action simulation by examining whether action simulation states, that is, motor imagery and action observation, run on either effector-specific and/or action-specific motor maps. Subjects had to observe or imagine three types of movements effected by the right hand or the right foot with different action goals. The functional magnetic resonance imaging results showed an action-specific organization within premotor and posterior parietal areas of both hemispheres during action simulation, especially during action observation. There were also less pronounced effector-specific activation sites during both simulation processes. It is concluded that the premotor and parietal areas contain multiple motor maps rather than a single, continuous map of the body. The forms of simulation (observation, imagery), the task contexts (movements related to an object, with usual/unusual effector), and the underlying reason for performing the simulation (rate your subjective success afterwards) lead to the specific use of different representational motor maps within both regions. In our experimental setting, action-specific maps are dominant especially, during action observation, whereas effector-specific maps are recruited to only a lesser degree.
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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.
Erkunden
Team
- Vaitl (4)
Eintragsart
Sprache
- Englisch (4)
Thema
- Adult
- action mapping (1)
- action observation (1)
- Analysis of Variance (1)
- Brain Mapping (3)
- Brain Mapping/methods (1)
- Brain/physiology (1)
- Dancing/physiology (1)
- Electromyography (1)
- Female (4)
- fMRI (1)
- Foot/physiology (2)
- Frontal Lobe/*physiology (1)
- Functional Laterality (1)
- Goals (1)
- Hand/physiology (2)
- Humans (4)
- Image Processing, Computer-Assisted (1)
- *Imagery, Psychotherapy/methods (1)
- Imagination/*physiology (2)
- Magnetic Resonance Imaging (2)
- Magnetic Resonance Imaging/methods (1)
- Magnetic Resonance Imaging/*methods (1)
- Male (3)
- Motion Perception/*physiology (1)
- Motor Activity/*physiology (1)
- Motor Cortex/*physiology (3)
- motor imagery (1)
- motor simulation (1)
- Movement/*physiology (3)
- Neuropsychological Tests (1)
- Parietal Lobe/*physiology (1)
- Photic Stimulation (2)
- Psychomotor Performance/*physiology (1)
- Recognition, Psychology/physiology (1)
- somatotopic mapping (1)
- Surveys and Questionnaires (1)
- Visual Perception/*physiology (1)
- Young Adult (2)