Search Results

You are looking at 1 - 10 of 37 items for :

  • "cerebellum" x
  • Sport and Exercise Science/Kinesiology x
Clear All
Restricted access

Hanneke I. van Mier, Joel S. Perlmutter and Steven E. Petersen

In the present study, brain activations were measured using positron emission tomography (PET) over the course of practice. Fourteen right-handed participants were scanned during six 1-min periods of practice tracing a cutout maze design with their eyes closed. Practice-related decreases were found in the right premotor and posterior parietal cortex and left cerebellum, increases in the supplementary motor area (SMA) and primary motor cortex. The decrease in right premotor activity and the increase in SMA was significantly correlated with a decrease in the number of stops, implying involvement in learning and storing the movement sequence. The significant correlation between decreases in errors and left cerebellar and right posterior parietal activity suggests a role in accuracy. Involvement of the primary motor cortex in motor execution is suggested by the correlation of increased activation and movement speed. These results suggest that different neural structures (involving a premotor-parietal-cerebellar circuit) play a role in a sequential maze learning task.

Restricted access

Yu-Ting Tseng, Sanaz Khosravani, Arash Mahnan and Jürgen Konczak

This review addresses the role of exercise as an intervention for treating neurological disease. It focuses on three major neurological diseases that either present in acute or neurodegenerative forms—Parkinson’s disease, cerebellar ataxia, and cortical stroke. Each of the diseases affects primarily different brain structures, namely the basal ganglia, the cerebellum, and the cerebrum. These structures are all known to be involved in motor control, and the dysfunction of each structure leads to distinct movement deficits. The review summarizes current knowledge on how exercise can aid rehabilitation or therapeutic efforts. In addition, it addresses the role of robotic devices in enhancing available therapies by reviewing how robot-aided therapies may promote the recovery for stroke survivors. It highlights recent scientific evidence in support of exercise as a treatment for brain dysfunction, but also outlines the still open challenges for unequivocally demonstrating the benefits of exercise.

Restricted access

Edwin M. Robertson

The concept of canonical representations within the motor system has been both supported and refuted using a variety of behavioral studies. Here, based upon neurophysiological data, I discuss the relationship amongst those neuronal substrates of action and the behavioral components of a movement. A novel view of reaching and grasping has been proposed which predicts that movements with similar kinematic and dynamic properties have a similar representation within the nervous system (Smeets & Brenner, 1999). However this is broadly inconsistent with a variety of neurophysiological findings that emphasize the independence amongst representations of action.

Restricted access

Daniel Bullock

Calligraphic writing presents many challenges for motor control, including: learning and recall of stroke sequences; critical timing of stroke onsets and durations; fine control of grip and contact forces; and letterform invariance under size scaling, which entails fine control of stroke directions and amplitudes during recruitment and derecruitment of musculoskeletal degrees of freedom. Experimental and computational studies in behavioral neuroscience have progressed toward explaining the learning, planning, and control exercised in tasks that share features with calligraphic writing and drawing. This article highlights component operations ranging from parallel sequence representations to fine force control. Treated in succession are: competitive queuing models of sequence representation, performance, learning, and recall; letter size scaling and motor equivalence; cursive handwriting models in which sensory-motor transformations are performed by circuits that learn inverse differential kinematic mappings; and fine-grained control of timing and transient forces by circuit models that learn to solve inverse dynamics problems.

Restricted access

Jeroen B.J. Smeets and Eli Brenner

We agree with Robertson that our new view on grasping is a description of motor behavior rather than an exploration into the nature of the neural processing underlying this behavior. However, neurophysiologists might be inspired by our new view to ask other questions, perform other experiments, and analyze these differently. In this way, they could generate new insights about the neural control of grasping.

Restricted access

Anis Kamoun, Omar Hammouda, Abdelmoneem Yahia, Oussema Dhari, Houcem Ksentini, Tarak Driss, Nizar Souissi and Mohamed Habib Elleuch

The present study aimed to investigate the effect of acute nocturnal melatonin (MEL) ingestion on sleep quality, cognitive performance, and postural balance in older adults. A total of 12 older men (58 ± 5.74 years) volunteered to participate in this study. The experimental protocol consisted in two testing sessions after nocturnal MEL (10 mg) or placebo ingestion the night before the tests. During each session, sleep quality tests, cognitive tests, and postural balance protocol were conducted. Static and dynamic postural control was assessed using a force platform. Most of the sleep parameters have been improved following nocturnal MEL ingestion without any effect on cognitive performance. Likewise, measurements related to the center of pressure (CoP) have been significantly decreased with MEL compared with placebo. In conclusion, postural control has been improved the morning following nocturnal MEL ingestion in older adults. This trend could be explained by the potential effect of MEL on sleep quality and cerebellum.

Restricted access

Jay P. Mehta, Matthew D. Verber, Jon A. Wieser, Brian D. Schmit and Sheila M. Schindler-Ivens

We used functional magnetic resonance imaging (fMRI) to record human brain activity during slow (30 RPM), fast (60 RPM), passive (30 RPM), and variable rate pedaling. Ten healthy adults participated. After identifying regions of interest, the intensity and volume of brain activation in each region was calculated and compared across conditions (p < .05). Results showed that the primary sensory and motor cortices (S1, M1), supplementary motor area (SMA), and cerebellum (Cb) were active during pedaling. The intensity of activity in these areas increased with increasing pedaling rate and complexity. The Cb was the only brain region that showed significantly lower activity during passive as compared with active pedaling. We conclude that M1, S1, SMA, and Cb have a role in modifying continuous, bilateral, multijoint lower extremity movements. Much of this brain activity may be driven by sensory signals from the moving limbs.

Restricted access

Bettina Brendel, Michael Erb, Axel Riecker, Wolfgang Grodd, Hermann Ackermann and Wolfram Ziegler

The present study combines functional magnetic resonance imaging (fMRI) and reaction time (RT) measurements to further elucidate the influence of syllable frequency and complexity on speech motor control processes, i.e., overt reading of pseudowords. Tying in with a recent fMRI-study of our group we focused on the concept of a mental syllabary housing syllable sized ready-made motor plans for high- (HF), but not low-frequency (LF) syllables. The RT-analysis disclosed a frequency effect weakened by a simultaneous complexity effect for HF-syllables. In contrast, the fMRI data revealed no effect of syllable frequency, but point to an impact of syllable structure: Compared with CV-items, syllables with a complex onset (CCV) yielded higher hemodynamic activation in motor “execution” areas (left sensorimotor cortex, right inferior cerebellum), which is at least partially compatible with our previous study. We discuss the role of the syllable in speech motor control.

Restricted access

Semyon Slobounov, Tao Wu and Mark Hallett

Human upright posture is a product of a complex dynamic system that relies on integration of input from multimodal sensory sources. Extensive research has explored the role of visual, vestibular, and somatosensory systems in the control of upright posture. However, the role of higher cognitive function in a participant’s assessment of postural stability has been less studied. In previous research, we showed specific neural activation patterns in EEG associated with recognition of unstable postures in young healthy participants. Similar EEG patterns have been recently observed in regulation of posture equilibrium in dynamic stances. This article evaluates participants’ postural stability in dynamic stances and neural activation patterns underlying visual recognition of unstable postures using event-related functional MRI (fMRI). Our results show that the “stable” participants were successful in recognition of unstable postures of a computer-animated body model and experienced egocentric motion. Successful recognition of unstable postures in these participants induces activation of distinct areas of the brain including bilateral parietal cortex, anterior cingulate cortex, and bilateral cerebellum. In addition, significant activation is observed in basal ganglia (caudate nucleus and putamen) but only during perception of animated postures. Our findings suggest the existence of modality-specific distributed activation of brain areas responsible for detection of postural instability.

Restricted access

Victoria Galea, Robyn Traynor and Michael Pierrynowski

& Hazeltine, 1995 ; Semjen, Schulze, & Vorberg, 2000 ; Wing, 2002 ). Recent evidence points to the likely organization by more than one central timekeeper ( Repp, 2005 ; Repp & Su, 2013 ). The cerebellum may be uniquely involved with this form of control ( Ivry, Keele, & Diener, 1988 ; Spencer, Ivry