Role of the cortex in visuomotor control of arm stability

Abstract

Whereas numerous motor control theories describe the control of arm trajectory during reach, the control of stabilization in a constant arm position (i.e., visuomotor control of arm posture) is less clear. Three potential mechanisms have been proposed for visuomotor control of arm posture: 1) increased impedance of the arm through co-contraction of antagonistic muscles, 2) corrective muscle activity via spinal/supraspinal reflex circuits, and/or 3) intermittent voluntary corrections to errors in position. We examined the cortical mechanisms of visuomotor control of arm posture and tested the hypothesis that cortical error networks contribute to arm stabilization. We collected electroencephalography (EEG) data from 10 young healthy participants across four experimental planar movement tasks. We examined brain activity associated with intermittent voluntary corrections of position error and antagonist co-contraction during stabilization. EEG beta-band (13–26 Hz) power fluctuations were used as indicators of brain activity, and coherence between EEG electrodes was used as a measure of functional connectivity between brain regions. Cortical activity in the sensory, motor, and visual areas during arm stabilization was similar to activity during volitional arm movements and was larger than activity during co-contraction of the arm. However, cortical connectivity between the sensorimotor and visual regions was higher during arm stabilization compared with volitional arm movements and co-contraction of the arm. The difference in cortical activity and connectivity between tasks might be attributed to an underlying visuomotor error network used to update motor commands for visuomotor control of arm posture. NEW & NOTEWORTHY We examined cortical activity and connectivity during control of stabilization in a constant arm position (i.e., visuomotor control of arm posture). Our findings provide evidence for cortical involvement during control of stabilization in a constant arm position. A visuomotor error network appears to be active and may update motor commands for visuomotor control of arm posture.

Contralesional Sensorimotor Network Participates in Motor Functional Compensation in Glioma Patients

“…We found an increasing tendency of alterations of nodal properties in the non-deficit group and an unchanging tendency in the deficit group compared with the healthy group. This finding further verified that the contralesional sensorimotor cortices are crucial for motor functional compensation (47,48). Moreover, our results showed that, regardless of the glioma location, the nodal efficiency, nodal clustering coefficient, and nodal local efficiency of the nodes (premotor-related thalamus) increased in the non-deficit group and decreased in the deficit group.…”

“…These findings indicated that the premotor-related thalamus played an important role in compensating for the damaged motor function in the nondeficit stage and significantly decreased the conveying efficiency in the deficit stage. Previous studies showed that the contralesional motor-related thalamus participated in motor plasticity by changing pathways and building midline-crossing contralesional corticospinal fibers (47,48). Hence, our findings verified this theory through functional networks and differed from previous verification through structural networks.…”

Altered Cortical Activity during a Finger Tap in People with Stroke

“…;Formaggio et al 2013;Snyder et al 2019), but there is also evidence of ipsilateral hemispheric involvement during a motor task, as shown in our study. Chen et al used repetitive Transcranial Magnetic Stimulation (rTMS) to brie y disrupt the ipsilateral motor cortex during a sequence of nger movements and found timing errors even with simple sequences (Chen et al 1997), suggesting that both hemispheres contribute to a simple motor task.…”

“…We collected EEG data while participants moved their index nger. During and at the end of the task, we quanti ed cortical activation using the change in EEG power relative to baseline in the beta band (13-26Hz) (Stancák and Pfurtscheller 1996; Pfurtscheller and Lopes da Silva 1999) and quanti ed connectivity between cortical areas using task-based coherence between EEG electrodes (Rappelsberger et al 1994;Gerloff et al 2006;Snyder et al 2019). We hypothesized that: 1.…”

Positional Stability of the Non-Dominant Hand is Associated with Difficulties in Daily Functioning in Schizophrenia

“…However, the relationship between the ability to maintain hand position and the performance of ADLs in patients with schizophrenia is not fully understood. A previous neurological study reported functional connectivity between the sensorimotor cortex and the visual cortex during arm posture maintenance, suggesting that motor commands are adjusted based on sensory information [15]. Patients with schizophrenia show sensorimotor coordination dysfunction [16].…”