Cortical mechanisms involved in visuomotor coordination during precision walking

Long-Lasting Working Memories of Obstacles Established by Foreleg Stepping in Walking Cats Require Area 5 of the Posterior Parietal Cortex

“…Moreover, we also limited the lesions to the ansate gyrus and part of the caudal bank of the ansate sulcus, because preliminary studies have found single neurons in this region that increase their activity when an obstacle passes under the walking animal (Drew et al, 2008) and when an animal is standing straddling an obstacle between the forelegs and hindlegs .…”

“…This is based on our finding that the memory of obstacle height in lesioned animals is not influenced for short pauses. This memory is used to generate appropriate activity in the foreleg region of the motor cortex to lift the forelegs over the obstacle and in the hindleg region of the motor cortex to lift the hindlegs over the obstacle if the animal does not pause (this portion of our model has been well studied) (Drew et al, 2008). We propose that area 5 receives a signal related to the enhanced flexion of the forelegs and that this signal leads to maintained activity in neurons in area 5 while the animal is straddling the obstacle.…”

“…The study of the visual control of walking has revealed many of the strategies used to detect and avoid obstacles in humans (Patla, 1997;Patla and Greig, 2006;Marigold et al, 2007;Cinelli and Patla, 2008;Marigold and Patla, 2008) and animals (Drew, 1993;Bellozerova and Sirota, 2003;Drew et al, 2008). One consistent theme that has emerged is that visual fixation of obstacles is rarely used to guide ongoing leg movements.…”

Versatile robotic interface to evaluate, enable and train locomotion and balance after neuromotor disorders

“…3). These deficits have been attributed to the loss of visuomotor control, which heavily relies on the damaged motor cortex 15 . We tested the hypothesis that impaired equilibrium maintenance ( Fig.…”

Development of Bipedal and Quadrupedal Locomotion in Humans from a Dynamical Systems Perspective

“…Apparently, their adaptive self-organizing brains explored the available solutions for slow and fast locomotion, with subsequent selection of the preferred patterns for traveling around. These outside-in mechanisms (see Stuart, 2007) may involve mesencephalic and subthalamic regions, cerebellum, basal ganglia, and hypothalamus (see Takakusaki et al, 2006); the posterior parietal cortex may plan the travel and the motor cortex may contribute to traveling through fields with obstacles (Drew et al, 2008), allowing the necessary modifications during traveling, and utilizing the adaptive self-organizing processes to explore, select neural groups, and execute the preferred locomotor patterns. For the adaptive self-organization in the brain, dynamic instability, a form of complexity, is typical for the neuronal systems (Friston, 2000a, b, c), allowing the selective consolidation of synaptic connections within the selected neuronal groups (Edelman, 1993).…”