Differentiating the Brain's involvement in Executed and Imagined Stepping using fMRI

The purpose of this study was to extend the extant literature regarding brain areas that are activated during executed and imagined lower limb movement. Past research suggests that stepping, as a cyclical movement, should activate the motor control areas of the brain that integrates smooth movements with spinal cord nerves. The neuronal activity needed to imagine that same activity is likely to recruit additional sensory-motor areas that provide initiation and inhibition signals, making this task take on a neuronal activity pattern that is more similar to discrete movements. To assess this research question, 16 participants took part in the current study where they executed and imagined stepping, with movement at the hip, knee, and ankle joints, while viewing a computer-generated image of a human walking. A block design with a total of 10 blocks for rest and task for each condition was used. Rest blocks lasted 18 seconds, followed by an 18-second display of the visual stimulus. Results showed that in the executed condition, areas of the brain that are most prominently associated with sensory-motor activity were activated. In the imagined condition areas of the brain associated with movement control, inhibition of movement, and the integration of sensory input and motor output (parietal and occipital) were also activated. These findings contribute to the literature identifying brain areas that are activated in lower limb locomotion.