ANAT 321 Lecture Notes - Lecture 24: Nature Reviews Neuroscience, Supplementary Motor Area, Primary Motor Cortex

• School: McGill University
• Department: Anatomy & Cell Biology
• Course: ANAT 321
• Professor: David Ragsdale

Document Summary

Sma and pre-sma are active during internally initiated responses: most of these areas are in the medial surface of the brain. In humans, lesions to these areas can cause paradoxical effects on volitional movement: alien limb syndrome. The affected hand will do things that are out of the person"s voluntary control. E. g. the phone rings and the person picks it up with one hand and the affected hand will take back the phone and hang it back up. The movements are purposeful, appear to be volitional movements, but are inappropriate for the situation: utilization behaviour. Kind of alien limb syndrome, but a repetition of a certain behaviour. After a large lesion, there is no spontaneous movement, no volitional movement: e. g. a person will lie in bed and do nothing, even in they"re not paralyzed. The patient will say that the feeling of wanting to move never happened process of internally generating volitional actions is affected.