Final answer:
The basal ganglia are primarily responsible for movement control and posture, and they also play a significant role in the regulation of motivation. Damage to these structures can result in motor impairments and issues with motivation.
Step-by-step explanation:
The primary function of the basal ganglia, a collection of interconnected brain areas, is to play an essential role in movement control and posture as well as in the regulation of motivation. These nuclei are part of a larger motor pathway that involves the intake of cortical information, which is then processed through direct and indirect streams. The direct pathway functions to cause the disinhibition of the thalamus leading to excited cortex and increased motor activity, while the indirect pathway typically decreases thalamus excitation through extra connections, resulting in decreased activity in the cerebral cortex and less motor activity. Damage to the basal ganglia, as seen in disorders like Parkinson's disease, can lead to motor impairments such as a shuffling gait and motivational regulation issues.