Final answer:
The experiment to discover the role of the premotor cortex in response selection was conducted by Wilder Penfield using direct cortical stimulation on awake patients. This revealed the cortex's role in planning and initiating movements, particularly the premotor cortex's input to the primary motor cortex which eventually stimulates muscle contractions.
Step-by-step explanation:
The experiment conducted to discover the premotor cortex's role in response selection involved the use of direct cortical stimulation while patients were awake, as conducted by Wilder Penfield and others. The premotor cortex is part of the frontal lobe of the cerebrum, which is responsible for planning and initiating movements. Penfield's technique included probing the surface of the cortex with electrical stimulation while the patient was under local anesthesia, allowing for the observation of muscle movements and other responses. This method provided insights into the functions of different cortical areas, including the precentral gyrus and its role in stimulating muscle contraction. Building upon such foundational work, we understand that the premotor cortex plays a crucial role in planning complex movements before they are executed by the primary motor cortex. It receives input from various brain areas, including the prefrontal cortex and the sensory regions, which is necessary for coordinating voluntary muscle movements. Large Betz cells within the primary motor cortex project through the corticobulbar and corticospinal tracts to lower motor neurons, which then stimulate skeletal muscles to produce coordinated actions.