The motor cortex is located on both sides of the brain and contains three regions: the primary motor cortex which controls movements, the premotor cortex which prepares movements, and the supplementary motor area which aids in motor planning. An experiment on monkeys showed that different neurons in the motor cortex reacted at different stages of a button pressing task: some fired after the first light cue, some after the second light, and one important neuron fired from the first light through the movement. Malfunctions in the motor cortex can cause muscle twitching, weakness, and even paralysis.

1. MOTOR CORTEX (MC)
Mimi Apple

2. LOCATION
• Both sides of the brain
• There are three regions of the MC:
1. Primary- main control of
movements
2. Premotor- preparation of
movement
3. Supplementary (SMA)
a) Posterior parietal- motor planning
b) Primary somatosensory- very minor
part of movement

3. RESEARCH
• Weinrich and Wise (1982)
• Experiment on monkeys in the MC
• A button would light up, signaling
the monkey which button to press
AFTER the next time the same
button lit up
• The same button would light up and
the monkey would hit that button

4. RESEARCH CONTINUED
• What was learned from that experiment through NEURONS?
• After the first light, certain neurons in the motor cortex reacted then the same
neurons ceases before the second light turned on
• After the second light and during the moment when the monkey hits the button
another neuron lights up, and then stops after the motion is done
• But the most important neuron that reacted started after the first light and didn’t
cease until after the movement; connecting the other two neurons together

5. MALFUNCTIONS
• The person might experience
muscle twitching, loss in muscle
tone leading to weakness and in
extreme cases then the muscles
can become paralyzed