- A majority of cells in the M1 are associated with directional movement of the limbs
- This is based on cell's ability to change their firing rates (release of electrical impulse) based on the direction that an organism wants to move its limb

M1 Cells and Directional Movement

- A minority of M1 neurons are associated with muscle contractions, which will change the degree of firing (electrical impulses) in order to allow a muscle contraction to take place

Muscle Contraction of M1 Cells

- As established, the M1 is responsible for different parts of the body 
- However, an important distinction to make is whether the M1 is responsible for muscle contraction or directional movement of different body parts
- The M1 is ultimately responsible for both 

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- As show below, different regions of the body will take up dispropriate amounts of space in the M1
- Another way of visualizing this phenomena is through the "motor homunculus" which shows a figure's body parts enlarged to various degrees, based on the space it takes up in the motor cortex 
- However, this has been described as "oversimplifying"  the organization of the M1, which can be increasingly complex

Size Breakdown of M1

Breedlove, S. & Watson, N. (2017). Behavioral neuroscience, eighth edition. Oxford University Press.

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