Lesson 14: M1 and S1 Flashcards
Primary Motor cortex (m1)
Where we send motor command to, initiates voluntary complex movements
Executes movements planned in the premotor cortex
Has layer 5 neurons (Betz cells) send AP down descending spinal tracts
The Motor Homunculus
Not about force but about dexterity, lots of fine motor control in hands and face
Connecticut chain, everything connects. Appears at more then one joint simultaneously.
Overlap
Monkey experiment
Longer you stimulate the brain in one area the more complex the movement
Longer=larger movement
M1 and spinal cord not the same
M1= more complex movement
-not stimulation of one muscle
Brain has to create a plan before it executes it
M1 population vector
In cortical recordings, certain movements have higher firing rates because you are looking at one neuron
Depends on that angle for which you are firing at for that particular neuron
M1 neurons have preferred directions of movement (optimal)
chart can be used to show neurons preferred direction and the length of line represents the firing rate
M1 pop and movement vector
Population vector processed the observed movement vector
Movement vector can be predicted by population vector
See how m1 population vector evolves during a more compelling movement
Somatosensory cortex (s1)
Primary somatic sensory cortex (s1) is for processing area for sensory information.
Thalamus (Relay centre)and Primary somatic sensory cortex are connected.
Thalamus have two nuclei
-Ventral posterier medial nucleus
-Ventral posterier lateral nucleus
VPMN: relays somatosensory information from the face/oral cavity
VPLN: Relays information from the body (anything below neck)
Medial to lateral
Additional info
Area in s1 for each body part
higher sensory in face and hands
s1= plasticty
Brain can change representation based on stimulus. Can delete a section of sensory to use for something else
Phantom limb:
Pain you feeling in the part of limb that was amputated
