#8.3 Cerebral Cortex, Corticospinal Tracts, Cerebellum

primary motor cortex

CEREBRAL CORTEX:

Directly stimulates the spinal motor neurons that control muscle contraction

primary motor cortex

CEREBRAL CORTEX:

Produces skilled, purposeful movements such as speech and hand coordination

primary motor cortex

CEREBRAL CORTEX:

Active during movement imagination, memory of movement, and processing of action verbs

primary motor cortex

CEREBRAL CORTEX:

Closely aligned with the somatosensory cortex for accurate sensory feedback during movement

primary motor cortex

CEREBRAL CORTEX:

Stimulation produced a certain outcome, not a particular muscle movement

posterior parietal cortex

CEREBRAL CORTEX:

First area to activate in movement planning

posterior parietal cortex

CEREBRAL CORTEX:

helps monitor body position relative to external space

posterior parietal cortex

CEREBRAL CORTEX:

Damage leads to difficulty locating objects or navigating around obstacles

posterior parietal cortex

CEREBRAL CORTEX:

plans movement in relation to environment

premotor cortex

CEREBRAL CORTEX:

Becomes active in response to external cues that guide movement (e.g., a green light indicating when to go)

premotor cortex

CEREBRAL CORTEX:

Helps plan motor actions based on incoming sensory information

supplementary motor cortex

CEREBRAL CORTEX:

Important in planning sequences of voluntary movements

supplementary motor cortex

CEREBRAL CORTEX:

Works with inhibition of incorrect motor actions (autopilot movements)

supplementary motor cortex

CEREBRAL CORTEX:

Especially active during self-initiated (has pattern + voluntary) movements rather than stimulus-driven ones

prefrontal cortex

CEREBRAL CORTEX:

higher level of cognition

prefrontal cortex

CEREBRAL CORTEX:

Responsible for decision-making before action execution

prefrontal cortex

CEREBRAL CORTEX:

Evaluates consequences of movement

prefrontal cortex

CEREBRAL CORTEX:

Immature in children → impulsive motor control behavior

adult: learned = knows consequences

prefrontal cortex

CEREBRAL CORTEX:

inactive during dreams, making it illogical

corticospinal tracts

movement output pathways

lateral & medial corticospinal tracts

corticospinal tracts < (2)

lateral corticospinal tract

CORTICOSPINAL TRACT:

Crosses in the medulla, controlling muscles on the opposite side

lateral corticospinal tract

CORTICOSPINAL TRACT:

Responsible for fine, independent movements of distal muscles, such as the fingers, hands, and feet

medial corticospinal tract

CORTICOSPINAL TRACT:

Includes axons from the cortex, midbrain tectum, vestibular nucleus, and reticular formation

medial corticospinal tract

CORTICOSPINAL TRACT:

Controls muscles of the trunk and neck, managing posture, walking, standing, bending, and bilateral motor coordination

cerebellum

mainly for rhythm, pattern, balance, and also speech

cerebellum

Coordinates and fine-tunes movement + Controls timing and precision

cerebellum

Important in rapid shifts in attention, motor learning, and error correction

cerebellum

Contains more neurons than the rest of the brain combined

cerebellum

damage = poor movement timing, inaccurate aiming, slurred speech, balance problems

basal ganglia

Initiates self-generated (spontaneous) movement

basal ganglia

Regulates movement vigor (strength, speed)

basal ganglia

Critical in forming automatic motor skills or habits (e.g., driving)

basal ganglia

Uses dopamine input from the substantia nigra to guide reward-based movement