Chapter 8 Key Terms Flashcards
What are effector and functional levels of motor representation?
The effector level focuses on the specific muscles and joints involved in a movement. The functional level emphasizes the goal or intention of a movement, transcending specific muscle activity to achieve the intended action
Give an example of how a movement can be generated without input from cortex.
Reflexes provide a clear example, such as the knee-jerk reflex. When the patellar tendon
is tapped, sensory signals from muscle spindles activate alpha motor neurons in the
spinal cord, causing the muscle to contract and the leg to extend
What are functional differences between lateral and medial motor regions? How are these areas involved in control of eye and hand movements?
Lateral motor regions, such as the premotor cortex, guide movements based on external
stimuli, like visual cues. Medial regions, including the supplementary motor area, plan
internally guided movements, like spontaneous eye or hand movements without
external prompts.
What are the distinct contributions of frontal and parietal cortices in motor planning? Describe the hierarchical control of action
The frontal cortex selects and sequences movements, integrating them into coherent
plans. The parietal cortex translates sensory input into motor commands, enabling
spatially accurate and goal-directed actions.
How do the evolutionarily new and old portions of M1 differ? Where are corticomotor neurons found and why are they evolutionarily important?
The older rostral M1 primarily modulates motor signals via spinal interneurons, while
the newer caudal M1 directly innervates alpha motor neurons. Corticomotor neurons
enable precise control of fine motor actions, crucial for tool use and complex behaviors.
Describe two organization schemes for motor cortex. Are these mutually exclusive? Describe ways they are compatible and incompatible with each other.
Motor cortex is organized into somatotopic maps (homunculus) and action maps. These
frameworks align, as action maps often localize within regions of the homunculus. However, the focus on ethologically relevant actions in action maps may conflict with
the muscle-centric view of the homunculus.
Why is population coding useful for motor planning?
Population coding represents movement across multiple neurons, allowing for accurate
and flexible control of complex actions involving multiple muscles and joints.
What is the evidence for multiple pathways between parietal and frontal cortex
supporting different functions?
The dorso-dorsal pathway facilitates visually guided reaching, while the ventro-dorsal
pathway aids in object manipulation and gesture production. These pathways illustrate the division of motor functions in parietal-frontal networks.
How do central pattern generators (CPGs) contribute to movement?
CPGs in the spinal cord produce rhythmic motor outputs, such as walking, without
cortical input. These circuits enable efficient, automatic control of repetitive movements, while higher brain regions oversee goal-directed adjustments.
What role does the cerebellum play in sensorimotor learning?
The cerebellum integrates sensory input with motor commands to refine movements,
enhancing coordination and accuracy. It plays a vital role in adapting motor skills
through error correction during practice.
What is the affordance competition hypothesis?
This hypothesis suggests that multiple action plans are simultaneously activated and
compete based on environmental affordances and goals, with the most suitable plan
winning and being executed
How does the basal ganglia influence motor control and learning?
The basal ganglia regulate action initiation through a balance of excitatory and
inhibitory signals. They enable selection of goal-relevant movements and suppression
of competing actions, facilitating motor learning via reinforcement signals.
What is the perception-action cycle, and how does it support motor control?
The perception-action cycle describes the continuous exchange between sensory input
and motor output. This loop ensures actions are adaptive, aligning with environmental
changes to achieve goals.
How do mirror neurons relate to motor cognition?
Mirror neurons fire both when performing an action and observing the same action
performed by others. They are believed to support understanding, imitation, and learning of motor behaviors.
adaptive learning
affordance competition hypothesis
Affordance
Competition
alpha motor neurons
gamma motor neurons
apraxia
ataxia
central pattern generators
common coding theory
corticomotor neurons
dorsal streams (motor)
ventral streams (motor)
effectors
efference copy
forward model
hemiballismus
hierarchical motor control
homunculus
internally guided movements
mirror neurons
motor chunks/ motor programs
motor hierarchy
motor theory of cognition
motor units
neuromuscular junction
optic ataxia
perception-action cycle
population vector
prism adaptation
sensorimotor learning
spinal motor circuits
spinal reflexes
basal ganglia (and components)
cerebellum
corticospinal tract
lateral prefrontal cortex
primary motor cortex
posterior parietal cortex/ inferior parietal lobule
secondary motor areas (premotor cortex and SMA)
supplementary eye fields
thalamus
