Chapter 8 - The Sensorimotor System Flashcards
Sensory feedback
Sensory signals that are produced by a response and are often used to guide the continuation of the response
Posterior parietal association cortex
An area of association cortex that receives input from the visual, auditory, and somatosensory systems and is involved in the perception of spatial location and guidance of voluntary behavior
Frontal eye field
A small area of prefrontal cortex that controls eye movements
Action map
A mental representation of the world or some part of it based on subjective perceptions rather than objective geographical knowledge
(via APA Dictionary of Pyschology)
pg.222 in the book
Astereognosia
An inability to recognize objects by touch that is not attributable to a simple sensory deficit or to an intellectual impairment
Movement vigor
The control of the speed and amplitude of movement based on motivational factors
Motor units
A single motor neuron and all of the skeletal muscle fibers that are innervated by it
Motor end-plate
The receptive area on a muscle fiber at a neuromuscular junction
Motor pool
All of the motor neurons that innervate the fibers of a given muscle
Flexors
Muscles that act to bend or flex a joint
Extensors
Muscles that act to straighten or extend a joint
Apraxia
A disorder in which patients have great difficulty performing movements when asked to do so out of context but can readily perform them spontaneously in natural situations
Contralateral neglect
A disturbance of the patient’s ability to respond to stimuli on the side of the body opposite to a site of brain damage, usually the left side of the body following damage to the right parietal lobe
Dorsolateral prefrontal association cortex
An area of the prefrontal cortex that plays a role in the evaluation of external stimuli and the initiation of complex voluntary motor responses
Secondary motor cortex
An area of the cerebral cortex that receives much of its input from association cortex and sends much of its output to primary motor cortex
Supplementary motor area
The area of secondary motor cortex that is within and adjacent to the longitudinal fissure
Synergistic muscles
Pairs of muscles whose contraction produces a movement in the same direction
Antagonistic muscles
Pairs of muscles that act in opposition
Isometric contraction
Contraction of a muscle that increases the force of its pull but does not shorten the muscle
Dynamic contraction
Contraction of a muscle that causes the muscle to shorten
Golgi tendon organs
Receptors that are embedded in tendons and are sensitive to the amount of tension in the skeletal muscles to which their tendons are attached
Muscle spindles
Receptors that are embedded in skeletal muscle tissue and are sensitive to changes in muscle length
Intrafusal muscle
A threadlike muscle that adjusts the tension on a muscle spindle
Intrafusal motor neuron
A motor neuron that innervates an intrafusal muscle
Skeletal muscle (extrafusal muscle)
Striated muscle that is attached to the skeleton and is usually under voluntary control
Patellar tendon reflex
The stretch reflex that is elicited when the patellar tendon is struck
Stretch reflex
A reflexive counteracting reaction to an unanticipated external stretching force on a muscle
Premotor cortex
The area of the secondary motor cortex that lies between the supplementary motor area and the lateral fissure
Mirror neurons
Neurons that fire when an individual performs a particular goal-directed hand movement or when they observe the same goal-directed movement performed by another
Primary motor cortex
The cortex of the precentral gyrus, which is the major point of departure for motor signals descending from the cerebral cortex into lower levels of the sensorimotor system
Somatotopic
Organized, like the primary somatosensory cortex, according to a map of the surface of the body
Motor homunculus
The somatotopic map of the human primary motor cortex
Stereognosis
The process of identifying objects by touch
Spindle afferent neurons
Neurons that carry signals from muscle spindles into the spinal cord via the dorsal root
Withdrawal reflex
The reflexive withdrawal of a limb when it comes in contact with a painful stimulus
Reciprocal innervation
The principle of spinal cord circuitry that causes a muscle to automatically relax when a muscle that is antagonistic to it contracts
Cocontraction
The simultaneous contraction of antagonistic muscles
Recurrent collateral inhibition
The inhibition of a neuron that is produced by its own activity via a collateral branch of its axon and an inhibitory interneuron
Central sensorimotor programs
Patterns of activity that are programmed into the sensorimotor system
Motor equivalence
The ability of the sensorimotor system to carry out the same basic movement in different ways that involve different muscle
Response-chunking hypothesis
The idea that practice combines the central sensorimotor programs that control individual responses into programs that control sequences (chunks) of behavior
