Module 10 Flashcards
What are the three principles of sensorimotor control mentioned in the text?
(1) The sensorimotor system is hierarchically organized. (2) Motor output is guided by sensory input. (3) Learning can change the nature and the locus of sensorimotor control.
How is the operation of the sensorimotor system compared to that of a large, efficient company?
Both are directed by commands that cascade down through hierarchical levels, with higher levels specifying general goals rather than specific plans of action.
What are the advantages of hierarchical organization in both the sensorimotor system and a large company?
Higher levels are left free to perform more complex functions, while lower levels execute more detailed tasks.
What characterizes the structure of both the sensorimotor system and a large company hierarchy?
They are parallel hierarchical systems, allowing control over lower levels through multiple paths.
What role does functional segregation play in the sensorimotor system and a large company hierarchy?
Each level is composed of different units (neural structures or departments), each performing a different function.
What is the main difference between sensory systems and the sensorimotor system in terms of information flow?
In sensory systems, information mainly flows up through the hierarchy, while in the sensorimotor system, information mainly flows down.
What role does sensory feedback play in directing responses in the sensorimotor system?
Sensory feedback plays an important role in directing responses, with most responses influenced by the sensory feedback they generate.
What are ballistic movements, and how are they influenced by sensory feedback?
Ballistic movements are brief, all-or-none, high-speed movements. They are not normally influenced by sensory feedback.
How are adjustments in motor output controlled during sensorimotor learning?
Many adjustments are controlled unconsciously by lower levels of the sensorimotor hierarchy without the involvement of higher levels.
What characterizes sensorimotor learning in terms of motor responses and conscious control?
During initial stages, individual responses are performed under conscious control; with practice, responses become organized into continuous sequences of action adjusted by sensory feedback without conscious regulation.
What are the two major areas of sensorimotor association cortex mentioned in the text?
The posterior parietal association cortex and the dorsolateral prefrontal association cortex.
What role does the posterior parietal association cortex play in sensorimotor control?
It integrates information about body position and external objects, directs behavior by providing spatial information, and directs attention.
What sensory systems does the posterior parietal cortex receive input from?
The visual system, the auditory system, and the somatosensory system.
Where does much of the output of the posterior parietal cortex go to?
It goes to areas of motor cortex located in the frontal cortex, including the dorsolateral prefrontal association cortex and various areas of secondary motor cortex.
What consequences can damage to the posterior parietal cortex produce?
Deficits in perception and memory of spatial relationships, accurate reaching and grasping, control of eye movement, attention, apraxia, and contralateral neglect.
Define apraxia.
Apraxia is a disorder of voluntary movement not attributable to paralysis or weakness, where patients have difficulty making specific movements, particularly out of context.
What is contralateral neglect?
Contralateral neglect is a disturbance of a patient’s ability to respond to stimuli on the side of the body opposite to the brain lesion, without simple sensory or motor deficits.
What is egocentric left?
Egocentric left is the deficit in responding to stimuli to the left of the patient’s own body, often observed in patients with contralateral neglect.
What is object-based contralateral neglect?
Object-based contralateral neglect is the failure to respond to the left side of objects, regardless of their position in the visual field.
How does unconscious perception manifest in patients with contralateral neglect?
Patients may exhibit unconscious perception by showing a tendency to look more in the direction of stimuli presented to their neglected side, or by demonstrating improved identification of fragmented drawings after exposure to complete versions they were not consciously aware of.
What are the two major areas of association cortex with important sensorimotor functions mentioned in the text?
The posterior parietal association cortex and the dorsolateral prefrontal association cortex.
What areas receive projections from the dorsolateral prefrontal association cortex?
Areas of secondary motor cortex, primary motor cortex, and the frontal eye field.
What types of activity do dorsolateral prefrontal neurons exhibit?
Some neurons show activity related to object characteristics or locations, while others show activity related to responses, firing before and during movement initiation.
What is the function of areas of secondary motor cortex?
They are involved in programming specific patterns of movements after receiving instructions from the dorsolateral prefrontal cortex.
What are mirror neurons?
Mirror neurons are neurons that fire both when an individual performs a specific action and when they observe the same action performed by another.
What is the significance of mirror neurons in social cognition?
They provide a possible mechanism for social understanding, cooperation, and imitation by mapping others’ actions onto one’s own action repertoire.
How do mirror neurons respond to the understanding of an action’s purpose?
They respond to the purpose of an action rather than superficial characteristics, firing even when the action is perceived indirectly or mentally represented.
Where have mirror neurons been found in macaque monkeys?
Mirror neurons have been found in several areas of the frontal and parietal cortex in macaque monkeys.
What is the main method used to study mirror neuron mechanisms in humans?
Functional MRI studies are the main method used to study mirror neuron mechanisms in humans.
What similarity exists between mirror mechanisms identified in humans and macaques?
The mirror mechanisms identified by functional MRI in humans tend to be in the same cortical areas as those identified by single-cell recording in macaques.
Where is the primary motor cortex located?
In the precentral gyrus of the frontal lobe.
What is the organization of the primary motor cortex known as?
Somatotopic organization, commonly referred to as the motor homunculus.
What is stereognosis?
Stereognosis is the process of identifying objects by touch.
What is the function of each primary motor cortex neuron traditionally thought to be?
Traditionally, each neuron was thought to encode the direction of movement.
What stimulation technique has been used to map the primary motor cortex in recent studies?
Longer bursts of current, which produce complex natural-looking response sequences.
What is the alternative to the idea that motor neurons are tuned to particular angles of movement?
The firing of many primary motor cortex neurons is related to the particular endpoint of a movement, not to the direction of the movement.
What does the firing of primary motor cortex neurons in freely moving monkeys suggest?
It suggests that many neurons are sensitive to the target location of movement, not just the direction.
What is the implication of primary motor cortex stimulation causing opposite movements depending on the starting position?
It implies that signals from every site in the primary motor cortex diverge greatly, allowing each site to get a body part to a target location regardless of the starting position.
What is a brain-computer interface (BCI)?
A brain-computer interface allows direct communication between a computer and the brain, usually via an array of electrodes placed in the brain.
What are some applications of brain-computer interfaces mentioned in the text?
Applications include controlling robotic arms and mitigating the effects of spinal cord damage.
What are the effects of extensive damage to the primary motor cortex?
It may disrupt fine motor control of specific body parts, produce deficits in stereognosis, and reduce the speed, accuracy, and force of movements. However, it does not eliminate voluntary movement completely.
What are the cerebellum and basal ganglia primarily responsible for?
They interact with different levels of the sensorimotor hierarchy and coordinate and modulate its activities.
What percentage of the brain’s neurons does the cerebellum contain?
More than half.
What types of information does the cerebellum receive?
Information from primary and secondary motor cortex, descending motor signals from brainstem motor nuclei, and feedback from motor responses via the somatosensory and vestibular systems.
What role is the cerebellum believed to play in motor learning?
It is believed to play a major role in motor learning, particularly in the learning of sequences of movements in which timing is a critical factor.
What are some effects of diffuse cerebellar damage on motor function?
Loss of accurate control of movement direction, force, velocity, and amplitude; difficulty adapting motor output to changing conditions; tremors; disturbances in balance, gait, speech, and eye movement.
What are some functions of the cerebellum beyond sensorimotor control?
Patients with cerebellar damage often display diverse sensory, cognitive, emotional, and memory deficits.
How do the cerebellum and basal ganglia differ structurally?
The cerebellum is organized systematically in lobes, columns, and layers, while the basal ganglia are a complex heterogeneous collection of interconnected nuclei.
What is the current understanding of the basal ganglia’s function?
In addition to their role in motor modulation, the basal ganglia are involved in cognitive functions, motivation, habit learning, and classical conditioning.
What is the theory regarding the basal ganglia’s role in movement vigor?
The basal ganglia are responsible for controlling the speed and amplitude of movement based on motivational factors.
What is the role of the basal ganglia in movement inhibition?
They are involved in actively suppressing motor activity that would otherwise be inappropriate or unhealthy, preventing symptoms of neurological or psychiatric disorders from emerging.
The _______ _______ association cortex provides important spatial information and helps direct attention to external stimuli.
posterior parietal
_______ movements are normally not affected by sensory feedback.
Ballistic
Motor learning, such as riding a bike, begins with responses under conscious control, but with practice these are adjusted by _______ feedback without conscious regulation.
sensory
_______ is a disorder of voluntary movement that cannot be explained by paralysis; rather, it is attributed to the inability to perform motor movements when instructed to do so.
Apraxia
_______ _______, a striking consequence of posterior parietal cortex damage, is a disturbance of a patient’s ability to respond to stimuli on the side of the body opposite to the side of a brain lesion in the absence of simple sensory or motor deficits.
Contralateral neglect
The supplementary motor area and premotor cortex are part of the _______ _______ cortex that is involved in programming patterns of movements.
secondary motor
_______ are 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.
Mirror neurons
The somatotopic layout of the human primary cortex is also known as the _______ _______.
motor homunculus
The _______ is involved in motor learning and the temporal association of motor actions. As such, damage to this area can cause detrimental effects on posture, gait, speech, and balance.
cerebellum
Recent views of the function of the basal ganglia suggest that they are involved in various cognitive functions including _______ learning.
habit.
How many pathways conduct neural signals from the primary motor cortex to the motor neurons of the spinal cord?
Four pathways.
What are the two collective names for the pathways descending in the spinal cord?
Dorsolateral motor pathways and ventromedial motor pathways.
What is the analogy used to describe the sensorimotor system’s communication?
Like a large company, with communication from the executive level (the cortex) to the office personnel (spinal motor circuits) and workers (muscles).
How do the dorsolateral tracts differ from the ventromedial tracts?
Dorsolateral tracts terminate in the contralateral half of one spinal cord segment, while ventromedial tracts innervate interneurons on both sides of the spinal gray matter and in several segments.
Which muscles do the motor neurons activated by the ventromedial tracts project to?
Proximal muscles of the trunk and limbs (e.g., shoulder muscles).
What experiment demonstrated the different functions of the dorsolateral and ventromedial tracts?
Lawrence and Kuypers’ experiment on monkeys.
What were the effects of transections of the dorsolateral tracts in monkeys?
Monkeys could stand, walk, and climb but had difficulty using their arms for reaching.
What were the effects of transections of the ventromedial tracts in monkeys?
Monkeys had severe postural abnormalities and difficulty walking or sitting.
1) What do these experiments suggest about the roles of ventromedial tracts?
2) What do these experiments suggest about the roles of dorsolateral tracts?
1) They are involved in controlling posture, whole-body movements, and exerting control over limb movements involved in such activities.
2) They control movements of the limbs.
What is the level of the sensorimotor hierarchy that the content has descended to?
The lowest level, the spinal circuits and the muscles they control.
How do psychologists often view the motor circuits of the spinal cord, and why might this be surprising?
As mere cables that carry instructions from the brain to the muscles; it’s surprising because spinal circuits show considerable complexity in their functioning independent of signals from the brain.
What are motor units?
Motor units are the smallest units of motor activity, comprising a single motor neuron and all the individual skeletal muscle fibers it innervates.
How do fast muscle fibers differ from slow muscle fibers?
Fast muscle fibers contract and relax quickly but fatigue quickly, while slow muscle fibers contract more slowly and weakly but can sustain contraction due to better vascularization
What are flexors and extensors, and how do they differ?
Flexors act to bend or flex a joint, while extensors act to straighten or extend it.
What are synergistic muscles, and what are antagonistic muscles?
Synergistic muscles produce the same movement, while antagonistic muscles act in opposition to each other.
What are the two types of muscle contraction?
Isometric contraction (increasing tension without shortening) and dynamic contraction (shortening and pulling bones together).
What receptors monitor the activity of skeletal muscles, and where are they located?
Golgi tendon organs (in tendons) and muscle spindles (embedded in muscle tissue).
What is the function of Golgi tendon organs?
They provide information about muscle tension and serve a protective function by causing the muscle to relax when contraction is extreme.
Why do muscle spindles have their own intrafusal muscle and motor neuron?
To maintain responsiveness to slight changes in muscle length despite contraction of the skeletal muscle.
What reflex involves a sudden leg extension in response to a strike on the patellar tendon?
The patellar tendon reflex.
What type of reflex is the patellar tendon reflex?
It is a stretch reflex, elicited by a sudden external stretching force on a muscle.
Describe the process of the patellar tendon reflex.
When the thigh muscle is stretched, muscle-spindle stretch receptors initiate action potentials carried to the spinal cord by spindle afferent neurons. This excites motor neurons in the spinal cord, leading to a compensatory muscle contraction and leg extension.
What is the function of the stretch reflex in real-life situations?
To keep external forces from altering the intended position of the body, such as counteracting unexpected muscle stretches caused by external forces.
What is reciprocal innervation, and how does it relate to the withdrawal reflex?
Reciprocal innervation refers to the fact that antagonistic muscles are innervated in a way that permits a smooth, unimpeded motor response. In the withdrawal reflex, a sudden painful event in one area triggers excitatory and inhibitory interneurons in the spinal cord, coordinating a pattern of motor output between agonists and antagonists.
What is recurrent collateral inhibition, and what role does it play in muscle function?
Recurrent collateral inhibition occurs when inhibitory neurons in the spinal cord inhibit motor neurons, momentarily shifting the responsibility for muscle contraction to other members of the muscle’s motor pool. This ensures that muscle fibers and motor neurons get occasional breaks.
Describe Grillner’s experiment with cats and the spinal cord’s role in controlling walking.
Grillner suspended cats with transected spinal cords over a treadmill. Despite no contribution from the brain, when the treadmill was started, the cats began to walk, showing that the spinal cord alone can control walking when receiving sensory feedback.
According to the concept of central sensorimotor programs, how are complex movements produced?
Complex movements are produced by activating appropriate combinations of programmed patterns of activity at different levels of the sensorimotor system.
What is motor equivalence?
Motor equivalence refers to the ability of the sensorimotor system to accomplish a particular task in different ways involving different muscles.
What brain structures are responsible for coordinating and ensuring the effectiveness of central sensorimotor programs?
The cerebellum and basal ganglia are responsible for coordinating and ensuring the effectiveness of central sensorimotor programs.
Where are central sensorimotor programs for specific tasks like signing one’s name stored?
Central sensorimotor programs for specific tasks are stored in areas of secondary motor cortex.
What is the evidence for the separation of conscious perception and sensory control of behavior?
Haffenden and Goodale (1998) showed that participants’ judgments of object size based on visual illusion differed from their reaching actions, indicating a separation between conscious perception and sensory control of behavior.
What is the significance of the preparatory gap between digits in Haffenden and Goodale’s study?
The preparatory gap between digits reflected the actual size of the objects to be picked up, rather than their perceived size, indicating the influence of sensory control of behavior over conscious perception.
Can central sensorimotor programs for species-typical behaviors develop without explicit practice?
Yes, central sensorimotor programs for many species-typical behaviors can develop without explicit practice.
What did Fentress (1973) demonstrate in his study with adult mice raised without forelimbs?
Fentress showed that these mice still exhibited the patterns of shoulder movements typical of grooming in their species, demonstrating the operation of central sensorimotor programs.
What are the two kinds of processes that influence the learning of central sensorimotor programs?
The two kinds of processes are response chunking and shifting control to lower levels of the sensorimotor system.
Define response chunking in the context of sensorimotor learning.
Response chunking is the process by which individual responses necessary for a task are combined into programs that control sequences (chunks) of behavior.
What are the advantages of shifting control to lower levels of the sensorimotor system during training?
Shifting control to lower levels allows higher levels to focus on more complex aspects of performance and permits greater speed as different circuits can act simultaneously.
What did the PET study by Jenkins and colleagues (1994) reveal about sensorimotor learning?
The study showed increased activity in cortical sensorimotor areas during the learning of new motor sequences, with decreased involvement of association areas and the cerebellum as sequences became well-practiced.
What changes occur at the level of the motor cortex with sensorimotor learning?
There is a strengthening of inputs from the thalamus and other motor cortex areas, along with an increase in dendritic spines, suggesting an increase in synapses.
What subcortical changes accompany sensorimotor learning?
There is a large increase in the number of oligodendrocytes in subcortical white matter, presumably due to an increased demand for myelination of axonal connections.
What is Step 1 in the process of sensory-motor transformation for a musician?
Step 1 involves low-level visual processing of the musical notation in the retina, detecting visual stimuli against a white background.
Describe Step 3 in the sensory-motor transformation process.
Step 3 involves high-level visual processing to integrate all symbols and notations such as notes, keys, tempo, and loudness.
What occurs during Step 5 of sensory-motor transformation?
During Step 5, the brain transforms visual signals into motor programs at the level of the motor cortex.
What is Step 7 in the process of sensory-motor transformation?
Step 7 involves ongoing feedback control, where sensory and motor systems send signals back to the brain during performance to detect deviations between the motor program and actual behavior.
How does sensory feedback contribute to sensory-motor function during Step 8?
Sensory feedback is used by the brain to adjust and correct movement execution in real-time based on deviations between the written musical notation and received sensory feedback.
What are the three principles of sensory-motor function outlined by Pinel and Barnes?
The three principles are hierarchical organization, sensory input guides motor output, and learning.
Provide an example of hierarchical organization in sensory-motor function.
Motor cortex determines appropriate movement sequences, which are then sent to and executed by lower levels of the motor system such as the spinal cord and muscles.
How does sensory input guide motor output in sensory-motor function?
Visual signals instruct the motor cortex to produce movement sequences, while feedback from the auditory system helps detect and correct errors.
Why is learning important in sensory-motor function?
Skilled musical performance requires learning and practice, demonstrating the necessity of extensive training and learning for proficient execution of music.
Early neuroanatomists found differences in the following parts of the brain of musicians
inferior temporal gyrus
visual cortex
superior temporal gyrus
prefrontal cortex
superior temporal gyrus
In right-handed musicians, the hand representation in the primary and somatosensory cortex shows greater changes for the right brain hemisphere. Why would this be the case?
a). the right hemisphere is responsible for the right hand, which is dominant in these individuals
b). the right hemisphere is responsible for the left hand, which benefits more from extensive training
c). the left hemisphere is non-dominant, giving the right hemisphere an advantage
d). both (a) and (c) are correct
b). the right hemisphere is responsible for the left hand, which benefits more from extensive training
What is the arcuate fasciculus?
a musical instrument played in Northern Germany
a fiber tract connecting the left and right hemispheres
axons connecting the frontal, temporal, and parietal lobes
axons connecting visual and motor areas
axons connecting the frontal, temporal, and parietal lobes
You are a biopsychologist studying facial expression. In your current study, you are investigating brain systems that are involved in detecting sudden, unexpected changes in emotional facial expression. Which of the following techniques would you use to conduct your study?
high-resolution structural MRI imaging
EEG
case studies involving brain damaged patients
all of the above
EEG
What anatomical changes have been consistently identified in the brains of musicians?
Anatomical changes include enlarged primary motor cortex, enlarged planum temporale, and enlarged anterior part of the corpus callosum.
What is the function of the corpus callosum in the brain?
The corpus callosum is the major fiber system connecting the two cerebral hemispheres, facilitating communication between them.
Why is a larger corpus callosum beneficial for musicians?
A larger corpus callosum facilitates communication between the two hemispheres, which is crucial for coordinating the precise movements of both hands required in playing musical instruments.
What behavioural differences have been observed in musicians compared to non-musicians?
Musicians exhibit astonishing levels of sensory-motor control skills, attributed to the complex demands of reading musical notations and translating them into skilled movements to play instruments.
What hypothesis can be formulated based on the assumption about musicians’ hand control?
Individuals playing musical instruments show a smaller difference of movement skill between the dominant and non-dominant hand compared to individuals without musical training.
How do motor skills acquired from playing musical instruments potentially benefit musicians in other tasks?
Motor skills gained from playing instruments can translate to other tasks, making activities such as typing on a keyboard with both hands easier and allowing for more balanced hand control overall.
What is noteworthy about the role of the non-dominant hand in playing certain musical instruments?
For some instruments, such as string instruments, the non-dominant hand performs more complex movements, leading to extensive training and skill development in both hands for musicians.
How has the study of musicians and their brains contributed to understanding sensory-motor function?
The study has shown that sensory-motor regions of the brain adapt to the demands of playing music with detectable changes in both anatomical and functional properties, highlighting the complexity of sensory-motor control in musicians.
Ischemic and hemorrhagic stroke refer to brain damage induced by
Rapture and blockade of a blood vessel, respectively
Blockade and rapture of a blood vessel, respectively
Blood accumulation and drainage in brain tissue, respectively
Drainage and blood accumulation in brain tissue, respectively
Blockade and rapture of a blood vessel, respectively
Did you detect a somewhat surprising, counterintuitive result in the study by Schneider et al.?
No, there is nothing surprising in the study
Yes, it is surprising that the simple act of playing music helped with motor recovery
Yes, it is surprising that the CG (conventional therapy group) did not show improvements
Yes, it is surprising that the music group did not show a greater enhancement of motor recovery
Yes, it is surprising that the CG (conventional therapy group) did not show improvements
What could be a potential explanation for this unexpected result?
The 3-week study period may be too short for conventional therapy to be effective
The 3-week study period may be too short for music therapy to be effective
The motor tests used (e.g., finger tapping) only show improvements in professional musicians
No explanation needed, as there was nothing surprising in the study
The 3-week study period may be too short for conventional therapy to be effective
