Motor Control and Sensory Processing Quiz

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Questions and Answers

Which area of the brain is primarily responsible for sensory processing?

Motor neurons

Visual cortex (correct)

Basal Ganglia

Prefrontal area

What is the role of the spinal cord in motor function?

Carries sensory information to the brain

Processes anticipatory signals from the CNS

Coordinates sensory input with motor output

Carries motor commands to motor neurons (correct)

Which component is involved in motor processing?

Cerebellum (correct)

Somatosensory Cortex

Visual cortex

Dorsal column/medial lemniscus

In Hedmann’s model for movement observation, what is emphasized in reaction time?

CNS anticipatory processing time Signup and view all the answers

What are the two main types of control concepts in motor program theory?

Open and closed loop control concepts Signup and view all the answers

What aspect is crucial for retraining motor control?

Upper extremity function recovery Signup and view all the answers

Which factor does NOT impact upper-extremity function?

Handedness Signup and view all the answers

What are the primary tasks involved in upper-extremity function?

Reach, Grasp, and Manipulate Signup and view all the answers

What type of tasks generally require high attentional demands?

Upper extremity tasks Signup and view all the answers

Which domain is NOT integrated into most self-care tasks?

Recreational activities Signup and view all the answers

What type of control uses past experiences to predict sensory consequences?

Feedforward control Signup and view all the answers

Which sensory system primarily assists in reactive control of movement?

Somatosensory system Signup and view all the answers

Which movement coordination is essential when reaching for objects in the far visual field?

Eye, head, and trunk coordination Signup and view all the answers

In the kinematics of reach and grasp, what factor significantly influences the phase of movement?

Task constraints and goals Signup and view all the answers

Which part of the body provides proprioceptive signals that help localize targets?

Eye muscles Signup and view all the answers

What describes the interaction between eye movements and hand movements?

One directs the other Signup and view all the answers

What aspect of the velocity profile changes based on the task goal in reaching tasks?

Velocity of the arm versus time Signup and view all the answers

Which model is referenced for describing invariant features of reaching tasks?

Motor program theory Signup and view all the answers

What does Fitt’s law suggest about movement time?

Movement time increases with distance and accuracy demands. Signup and view all the answers

What do Distance Programming Theories focus on?

The activation of agonist muscles based on perceived distance. Signup and view all the answers

How do Location Programming Theories describe the function of limb muscles?

They act similarly to springs, adjusting stiffness based on target location. Signup and view all the answers

What does the Dual Task Paradigm illustrate about cognitive and motor tasks?

Reaction time increases while movement time remains constant. Signup and view all the answers

Which brain regions are involved in the motivation aspect of motor control?

Prefrontal Cortex and Limbic System Signup and view all the answers

What is the primary role of the dorsal pathway in the visual system?

Action and movement-related processing Signup and view all the answers

What disorder can result from damage to the temporal association area?

Prosopagnosia Signup and view all the answers

Which of the following encompasses the concept of spatial cognition?

Attention to spatial environments and movement Signup and view all the answers

What is a crucial aspect of visual guided reaching according to clinical implications?

Separate assessment of perceptual and action components Signup and view all the answers

What is involved in sensorimotor transformation as mentioned in the content?

Movement planning and internal body maps Signup and view all the answers

What impairment may occur with damage to the lateral association in the parietal lobe?

Unilateral hemispatial neglect Signup and view all the answers

Which component is NOT part of the anticipatory control for reach and grasp?

Emotional analysis of the object Signup and view all the answers

What type of information is used to determine the characteristics of an object to be grasped?

Visual and somatosensory information Signup and view all the answers

What factor influences movement compensation during reaching when elbow extension is limited?

Weak elbow extensors Signup and view all the answers

Which type of grasp involves directing finger and thumb pads toward the palm?

Power grip Signup and view all the answers

What role does postural support play during reaching and grasping?

It stabilizes the body for movement Signup and view all the answers

What is the relationship between reach and grasp in motor coordination?

They are kinematically coupled Signup and view all the answers

How does the cerebellum contribute to gripping objects?

By predicting required forces Signup and view all the answers

What does reaction time (RT) indicate about a movement?

Complexity of movement and processing time Signup and view all the answers

What type of grip is characterized by force transmission through the fingers and thumb?

Precision grip Signup and view all the answers

What does anticipatory control during grasping involve?

Adapting grip for different object characteristics Signup and view all the answers

Which system is responsible for maintaining the alignment of postural segments during arm movements?

Postural control system Signup and view all the answers

What type of adjustment refers to changes made in anticipation of movements?

Anticipatory postural adjustments Signup and view all the answers

Study Notes

Neural Contributions to Reach, Grasp, and Manipulation

The course is DPT 425 Functional Neuroscience, Fall 2024 at Saint Joseph's University.
The primary resource is Shumway-Cook and Woollacott Motor control text, Chapter 17.
Students will describe upper extremity functions and neural contributions to UE Reach, Grasp, and manipulation.

Introduction

Upper-Extremity (UE) Function is the basis for fine motor skills, and plays a role in gross motor skills.
Recovery of function is an important aspect of retraining motor control
Contextual factors (environment and individual) impact upper-extremity function.
UE function is integrated into most self-care, work, and household activities.

International Classification of Function (ICF)

ICF categorizes health conditions (disorders or diseases), body structure and function, activities, and participation.
Body Structure and Function focuses on individual capabilities like neuromusculoskeletal and movement-related functions, control of voluntary movements, visually directed movements, and eye-hand coordination.
Activities include mobility, carrying, moving, and handling objects, and represent tasks like reaching, grasping, and manipulating.
Participation relates to self-care (dressing, feeding), domestic life (cooking, cleaning) and real-world activities.

Sensorimotor Processing for Eye Head and Hand Coordination

Sensorimotor processing for eye, head, and hand coordination considers the constraints of individuals, the type of task, and specific environmental constraints.
The goal is to understand how individuals' CNS control upper extremity movements.

What is going on in the Brain?

Visual cortex, Posterior Parietal Association area, Somatosensory Cortex, Prefrontal area, Pre motor cortex, Primary motor cortex, Basal Ganglia, Cerebellum, Spinal cord, Motor neurons, Sensory receptors on fingers and hand, Spinal cord pathways (Dorsal column/medial lemniscus), Somatosensory Cortex are involved in the brain processing for reaching, grasping and manipulation.

Hedmann's Model for movement observation analysis

The model displays a framework for analyzing movement observation.
It shows how initial conditions affect the preparatory, initiation, execution and termination phases of a movement, with detailed outcome measures.
Reaction time is a critical part of understanding CNS anticipatory processing time.

Motor Control Principles (SC&W PP 466)

Feedforward and Feedback control are used in the motor control processes, from the motor control lecture.
Motor program theory is equal to open and closed loop control concepts.
The visual system is actively involved in feedforward (anticipatory) control.
Somatosensation greatly contributes to feedback (reactive) control.
Important aspects to reaching and grasping are Locating a Target and Reach and grasp: kinematics.

Feedforward versus Feedback Control of Movement

Efficient reaching involves both feedback and feedforward control processes.
Feedforward (anticipatory) involves leveraging prior experiences to predict results of sensory information.
Feedback control relies on sensory input to fine-tune movements.

Feedforward control: command specifies response

Input processing, sensor detection, controller, and actuator are major entities involved in these stages of feedback control
Disturbance is a factor in both feedforward and feedback control.

Feedback control: command specifies desired state

Desired state, reference signal, error signal, controller, actuator, disturbance, comparator, and feedback signal are central parts of this process.

Locating a Target

Eye-head-trunk coordination is crucial, with vision guiding hand movements.
Reaching involves coordinating eye, head, and trunk movements for objects in the far visual field.
Interactions exist between eye and hand movements, where eye and hand movements influence each other.
Proprioceptive signals from eye muscles are crucial to localize targets in extrapersonal space.

Kinematics of Reach and Grasp

The ability to adapt how we reach is essential to upper extremity function.
Task constraints and goals strongly influence the reaching phase of movement.
Velocity profiles (arm velocity over time) change based on task goals (e.g., grasping vs. pointing).
Invariant features of a reaching task exist, aligning with motor program theory.

Neural control of Reach and grasp

Brain regions responsible for reaching and grasping include the frontal heteromodal association cortex (prefrontal cortex), limbic cortex, motor association cortex, primary motor cortex, central sulcus, primary somatosensory cortex, somatosensory association cortex, lateral parietal and temporal heteromodal association cortex, visual association cortex, primary visual and auditory association cortex.

Association cortices - perceptions and planning

Brain regions for movement, perception of space and location of limbs, auditory perceptions, and visual perceptions are identified.

Sensory system

Sensory systems inform us of the environment around us.
We use sensory information to perceive where we are in space and how our joints position relative to each other, which are crucial in the body position map or somatosensory system.
Sensory information is used to plan and execute movements.
Feedback from sensory systems helps adjust and refine movement and error correction.

Schematic of visual pathway

Visual information is conveyed through serial and parallel pathways.
The "Where" stream deals with location and movement, with a pathway to the posterior parietal cortex.
The "What" stream is involved in shape, form, and object recognition, using a pathway to the inferior temporal cortex.

Clinical implication

Clinicians must assess the perceptual and action components of visual guided reaching, recognizing differences in neural substrates.
Understanding the essential features of an object is as important as modifying the grasp to accommodate those features for successful grasping.
Interventions should train both perceptual and action components of the movement.

Posterior Association Areas

The Posterior Parietal Association area plays a wide role in spatial cognition and mediating attention to interpersonal and extrapersonal space.
Damaging the parietal lobe can lead to unilateral hemispatial neglect and prosopagnosia.
Facial recognition is mediated by the temporal association area, with damage resulting in prosopagnosia.
Object identification is also a function of these posterior association areas.

What is happening in the Posterior Parietal Cortex?

The Posterior Parietal Cortex is active during sensory and movement related activities.
It is crucial for sensorimotor transformations, movement planning, intentional map creation, and early motor planning.
Eye, head, trunk, and limb maps are active within this area.
The Posterior Parietal Cortex is integral for forming internal models of body representation.
Coordinate transformations are vital for accurate spatial cognition within this area.

Role of Sensory information in Anticipatory(Feedforward) control of Reach and grasp

Vision is crucial for locating target objects and determining the initial direction of reaching, as well as the characteristics of the grasped object.
Vision supports hand positioning and object location.
Vision accuracy is affected if the hand is not visible.
Somatosensory input helps determine the initial position and limb segment coordination, like the body or limb position.

Role of Sensory Feedback to Reach and grasp

Visual feedback is helpful in achieving accuracy with reaching but is slower.
Without visual feedback, reaching can be faster, but less accurate.
Visual feedback is less important for the grasp itself, compared to somatosensory input.
Somatosensory feedback is critical for complex movements, especially with limb deviations from the initial plan.
Cutaneous and proprioceptive feedback are needed for accurate grasping and hand manipulation.
Continuous object manipulation depends on visual feedback—for example, solving a rubrics cube.

Motor System in Reach and Grasping Execution of Movement

Premotor and Primary Motor Cortexes receive inputs from Posterior Parietal Cortex.
Premotor and and primary motor cortex contribute to information about the goal and characteristics of the desired movement.
Evidence demonstrates that Posterior Parietal Cortex encodes visual reference coordinates, and Premotor cortex encodes body reference coordinates for reaching.

Two Separate Descending Pathways for Reach and grasp

Motor development for reaching and grasping occurs early and hand manipulation develops later.
Corticospinal tract maturation relates to reaching and grasping development.
Individuals with corticospinal injuries may have grasping and manipulation impairments, but transport (reach) may be intact.
“Transport” component involves the shoulder and elbow, utilizing descending projections arising in the brainstem and midbrain (i.e., reticulospinal, rubrospinal).
“Grasp” (hand precision) components involve the wrist and hand and depend heavily on corticospinal pathways.

Musculoskeletal contributions

Neural and musculoskeletal systems have a complex relationship.
Changes in range of motion, strength, and muscle tone affect neural commands.
Compensation occurs in reaching due to limited elbow range of motion or weak elbow extensors.
Scapular control affects hand positioning during reaching and grasping.

Postural support of reaching and grasping

The postural system is important to maintain the upright orientation during reaching and grasping, in anticipatory and feedback control modes.
Postural adjustments include anticipatory and reactive types.
Further discussion on these mechanisms is scheduled for week 13.

Motor control elements

Goal-directed commands influence posture, reaching, and grasp-manipulation.
posture involves medial activation of medial spinal tracts.
reaching utilizes rubrospinal and reticulospinal pathways
grasp and manipulation use corticospinal pathways.

Grasping Patterns

Power grip uses finger and thumb pads directed toward the palm to transmit force.
Examples include hook grip for hanging, spherical grip for balls, and cylindrical grip for cans.
Precision grip involves force transmission through fingers and thumb (e.g., 'poke', 'pinch', 'clench'). Palm is also utilized for grasping objects.

Anticipatory Control of grasp and lift

Grip formation occurs during the transport phase so the grasp of the object is anticipated.
The hand adapts to the object's size and shape during use.
Finger movements are timed to the transport phase of lifting.
The nervous system anticipates weight and surface characteristics of the item being lifted.
The cerebellum plays a role in predicting the forces needed to maintain the stable grip during the lift.
Feedback loops assist in refining the lift and adapting to grip errors.

Coordination of reach and grasp

Reach and grasp movements are kinematically coupled.
Invariant movement features (e.g., timing of transport and hand opening) likely exist as a generalized motor program, stored in the central nervous system.
Other factors (reach, direction, distance, speed, grasp types) adjust based on initial conditions of the task, as seen in motor program theory.

Reaction Time (RT)

Reaction time (RT) is a measure of time to process sensory information prior to movement.
RT is used to assess complexity in movement control.
Discrete tasks (e.g., reaching) are measured using RT, a basic research tool.
Movement time is the time taken for the actual motor movement and is often included alongside response time.

Simple versus Choice Reaction Time

Simple reactions have one stimulus-response pair, whereas choice reactions have multiple stimulus-response options.
Choice reactions take longer than simple reactions due to greater visual processing and motor response selection.

Fitt's law of movement

Fitt's law describes the trade-off between speed and accuracy in movements.
Movement time increases as distance and accuracy demands increase.
Movement time depends on visual processing constraints.

Theories of Reaching control

Distance programming theories suggest the central nervous system (CNS) activates a set of agonist muscles based on perceived distance, heavily dependent on initial visual input.
Impulse driven control is followed by feedback correction, to adjust for any errors.
Location programming theories propose that limb muscles act like springs, and the CNS adjusts their stiffness based on the target's location.

Interference between reaching and cognitive tasks

A dual task paradigm shows that the simultaneous performance of a motor task (such as reaching) and a cognitive task (such as reading or attending to visual stimuli) impacts motor task performance through increases in reaction and movement times. The cognitive task can "interfere" with the movement task and thus impair movement performance.

Prefrontal Cortex and Limbic System influence

The Prefrontal Cortex is involved in perception, action, stopping and choosing actions, and analyzing behavior in context with goal directed movement.
Limbic System is involved in explicit memory learning, emotion and drive.

Conceptual mapping of Neural control of Reach and Grasp

A conceptual map incorporating various brain regions and their roles in reaching and grasping control would likely be created by students.

What might be the elements of the conceptual map?

Visual cortex (target location, identification, posterior parietal area, planning, sensory processing, formation of internal models).
Prefrontal Area (environmental goal, selection of plan and sequence).
Premotor Cortex (motor plan selection).
Primary Motor Cortex (command of movements).
Basal Ganglia (adjusting grasp force).
Cerebellum (correcting errors, and maintaining grasp force).
Sensory pathways (feedback from sensory receptors including dorsal column, medial, lemniscus, and inferior olive).
Spinal cord and motor neurons (carrying motor commands to muscles).
Somatosensory and sensory cortex (providing feedback on the grasp itself).

Example of conceptual Map

This section describes the integration of sensory and motor pathways in the context of the body, environment, and object.
This should help illustrate how the brain manages spatial tasks.

Extrapolate reaching and grasping research

Reaching and grasping research can be applied to other upper-extremity tasks like picking up a spoon, and overhead throwing.

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Description

Test your knowledge on the brain's role in sensory processing and motor functions with this quiz. Explore essential concepts like motor program theory and the factors affecting upper-extremity function. Perfect for students studying neuroscience or motor control principles.