week 3 sensorimotor control

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Questions and Answers

What does the middle temporal visual area (MT) specialize in?

Recognizing colors of visual stimuli

Understanding spatial relationships

Interpreting auditory information

Processing the direction of movement (correct)

Cerebral akinetopsia is primarily associated with damage to which part of the brain?

Primary auditory cortex

Parietal lobe

Ventral visual stream

Middle temporal visual area (MT) (correct)

Which sensory systems contribute predominantly to motor control?

Vision and touch

Proprioception and vestibular sense (correct)

Hearing and vision

Kinaesthesia and olfaction

Which type of sensory input is vision primarily considered when mismatches occur?

The dominant modality Signup and view all the answers

What role does the dorsal stream of the visual system primarily serve?

Processing movement and spatial awareness Signup and view all the answers

Which characteristic distinguishes the ventral stream from the dorsal stream?

It is involved in object recognition. Signup and view all the answers

Which of the following best describes proprioception?

A sense of body position and movement Signup and view all the answers

What is the primary function of V4 in the visual system?

It processes color information irrespective of movement. Signup and view all the answers

What is the primary function of the dorsal stream pathway in visual processing?

Monitoring movement and spatial relationships Signup and view all the answers

How do the magnocellular and parvocellular cells differ in their function?

Magnocellular cells are larger and handle dynamic visual information, while parvocellular cells are smaller and handle detailed visual information. Signup and view all the answers

Which of the following statements about the dorsal stream is true?

It alerts the ventral stream to focus on relevant targets. Signup and view all the answers

What type of visual information is the dorsal stream less sensitive to?

Color differentiation Signup and view all the answers

Which of the following is an example of an action controlled by visual information from the dorsal stream?

Catching a rapidly thrown ball Signup and view all the answers

In visual processing, what does the term 'where' refer to?

The location and movement of objects in the visual field Signup and view all the answers

Which motor control function utilizes visual information according to the content?

Maintaining balance while observing the horizon Signup and view all the answers

How does visual information from different pathways interact during processing?

They partly converge at various stages before reaching higher visual areas. Signup and view all the answers

What is the primary challenge in coordinating different senses for an end effector like the hand?

Aligning proprioceptive and retinal signals Signup and view all the answers

Which type of interaction involves sensory input that initiates reflex responses?

Reflexes Signup and view all the answers

During which interaction is sensory feedback used to adjust movements as they are performed?

Corrective action Signup and view all the answers

What is an efferent copy in the context of sensorimotor integration?

A duplicate of a motor command sent for evaluation Signup and view all the answers

What role does motor planning play in sensorimotor interactions?

Forms a motor plan requiring sensory input Signup and view all the answers

What is the function of reafferent signals in motor control?

To provide feedback generated by the movement itself Signup and view all the answers

Which of the following is NOT a type of sensorimotor interaction?

Efferent adaptations Signup and view all the answers

How do sensory inputs modify the motor circuit during motor learning?

By updating motor commands for better performance Signup and view all the answers

Which method is NOT a way the nervous system processes sensory signals?

Using only single receptor inputs Signup and view all the answers

What role do proprioceptors play in the processing of sensory signals?

They help in estimating limb position. Signup and view all the answers

Why is averaging over time important in sensory processing?

It decreases response variability. Signup and view all the answers

How does the nervous system enhance its interpretation of sensory inputs?

By associating partial inputs with past experiences. Signup and view all the answers

What is a significant feature of the motor control system regarding sensory information?

It has access to sensory information beyond conscious awareness. Signup and view all the answers

Which statement about context in sensory processing is accurate?

Context helps to estimate likely stimuli from ambiguous inputs. Signup and view all the answers

In what way does the proprioceptive system calibrate itself?

Through vision and spatial awareness. Signup and view all the answers

What limitation is associated with input from a single receptor in sensory processing?

It may lead to ambiguous interpretations. Signup and view all the answers

What is primarily suppressed during each saccade to prevent vision blur?

Vision during eye movement Signup and view all the answers

What region of the retina is responsible for providing high resolution vision?

The foveal region Signup and view all the answers

How is a high resolution image of a visual scene constructed?

By stitching fragmented images from after each saccade Signup and view all the answers

What is used to allocate each visual scene fragment to its correct location in the visual image?

The location of eye movement Signup and view all the answers

What aspect of tactile perception enhances sensory input understanding?

Knowledge of exploratory movement performed by hands and fingers Signup and view all the answers

What is the result of the integration of sensorimotor functions during visual processing?

A coherent visual image formed from fragmented information Signup and view all the answers

What happens to sensory processing when eye movements occur?

Fragmented visual information is compiled for clarity Signup and view all the answers

What technique is primarily used to analyze tactile exploration?

Combining sensory input with exploratory movement patterns Signup and view all the answers

Study Notes

Processing Sensory Signals

Sensory signals are integrated within a single modality as individual receptors alone may be ambiguous.
Across fiber pattern encoding exemplifies color encoding in the visual system.
Integration occurs across different receptor types, such as proprioceptors (muscle spindles, Golgi tendon organs, joint receptors), tactile receptors, and visual inputs to estimate limb position.
Temporal integration averages out noise over longer periods, enhancing signal clarity.
Contextual association helps interpret partial and ambiguous sensory inputs by comparing them with past experiences.
Proprioceptive calibration is influenced predominantly by visual feedback.

Sensory Inputs in Motor Control

All classical senses contribute to initiating and guiding movement based on biological context, from chemotaxis in primitive organisms to complex motor functions.
Motor control can utilize sensory information beyond conscious awareness, enabling refined coordination.
Proprioception, kinaesthesia, and vestibular sensitivity are crucial for motor-related processes while vision, hearing, and touch also play integral roles.
Visual perception often dominates when there are discrepancies between sensory modalities.

Visual System: Ventral and Dorsal Streams

25 areas are identified primarily for visual functions; V4 specializes in color response, while Middle Temporal (MT) area is tuned to movement direction.
Damage to MT causes Cerebral akinetopsia, leading to challenges in perceiving motion.
The dorsal stream corresponds to "where" (motion, speed) in egocentric reference frames, while the ventral stream corresponds to "what" (shape, texture) in allocentric frames.

Use of Visual Information in Motor Control

The dorsal pathway is faster than the ventral pathway and less focused on color and detail.
“Where” pathway assists the “what” pathway by identifying movement targets.
Visual guidance is essential for actions such as grasping, intercepting moving objects, and maintaining balance.
Eye movements exemplify specialized motor control integrating visual input.

Object Properties and Movement Analysis

Two neuronal cell types aid in processing distinct information types: magnocellular (large neurons) for movement and parvocellular (small neurons) for detail.
Effective sensory coordination is essential when aligning proprioceptive signals and retinal location signals.

Sensorimotor Integration

Reflexes initiate responses based on sensory input, while motor planning relies on sensory information for action formulation.
Corrective actions utilize sensory feedback during movement, enhancing control.
Motor learning benefits from sensory input, updating motor commands for improved performance.
Efferent copies help predict sensory consequences of movements, facilitating error assessment against planned actions.

Building Visual Images

High-resolution vision is limited to the fovea; comprehensive visual understanding is constructed via snapshots from saccades.
Motor commands suppress vision during saccades to prevent motion blur, and eye movements contextualize visual information during this process.
Tactile exploration combines sensory inputs and knowledge of movement patterns, demonstrating the integration of sensory and motor systems.

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Description

This quiz explores how the nervous system processes sensory signals, focusing on integration within sensory modalities and across different receptor types. It examines concepts like ambiguity in single receptor input and across-fibre pattern encoding, particularly in the visual system. Test your understanding of these critical processes in sensory perception.