Sensorimotor Behaviors Flashcards
Saccades are…
rapid eye movements to direct attention to discrete locations
Smooth pursuit enables us____
to lock our gaze on a moving target.
Which reflex is activated in response to the movement of the visual field?
Optokinetic Reflex follows the visual field (and Nystagmus brings the eye back)
Which of the following areas is not involved in vestibular processing?
Hippocampus, Vestibular nuclei, Thalamus, Cerebellum.
Hippocampus
Adaptation of the vestibular-ocular reflex is associated with which brain area?
Cerebellum (primarily LTD in Purkinje cells and Parallel Fibers)
What are sensorimotor behaviors? Give a few examples
Sensorimotor behaviors are those with an ongoing relationship between sensory inputs and motor outputs.
When a motor behavior implies the sensory feedback in the loop consisting of the motor environment and the body.
Examples: VOR, Optokinetic reflexes, grasping an object (force on hand specifies tactile feedback)
What are saccades?
A saccade is a quick eye motion between points of fixation.
Example: While reading, one performs saccades in between fixating on specific words. We do not move our eyes continuously, but discontinuously.
What is the optokinetic reflex (OKR)?
OKR is a reflex that locks your eye with an object in a moving field (a tree passing by the train window).
When you ‘snap back’, this is called a ‘nystagmus’. It is a reflex that can normally be suppressed.
> See this video <
What is the function of the semicircular canals and the vestibular system?
They measure the rotational acceleration of the head.
The vestibular system is a sensory system that provides information about motion, head position, and spatial orientation.
The semicircular canals are filled with endolymph. The endolymph flows through the canals and moves the cilia. When the cilia are pushed in one (preferred) direction, the hair cells will be depolarized. If the cilia are pushed in the opposite direction, the hair cells will be hyperpolarized.
How can you define sensorimotor integration?
Sensorimotor integration is a process that produces task-specific motor output based on selective and rapid integration of sensory information from multiple sources.
The visual system temporarily shuts down during a _____ movement
saccadic
What does a tonic neuron do in an eye circuit?
Maintains eye position, the ‘step’ signal.
A bursting neuron in an eye circuit most likely encodes____
the ‘pulse’, the signal for saccades.
An omnipause neuron in an eye circuit____
stops firing during an eye movement
Rotational acceleration of the head is picked up by____
semicircular canals
The translational movement of the head is picked up by____
otoliths
What is proprioception?
Proprioception is the sense of the position and self-generated movements of our body (muscle contractions and posture). It depends on the relationship between the nervous system and the muscular tissue.
Which feature of visual image do the Retinal Ganglion Cells extract?
edges
What is the function of the vestibulo-ocular reflex (VOR).
VOR is a reflex that stabilizes the gaze during head movements. The eyes move to the opposite direction of the ‘vestibular world’.
What are some of the differences between optokinetic and vestibulo-ocular reflexes?
In the case of OKR, the visual world is moving, and the eyes follow. Something visually or optically drives the eye movement.
In the case of VOR, the vestibular world is moving and the eyes move in the opposite direction in order to stabilize the gaze.
What is the name of the reflex that causes our eyes to follow smooth motion of objects?
Smooth pursuit
What is the optokinetic reflex (OKR)?
The reflex that locks eyes onto motion of the world.
(such as your eyes as you look outside of a moving train and fixate on the environment. Incidentally, the movement that brings the eyes back when they are at the edge is called “Nystagmus”).
What are muscle synergies?
A muscle synergy is a group of muscles and their skeletal constraints that contribute to a particular (stereotypical) movement.
(“Their action is more than the sum of their parts”).
Muscle synergies reduce the dimensionality of muscle control. Single synergies activate multiple muscles.
Explain the role of transformations in sensorimotor loops.
Sensorimotor coupling is the loop between the sensory system and the motor system that is closed via the environment.
This integration allows an animal to transform sensory information (e.g. sight) into motor behavior.
What are sensorimotor loops?
The idea that motor actions create specific feedbacks to the sensory systems.
Another way to say this is that the embodiment of the brain necessitates certain aspects of the feedback.
What is a sensorimotor contingency?
It is a quantifiable and predictable relationship between motor action and its sensory consequence.
