Sensorimotor (EXAM 2 Info)
What did Ebitz study show?
**
What is contralateral (spatial) neglect?
aka hemispatial neglect dysfunction and/or disregard of stimuli on the contralateral side of damage *common in stroke victims
What is the posterior parietal cortex? What is involved in?
aka the "association" cortex INTEGRATES visual, auditory, and somatosensory info spatial attention, integration of body position relative to surroundings
What are examples posterior parietal association cortex dysfunction?
apraxia contralateral (spatial) neglect
How was the hierarchical organization developed? Are there connections between this organization and differences in the hierarchy?**
higher level of organizations are allowed in species with more developed brains animals miss some of that higher level processing that complex functions require abstract functions
What does the posterior parietal cortex send signals?
sends out signals to dorsolateral prefontal cortex and motor cortex
What outputs does the dorsolateral prefrontal association cortex send?
signals to primary motor cortex, secondary motor cortex, frontal eye field
The way mirror neurons work may provide insight into what mechanism?
social cognition - understanding another's perception and intention when the monkey saw a human pick up the ball it fired same neurons as the person who picked up the ball even though the monkey did not pick up the ball
What are mirror neurons?
special neurons that selectively fire in response to specific goal directed movement performed by oneself or when another person performs the movement aka fire in response to the understanding of purposeful action
What is the highest level of region of processing?
the association cortex comprised of 2 major regions posterior parietal cortex dorsolateral prefrontal cortx
How is our sensorimotor system organized hierarchically?
the sensorimotor system involves high and low levels of processing + higher level systems performing complex functions + lower level systems performing simple/reflexive tasks
How is the sensory motor system redundant?
the sensorimotor system relies on several different inputs and outputs between each level loss of function in one area can sometimes not be as bad as other parts
Are there times when motor output guiding sensory input interferes with the hierarchical organization?
yes lower level processes are not necessarily always unconscious processing even if we don't notice our breathing or heartbeat there are times when we are aware ex; balancing on a ledge and feel like worrying about falling off and whether or not ur balanced so you have to think about it more clearly if you don't think you might lean forward
Is there overlap between the two domains of secondary motor cortex?
yes all areas are involved in the main functions
What are the 3 principles of sensorimotor function?
1. organized in a hierarchy 2. motor output is guided by sensory input 3. learning changes the nature and locus of sensorimotor control
What are the two domains of secondary motor cortex?
1. supplementary motor area 2. premotor cortex
What does the reciprocal neural connections between basal ganglia and the rest of the brain imply?
basal ganglia send info back and forth within the brain implies a modulatory role in sensory motor processing don't do any active control, involved in sensory integration and minor adjustments and modulation of other regions with more direct involvement
What happens with cerebellar damage?
causes severe motor deficits + some cognitive /emotional defects
What is the basal ganglia?
collection of nuclei create neural loops of reciprocal connections between themselves and other areas (association cortex)
What does the premotor cortex coordinate?
coordinates movements in response to more abstract stimuli -movement initiated by us
What does the supplementary motor area coordinate?
coordinates repeated sequences of movements things we have complete before ex; dancer- moves
What is the difference between sensory and sensorimotor?
difference between sensory and sensorimotor in sensorimotor systems, primary flow of info is down the hierarchy
What is apraxia?
difficulty in making skilled, intentional movements patients may retain ability to make movements successfully when unintentional hard to act out consciously, not necessarily not able to *can do unconsciously*
What is functional segregation?
each level (low->high level processes) of our sensorimotor system interacts but has discrete functions each level is composed of subunits with distinct functions -thalamic regions for sensory relay of differing origins
What is the frontal eye field important for?
important for directing of attention, saccades (direct eye movement) highly spatially selective *popular region of interest in animal research
What is the dorsolateral prefrontal association cortex important for?
important for executive function,working memory, initiation of voluntary movements
What does the dorsolateral prefrontal association cortex do?
integrates info from parietal association cortex and then sends it out out to frontal eye field, secondary motor cortex
What is the function of the cerebellum?
largely involved in motor coordination correction rapid learning of motor sequences -learning under time crunch posture and balance -take in sensory info during movements and fix ex; you missed grabbing a mug, it adjusts mo
What changes sensorimotor control?
learning when we first learn something each action is being consciously controlled with practice these actions become more unconscious (muscle memory) ex; driving a car with practice can also improve our performance of actins ex; video games, texting, sports
What is the cerebellum?
little brain 10% of brain mass, but more than half of the brain's neurons has simple, small numerous granule cells
What occurs with parietal cortex dysfunction?
not damaging eyes or ears and the parts of the brain they send signals to but can't process/integrate the info well
How is motor output guided by sensory input?
our eyes, muscles, joints, etc all modulate activity based on sensory feedback - pupil dilation in response to light - adjust our hold on a pencil while writing -balancing on a ledge -reacting to a noise upward flow of info
What is the primary motor cortex responsible for?
plays an integral role in the initiation of movements primary input and output area of sensorimotor signals in the cortex takes input from all over the body (motor homunculus) not accurate but useful
What input does the secondary motor cortex receive? What is it involved in?
receives direct input from posterior parietal and dorsolateral prefrontal association cortex involved in complex voluntary movements + specific patterns of movements
What inputs does the dorsolateral prefrontal cortex receive?
recieves input from posterior parietal association cortex
What is the motor homunculus?
refers to how our body is mapped on the brain - not entirely accurate as each region are involved in more than one thing