Midterm 2 - Units 4-5 Flashcards
What is the pathway for first order neurons?
They enter the spinal cord, and will split, one branch will ascend in the dorsal column to the brainstem ipsilaterally.
What is the pathway for second order neurons?
From the brainstem this branch will synapse with second order neurons. They cross the midline and ascend up to the thalamus.
What is the Anterolateral Pathway from the Periphery?
Periphery → Spinal Cord → The primary sensory neuron → Dorsal Horn → Second order neuron → Cross the spinal cord → Thalamus → Third order → Somatosensory Cortex.
DCML heavily influences what?
Vibration, Proprioception and Light Touch.
Anterolateral pathways influence what?
Pain, Temperature and Crude Touch/Tickle/Itch.
What is the Somatosensory Cortex?
Most complex processing of somatosensory information. (process from the contralateral side)
What factors are involved in coordinated movements?
Proprioception, Motor Planning, Nervous System Intergration.
What is the primary somatosensory system function and pathway?
Relays informations to the secondary somatosensory cortex then will be relayed to the parietal cortex.
What is the Parietal Cortex known as?
The “Multimodal Association Cortex”
What is the Parietal Cortex Function?
Involved in Spatial Analysis, Integration, Vision, Somatosensory and Vestibular System.
What is the pathway of the Vestibular System from the Periphery?
Periphery → Vestibular Nuclei via Vestibulo-Cochlear Cranial Nerve → Ipsilateral Side.
Where does information from the Vestibular System go?
The Brainstem → Cortex → Thalamus
What is the Vestibular System involved in?
Integration with Visual, Somatosensory information in the Parietal Cortex and Cerebellum
When does information get processed?
Not until 200ms that visual information is used to correct any error
The Nervous System uses Sensory input to…
Control motor commands, trigger commands and correct error.
Dorsal Column-Medial Lemniscus System Pathway
- First Order Neurons from the periphery to ipsilateral brainstem (medulla).
- Second Order Neurons From Medulla to the Contralateral Thalamus.
- Third Order Neurons from the Thalamus to the ipsilateral somatosensory cortex.
What are the three Anterolateral Pathways?
Spinothalamic, Spinorectular and Spinosencephalic Pathways.
What happens to second order neurons (Antrolateral)?
They cross the midline and ascend in the anterolateral white matter to the thalamus.
What is the Somatotopic Map?
They are neighboring neurons that represent neighboring body parts.
What are the Vestibular Nuclei Outputs?
Cortex and Cerebellum.
What is the difference between Somatosensory and Vestibular?
Somatosensory: Input triggers postural response (timing)
Vestibular: Input scales the response (amplitude)
What is Selective Attention?
The process of directing our awareness to relevant stimuli while ignoring irrelevant stimuli in the environment.
What factors do we have to shift our attention between?
Events in the environment, Correcting our actions, and Planning future events.
What is Endogenous Attention?
Consciously direct attention to a particular aspect in the environment. (Voluntary choice based on current goals)
What is Exogenous Attention?
Unexpected stimulus causing a shift of attention/focus from what’s being attended to.
What is Visual Selective Attention?
Measured by recording eye movements.
What is Foveation?
Only a small area in the retina that has clarity with perception.
What is Fixation?
Eyes are fixed on an object, determine whats important.
What is Saccade?
The shift from one fixation to another (Rapid/Involuntary).
What is Smooth Pursuit?
Eye movement where we are taking in information (Slow/Tracking).
What is Auditory Selective Attention?
Paying attention to one ear while ignoring the other, limited capacity to process multiple inputs.
Signal Detention Theory?
The ability to differentiate between “information-bearing patterns” stimulus and “random patterns” that are distractors.
What is perceptual sensitivity (d’) ?
The ability to make correct decisions by distinguishing signals from noise.
What is Criterion (B) ?
A cut off point; moving it changes the outcome.
What are the effects of shifting the criterion?
Top: Criterion is low leading to an increase of hits and high false alarms.
Bottom: Criterion is high leading to a decrease of hits and low false alarms.
What happens when there are beta changes?
The position of the criterion effects the number of correct hits/errors.
What is Discrimination Reaction Time?
More than one signal, but only one correct response.
What impacts DRT?
Crossman’s Confusion Function
What is Static Visual Acuity?
The ability to distinguish details of static objects when both object and subject are static.