NEUR2020 Quiz 3

T or F? information is inputted through the dorsal root ganglion and outputted through the ventral root?

true

What are the direct and indirect dorsolateral tracts?

corticospinal tracts, corticorubrospinal tracts

What do dorsolateral tracts control?

the movements of the limbs, especially independent movement

What are the two ventromedial tracts?

ventromedial corticospinal and cortico-brainstem-spinal

What do ventromedial tracts control?

posture and whole-body movements, control the limbs movements involved in these activities

What is the two main functions of the cerebellum?

• input from primary and secondary motor cortex

• feedback from motor responses from somatosensory and vestibular systems

What is the function of the basil ganglia?

modulate voluntary movement sequences eg. habitual responses, implicit learning, dancing

What are the implications of an imbalance between direct and indirect pathways between the thalamus and basal ganglia?

parkinson's disease

Is dopamine one receptor is inhibitor/excitatory and direct/indirect?

direct excitatory

Is dopamine two receptor is inhibitor/excitatory and direct/indirect?

indirect inhibitory

What happens when substansia niagra is damaged?

impaired balance of indirect and direct connections which impairs movement (too much or too little)

What happens when an inhibitory neuron is super exicted?

it becomes MORE inhibited

What are the positive symptoms in Parkinson's disease?

• tremor

• rigidity and akinesia

• with/without congitive dysfunction, dementia, depression

How can both rigidity and tremor occur at the same time in Parkinson's?

deficits and overcompensation in muscle production

What are the negative symptoms of parkinson's disease?

• reduction in spontaneous movement (hypokinesia)

• slow initiation of movement (akinesia)

• slowing or freezing during a movement

• reduced range and scale of movement

• dull, weak voice without inflection (hypophonia) and slow speech

• mask-like, unemotional expression

What happens to people writing in Parkinson's disease?

it will start sufficient and then progressively get smaller

What is hypophonia?

soft speech without inflections (emotion)

What is L-dopa?

synthetic dopamine

What is the side effects of L-dopa?

• hypotension

• arrhythmia

• nausea

• confusion

• affect

• auditory/visual hallucinations

• poor working memory

• dyskinesi at peak dose

• end-of-dose dysfunction

• on-off cycles

• freezing

• eventual drug failure

How does deep brain stimulation aid parkinson's disease?

invasive surgery which implants neurotransmitters to normalise connections

What are the three peculiarities of Hungtington's disorder?

• hereditary nature

• manifestation in adulthood

• tendency to insanity and suicide

What are the attributes to huntington's disease?

• destruction of GABAergic

• gaba is an inhibitory transitter

What are the first affective signs of Huntington's disease?

• depression

• anxiety

• irritability

• impulsivity

• aggression

What are the lateral signs of huntington's disease?

• restlessness, clumsiness, poor coordination, forgetfulness and personality changes

• altered speech and writing, saccadic changes

• bradyphrenia and bradykinesia

• poor motor dexterity, unsteadiness, reduced speed

• athetosis, chorea

What are the two types of tics?

• motor

• verbal

What is hemiplegia?

paralysis of a body part, respective of region

T or F - secondary motor cortex receieved input from association cortex and output to primary motor cortex

true

T or F - the secondary motor cortex, programs specific patterns of movement with input from the dorsolateral and prefrontal cortex

true

Whee does sensorimotor association cortex take information from?

any sensory system and the memory

What happens after damage to the sensorimotor association cortex?

ataxia and impaired body representation

What are the three functions of the sensorimotor association cortex?

1. integrates knowledge of (position of) objects and body parts

2. directs attention

Where does output from sensorimotor association cortex go?

• dorsolateral prefontal association cortex

• secondary motor cortex

• frontal eye fields

T or F? sensorimotor association is involed in the decision to make the action, not the action itself or processing the object (priors)?

T

What is ataxia?

• inability to use visual information to guide movement of hands

• incorrect/awkward movements

• errors in accuracy (over/undershoots)

What is apraxia?

A disorder of skilled movement. Patients are not paretic but have lost information about how to perform skilled movements

What is superior parietal lobe critical for?

sensorimotor integration by maintaining integral representation of the body's state

What is an affordance?

objects elicit behaviours (some are appropriate or inappropriate)

What is a desired, estimated and predicted state?

desired = goal

estimated = the movement you are doing

predicted = what the state of goal will feel like

T or F? thinking about a movement, elicits the same pathways of actually doing that movement

true

T or F? does robotic stimuli produce the same mirror neuron effect?

true

T or F? visual speech greatly improves perception of noise

true

What is superadditivity?

A response to a combined stimulus that is greater than the sum of the responses to each stimulus presented separately

Multiple sensory stimuli present at once makes us slower than individual stimuli

false - we are faster in response to multimodal stimuli

Explain the phenomena - "flavour is in the brain"

flavour is the integration of taste, smell and somatosensory experiences. Other modulators change the flavour including sigh, sounds, smells, expectation.

What is the primary role of the brain?

• what is "out there" in the world

• what is the best and appropriate action to respond to that

What are four elements, that generate information in multiple ways?

light, sound, mechanical and chemicals

When it is dark which senses will substitute to be in higher use, vision or audition?

audition will be in higher use because vision is lost in the dark

What is noisy speech an example of?

resolving perceptual ambiguities

What are the two models did Miller propose as a result of the redundant targets effect?

1. statistical facilitation - independent (parallel) processing

2. neural coactivation - integrated signals

What is statistical facilitation?

Both elements of the audio-visual processed independently, one that reaches output first triggers response

What is neural coactivation?

both components of the signals, activate a single criterion neuron. Activation is reached faster when there is two sources rather than one

What was the conclusion for going with the neural coactivation (MSI) approach?

responses to redundant signals are TOO fast

What are the factors influencing MSI?

• temporal coincidence

• spatial coincidence

• temporal patterning

• crossmodal correspondence

• stored knowledge

• context

• recent experience

• expectation

• attention

What factors are bottom up justification for MSI?

• temporal coincidence

• spatial coincidence

• temporal patterning

What factors are top-down justification for MSI?

• crossmodal correspondence

• stored knwoledge

• context

• recent experience

• expectation

• attention

T or F? multisensory neurons are found at nearly every level in the CNS

true

What are the brain areas responsible for multimodal integration?

• intraparietal sulcus

• superior temporal sulcus

• superior/inferior colliculus

What does reflexive orienting function in the superior colliculus?

"keeping you alive functions"

What are 4 elements of the MS cells?

• inputs from 2 or more sensory systems

• overlapping receptive fields

• can respond to singe sensory input

• preferentially (stronger) response to multiple inputs

What are the three drivers of MS enhancement (super-additivity)?

1. spatial rule

2. temporal rule

3. principle of inverse effectiveness

What is superior temporal sulcus (sts) involved with?

audio-visual speech processing, binding auditory and visual inputs regardless of speech or biological motion

What did Beauchamp et al. 2010 find?

used fMRI to identify MS area:

• no TMS, mostly illusions

• TMS of left sts - illusion down to 50% of trials

• both controls had no effect

What are the broad categories of behaviour?

• reflex

• reaction

• action

• habit