EXAM 1 REVIEW TEST Flashcards
What is the Thalamic Nuclei for the Auditory system
- Medial geniculate body
What is the Thalamic Nuclei for the Visual system
- pulvinar and lateral geniculate nucleus
What is the Thalamic Nuclei for the Somatosensory system
-Ventral-Lateral Area
What is the Thalamic Nuclei for the Olfactory system
- Mediodorsal nucleus
What is the Thalamic Nuclei for the Gustatory system
-Ventral Posteromedial nucleus
Explain sensory deprivation
- Your brain is so dependent upon sensory stimulation
- it is primed to interpret and analyze environmental stimuli so when deprived of this information/ stimulation, the brain makes it up
What is a Homunculus?
Are there plural?
Who discovered this concept?
- the homunculus refers to a sensory map of the human body ( topographic representation)
- it refers to a sensory map of the human body and shows a depiction of what we would look like if our body parts grew in proportion to how much sensation we feel with them
- Wilder Penfield
What are the two kinds of Homunculi
- Motor and Sensory
What are the 5 ways to study asymmetry in patients
- Brain stimulation
- Double Dissociation
- Split Brain and Commissary patients
- Split face test
- Wada Test
What is Brain Stimulation?
What happens with stimulation of the RH and LH?
- Wilder Penfield
- stimulating certain brain regions produces certain behaviour
- found that the RH produces interpretative and experiential responses that are not produced by stimulation of LH
example- Deja Vu, fear, sense of dreaming, religious thoughts/feelings - RH stimulation also produces disruptions in the judgements on line orientation, facial expressions and STM for faces
- LH accelerated speech production/ responses or block speech if the individual is already engaged
What is Double Dissociation
- uses case studies, neuroimaging and neuropsychological testing to identify the neural substrate of a PARTICULAR brain function
- 2 manipulations that each have different effects on 2 different variables
(one manipulation affects the 1st variable and not the 2nd and the other manipulation affects the 2nd not the 1st)
Left Hemisphere lesions in right handed participants consistently produce deficits in what
- language functions
removal of the anterior part of left temporal lobe shows what deficits?
- superior intelligence
- significant deficits on tests of verbal recall and memory quotient (verbal memory)
- over time there will be a general decrease in intelligence ratings, and a further decrease in verbal memory
right temporal lesion produces what deficits?
- low scores on recall of complex drawings
- overtime there is decrease in performance IQ and nonverbal memory
What is the Split Brain and Commissurotomy procedure?
Who first performed this procedure?
- When medication fails to help epileptic seizures, cutting of the commissure (CC) in a Commissurotomy procedure will disconnect the two hemispheres
- William Van Wagen 1940
How do we connect both sides of the visual world
information presented to the LVF travels first to the RH and then through the corpus callosum to the LH
What happens when the LH of a split brain patient has access to information
- it can initiate speech and communicate the information
What happens when the RH of a split brain patient has access to information
- good recognition abilities but lacks the initiation of speech because it lacks access to the speech mechanisms in the LH
- can draw or write it down
EXAMPLE
shown spoon to LVF they will say “I see nothing”
Explain the Interpreter Test and results
Who created it?
split brain patients are presented with two images (one for each hemisphere) then asked to select a third image that matches the scene
- each hand will choose appropriate to the scene visible to the corresponding visual field (Left hand will choose what was seen in LVF)
- when asked to explain the choice the patient will describe the image selected by the right hand in terms of the scene on the right
- this suggest that only the LH is engaged in the interpretation of the situation
- Michael Gazzaniga
What is the Split Face test
Shows RH specialization for recognizing faces
- Pictures of faces split down the middle and recombined in improbable ways
- when presented to split brain patient, the patient is unaware because they are only seeing the normal half in each hemisphere
- when u ask them which was the original group of faces they will say the one that was shown in the LVF or RH
What is the WADA test
- Carotid Sodium Amobarbital injection
- this drug anesthetizes the hemisphere
- L carotid artery injection anesthetizes the L hemisphere and vice versa
- Patients are aphasic after (dont remember)
What happens with a Carotid Sodium Amobarbital injection to the left carotid artery
- patient cannot speak, move R arm, no RVF
- RH nondominant but aware for speech so they cannot report on the experience later
What happens with a Cartoid Sodium Amobarbital injection to the right cartoid artery
- sensory and motor disturbances but no speech disturbances
- UNLESS they are RH dominant for speech
What is lateralized in the brain? ( what are the two distinct forms of functional lateralization in the brain)
- Specialization theories - unique functions for each hemisphere (LH bias for self interaction, RH integrated)
- Interaction models - both hemispheres have the capacity to perform all functions but dont (cooperation between hemispheres)
What are the three interaction models
- The two hemispheres function simultaneously but work on different aspects of processing
- Although the two hemispheres have the capacity to perform a given function they inhibit or suppress each other activity
- Either the two hemispheres receive information preferentially and thus perform different analysis simultaneously or some mechanism enables each hemisphere to pay attention to specific types of information thus leading to different hemispheric analyses
What is the function of the posterior hippocampus?
memory and spatial navigation
What is the function of the anterior hippocampus?
anxiety related behaviours
What is Handedness associated with ?
- cerebral asymmetry and lateralization of the brain
- also associated with differences with cerebral blood flow, anatomical asymmetries and lateralization of functions like language
When does hand preference begin
10 weeks of fetal development
What are the four categories of theories for left handed vs right handedness
- environmental
- anatomical
- hormonal
- genetic
What percent of the population Is left handed
10%
What three subcategories do environmental theories break down into
- Utility: mothers are more likely to hold infant in the left hand so they are closer to the mothers heart and so the mothers right hand is free to do other tasks
- Reinforcement: for centuries children have been taught to write with their right hand, but modern education is not accepting left handedness (prevalence has not gone up)
- Damage: there may be some genetic bias toward being right handed. suggesting that being left handed is the result of a genetic anomaly or stressful in-utero development
(ex. 18% of twins are left handed which is close to twice that of regular population 10%)
What are the two subcategories for the anatomical theories of handedness?
- enhanced maturation: the LH generally shows enhanced maturation and greater development which may influence handedness
- Those seen in nature:
- this theory points out that the heart is on the left side of the chest, the temporal lobe is larger on the left, and the areas that influence birdsong are found in the LH of brain
- LH dominance for language and motor control may just be another manifestation of this trend
(the research on these theories is little to none)
what are the hormonal theories of handedness
- exposure to different levels of testosterone early in life could impact cerebral organization and asymmetry
- testosterone is generally inhibitory on development
- testosterone acts on the LH of the brain leading to great development of the RH and Left handedness in some individuals
STUDIES EXAMINING AMNIOTIC FLIUD HAVE NOT SUPPORTED THIS THOERY
What are the genetic theories of handedness
there could be a dominant gene for handedness
- a more widely researched variant suggests the dominant gene encodes left hemisphere speech ( if there was a r handed gene it would also encode LH speech
- Genes that favour left hemisphere speech also favour an advantage in motor control of the right hand
What are the sex differences in Symptomatology
women- affective and cognitive
men- more motor deficits
What are the 5 classes of cognitive behaviours Kimmura examined
- motor skills
- spatial analysis
- mathematical aptitude
- perception
- verbal abilities
What are the tasks favouring women
- mathematical calculation
- verbal memory (recall)
- object memory (where this are)
- fine motor skills, coordination
- perception (rapidly matching)
What are the tasks favouring men
- mathematical reasoning
- geometric form perception
- mental rotation
- target-directed motor skills
- visual imaging
Sex differences in motor skills
- men are superior at target throwing and catching
- females have superior fine motor skills such as the peg board
- differences present early in like, as young as 3
Sex differences in spatial analysis
Men
- generally better at spatial tasks requiring mental rotation and navigation
- generally quicker at learning spatial navigation tasks
Women
- improve on mental rotation tasks when block figures are replaced by human shapes in different postures
- the human figure rotation task
- women better at identifying which objects have been moved or displaced, better recall for landmarks
the sex differences in spatial ability tasks is not in spatial information its the difference related to what you do with the info
Sex differences in mathematical Aptitude
Men - mathematical reasoning Females - computation - much better at reading (3x more than that of men in math)
Sex differences in brain structure that favour women
- larger language areas
- larger medial paralimbic areas
- larger lateral frontal areas
- greater relative amount of gray matter
- more densely packed neurons in temporal lobe
- more gyri
- thicker cortex
Sex differences in brain structure that favour men
- larger medial frontal areas
- larger cingulate areas
- larger amygdala and hypothalamus
- larger overall white matter volume
- larger cerebral ventricles
- larger right planum parietale
- more neurons overall
- larger brain
What are the influences of sex hormones on brain structure
- differences in the distribution of estrogen and androgen receptors during development could affect brain structure
- there are sexually dimorphic regions of the brain in the prefrontal cortex, the paralimbic cortex and the posterior parietal cortex
What are the sex differences in brain volume relative to cerebral size
Women
- prefrontal and medial paralimbic regions brain volume significantly higher in women
- estrogen receptors during development
Men
- larger relative volumes in the medial and orbital frontal cortex and the angular gyrus
- androgen receptors during development
Sex differences in concentration of gray matter
- males have uniform concentration of gray matter but females have some areas of high and low concentration
What are the symmetrical differences between sexes
- women brain more symmetrical than mens
- the asymmetry of the planum temporal and sylvian fissure is more common in men which supports the differences associated with language related structures
- women have more inter-hemispheric connections
Can you differentiate between a male and female brain by looking at them
no
- but by the patterns of connections between brain regions found in resting-state fMRI are reliable predictors
- males show greater connectivity in RH
- females LH