MT3 Flashcards
1
Q
parietal lobe
1. main functions
2. somatosensory sys
3. borders of the parietal lobe
A
- Integrate and process vis and somatosensory info; memory through close relation between post parietal region and PFC and limbic sys spatially guided behaviour and navigation (viewer centered object id/egocentric space)
- Multimodal sensory sys comp receptors and processing centres to produce various types of sensory perception such as touch, temp, proprioception, and nociception
- Anterior border is central fissure, ventral border is Sylvian/lat fissure, dorsal to cingulate cortex, post border is parietal occipital sulcus
2
Q
major parietal sulci and gyri
1. post central gyrus
2. inferior parietal lobe
3. STS
4. STG
A
- Main sensory receptive area for touch
- Multimodal associative area for aud, vis, and somatosensory input; later structural maturity, why children do not read or write until 5-6; consists of the highly interconnected supramarginal gyrus involved in language processing, production, and comprehension (phonological processing during dev of speech and has errors in recog and processing sounds), higher order cognitive and spatial perception, attention, and awareness, and numerical abilities; and highly innerconnected angular gyrus for intergrating vis info with language and numerical processing for reading, comprehension, and math
- Multimodal processing for theory of mind, biological motion, voices, faces, and language (Wernicke’s area is in the posterior STG)
- Close to parietal lobe, wernicke’s area for language processing
3
Q
cytoarchitecture of the human brain
1. Cecile and Oskar Vogt
2. Brodmann’s regions
3. Economo’s regions
4. posterior parietal pathways
A
- Electrophysiological mapping of human and monkey brains to understand functional role of brain regions
- Subdivision of cerebral cortex into areas based on differences in distribution, density, shape, and size of cells; anterior zone close to frontal lobe comp areas 1, 2, 3, and 43 comp somatosensory cortex, posterior close to occipital is other areas
- Div post parietal into PE, PF, and PG for integrating multimodal info; superior ant parietal PE for somatosensory and guide movement by providing proprioceptive feedback, connects to S1, M1, and PF; ant inferior PF is part of mirror neuron sys involved in learning through observing and copying other’s actions, connects to S1, M1, premotor cortex in precentral gyrus for movement planning, and PG; posterior inf PG for dorsal stream and parietotempoccipital crossroad receiving complex connections for various sensory input and cingulate connections
- parietopremotor is dorsal pathway; parietoprefrontal is working memory; parietomedial temporal is spatial navigation
4
Q
parietal lobe dysfunctions
1. symptoms of parietal lobe lesions
2. astereognosis
3. simultaneous extinction
4. asomatognosia
A
- afferent paresis (clumsy finger movement due to lack of feedback about finger position), deficits in tactile perception (stereognosis), and abnormally high sensory threshold (req high stimuli to be detected)
- somatoperceptual disorder; inability to recog object by touch; test by placing pattern in palm of blindfolded subject and having them id the pattern after handling 6 diff patterns or match paired patterns by touch
- somatoperceptual disorder; inability to perceive multiple stimuli of same type (80% similar), usually only see object in right vis field; test by pres 2 identical, different, and same kind of object
- somatosensory disorder; loss of knowledge of body’s condition, anosognosia is unawareness or denial of illness, anosodiaphoria is indifference ot illness, asymbolia for pain is absence of normal reaction to pain, finger agnosia is inability to show or point to finger
5
Q
posterior parietal lobe dysfunctions
1. Balint’s syndrome
2. contralateral neglect
3. object recog
4. vis perception
5. apraxia
A
- lesion in superior parietal region (PE); can move eyes but cannot focus on specific object, has simultagnosia, and optic ataxia (difficulty reaching for stationary object with visual guidance, easier with movement of object since recruits M1 to help guide movement)
- inattention to sensation and perception on one side, usually left, most often is lesion in right inferior parietal lobe in right intraparietal sulcus and right angular gyrus; can happen with lesions to frontal lobe and cingulate cortex; two recovery phases, exp allesthesia (begin to respond to neglected stimuli as if on attended side of body), then simultaneous extinction
- unable to recog objects in unfamiliar views due to dmg to right inferior parietal lobule
- Mooney closure face test to id perception of objects (face)
- loss of skilled movements; inability to copy movements is ideomotor and inability to org spatial movements is constructional; test using Kimura box test by doing a sequence of movements
6
Q
spatial attention and cog in parietal lobe
1. selective attention and disengagement
2. cog
3. somatosensory threshold
4. tactile form test
5. spatial relation
6. language
A
- spatial attention attending to specific stimuli to not overload brain processing; disengagmentis shifting attention from one stimuli to another
- ability to use and manipulate spatial properties of stimuli; posterior leisons in both left and right side produce spatial cog deficits; left side dmg results in inability tot gen appropriate mental img; right side dmg results in inability to manipulate mental img; topograpical deficits more likely to be assoc with right
- lesions to postcentral gyrus increase somatosensory threshold on contralat side; test by using two point discrimination test where blindfolded subject reports one or two points on skin as distance between points decrease
- Seguin-Goddard Form Board test where subject must slot different shapes into holes using touch and then draw board from memory; deficits in tactile recog indicates PE and PF, deficits in drawing indicate lesion in PG
- right-left differentiation test id left or right body parts, deficits can indicate left parietal lobe dmg and left frontal lobe dmg
- Token test with different coloured and shaped token, have to touch indicated colored shape; deficits indicate PG dmg
7
Q
temporal lobe
1. main functions
2. anatomy
3. Insula
4. symptoms of temporal lobe lesions
A
- Contains primary aud cortex for aud processing; hippocampus for short term memory formation, consolidation into long term memory, and memory retrieval; amygdala for emotional reg, emo sig, and emotional memory and response
- Anterior to occipital lobe, below lat/Sylvain fissure; subcortical temporal lobe circuit is the limbic cortex with amygdala, hippocampus, and cingulate cortex
- Insula is inferior to sylvian fissure, contains the gustatory cortex for taste, and auditory association cortex
- Auditory disturbance, disorder of music perception, impaired org and categorization, inability to use contextual info, memory problems, altered personality and affective behaviour, altered sexual behaviour
8
Q
hippocampus
1. function
2. Forming long term memory
3. alzheimer’s
A
- Part of limbic cortex, role in memory and spatial navigation; dmg lose ability to form and retain new memory, hippocampus releated to epilepsy, schizophrenia, amnesia, and PTSD, involved in functional connectivity (functional integration between spatially separated areas) in complex neuro networks
- Info in cortex sent to hippocampus to form short term memory, if significant emotionally then proteins in hippocampus consolidate memory and send back to cortex for long-term storage; procedural memory stored in the basal ganglia
- irreversible, destroy’s brain cells, partly occur due to dmg to hippocampus, cause thinking and memory to deteriorate, first symptoms vary. can be decline in cognition, vision and spatial issues, and impaired reasoning or judgement
9
Q
visual processing in temporal lobe
1. Hasson et al
2. face processing
3. disorders of visual perception
A
- use fMRI to montior cortical changes to img of faces or landscapes; found extensive activity in aud and vis region in temporal lobe in STS and cingulate regions with selective activation of the fusiform face area to close ups of faces and parahippocampal place area to landscapes
- dogs temporal lobes respond strongly to pictures of dog and human faces comp inanimate objects; since dogs spend long time looking at dog or human faces; humans also spend most time looking at faces, experience has high impact on perception; low sighted or blind individuals have smaller face processing regions than sighted people
- left temporal dmg can impair object recog and complex pattern recog since it form the ventral pathway; test using various tests such as mier and french test (id different img), complex figure test (id different shapes within complex img), hidden figure test (id shape with in each diagram), mooney closure test (id face)
10
Q
auditory processing in temporal lobe
1. beat
2. rhythm
3. music perception
4. fundemental pitch
5. spectral pitch
6. aud hallucinations
A
- steady sound repearting, heartbeat of song; right hemisphere perceive beat
- melody, pattern of different sounds and notes arranged in song; left temporal lobe is major region for temporal grouping of rhythm
- music perception based on relation of loudness (mag of sound sensation), timbre (distinct characteristic), and pitch (how high or low notes is); right temporal lobe extract pitch from sound; prosody is the pitch in speech known as tone of voice; musicians have larger Heschl’s gyrus near primary auditory cortex
- basic pitch used to id different notes; left hemisphere
- mix of different sound waves to make a sound; right hemisphere
- most common symptom of schizophrenia, verbal hallucinations activate primary auditory cortex and Broca’s area
10
Q
model of sys for face perception
A
- core sys for visual analysis comp inferior occipital gyri for early perception of facial features, fusiform face area for perception of unique identity, STS for changeable aspects of faces such as eye gaze, expression, and lip movements
- extended sys further processes info with other neural sys including ant temporal cortex responsible for personal id such as name and biographical info, auditory cortex for prelexical speech perception, intraparietal sulcus for spatially directed attention, and amygdala, insula, and limbic sys for emotion
11
Q
temporal lobe functions
1. contextual info
2. memory
3. affect and personaility
A
- interpret stimuli differently depending on context
- lesion in left temporal lobe lead to verbal memory deficit; lesion in right temporal lobe lead visual memory deficit, with limited immediate recall and little recall after 10 mins
- stim ant and med temporal lobe (near amygdala) produce fear; temporal lobe personality overemphasized trivial details, pedantic speech, egocentric, and perseveration (preoccupation on one thing)
12
Q
frontal lobe
1. function
2. primary motor cortex
3. pre motor areas
4. connectiosn of motor and premotor areas
5. disturbances of motor function
A
- Later maturity, responsible for executive function, higher order cog, and advanced problem solving
- Area 4, final selection and execute movement, fine motor skills, strength, and dir of movement
- Adj to M1, responsible for corollary discharge (stable environment despite movement of eyes), motor strength, mirror neurons, and eye movements; lat area 6 for premotor plan appropriate movements, medial area 6 for supplementary refining and send info to M1, area 8 for frontal eye field, area 8A for supplementary eye field, area 44 is Broca’s area
- M1 send info to sp cd and cranial nerves, basal ganglia, and red nucleus; premotor sends to sp cd and M, receive info front post parietal areas and dorsolat PFC; eye fields receive info from PG and sup colliculus
- Loss of fine motor, speed, and strength after dmg to M1, loss of movement programming due to dmg to premotor or dorsolat cortex, and change in vol gaze due to dmg to frontal eye fields
13
Q
prefrontal cortex
1. asymmetry
2. dorsolateral connections
3. orbitofrontal connections
4. ventromedial conenctions
5. functions
6. exectutive function
A
- Left responsible for language and encoding memory for long term storage; right for non-verbal movements, facial expressions, and retrieving memories
- Connect to post parietal, STS, basal ganglia, and sup colliculus
- Connect to aud regions of sup temporal gyrus, STS, and vis regions of inferior temporal cortex (area TE), limbic regions, and PAG for sensation feedback during movement and species-typical behaviour
- Connect with dorsolat PFC, subcortical limbic sys, and PAG
- Cog processes for appropriate behaviour using internal cues (info from dorsal and ventral streams within mind or body to form chronological order of events) and external cues (feedback from the environment), contextual cues from social interactions, and autonoetic awareness (self knowledge from experience that forms continuous awareness)
- Plannning, selection, persistence, focus, memory, and responding to int, ext, and context cues
6.
14
Q
frontal lobe lesions
1. convergent thinking v. divergent thinking
2. Other symptoms
3. schizophrenia
4. parkinson’s
5. korsakoff’s syndrome
A
- convergent has single correct or well def answer, divergent has multiple answers or interpretations allowing for creativity; frontal lobe dmg impairs divergent thinking due to loss of behavioural spontanetiy resulting in decreased verbal fluency and design fluency
- Increased perseveration (focus on single concept), inability to strategize, loss of response inhibition; impaired social and sexual behaviour such as change in personality like pseudodepression from lesions of left frontal lobe (depression like symptoms) and pseudopsychopathy from lesions of right frontal lobe (immature behaviour, lack of restraint, promiscality)
- Abnormal mesocortical dopaminergic projection from ventral tegmental area resulting in decreased BF to frontal lobe, atrophy
- Loss of dopamine in substantia nigra projecting to PFC resulting motor problems
- Alch induced dmg to dorsomed thalamus and deficiency in frontal lobe catacholamine
