lecture 3 Flashcards
karl lashley - lesion findings
the law of mass action
not location of lesion but extent of lesion.
equipotentiality & plasticity can take over damaged area and recover function.
*equipotentiality believed now.
Penfield - localization of function.
- anterior intraparietal sulcus (splits inferior parietal lobe) lesion =?
map homunculi in surgical patients
AIP sulcus lesion = inability to pre-shape hands during grasping
fodor - modularity of mind.
encapsulated mental processes, impervious to other things..
** read up on this**
different mental parts of mind.
essential, automatic, fast and highly specialized system for orienting, actions, and face recognition.
closed head injury
acceleration/deceleration = hit head, no break in skull.
cerebral oedema
altitude change causes swelling of brain due to fluid
infarction
neuronal necrosis = tissue death assoc w inadequate blood supply.
ischaemia
decreased blood flow
thrombosis
clot
stroke
loss of blood supply in brain
haemorrhage
bleeding
tumor
intervention = = take out layer of healthy tissue
= displace tissue,
anoxia
no oxygen to tisue.
encephalopathy
toxicity= inflammation of brain associated with altered mental state.
encephalitis
inflammation in brain due to infection
primary (from brain)
secondary (from body)
hydrocephalus
- overproduction of CSF
decreased absorption of CSF
surgery
tumor, epilepsy, DBS etc. may be issues with that.
HC - seizures.
had left hemispherectomy to minimize and abate seizures
lost site in right VF - no neglect (contralateral)
limp in right leg, preserved right hand control in left hand - possible right motor cortex compensates.
language = right side (usually more on left) - plasticity due to age?
disrupt electrical connection to stop seizure.
galen - patients with circumscribed brain damage
- knew there were links btw brain (injury) and mind (behaviour)
lesion methods: neural substrates vs cognitive function
NS = know where brain damage is, look for deficits.
CF = people with various stroke lesions that suffer same problem = put together all lesions and see where common areas of damage are - correlate to deficits in behavior
brenda milner and hippocampal function
- what lesion method?
- hippocampal function?
- used neural substrates technique.
- hippocampus = spatial navigation, LTM, STM.
hemineglect patients
not aware of portions of space
double dissociation
ex:
lesion A = deficit in A but not B
lesion B = deficit in B but not A.
language - broca’s (output) vs Wernicke’s (comprehension)
caveats to lesions
variability in popln = age, gender, education, experience.
lesion (no two are the same)
etiology (cause of lesion)
indirect observations - part of brain actually involved in behaviour or evolved in connection to critical parts or connection through to important areas? alternate strategies = test and make inferences to do tasks in more than one way.
multiple case studies
- need to relate test to different types of people. need large population for each group.
neurologically intact individuals
- what kind of group?
control group. match subjects to the experimental group in terms of age, gender, handedness.
non-human animals
use for neuropsych research.
test parietal cortex: memory, attention, visuo-motor control
clinical neuropsych assessment:
- cognitive capacity profile
- baseline, prognosis.
ID weaknesses and strengths. provide baseline for rehab.
prognosis - what they expect the healing would be.
- in conjunction with full neuro exam.
principles of assessment
- ID presence and type of mild disturbance
- differentiate btw brain injury and psych disorder
- deficit evaluation and rehab planning
- evaluate effects of surgery and drug therapy.
- evaluate scholastic problems in children
- objective data for research
legal forensics
legal assessment for suitability of person to work, retain child custody.
mini mental state exam (MMSE)
orientation - where is person? specifics.
registration - name 3 unrelated objects, repeat back.
attention/calculation - spell backwards, cont backwards from 100 by 7’s
recall - ask names of 3 previous objects
language - name, commands, repeat, write sentence
similar to concussion test
halstead-reitan battery
- 11 tests
category, tactual, rhythm, speech (repeat), 10 second finger tapping.
WAIS-III
test working memory.
verbal and non-verbal (visuospatial), verbal comprehension, processing speed.
raven progressive matrices
- match empty space with what matches pattern
judgement of line orientation test
- dot localization
- match line with protractor.
- empty grid next to number filled. which numbers do dots cover?
issues in neuropsych assessment
- reliability
- validity
- R = same result under same condition to same person.
- V = testing what you thin you’re testing
types of validity
construct = test targeted cognitive function? localization = reflect focal lesions? diagnostic = diagnose disease? ecologic = predict everyday relevant behaviour
issue in neuropsych assessment = premorbid functioning
= performance levels prior to injury.
- low functioning premorbidly = risk of misattributing low score to injury
- high-functioning pre = risk of overlooing dysfunction due to compensatory strategies
issue in neuro assess
- psychiatric disorder
- compliance and malingering
- rule out axis 1.
- malinger = exaggerate minor deficit. extend deficit to match what others suffer with. = not always “faking” - self awareness is low.
- MMPI - loo for exaggerated or unrealistic response patterns
experimental psych vs neuro psych assess
E: volunteers, resilient. research, aggregate behaviour, average behaviour. avoid false positive
N : patients - sensitive. application, specific behaviour, disordered behaviour, avoid false negatives, hypotheses about brain dysfunction
