Week 4.2 Cog Neuro Flashcards
5 causes of brain damage (slective to diffuse)
surgery
tumour
stroke
traumatic brain injury
neurodegeneration
classical neuropsychology approach
mapping brain areas to cog functions
performed at group level
answers clinical questions
cognitive neuropsychology approach
determines whether functions dissociate under damage
single-case studies
focus on cog processes
damage not localised
a single dissociation
patient impaired on task A but spared on task B
a double dissociation
two single dissociations have a complementary profile of abilities
associations
equally bad at reading nonwords and irregular words
- could have damaged a neural system necessary for both functions
- could have damaged two different systems close to each other in the brain
fractionation assumption
brain damage can selectively affect different cog/neural systems
transparency assumption
brain lesions can affect existing cog systems but do not create new systems
universality assumption
all cog systems are basically the same
connectionist triangle model of reading
to read irregular words correctly we have to activate their meanings (semantic)
dual-route cascaded model
to read irregular words correctly we use lexical representations (not semantic)
strong association between irregular reading and semantic knowledge
semantic dementia
impaired semantic knowledge of word meanings correlated with poor irregular word reading
suggest semantic knowledge = necessary to pronounce irregular words
patient EM
single-case dissociation between irregular reading and semantic knowledge
impaired semantic
spared irregular word reading
suggests semantics is not necessary
problem with single-case studies
lesions may affect different people in different ways if their cog systems are already different
split-brain
a surgical procedure in which fibers of the corpus callosum are severed
strokes
disruption in the blood supply to the brain
cerebrovascular accidents (CVA)
aneurysm
over-elastic region of arterty prone to rupture
task-resource artifact
if two tasks share same neural cognitive resource but one uses it more then damage to this resource will affect one task more than the other
task-demand artifact
one task performed worse than another because it is performed sub-optimally (not because some aspect of the task is compromised)
dysgraphia
difficulties spelling and writing
syndrome
cluster of different symptoms that are believed to be related
edema
swelling of brain following injury
diaschisis
discrete brain lesion can disrupt functioning of distant regions that are structurally intact
behavioural neuroscience
cog neuro in nonhuman animals
cathodal tDCS
decreases cortical excitability and decreases performance
anodal tDCS
increases cortical excitability and increases performance
transcranial magnetic stimulation (TMS)
- stimulating region of cortex placed beneath current-carrying coil
- stimulation temporarily interferes with ongoing cognitive activity + provides info about necessity of region for performing task
- virtual lesion
TMS vs tDCS
- transcranial direct current stimulation has poorer temporal + spatial resolution to TMS
- has advantage of being able to facilitate cog function (anodal tDCS)
