neuropsychology Flashcards
what brain regio is involved in alien hand syndrome
corpus callosum
what is reverse engineering
checking the function of a region by removing it and measuring the effect on the rest of the system
type of surgery in HM
removal of the bilateral medial temporal lobes to treat seizures
CVA
cerebrovasculair accident
stroke
an accident in arteries of the brain
% ischemic infarction
80
% hemmorage
20
ischemic infarction
certain parts of the brain don’t get blood due to a blockage of the artery
cause of ischemic infarction
atherosclerose (slagaderverkalking)
two things that can happen with ischemic infarction
embolism and thrombose
embolism
fatty clot pushed towards smaller vessel
thrombose
stationary clot that becomes bigger
hemmorage
Small arteries rupture and bleed into the brain tissue this interferes with the functioning of the system and the supply of energy and oxygen
reason 1 hemmorage
because the walls of the blood vesselss are weak
reason 2 hemmorage
aneurysm
aneurysm
an abnormal swelling or bulge in the wall of a blood vessel, such as an artery.
signs of hemmorage
slurred speech, loss of speech, left side of face stops working
inject contrast fluid hemmorage
accumulated hemoglobins light up
inject contrast fluid ischemic infarction
the water content of the affected brain tissue increasesresulting in a darker image. The contrast agent doesn’t go to the place of the infarction
coup
damage at the site of impact
contracoup
damage due to pressure from a coup pushes the brain to the opposite end or side of the skull
open traumatic brain injury
more localized
tumor
mass of new tissue that persists and grows independently
cell types tumor
meninges and glia
benign tumor
meningiomas
malignant tumor
gliomas
worst tumor
glioblastoma
infection
invasion of the body by disease-producing micro-organisms and subsequent tissue reactions
how do infections kill neurons
1) interference with blood supply 2) disturb glucose or oxygen metabolism 3) alter cell membranes 4) form puss 5) cause edema
edema
fluid retention
neurodegenerative disorders
progressive loss of neurons and increasing impairments in one or more cognitive functions
athropy
decrease in size or wasting away of body parts or tissue
dissociation
one patients has a different problem than the other
Double dissociation
two patients with a opposite profile
single dissociation
patient is impaired on task A but spared on task B
classical single dissociation
only an impairment on one task, other one very normal
strong single dissociation
both tasks are impaired, but one more than the other
double dissociation
two tasks use separate neural resources
association of symptoms
patient is impaired on task A and B
association syndromes
a cluster of different symptoms that are believed to be related in some meaningful way
fractionation assumption
damage to the brain can selectively impair a cognitive function
transparency assumption
other cognitive functions at normal pre-injury levels of efficiency
universality assumption
all individuals share the same cognitive systems
group by syndrome
useful for investigating neural correlates of a disease pathology but nog for dissecting cognitive theory
group by behavioral symptom
can potentially identify multiple regions that are implicated in a behavior
group by lesion location
useful for testing predictions derived from functional imaging
diaschisis
brain damage can induce functional lesions at a distance
single case studies
important to determine what the components of cognitive systems are
group studies
important for establishing whether a given region is critical for performing a given task
aspiration
aspiration of brain regions using a suction device
transection
cutting discrete white matter bundles
neurochemical lesions
using toxins that kill the neurons
reversible lesions
using pharmacological manipulations or cooling to temporarily disrupt neural activity
mental representations
the way in which properties of the outside world are copied by cognition
neural representations
the way in which properties of the outside world manifest themselves in the neural signal
neural signal
action potential
single cell recordings
electrodes placed in or near a neuron measure number of action potentials per second
electro-encephalography (EEG)
electrodes placed on the skull measures summed electrical potentials from millions of neurons
action potential of signal neurons is
basis of neural communication
single cell recordings intracellular
small electrode implanted into axon
single cell recordings extracellular
small electrode implanted outside axon membrane
kinds of neural codes
1) local representation (grandmother cells), 2) fully distributed representation 3) sparse distributed representation
grandmother cells
each time you see a person the neurons get activated for this person (not a lot of neurons)
fully distributed representation
many neurons, all would be relevant to understanding who the person is
sparse distributed representation
in between some neurons are more important than others, might not just be a few neurons that represent the full knowledge of this person
rate coding
greater rate or response used to code information
temporal coding
greater synchrony of response used to code information
EEG temporal resolution
excellent
EEG spatial resolution
poor
ERP’s
event related potentials
representational dynamics
use of multivariate statistics and machine learning to investigate how representations change across time
increased alpha frequency
linked to visual attention
increased gamma
linked to perceptual grouping
HZ
times a signal goes up and down in a minute
ERP
EEG signal is averaged over many events and aligned to some aspect of the event
mental chronometry
measuring the timing of cognition to infer its structure
N170
negative value specific for faces
CT
skull and bone visible, soft tissue not so
MRI
differentiate gray and white matter
MRI
magnetic resonance imaging
VBM
voxel-based morphometry
voxel
smallest unit of measurement in MRI machine
DTI
diffusion tensor imaging
DTI measures
white matter organization
functional imaging
poor temporal resolution, good spatial resolution
PET
positron emmision tomography
peat measures
local blood flow
fMRI
functional magnetic resonance imaging
hemodynamic parameters
blood volume and oxygenation
linking structure to function
voxel based morphometry and diffusion tensor imaging
fractional anisotropy
limited diffusion of water molecules in axons
PET uses
radioactive tracer injected into blood stream
PET temporal resolution
very slow
PET spatial resolution
effective around 1cm
fMRI signal
affected by the concentration of deoxyhemoglobin in the blood
BOLD response
blood oxygen level dependent contrast
change in BOLD response over time
hemodynamic response function (HRF)
HRF resolutions
limited temporal resolutions, high spatial resolution
cognitive subtraction
comparing relative difference in brain activity between two or more conditions
brain region is active when
it shows a greater response in one condition relative to the other (baseline)
functional connectivity with fMRI
correlations over time with posterior cingulate
PCC
posterior cingulate cortex
MPF
medial prefrontal cortex
IPS
intraparietal sulcus
cognitive neuroscience
relating the proporties of the underlying neuroscientific properties if the system to cognitive models of information processing
left space to right brain
everything we see from the left of what we look at goes to the right hemisphere and vice versa
quadrantanopia
only part of the fibers are damaged
damage to optic nerve before optic chasm
lose vision in one eye
optic chasm us cut
loose different part of the vision in both eyes
total damage of the optic tract
hamianophia
