cognitive methods

Question 1

patient HM

Answer 1

neurosurgery for epileptic seziures
hippocampus - amnesia - brain areas association with memory
donated brain to research

Question 2

prosopagnosia findings

Answer 2

lesions to the temporal lobe recognise faces

Question 3

Achromatopsia

Answer 3

grey visuals- lesions - atoprhy to temporal lobes

Question 4

patient GY

Answer 4

lesion to the left hemisphere - trauma - blind sight
primary visual cortex is not the only area associated with vision
V5 = can respond to visual motion but not static

Question 5

what is a double dissociation

Answer 5

two brain areas are not associated and have different functions discovered doing two tests

e.g., language
comprehansion and production arent in the same area

Question 6

TMS - transcranial magnetic stimulation

Answer 6

temporialy disables an area in the brain via stimulation effecting the magnetic field around the brain

Question 7

how does an EEG work?

Answer 7

dipoles in body formed by pyramidal neurons
when pyramidal neurons recieve action potential from presynaptic neuron the membrane potential changes
organised in a regular way
on scalp
record with eeg

Question 8

problems with EEG

Answer 8

spatial prescision
is it recording excitatory or inhabatory effects

Question 9

wheel and Wiesel

Answer 9

bar in vision, moved it around and listened to the action potential of neuron to understand how we see and where
mapped out visual

Question 10

semir zeki

Answer 10

captured different neural response and what they and their arrangement.
visual cortex has different tunings with specific properties
v1 = blobs

Question 11

single unit electrophysiology

Answer 11

microelectrodes to record action potential firing to faces but no other stimuli

Question 12

ERP

Answer 12

loads of trial like 100
to get rid of background oscciliations
selectivity to objects

Question 13

problems with ERP

Answer 13

so many singlas in the brain can give response to the same pattern across the scall

Question 14

MEG scan

Answer 14

uses magnetic field rather than electrodes
magnetic field changes are small so requirs powerful detector
cool with liquid helium, expensive
need magnetic shield room
more reliable

Question 15

how does MRI work?

Answer 15

nucleus of atoms have charged particles
these spin
spinning charges have magnetic properties
when protons in magnetic field they align with it
some parallel some anti parallel
the difference in parallel and anti parallel provides the basis of signal we use to read MRI scan

Question 16

diffusion tensor imaging

Answer 16

measures the wiring of the brain

focus on cortex
white matter connects brain regions
captures diffusion of water, greater along axon
a signature of brain direction can be measured

Question 17

PET scan

Answer 17

intravenously insert radiation
positron and electron collide
annihilate each other
photons come from this in both directions
these photons are measured
more photons where these is most activity

Question 18

when is PET used

Answer 18

useful clinically but too harmful for research
cancer and AD
invasive

Question 19

how does an fMRI work?

Answer 19

neural activity consumes oxygen
decreased in oxygenated blood
then an increase in more than what was at rest
blood oxygen changes magnetic properties
changes mri signal

Question 20

what is the change in mri signal due to change in magentic properties called

Answer 20

BOLD signal

Question 21

what does BOLD stand for

Answer 21

BLOOD OXYGENATED LEVEL DEPENDENT

Question 22

what is the bold signal

Answer 22

slow
5-10 seconds after stimulus is presented
poor temporal res

Question 23

how is BOLD signal resolved

Answer 23

resolve using block designs
stimulation stage vs controlled stage

Question 24

what is unique about the V4

Answer 24

only been found in the human brain, for colour perception