Measurement Techniques Flashcards
3 categories of measuring pyschology
- behavioural
- neuropysiological
- psychophysiological
types of behavioural techniques
conditiniong questtionatires animal tests cognitive tests puschophysics infants and habituation
types of neurophsyioloical techniques
lesion studies MRi, Pet, TMS EEG MEG TMS CT X ray
types of psychophysiological techniques
galvanic skin conductance
salivdary hormones
eye tracking
electrocardiography
what are electrophysiological readings
microelectrodes are placed into monkey/cat/mice brains to record neural activitiy
usually involves surfering on an animal where an area is removed and the electrodes are placed
what are electrophysiological readings used for
measurements of the electrical activity of neurons, and, in particular, action potential activity
used to record responses to stimuli that affect rate of neronal firing near electrode
used to map brain’s sensory somatic cortex using electrical stimulation to see how the body responds
advatnges of electrophysiological readings
direct recording of neural activity
high spatial resolution
high temporal resolution
disadvantages of electrophysiological readings
invasive= unethical to use on humans
looks at SINGLe neurons but not networks
difficult to study complex tasks as its mono-functional
when can electrophysiological readings be used on humans
cancer patients where tumor removal occurs
types of lesions
- aspiration lesions
- radiofrequency lesions
- knife cuts
- reversible lesions
aspiration lesions
Skin lesion aspiration is the withdrawal of fluid from a skin lesion (cortical tissue) and insert stimuli= accessible to eyes and instruments of sureons
radiofrequency lesions
using radiofrequency currents that pass through target tissue
knife cuts
elimiante conductinos in nerve tracts
reversible lesions
temporary eliminate activity in a brian area using anaestehthic or cooling
what do lesions allow
insights into brain functional organization
famous lesion cases
- brocas area (non-fluent aphasia)
- wernickes area (fluent aphasia)
== anoatmication language dissociations
pros of lesion studies
establish cause-effect of brain area and function
noninvasive (but patients might tire from experiments)
cons of lesion studies
no two lesions same (not common; inaccurate)
damage widespread
damage may effect other cognitive abilities
platicity of brain (hence changes might result of function-area; i.e. stroke tennis player)
what (in humans) is used to study pyschophysiological activity
eeg= electroencephalography
set-up of EEGs
measures electrical signals by placing electrode ‘swimming cap’ onto patients head + weakly measure neural activity passing through skull
- measures different wave variations (alpha, beta, etc.) aand their length/speed
what are ERPs
event related potentials: other factors such as noise that can affect an EEG reading and create signals
as a result= signals are averaged to reduce ‘background’ noise
what do EEGS measure
electircal signals and brain activity/consciousness
what is N170
a type of Event Related Potential: evidence for face slectivity in human brain as 170ms after a negative face stimuli elecits a response
pros of EEG
high temporal resolution (up to 1 ms)
non inavsive
can even be used on infants
cheaper than fMRI
cons of EEG
poor spatial resolution
infiinte possiblities for what aused a wave
can only measure weak signals from neurons in specific orietnations
no causal inference
synchronous firings of neurons can sometimes make it hard to find a measurable signal
Magnetoencephaolography (MEG) set up
magenetic fields placed into brain
expensive than EEG
weak
provides high spatial resolution/3D images
what do PET scans do
branin imagies= identify active brain areas used radioactive markers that indicate ‘active’ brain areas (glucose consumption= conecentraion)
allows the measurment of moleculers using radioative ligands to study addiction/parkinsons/ etc and how brain responds to reward allocation
(radioative fluorodeyoxguclose insterd into brain and taken up by energy consumping scelles which a Pet scan measures)
pros of pet scans
measures specific molecule concentraitons
spatial resolution better than an EEG
can imagine whole brain
provide FUNCTIONAL brain images
cons of pet scan
invasive (radioactive tracesr)
no clear anatomical linkages
poor temporal resolution
no causal inference
what techniques are used for structural brain imaging
fMRI
DTI
MRi
MRI set up
magnetic resonance imaging; measures water concentraiton in brain tissues where participants placed in a ‘scanner’ and hydrogen protoons are measured
looks at how brain works in response to stimuli
e.g. mcgill hippocampus study on london taxi drivers
MRI set up
measures water concentraiton in brain tissues where participants placed in a ‘scanner’ and hydrogen protons are measured
compares activities with each other (structural and funcitonal)
looks at how brain works in response to stimuli
e.g. mcgill hippocampus study on london taxi drivers
MRI pros
excellent spatial resolution
can image whol brain
MRI cons
poor temporal
indriect measure of neural activit (only oxygen consumption)
DTI set up
Diffusion Sensor Imagery= water molecular pathways are identified
- tracks fibres
- estimates location/orientation of white matter
- used in schrozophenia studies
what is TMS used for
for inference and manipulation of the brain and body
set up of TMS
magnetic fields created using coils that hyperpolarize temporarily brain areas and allow for inference of cause-effect relations between brain areas and motor functions
uses mri to identiy the brain areas to be stimulated
pros of TMS
reversible
may have therapeuc benefits (depresion patients)
precising timing of TMS pulses
enable cause-effect inferences in specific brain areas
what is the common test battery
a way to measure ingglience other than IQ; instead using the WAIS (Weschsler Adult Intelligence Scale)
new creative solutions
- neuroprosethethics to replace malfunctioning brain areas
- optogenetics
- human brain project
what needs to be considered when using a tool
- is it safe?
- how well can inferences be drawn?
- spatial and temporal variations?
EEG waves and states of consciousncess
beta and gamma= high frequency/exicted and awake
delta= asleep
alpha= relaxed
theata= drowsy
set up of TMS
magnetic fields created using coils that hyperpolarize temporarily brain areas/cortex and allow for inference of cause-effect relations between brain areas and motor functions
acts on synapses
uses mri to identiy the brain areas to be stimulated
pros of TMS
reversible
may have therapeuc benefits (depresion patients; increases seratonin)
precising timing of TMS pulses
enable cause-effect inferences in specific brain areas
what is the BOLD signal
in FMRI; the “Blood-Oxygen-Level-Dependent” signal
how can muscle tension be measured
using electromyographies= place 2 electrodes in skin over muscle
how can eye movement be measured
electroculography (EOG) that measures electircal potentials in electrodes around eye
or
eye tracking
galvanic skin conductance
tests respones sto stress in ability of skin to conduct electricity
how can cardiovacular activiy be measured
heart rate (electrocardiography)
blood pressure
blodo volume
what can’t FMRI distinguish between
- function-specific processing and neuromodultiation
- between bottom up/top down signals
- confuses excitation and inhibition
- can’t quantify EXACT brain regions (and intensity)
- diffiggertaite between tasks of same region
assumptions made on fMRI:
- the brain can be localized (brain architecture is modular) and each ‘avitivty area’ can be studied with fMRI
