Research Methods Flashcards
MRi
uses magnets to line up atoms in body
functional MRi
overlays functional information on top of structure
can tell what parts of brain are receiving oxygenated blood
what does fMRI rely on
difference in reasonance of oxygenated vs deoxygenated blood
what is fMRI used for
compares brain areas active during different tasks
used for clinical groups, what happens in brain depending on diagnosis
how can you assess neurotransmitters (in vitro and in vivo)
post mortem (in vitro) - after death, infuse brain with substance which direct measures the extent that receptors bind
in vivo - PET scan, measures metabolite in blood/urine/cerebrospinal fluid, change levels by giving drugs
tryptophan
a neurotransmitter needed to make serotonin
remitted depressed people relapse when it is removed
mimics symptoms of depression in healthy people
what are neuropsychological tests used for
to measure problems in behaviour and thought which arises from brain dysfunction
how would NeuroTest determine spatial neglect
inability to draw clock and lining up the numbers
examples of behaviours shown by neurotest
spatial neglect
working memory
language (aphasia, comprehensions vs production of speech)
executive function - exert PF control over basic learned response
EEG measures and features
electrical signals in brain
has good temporal resolution
used to assess sleep, seizures, attention, cogntive function
why have neuro and psych tests not made it to clinical practice
expensive
inability to serve everyone who requires mental health care
crude measures
many are subjective to interpretation, confirmation bias
validity issues
cultural and ethnic issues with psych testing
many are developed and ‘normed’ based from americans, and europeans
how to reduce cultural and ethic bias
be aware of bias
do not generalise
multiple forms of measurement (convergence)
establish norms which are appropriate to specific groups and cultures
basic principles of research
theory
hypothesis
what is a theory
set of propositions to explain set of observations
what is a hypothesis
set of precise expectation about what should happen if theory is correct
- should be a falsifiable test, to refine theory
what are the constraints on theories
clearly defined principles
based on reproducible data
not fixed and final, refined and abandoned with new evidence
should not be based on opinion, intuition, anecdotal evidence
should not be impossible to disprove
not based on exclusivley explanations of pre-existing data
examples of important research methods
case studies
generating hypotheses
rare phenomena
issues of case studies
smallest sample size
cannot generalise
describes something already happened - conductive approach
what do correlations tell us
there may be relationship between 2 variables, but does not = causation
but do not know which explanation is true
what are epidemiological studies
surveys conducted on large groups to get estimate of entire population
characterises how many and where certain diseases exist
what do Epidemiological studies tell us
incidence and prevlance
incidence?
proportion of people who develop a new case of a disorder in some period
prevalence?
proportion of people with the disorder currently or during their lifetime, accumulative
risk factors?
variables that are related to the likelihood of developing disorders (lifestyle, education)
what are GWAS
genome wide association studies
what does GWAS study
genes are tested without specific hypothesis, and tested for correlations with disorders
what two factors are needed to draw valid conclusions
internal and external validity
internal validity
is the study confounded - is a different variable driving results than what was thought
external validity
do the results of the study sample generalise to others
can they be applied to other disorders etc
what are randomised controlled trials ?
when subjects are randomly assigned to either recieve experimental or control treatment
how does confirmation bias ruin experiments
if they know which group the ppt is in, may affect how the symptoms are scored etc
publication bias
phenomenon where studies that fail to show an effect are less likely to be published
