chapter 3 Flashcards
5 types of research
- descriptive methods: case studies, naturalistic observation, surveys
- correlational/ quasi experimental
- experimental
disadvantage of case studies
- focuses on one particular person
- sample size is 1 which is too small
disadvantage of correlational work
- we can only say two things are related, but NOT that one causes the other
- correlation does not equal causation
goal of cognitive psychology work
to identify the differential mental operations or transformations required to perform a specific task (and exploring limitations of tasks)
-try to figure out what is happening based on what is going in and what is coming out
Sternberg item-recognition task measure
- measures working memory
- serial
Stroop cognitive control task measure
- cognitive control
- subjects ask to identify the ink color
- color doesn’t match word = task takes longer
3 causes of brain lesions in humans and what case studies of these individuals can tell us
- naturally occurring lesions
- experimental ablation
- perturbing neural function
- can tells us the role of a particular brain region for cognitive function
- help us study brain functions
2 types of strokes
- ischemic: blockage of blood vessel in brain, stops blood flow and oxygen to regions of the brain, causes tissues to die
- hemorrhagic :blood overflow causes vessel to burst and loss of blood supply
2 types of brain tumors
- meningoma: outer surface of the brain
- glioma: affecting the glial cells
strengths and weaknesses of studying naturally occurring brain lesions
- strengths: determines whether a region is necessary for cognitive function, compelling, see which functions tend to go together and which are isolated from each other
- weaknesses: groups studies are hard because patients differ, neural plasticity strategies could make a cognitive deficit, don’t know if damage region is of primary or secondary importance for function
double dissociation … why is it important
-helps find another task that is also associated with the same part of the brain to see whether that region is responsible for a specific function
experimental ablation
-removal or destruction of a part of the brain of an experimental animal to study the function of that region of the brain
describe how pharmacological studies inform our knowledge of the nervous system
can help us learn about how a neurotransmitter affects the nervous system
TMS
- uses a pulse of magnetic energy stimulation to briefly disrupt cognitive processing
- can turn off neural functioning briefly depending on the region it is put on
TMS strengths and weaknesses
- strengths: good temporal resolution, noninvasive, transient effects
- weaknesses: can only get to surface areas not deep parts, limited, effects don’t last long
what do structural methods tell us about the brain? 3 examples
-gives us a picture of the brain, but does NOT tell us about a function
- CT
- MRI
- diffusion tensor imaging
functional methods
- EEG
- PET
- fMRI
-measures neural activity
CT scan work.. strengths…weaknesses
- uses X-ray technology to give a simulated picture of the brain
- S: noninvasive, quick pic of brain, most people can get it
- W: not detail, not use in research studies, uses x-ray
MRI work… S and W
- takes slices of the brain and creates a 2d pic of the brain
- S: good spatial resolution, very detail, noninvasive
- W: too expensive, some people can’t use bc is magnetic and sensitive to movement
Diffusion tensor imaging work…S and W
- White matter tract = water not very movable, because water is confined to the white matter tract thus we can see the white matter
- S: we can see white matter tracts
- W: too expensive, uses an MRI
single-cell recording
- an electrode is inserted into the brain, and electrical activity measured in vicinity of the neurons
- not done in humans = very invasive
EEG work…. S and W
- Electrodes are placed on the scalp to measure electrical activity through the skull
- Does not measure individual neurons, but populations of neurons firing synchronoously
- S:good temporal resolution, noninvasive
- W: poor spatial resolution
Event-related Potential (ERP) work…S and W
- Small changes in the scalp-recorded electroencephalogram time-locked to the onset of a task
- S: noninvasive, cheap
- W: bad spatial resolution, looking at population of neurons not one
Magnetoencephalography (MEG) work…..S and W
- Imaging technique that measures the weak magnetic fields emitted by neurons
- Time locked to an event gives you event-related fields (ERFs)
PET work….S and W
- Uses PET scanner to measure blood flow, oxygen use, and sugar (glucose) metabolism following injection of a radioactive tracer
- S: noninvasive
- W: uses radioactive tracers, very expensive, poor temporal resolution, ok spatial resolution
fMRI work
- Indirect measure of neural activity
- Measuring blood flow, with the idea that the areas of the brain that are more active will use more oxygen blood flow
- Showing more blood flow (activity) when the word was remembered compared to forgotten
fMRI S and W
- S: noninvasive, safe, measuring activity in the brain, good spatial resolution
- W: analysis very complex, poor temporal resolution
what is the difference between block design and event-related design
d
