Chapter 3 Methods Flashcards
(41 cards)
What is cognitive psychology?
The study of mental activity as an information-processing problem. The goal is to identify internal processing that underlies behavior.
What are the two concepts of cognitive psychology?
1) Information processing depends on mental representations
2) Mental representations undergo internal transformations (encoding, comparing, deciding, responding)
What is the word superiority effect?
People are most accurate in identifying a target when stimulus is a word, because we activate multiple representations
What is the stroop task and what does it show?
The task activates multiple representations simultaneously and shows that this ability isn’t always handy.
Stroop task = e.g. showing the word ‘red’ in the color blue
What are 6 causes of neurological dysfunction?
1) Vascular disorders
2) Tumors
3) Degenerative disorders
4) Infectious disorders
5) TBI (traumatic brain injury)
6) Epilepsy
What is: ischemia - aneurysm - artherosclerosis?
Ischemia = drop in blood pressure resulting from shock/blood loss
Aneurysm = sudden rise in blood pressure resulting in rupture in a blood vessel
Artherosclerosis = blockage of artery by fatty tissue (embolus)
What is the difference between malignant and benign tumors?
Malignant = tumor spreads, likely to recur after removal
Benign = tumor remains in place and unlikely to recur after removal
What are denegerative disorders? Name three examples
Disorder characterized by progressed loss of functions.
Cause is balance between genetic abberations and environment
Examples:
- Huntington: strong genetic connection
- Parkinson: less genetic
- Alzheimer: less genetic, atrophy cerebral cortex
Name two examples of infectious disorders and what these cause
- HIV: destroys axons, resulting in dementia
- MS (perhaps): infection of CNS, occurs most often in temperate climates
What can happen during a traumatic brain injury at anatomical level?
Brain shakes within the skull, what can result in
- Edema: swelling –> more pressure –> less blood flow –> ischemia + secondary lesions
- DAI: diffuse axonial injury = twisting of white matter, with disruption of cytoskeleton and axonal transport
What is epilepsy and how can it be treated?
Excessive/abnormal patterned brain activity
Treatment: removal of brain area that initiates epilepsy / callosotomy (not that common anymore)
What is the difference between single and double dissociation?
Single = Lesion to brain area impairs ability of doing A, but not B
–> A and B use different brain areas
Double = Lesion to X impairs A, but not B. Lesion to Y impairs B, but not A.
–> A and B are complementary (e.g. Wernicke and Broca area)
What is the difference between an agonist and antagonist? What is the downside of using these?
Agonist = drug that works like neurotransmitter
Antagonist = drug that blocks neurotransmission
Interference means changing signaling. The effect is very unspecific and affects the entire brain
How do genetic manipulations contribute to the study of the brain?
- Selective animal breeding
- Knockout procedure, where a gene is being manipulated so it doesn’t express itself
What is the difference between invasive and non-invasive stimulation methods?
Invasive: surgical intervention
What is deep brain stimulation (DBS) and for what can you use it?
Implanting electrodes in brain regions for a long period to modulate neuronal activity
Use it for treatment of Parkinson (implant in basal ganglia) or coma, OCD or PTSD
What is optogenetics?
Controlling neuronal activity with viral transduction. The genetic material responsible for a certain trait is inserted in a virus and then injected in the target brain area. It will infect targeted neurons, which makes them e.g. more reactive to light
What is TMS and how do you apply it? What is the difference between single pulse TMS and repetitive TMS?
Transcranial Magnetic Stimulation
1 Strong coil produces magnetic field
2 Magnetic field induces changing electrical field in underlying brain area
3 Causes neuronal (motor) activity. Strong pulse causes temporary lesions, weak pulse causes activation
Single pulse: one pulse per trial
Repetitive: temporarily changes area
What is tDCS and tACS?
tDCS: transcranial direct current stimulation
- Two electrodes on scalp that can selectively excite or inhibit neural areas
- Short term treatment for pain patients
tACS: transcranial alternating current stimulation
- oscillatory movement in current electrode. Different frequencies affect different cognitive functions
What is the downside of tDCS, tACS and TMS?
Poor spatial resolution, no strong inferences possible
What is CT and how does it work?
Computerized tomography uses X-rays to create 2D pictures of the body/brain. It’s a tool for structural analysis, but now it’s only used in medical imaging
What is MRI and how does it work?
Magnetic Resonance Imaging: structural imaging
1 MRI creactes magnetic field
2 Radio fields pass through magnetized regions, protons absorb this energy
3 Radio field is turned off and protons release energy and align toward orientation of magnetic field
4 Detectors get the energy signals and construct image
What is DTI and how does it work?
Diffusion tensor imaging gives you an image of structural connectivity in the brain
MRI scanner measures density + flow of water in axons. With two pulses to the magnetic field, the MRI is sensitive to diffusion of water.
What are the 5 main categories of methods?
1) Stimulation methods (TMS/DBS)
2) Structural imaging methods (MRI/CT)
3) Functional imaging methods (fMRI/PET)
4) Measuring neural activity (EEG/MEG)
5) Neural disruptions and genetic manipulations (TBI, breeding)