Term
| Single dissociation study |
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Definition
create lesion in the brain
-lesion A disrupts function X but not function Y |
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Term
| Double dissociation study |
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Definition
Two lesions in the brain
-lesion A affects task X and not task Y
-lesion B affects task Y but not task X
-if you can demonstrate this then you have a much better argument in your inferences about brain function and function localization |
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Term
| Direct Electrical/Cortical Stimulation |
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Definition
-placing electrode onto or into brain area of interest
-highly invasive
-may cause seizures |
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Term
| Transcranial Magnetic Stimulation (TMS) |
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Definition
-least invasive of perturbation methods
-place magnet on head over brain area of interest to create artificial lesion by disrupting normal brain function
-may cause seizures, stimulation of head/face muscles, hard to target specific area, only get surface of brain |
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Term
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Definition
-record electrical activity of small group of neurons
-used experimentally in animals but not in humans
-High spatial and temporal resolution
-highly invasive
-hard to establish casual relationship between firing pattern of neuron and the underlying process |
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Term
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Definition
-electrodes measure summed potential of neurons near scalp
-activity is measured between each electrode and a vertex reference electrode
-broken down into different frequency bands
-used to extract ERPs |
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Term
| ERP (event related potential) |
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Definition
-voltage fluctuations that correspond in time to sensory or cognitive events
-collected from EEG signal
-good temporal resolution
-poor spatial resolution |
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Term
| Segmenting raw EEG/ERP recordings |
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Definition
-from data you take a certain chunk of time before and after each ERP occurs
-this gets rid of extraneous info not related to ERPs
-you can then average the ERPs |
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Term
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Definition
-positive and negative peaks
-named according to polarity (N or P) and latency
ex. P300 is a positive ERP that occured 300ms poststimulus onset |
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Term
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Definition
-biggest criticism of source analysis (equivalent current dipole analysis)
-idea that the pattern of current on the scalp can be produced by multiple combinations of dipoles (not unique) |
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Term
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Definition
-noninvasive neuromagnetic recording
-mesaures magnetic field produced by flowing electric currents
-can extract EMFs |
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Term
| MEG advantages/limitations |
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Definition
-expensive
-good temporal, not great spatial resolution
-maily sensitive to activity in sulci rather than gyri due to direction of magnetic field (right hand rule)
-susceptible to noise |
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Term
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Definition
-radioactive isotopes incorporated with bio relevant molecules and injected into blood
-these will decay and positrons will collide with electrons to produce detectable gamma rays |
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Term
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Definition
-limited spatial resolution
-no temporal resolution
-need access to cyclotron
-exposure to radiation |
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Term
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Definition
effect of increased blood flow on capillaries
-all capillaries sort of even out - slower caps become faster to equal other faster flowing ones
-higher amount of O2 able to be used by neurons and greater O2 exchange at capillary level |
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