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17 Cards in this Set
- Front
- Back
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How much does CBF consume of the body's mass vs. it's energy? |
Consumes 2% of body's mass, and 20% of body's energy - it's greedy! |
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Who wrote the first Psychology book (and was interested in CBF!)? |
William James (1890) - Principles of Psychology |
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What is cognitive neuroscience? Give 4 areas. |
Branch that studies biological foundations of mental phenomena. Generating verbs: Wernicke's area. Speaking words: Broca's area. Hearing words: Auditory cortices. Seeing words: Visual cortices. |
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What are neuroimaging techniques? Give 3 examples. |
Neuroimaging = colourful maps of cerebral activity. EEG - electroencephalogram. PET - positron emission tomography. MRI - magnetic resonance imaging (attempts to measure neural activity! - i.e. neurons firing, action potentials). |
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Why is MRI good? |
No radioactivity! |
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How is an EEG carried out? |
Insert electrodes & collect raw data from each. |
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Give two problems with EEG. |
1. Animal models of higher cognitive abilities (e.g. playing instrument) = hard to find! 2. Can't stick electrodes in human brain (only on scalp) - even if we could we'd only get a small amount of neurons. |
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What does an EEG do? |
Records voltage change in each area of brain. Average data may point towards inference. Trial waveform: P1 = 1st positive, N2 = 2nd negative. May get related to different aspects of cognition - hard to interpret! |
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What is a positive of EEG? |
Good temporal resolution - for fast brain activity. |
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What are the two negatives of EEG? |
Bad spatial resolution - not because of how many electrodes you can get on head - brain waves go all over the place, add up & cancel out! Difficult to interpret & LOCALISE! |
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Are there other localised changes occurring in the brain with neural activity that may be easier to detect? |
Cerebral bloodflow - but how do we measure this?! |
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What does PET do? |
Measures CBF - detects radioactivity (where & how much). Why? Measures physiology; simplest form. |
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How is a PET performed? |
Inject radioactive tracers into blood (IV) & see where they end up! Inject radioactive water - used to measure cerebral bloodflow (CBF). The water stays in the brain & amount there = proportional to flow of that region. |
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What does more radioactivity lead to in PET? |
More bloodflow! |
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Who are Raichle et al (1986, 1988) and what did they find? |
invented PET and used it to measure CBF! Activated visual cortex by resenting visual stimulating. CBF Red = very high and Blue = very low! |
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Name 3 problems with PET. |
1. Poor temporal resolution - takes time for injected radioactive water to reach/grow accustomed to cerebral activity. 2. Poor spatial resolution. 3. Radioactivity = can't retest same subject too much. |
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What is a positive of PET? |
Gives measures in absolute units. |
