| BOLD Impulse Response Model |
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| • | Function of
blood oxygenation, |
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| flow, volume
(Buxton et al, 1998) |
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| • | Peak (max.
oxygenation) 4-6s |
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| poststimulus;
baseline after 20-30s |
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| • | Initial
undershoot can be observed |
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| (Malonek &
Grinvald, 1996) |
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| • | Similar across
V1, A1, S1… |
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| • | … but
differences across: |
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| other regions (Schacter et al
1997) |
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| individuals
(Aguirre et al, 1998) |
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| Peak |
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| Brief |
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| Stimulus |
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| Undershoot |
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| Initial |
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| Undershoot |
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| Columbia fMRI |