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Titolo:
Event-related fMRI contrast when using constant interstimulus interval: Theory and experiment
Autore:
Bandettini, PA; Cox, RW;
Indirizzi:
Med Coll Wisconsin, Biophys Res Inst, Milwaukee, WI 53226 USA Med Coll Wisconsin Milwaukee WI USA 53226 s Inst, Milwaukee, WI 53226 USA
Titolo Testata:
MAGNETIC RESONANCE IN MEDICINE
fascicolo: 4, volume: 43, anno: 2000,
pagine: 540 - 548
SICI:
0740-3194(200004)43:4<540:EFCWUC>2.0.ZU;2-C
Fonte:
ISI
Lingua:
ENG
Soggetto:
HUMAN BRAIN-FUNCTION; HUMAN VISUAL-CORTEX; SENSORY STIMULATION; ACTIVATION; MRI; OXYGENATION; TASK; RESPONSES; DYNAMICS; TRIALS;
Keywords:
human brain mapping; fMRI; BOLD; event-related;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
46
Recensione:
Indirizzi per estratti:
Indirizzo: Bandettini, PA NIMH, Lab Brain & Cognit, NIH, Bldg 10,Room 4C104,10 Ctr Dr,MSC 1366, Bethesda, MD 20892 USA NIMH Bldg 10,Room 4C104,10 Ctr Dr,MSC 1366 Bethesda MD USA 20892
Citazione:
P.A. Bandettini e R.W. Cox, "Event-related fMRI contrast when using constant interstimulus interval: Theory and experiment", MAGN RES M, 43(4), 2000, pp. 540-548

Abstract

Event-related functional magnetic resonance imaging (ER-fMRI) involves themapping of averaged hemodynamic changes resulting from repeated, brief (<3sec) brain activation episodes. In this paper, two issues regarding constant-interstimulus interval ER-fMRI were addressed. First, the optimal interstimulus interval (ISI), given a stimulus duration (SD), was determined. Second, the statistical power of ER-fMRI relative to that of a blocked-design paradigm was determined. Experimentally, it was found that with a 2-sec SD,the optimal ISI is 12 to 14 sec. Theoretically, the optimal repetition interval (T-opt = ISI + SD) is 12 to 14 sec for stimuli of 2 sec or less, for longer stimuli, T-opt is 8 + 2 SD. At the optimal ISI for SD = 2 sec, the experimentally determined functional contrast of ER-fMRI was only -35% lowerthan that of blocked-design fMRI. Simulations that assumed a linear systemdemonstrated an event-related functional contrast that was -65% lower thanthat of the blocked design. These differences between simulated and experimental contrast suggest that the ER-fMRI amplitude is greater than that predicted by a linear shift-invariant system. (C) 2000 Wiley-Liss, Inc.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/04/20 alle ore 21:44:48