Open AccessStimulus repetition and hemodynamic response refractoriness in event‐related fMRI
Author(s) -
Soon ChunSiong,
Venkatraman Vinod,
Chee Michael W.L.
Publication year - 2003
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.10122
Subject(s) - stimulus (psychology) , refractory period , psychology , audiology , haemodynamic response , neuroscience , fusiform face area , perception , cognitive psychology , face perception , medicine , cardiology , heart rate , blood pressure , radiology
We investigated the extent of hemodynamic recovery following the paired presentation of either identical or different faces at two different inter‐stimulus intervals (ISI). Signal recovery was consistently better at an ISI of 6 sec compared to 3 sec. Significantly less signal recovery was associated with identical faces compared to different faces in bilateral mid‐fusiform and right prefrontal regions but not in the calcarine and posterior fusiform regions. Repetition suppression effects contributed significantly to incomplete signal recovery in a region‐specific manner. Simulations using empirically derived data suggest that experiments with shorter ISI (average 4.5–6.0 sec) are as sensitive as experiments with intermediate ISI (average 9 sec) in detecting response differences if experimental duration is equivalent. However, designs using intermediate ISI may be more appropriate if the expected difference in responses is small and if the number of suitable stimuli is limited. Hum. Brain Mapping 20:1–12, 2003. © 2003 Wiley‐Liss, Inc.