Evaluating functional localizers: the case of the FFA.
Functional localizers are routinely used in neuroimaging studies to test hypotheses about the function of specific brain areas. The specific tasks and stimuli used to localize particular regions vary widely from study to study even when the same cortical region is targeted. Thus, it is important to ask whether task and stimulus changes lead to differences in localization or whether localization procedures are largely immune to differences in tasks and contrasting stimuli. We present two experiments and a literature review that explore whether face localizer tasks yield differential localization in the fusiform gyrus as a function of task and contrasting stimuli. We tested standard localization tasks-passive viewing, 1-back, and 2-back memory tests--and did not find differences in localization based on task. We did, however, find differences in the extent, strength and patterns/reliabilities of the activation in the fusiform gyrus based on comparison stimuli (faces vs. houses compared to faces vs. scrambled stimuli).
Berman
Marc G
MG
Department of Psychology, University of Michigan at Ann Arbor, MI 48109-1043, USA. bermanm@umich.edu
Park
Joonkoo
J
Gonzalez
Richard
R
Polk
Thad A
TA
Gehrke
Amanda
A
Knaffla
Scott
S
Jonides
John
J
D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D003463:Cues; D005145:Face; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008568:Memory / Q000502:physiology; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011930:Reaction Time; D012815:Signal Processing, Computer-Assisted; D013702:Temporal Lobe / Q000502:physiology; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult