Functional magnetic resonance imaging of brain activity in the visual oddball task.
Abnormalities in the P300 ERP, elicited by the oddball task and measured using EEG, have been found in a number of central nervous system disorders including schizophrenia, Alzheimer's disease, and alcohol dependence. While electrophysiological studies provide high temporal resolution, localizing the P300 deficit has been particularly difficult because the measurements are collected from the scalp. Knowing which brain regions are involved in this process would elucidate the behavioral correlates of P300. The aim of this study was to determine the brain regions involved in a visual oddball task using fMRI. In this study, functional and high-resolution anatomical MR images were collected from seven normal volunteers. The data were analyzed using a randomization-based statistical method that accounts for multiple comparisons, requires no assumptions about the noise structure of the data, and does not require spatial or temporal smoothing. Activations were detected (P<0.01) bilaterally in the supramarginal gyrus (SMG; BA 40), superior parietal lobule (BA 7), the posterior cingulate gyrus, thalamus, inferior occipitotemporal cortex (BA 19/37), insula, dorsolateral prefrontal cortex (BA 9), anterior cingulate cortex (ACC), medial frontal gyrus (BA 6), premotor area, and cuneus (BA 17). Our results are consistent with previous studies that have observed activation in ACC and SMG. Activation of thalamus, insula, and the occipitotemporal cortex has been reported less consistently. The present study lends further support to the involvement of these structures in visual target detection.
Ardekani
Babak A
BA
Center for Advanced Brain Imaging, Nathan Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA. ardekani@nki.rfmh.org
Choi
Steven J
SJ
Hossein-Zadeh
Gholam Ali
GA
Porjesz
Bernice
B
Tanabe
Jody L
JL
Lim
Kelvin O
KO
Bilder
Robert
R
Helpern
Joseph A
JA
Begleiter
Henri
H
D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004569:Electroencephalography; D018913:Event-Related Potentials, P300; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D010775:Photic Stimulation; D012016:Reference Values