Using concurrent EEG and fMRI to probe the state of the brain in schizophrenia.
Perceptional abnormalities in schizophrenia are associated with hallucinations and delusions, but also with negative symptoms and poor functional outcome. Perception can be studied using EEG-derived event related potentials (ERPs). Because of their excellent temporal resolution, ERPs have been used to ask when perception is affected by schizophrenia. Because of its excellent spatial resolution, functional magnetic resonance imaging (fMRI) has been used to ask where in the brain these effects are seen. We acquired EEG and fMRI data simultaneously to explore when and where auditory perception is affected by schizophrenia. Thirty schizophrenia (SZ) patients and 23 healthy comparison subjects (HC) listened to 1000 Hz tones occurring about every second. We used joint independent components analysis (jICA) to combine EEG-based event-related potential (ERP) and fMRI responses to tones. Five ERP-fMRI joint independent components (JIC) were extracted. The "N100" JIC had temporal weights during N100 (peaking at 100 ms post-tone onset) and fMRI spatial weights in superior and middle temporal gyri (STG/MTG); however, it did not differ between groups. The "P200" JIC had temporal weights during P200 and positive fMRI spatial weights in STG/MTG and frontal areas, and negative spatial weights in the nodes of the default mode network (DMN) and visual cortex. Groups differed on the "P200" JIC: SZ had smaller "P200" JIC, especially those with more severe avolition/apathy. This is consistent with negative symptoms being related to perceptual deficits, and suggests patients with avolition/apathy may allocate too few resources to processing external auditory events and too many to processing internal events.
San Francisco VA Medical Center, 4150 Clement St, San Francisco, CA 94121, United States; University of California, San Francisco, 505 Parnassus Ave, San Francisco, CA 94143, United States.
Judith M
JM
Ford
San Francisco VA Medical Center, 4150 Clement St, San Francisco, CA 94121, United States.
Brian J
BJ
Roach
San Francisco VA Medical Center, 4150 Clement St, San Francisco, CA 94121, United States.
Vanessa A
VA
Palzes
San Francisco VA Medical Center, 4150 Clement St, San Francisco, CA 94121, United States; University of California, San Francisco, 505 Parnassus Ave, San Francisco, CA 94143, United States.
Daniel H
DH
Mathalon
D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D004569:Electroencephalography; D005071:Evoked Potentials; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology
Avolition/apathy; Concurrent EEG + fMRI; N100; P200; Perception; Schizophrenia