Interpreting abnormality: an EEG and MEG study of P50 and the auditory paired-stimulus paradigm.

摘要: Interpretation of neurophysiological differences between control and patient groups on the basis scalp-recorded event-related brain potentials (ERPs), although common promising, is often complicated in absence information distinct neural generators contributing to ERP, particularly regarding individual generators. For example, while sensory gating frequently observed patients with schizophrenia P50 paired-click paradigm are typically interpreted as reflecting group generator source strength, latency and/or orientation may also account for differences. The present study examined how variability amplitude, or affects component ERP. In Experiment 1, simulations effect changes orientation, superior temporal gyrus (STG) dipoles recorded at Cz. 2, within- between-subject left right M50 STG dipole latency, was 19 subjects. Given reported anatomy function, substantial inter-subject inter-hemispheric these parameters were expected, important consequences Cz reflects activity from relevant simulated responses computed hypothetical left- right-hemisphere generators, varied systematically. electroencephalographic (EEG) magnetoencephalographic (MEG) data collected Generators modeled MEG assess illustrate evaluated parametrically 1. realistic amounts produced ERPs which scoring compromised interpretation complicated. significant within subject hemisphere sources. amplitude here nonpatient subjects, future studies should examine whether ratios vs. specific a particular hemisphere, well due combination parameters. Present analyses focused P50/M50 merely an example broader need evaluate scalp phenomena light underlying development widespread use EEG/MEG localization methods will greatly enhance value data.