Rate of stimulation affects schizophrenia-normal differences on the N1 auditory-evoked potential

Department of Psychology, University of Georgia, Athens, GA 30602-3013, USA.
Neuroreport (Impact Factor: 1.52). 01/2005; 15(18):2713-7.
Source: PubMed


The present study examined how increasing the rate of steady-state stimulation affects schizophrenia-normal differences on the N1 auditory-evoked potential, an index of auditory integration. Dense-array EEG was recorded while schizophrenia and normal subjects heard 1 kHz tones amplitude modulated at 10, 20, 40, or 80 Hz. Spectral power across frequency and time was calculated. The typically lower N1 amplitude in schizophrenia, observed at the 10 Hz burst rate, increased to nearly equal that of normal individuals at 20 Hz. Unlike normal subjects, schizophrenia subjects' power at N1 failed to increase at the 40 and 80 Hz burst rates. These results suggest steady-state stimuli, up to a point, provide the extra information needed for schizophrenia patients to more efficiently integrate auditory information.

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    • "Auditory sensory processing abnormalities in schizophrenia (SZ) have been quantified with transient evoked responses (e.g., N/M100) to abrupt stimulus onsets (Rosburg et al., 2008) and auditory steady-state responses (aSSR) to repeating auditory stimulation (e.g., a 40 Hz steady-state stimulus is a repetition every 25 ms). Low N100 amplitude in SZ is one of the most replicated effects in this literature (Shelley et al., 1999; Blumenfeld and Clementz, 2001; Ford et al., 2001; Gilmore et al., 2004; Hamm et al., in press). Theoretically, deficiencies of excitatory drive on (Goff and Coyle, 2001) and/or coordination between (Benes and Berretta, 2001) neuronal ensembles supporting auditory stimulus processing cause these abnormalities in SZ. "
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