OADES, R.D., & ZERBIN, D. (1991). Signs of differential stimulus processing problems: a comment on event-related potentials in young schizophrenic and autistic subjects.
In, "Schizophrenia and Youth" Ed. C. Eggers, Springer-Verlag, Wien, 119-123.(pdf file)

A comparison of the Nd (negative difference ERP) in a 3-tone auditory oddball paradigm (task-minus-nontask conditions) for a 16 y-old healthy adolescent with a 16y-old patient with paranoid schizophrenia. Early (100-200 ms) and late Nd components (200-300 ms) were reduced in amplitude and shifted in topography centromedially in the patient.
While we have recorded a similar impairment in schizoaffective patients, this problem was not evident in disorganised schizophrenia or OCD. Indeed, no impairment of Nd amplitude was observed in a comparison of 7 healthy children with 7 patients with childhood autism.