The relationship between preattentive sensory processing deficits and age in schizophrenia patients

Abstract 

Objective

Auditory mismatch negativity (MMN) and P3a index preattentive detection of rare stimuli. Their amplitudes normally decrease with age. Previous studies have reported generally smaller than normal MMN and P3a in schizophrenia patients. We aimed to further characterize the course of these deficits over schizophrenia patients’ lifespan.

Methods

In 253 schizophrenia patients and 147 normal comparison participants (NCPs) encompassing a wide age range (18–65), event-related potentials were recorded while participants watched a silent video and were presented binaurally with 1-kHz tones 500ms apart, including standards (P=.90, 50-ms duration) and deviants (P=0.10, 100-ms).

Results

Over the entire age range, MMN and P3a were smaller in schizophrenia patients than NCPs. MMN amplitude declined with age in both groups, though slightly less steeply in schizophrenia patients than NCPs. P3a amplitude declined with age in NCPs but not in schizophrenia patients.

Conclusions

In our cohort of schizophrenia patients, MMN and P3a deficits were already present at the youngest ages. MMN declined further with age, whereas P3a amplitude remained stable.

Significance

This knowledge about how MMN and P3a amplitudes vary with age in schizophrenia patients compared to NCPs can help improve the utility of these indices as clinical endophenotypes or biomarkers.

Keywords: Event-related potentials, Electroencephalography, Mismatch negativity, Preattentional processes, Neurophysiology, Aging