Beta/Gamma Oscillations and Event-Related Potentials Indicate Aberrant Multisensory Processing in Schizophrenia.

Yadira Roa Romero,Martin Krebber,Julian Keil,Michael Niedeggen,Jürgen Gallinat,Daniel Senkowski,Johanna Balz

doi:10.3389/fpsyg.2016.01896

Yadira Roa Romero, Martin Krebber + Show 5 more

Open Access

https://doi.org/10.3389/fpsyg.2016.01896

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Abstract

Recent behavioral and neuroimaging studies have suggested multisensory processing deficits in patients with schizophrenia (SCZ). Thus far, the neural mechanisms underlying these deficits are not well understood. Previous studies with unisensory stimulation have shown altered neural oscillations in SCZ. As such, altered oscillations could contribute to aberrant multisensory processing in this patient group. To test this assumption, we conducted an electroencephalography (EEG) study in 15 SCZ and 15 control participants in whom we examined neural oscillations and event-related potentials (ERPs) in the sound-induced flash illusion (SIFI). In the SIFI multiple auditory stimuli that are presented alongside a single visual stimulus can induce the illusory percept of multiple visual stimuli. In SCZ and control participants we compared ERPs and neural oscillations between trials that induced an illusion and trials that did not induce an illusion. On the behavioral level, SCZ (55.7%) and control participants (55.4%) did not significantly differ in illusion rates. The analysis of ERPs revealed diminished amplitudes and altered multisensory processing in SCZ compared to controls around 135 ms after stimulus onset. Moreover, the analysis of neural oscillations revealed altered 25–35 Hz power after 100 to 150 ms over occipital scalp for SCZ compared to controls. Our findings extend previous observations of aberrant neural oscillations in unisensory perception paradigms. They suggest that altered ERPs and altered occipital beta/gamma band power reflect aberrant multisensory processing in SCZ.

Highlights

An increasing body of literature suggests that individuals with schizophrenia (SCZ) have deficits in the processing and perception of sensory information (Giersch et al, 2013; Onitsuka et al, 2013; Javitt and Freedman, 2015)
In the present EEG study we examined perception, event-related potentials (ERPs), and neural oscillations during the sound-induced flash illusion (SIFI) in SCZ and healthy control participants (HC)
The partial correlation analyses between SIFI illusion rates and clinical symptoms (i.e., Positive and Negative Syndrome Scale (PANSS) subscale scores), in which medication dose in SCZ served as control variable, were not significant

Summary

Introduction

An increasing body of literature suggests that individuals with schizophrenia (SCZ) have deficits in the processing and perception of sensory information (Giersch et al, 2013; Onitsuka et al, 2013; Javitt and Freedman, 2015). Another study investigated perceptual fusion of visual stimuli using the three-flash illusion paradigm (Norton et al, 2008; Chen et al, 2014). In this paradigm two flashes are perceived either as one, two, or three flashes, depending on the inter-stimulus interval between the two visual stimuli. The study by Norton et al (2008) revealed that the three-flash illusion occurred more often in SCZ than in HC when the inter-stimulus intervals were longer. There is substantial evidence suggesting altered unisensory stimulus processing in SCZ

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