Reduced frontal theta oscillations indicate altered crossmodal prediction error processing in schizophrenia

Abstract

Our brain generates predictions about forthcoming stimuli and compares predicted with incoming input. Failures in predicting events might contribute to hallucinations and delusions in schizophrenia (SZ). When a stimulus violates prediction, neural activity that reflects prediction error (PE) processing is found. While PE processing deficits have been reported in unisensory paradigms, it is unknown whether SZ patients (SZP) show altered crossmodal PE processing. We measured high-density electroencephalography and applied source estimation approaches to investigate crossmodal PE processing generated by audiovisual speech. In SZP and healthy control participants (HC), we used an established paradigm in which high- and low-predictive visual syllables were paired with congruent or incongruent auditory syllables. We examined crossmodal PE processing in SZP and HC by comparing differences in event-related potentials and neural oscillations between incongruent and congruent high- and low-predictive audiovisual syllables. In both groups event-related potentials between 206 and 250 ms were larger in high- compared with low-predictive syllables, suggesting intact audiovisual incongruence detection in the auditory cortex of SZP. The analysis of oscillatory responses revealed theta-band (4-7 Hz) power enhancement in high- compared with low-predictive syllables between 230 and 370 ms in the frontal cortex of HC but not SZP. Thus aberrant frontal theta-band oscillations reflect crossmodal PE processing deficits in SZ. The present study suggests a top-down multisensory processing deficit and highlights the role of dysfunctional frontal oscillations for the SZ psychopathology.

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

“…However, this was not the case. Recently, Stekelenburg et al (2013) and Roa Romero et al (2016b) also reported group differences in multisensory ERPs without showing effects in behavioral data. In an interesting framework on multisensory processing, Bizley et al (2016) suggested different stages of multisensory integration, in which the initial integrative processing can occur, at least partially, independent of later perception-related processing.…”

“…In addition to findings of unisensory processing deficits, there is also some evidence for aberrant multisensory processing in SCZ (Foucher et al, 2007; Stekelenburg et al, 2013; Roa Romero et al, 2016a,b; Stevenson et al, 2016; for a review see Tseng et al, 2015). One study examined simultaneity judgments in unisensory and multisensory stimuli and found that SCZ have a lengthened window of simultaneity for unisensory visual, unisensory auditory, and bisensory audiovisual stimuli (Foucher et al, 2007).…”

“…Thus, the absence of the N1 reduction in bisensory stimulation likely reflects aberrant audiovisual processing in patients. Notably, recent studies have also provided first evidence for altered neural oscillations during multisensory processing in patients (Stone et al, 2014; Roa Romero et al, 2016b). Overall, these findings indicate altered multisensory processing in SCZ.…”

An Integrative Model of Effortful Control

“…Neuropsychological studies confirm this hypothesis. For instance, decreases in task-related theta band activity have been regularly reported in schizophrenic patients (Popov et al, 2015;Roa Romero et al, 2016; for a review, Galderisi et al, 2009) who have long been associated with motivational impairment and aberrant effort-based decisionmaking (Culbreth et al, 2018). More interestingly for the purpose of this section, theta activity is observed throughout the entire duration of a vigilance task in humans (Boksem et al, 2005;Wascher et al, 2014).…”

ERP and oscillatory differences in overweight/obese and normal-weight adolescents in response to food stimuli

“…Similar to the analysis of ERPs, time-frequency power was split according to the conditions and averaged for the electrode pair PO7/PO8. It was then examined for periods of significant interaction of the between-subjects factors Group (OW/OB and NW) and the within-subjects factor Condition (neutral, low-calorie, highcalorie) in the time window from stimulus onset (0 ms) to 1000 ms using a repeated measures ANOVA [59]. To account for alpha error accumulation due to multiple testing, 3dClust-Sim (http://afni.nimh.nih.gov/afni/) [60,61] was used to estimate the probability of false positives.…”