Auditory P300 as a Neurophysiological Correlate of Symptomatic Improvement by Transcranial Direct Current Stimulation in Patients With Schizophrenia: A Pilot Study

Abstract

<jats:p> Background. The reduced amplitude, prolonged latency, and increased intertrial variability of auditory P300 have been consistently reported in relation to the symptomatic severity of schizophrenia. This study investigated whether auditory P300 event-related potentials can be used as an objective indicator of symptomatic improvement by transcranial direct current stimulation (tDCS) in patients with schizophrenia. Methods. Ten patients with schizophrenia received 20 minutes of 2-mA tDCS twice a day for 5 consecutive weekdays. The anode was placed over the left dorsolateral prefrontal cortex, and the cathode was placed over the left temporo-parietal cortex. The Positive and Negative Syndrome Scale (PANSS) and the auditory P300 were measured for each participant at baseline and after the completion of the tDCS applications. Results. The participants showed significant improvement in the positive and negative symptoms as indexed by change in the PANSS scores by the tDCS. The P300 amplitude, latency, and intertrial variability did not statistically significantly differ after the tDCS application. However, a significant association was observed between the reduced P300 intertrial variability and improvement in the positive symptoms by tDCS. In addition, the changes in both the P300 latency and intertrial variability were significantly correlated with reduced negative symptoms after the tDCS application. Conclusions. Although this pilot study is limited by the small sample size and lack of a sham control, the results suggest that auditory P300 may be a putative marker reflecting the effect of tDCS on the positive and negative symptoms of schizophrenia. </jats:p>

Auditory P300 in individuals with high schizotypy: associations of schizotypal traits with amplitude and latency under different oddball conditions

“…Although the significant between-group difference was shown in the duration P300 in our study, weaker P300 amplitude existed in all tests. These findings are similar to those from clinical individuals with schizophrenia-spectrum disorders ( Wang et al, 2003 ; Bramon et al, 2004 ; Higuchi et al, 2013 , 2021 ; Kim et al, 2015 , 2020 ), and consistent with the previous non-clinical report ( Klein et al, 1999 ), indicating schizophrenia-related impairment of attention and working memory in acoustic information process ( Kim et al, 2015 ). This process impairment may be related to the poor information flow in individuals with high schizotypy ( Hu et al, 2020 ), which was supported by the evidence of machine learning study ( Zandbagleh et al, 2022a ), that reduced connectivity between prefrontal and parietal regions in the beta band, and decreased frontal connectivity in the alpha band in participants with high schizotypy.…”

“…At present, P300 has been studied as a potential neural biomarker to achieve the goal of improving the accuracy in detection of early episodes of psychosis ( Zandbagleh et al, 2022b ), or as a predictor of treatment and prognosis ( Kim et al, 2020 , 2015 ), that are of significance in the research on psychopathology and early-intervention of schizophrenia-spectrum. Considering the various associated tendencies between auditory P300 effect and schizotypy dimensions in our result, elaborated characteristics and parameters should be used in the oddball paradigm to enhance the application of P300 in future studies of schizophrenia-spectrum.…”

“…According to previous studies on P300 ( Tsolaki et al, 2015 ; Habelt et al, 2020 ; Kim et al, 2020 ; Higuchi et al, 2021 ; Zeng et al, 2022 ), we defined 300–500 ms after the target sound as time-window, and a positive maximum peak amplitude was detected within this time window by ERPLAB (v7.0.0). Peak latency was defined as the time point of maximum positive amplitude within the specific latency window.…”

Does Transcranial Direct Current Stimulation Affect Potential P300-Related Events in Vascular Dementia? Considerations from a Pilot Study

“…Increased amplitude suggests a stronger response, indicating greater cognitive resource engagement. Although there is evidence of the effectiveness of ERPs in monitoring symptomatic improvements resulting from tDCS [ 56 , 57 , 58 ], there is a lack of research in this area. While some studies have investigated the neurophysiological effects of tDCS in individuals with mild cognitive decline [ 59 , 60 , 61 ], few studies have been conducted on the patients with vascular dementia.…”