Impaired 2.5-Hz auditory steady-state response in schizophrenia

Delta-band (1-4 Hz) oscillation contributes to speech recognition and may be impaired in schizophrenia. This study primarily aimed to investigate the impairment of the 2.5-Hz auditory steady-state response (ASSR) and its correlation with other auditory cognitive indicators, clinical symptoms, and multidomain cognition in individuals with schizophrenia.

In this cross-sectional study, 30 patients with schizophrenia and 30 healthy controls underwent 2.5- and 40-Hz ASSR and mismatch negativity (MMN) assessment. The Positive and Negative Syndrome Scale (PANSS) was utilized to assess the patients' clinical symptoms, and the MATRICS consensus cognitive battery (MCCB) was used to evaluate cognitive function.

The 2.5-Hz ASSR inter-trial coherence (ITC) was significantly lower among patients with schizophrenia than among healthy controls (P = 0.012, Cohen's d = 0.66). The 2.5-Hz ASSR ITC alone distinguished these groups, with 53.3 % sensitivity, 70.0 % specificity, and 61.7 % accuracy. In the schizophrenia group, the 2.5-Hz ASSR ITC did not correlate significantly with the MMN amplitude or any clinical symptoms or cognitive measurement. In healthy controls, the 2.5-Hz ASSR ITC correlated positively with verbal learning (r = 0.381, P = 0.038), although this correlation was not significant after Bonferroni correction.

The evoked activity maintaining delta-band oscillation entrainment in the auditory system reveals a deficit in schizophrenia and is valuable for the objective diagnosis of this disorder.