Abnormal Cortical Activation Patterns Among Chinese-Speaking Schizophrenia Patients During Category and Letter Verbal Fluency Tasks Revealed by Multi-Channel Functional Near-Infrared Spectroscopy

Abstract

Background: Functional near-infrared spectroscopy (fNIRS) has many advantages over other neuroimaging modalities for routine measurement of task-dependent cortical activation, but most fNIRS studies of schizophrenia have used letter fluency tasks (LFTs). Further, performances on category fluency tasks (CFTs) and LFTs may be distinct in Chinese patients due to the unique semantic features of Chinese written characters. To identify unique disease biomarkers measurable by fNIRS in Chinese schizophrenia patients, this study compared cortical oxygenated hemoglobin changes ([oxy-Hb]) during a Chinese LFT and CFT between patients and healthy controls.Methods: Inpatients of the Second Affiliated Hospital of Xinxiang Medical University were recruited from Match 2020 to July 2021. The Positive and Negative Symptom Scale (PANSS) was used to evaluate psychiatric symptoms. Dynamic changes in [oxy-Hb], an indicator of neural activity, were measured during CFT and LFT performance by 52-channel fNIRS.Results: Forty-seven schizophrenia inpatients and 29 healthy controls completed all tests. Schizophrenia patients showed significant cortical activation at 15 channels covering the left hemisphere and 17 channels over the right hemisphere during the CFT. During the LFT, activity was significantly increased at only six channels, all over the left hemisphere (FDR P < 0.05). In healthy controls, significant [oxy-Hb] increases were found at 24 channels over the left hemisphere and 19 channels over the right hemisphere during CFT. While during the LFT, the significant increases were found at 7 channels all over the left hemisphere (FDR P < 0.05). When years of education was included as a covariate, the schizophrenia group demonstrated no significant hypoactivation relative to healthy controls at any channel after FDR correction (FDR P < 0.05) during CFT while demonstrated significant hypoactivation at channel 11 during LFT (FDR P < 0.05). There were no significant associations between PANSS scores and [oxy-Hb] changes after FDR correction (FDR P < 0.05).Conclusions: Left lateralization during CFT was reduced among schizophrenia patients and may be related to the semantic deficit. The Chinese-CFT could be a more sensitive indicator of frontal-temporal dysfunction in schizophrenia.

Atypical frontotemporal cortical activity in first-episode adolescent-onset schizophrenia during verbal fluency task: A functional near-infrared spectroscopy study

“…This is inconsistent with a former VFT study on adult patients with first-episode SCZ (32); they found that although oxy-Hb concentration increase in the patient group was lower than in HC, the patients showed significantly increased frontotemporal activities during the VFT in most channels. Similar frontotemporal activation pattern was also found in adult patients with chronic SCZ (22,33,34). However, in the present study, the patient group showed no obvious increase in oxy-Hb concentration after the 60-s task period started, and even a decrease of oxy-Hb concentration was found in some channels (Figure 3).…”

“…Concerning the VFT performance is associated with the difficulty of task ( 36 ), the phonological fluency task used might be equally difficult for the adolescents with first-episode SCZ and HCs. Some researchers proposed that the category fluency task (CFT) might be superior for the evaluation of Chinese-speaking patients with psychiatric disorders ( 34 ). Thus, further studies on potential inter-task effects in adolescents are still needed.…”

The promising fNIRS: Uncovering the function of prefrontal working memory networks based on multi-cognitive tasks

“…The symptoms (states) are identified and analyzed in the way of full-channel waveform, phase changes, and waveform composition ratios, and six typical waveforms (see Figure 2 ) with clinical significance are summarized to correlate with the typical symptom among various mental disorders ( 17 ). It has helped in the diagnosis of bipolar disorder and unipolar depression ( 15 ), major depressive disorder and generalized anxiety disorder ( 16 ), schizophrenia ( 28 ), and other mental disorders.…”

Associations between Verbal Fluency and Asymmetry of White Matter Integrity in the Superior Longitudinal Fasciculus in At-Risk Mental States for Psychosis

“…A meta-analysis reported that category fluency and letter fluency are impaired in patients with schizophrenia [ 9 ]. A lack of verbal fluency is considered a predictor of psychosis, whereas, in patients with chronic schizophrenia, the symptoms are fixed [ 10 ]. In another study, a category fluency task was administered to adolescent patients with schizophrenia and was found to be significantly correlated with other cognitive functions and psychiatric symptoms, particularly those related to verbal learning, working memory, and processing speed.…”