02 September 2025 : Review article
Functional Near-Infrared Spectroscopy in Schizophrenia Research: Progress, Challenges, and Future Directions
Yudiao Liang E 1,2, Zhang Sha F 2, Liu Kezhi AG 3*DOI: 10.12659/MSM.949491
Med Sci Monit 2025; 31:e949491
Table 2 Summary of fNIRS studies in schizophrenia research.
| Author | Year | Research method | Key findings | Conclusion |
|---|---|---|---|---|
| Kumar V, et al | 2021 | fNIRS combined with N-back task | Patients with schizophrenia showed lower deoxyhemoglobin concentration in the right frontopolar cortex (BA10), and olanzapine dosage correlated negatively with right frontopolar cortex activation | Delayed but compensatory hyperactivation in the right frontopolar cortex may underlie working memory deficits in schizophrenia |
| Ma CC, et al | 2024 | fNIRS combined with 2-back task | The 2-back task significantly activated the left DLPFC | The 2-back task can be combined with tDCS for treating negative symptoms in schizophrenia |
| Hirata K, et al | 2018 | fNIRS combined with social and non-social cognitive tasks | Patients with schizophrenia showed significantly reduced activation in the left frontotemporal area compared to healthy controls | Schizophrenia and autism spectrum disorder have distinct brain pathophysiologies in cognitive processing |
| Chou PH, et al | 2020 | fNIRS combined with clinical assessment | fNIRS can serve as a potential biomarker for schizophrenia | fNIRS has broad prospects in psychiatry and requires further optimization |
| Wei Y, et al | 2022 | fNIRS combined with VFT | Individuals at clinical high risk for psychosis showed significantly reduced activation in the rSTG | Abnormal activation in the rSTG may be associated with working memory deficits in the early stages of psychosis |
| Singh R, et al | 2025 | fNIRS combined with EEG and facial features | Multimodal data (fNIRS and EEG) improved the classification of first-episode psychosis | Multimodal approaches are advantageous for predicting early psychosis |
| Gao C, et al | 2025 | fNIRS combined with TBS treatment | TBS improved negative symptoms in chronic schizophrenia, with fNIRS showing changes in brain activity | TBS is an effective method for improving negative symptoms in chronic schizophrenia |
| Zouraraki C, et al | 2023 | fNIRS combined with resting-state functional imaging | Individuals with high schizotypal traits and schizotypal personality disorder showed functional alterations in the striatum, frontal, and temporal regions | Brain dysfunctions are evident in the subclinical part of the schizophrenia spectrum |
| Cattarinussi G, et al | 2024 | fNIRS combined with multiple neuroimaging techniques | Catatonia is characterized by structural, functional, perfusion, and metabolic cortico-subcortical abnormalities | Further research is needed to clarify the neural mechanisms underlying catatonia |
| Akın A | 2021 | fNIRS combined with Stroop task | A new NCR was proposed, showing high sensitivity and specificity | NCR can be a reliable biomarker for neuropsychiatric diseases |
| Storchak H, et al | 2019 | fNIRS combined with neurofeedback | fNIRS neurofeedback reduced auditory verbal hallucinations | fNIRS neurofeedback has potential in treating hallucinations |
| Curtin A, et al | 2019 | fNIRS monitoring of bilateral prefrontal cortex activity combined with vSAT | Activity in the left MFG correlated strongly with PANSS negative symptom scores in patients with schizophrenia | Abnormal activation in the left MFG may indicate attention network dysregulation linked to negative symptoms |
| Bhargav H, et al | 2014 | fNIRS monitoring of frontal hemodynamic responses to high-frequency yoga breathing | Patients with schizophrenia showed significantly lower bilateral prefrontal activation during high-frequency yoga breathing compared to healthy controls | Hypo-frontality in schizophrenia patients during high-frequency yoga breathing may support future diagnosis |
| Iwashiro N, et al | 2016 | fNIRS and MRI combined with VFT | UHR and FES groups showed significantly reduced brain activity in the left PT, and activity correlated positively with volume in the left PT | The relationship between neural activity and gray matter volume in the left PT may reflect a specific pathophysiology related to schizophrenia onset |
| Kopf J, et al | 2011 | fNIRS combined with N-back task | Short allele carriers showed greater increases in oxyhemoglobin in task-related areas, possibly indicating a compensatory mechanism | NOS1 gene polymorphism may influence prefrontal oxygenation during working memory tasks |
| Sayar-Akaslan D, et al | 2021 | fNIRS combined with theory of mind task | Cortical activity in patients with schizophrenia and bipolar disorder differed from healthy controls | Schizophrenia and bipolar disorder may share common neurobiological mechanisms in social cognition processing |
| Hirano Y and Tamura S | 2021 | fNIRS and EEG combined with neurofeedback | fMRI-based NF can alleviate treatment-resistant AVH, while EEG-based neurofeedback failed to modulate auditory-evoked potentials | Real-time neurofeedback training can help reduce severe symptoms and improve social functioning |
| Balconi M, et al | 2018 | fNIRS and EEG combined with emotion regulation task | Implicit measures showed modulation and improved capabilities after NF training, while explicit measures correctly identified emotional valence before and after treatment | Emotion processing showed abnormalities in spatial and temporal expression, but explicit evaluation of emotional stimuli was preserved |
| Table 2 summarizes 18 functional near-infrared spectroscopy (fNIRS) studies investigating schizophrenia, including research methodologies, key neuroimaging findings, and clinical conclusions. Studies are ordered chronologically (2011–2025) and highlight fNIRS applications in: working memory assessment (N-back tasks), social cognition, neurofeedback interventions, multimodal integration (EEG/MRI), biomarker development, and treatment monitoring (TBS/tDCS/yoga). Key patterns include prefrontal hypo-frontality, compensatory activation mechanisms, and distinct functional alterations across schizophrenia spectrum disorders. fNIRS – functional near-infrared spectroscopy; BA – Brodmann area; DLPFC – left dorsolateral prefrontal cortex; tDCS – transcranial direct current stimulation; TBS – theta burst stimulation; VFT – verbal fluency test; EEG – electroencephalography; MRI – magnetic resonance imaging; NCR – neurocognitive ratio; PANSS – Positive and Negative Syndrome Scale; SANS – Scale for the Assessment of Negative Symptoms; UHR – ultra-high risk; FES – first-episode schizophrenia; PT – pars triangularis; MFG – middle frontal gyrus; vSAT – visual spatial attention task; AVH – auditory verbal hallucinations; NF – neurofeedback; NOS1 – nitric oxide synthase 1. | ||||