Abstract
Rationale: Mirror neurons are visuomotor neurons that perform mirror mechanisms, meaning each time an individual observes another individual performing an action, these neurons which encode that action, are activated in the observer’s cortical motor system. One of the cognitive domains of controversy in schizophrenia is Motor Resonance, also known as the Mirror Neuron System (MNS). In the current paper, we aim to review all the available literature regarding mirror mechanism examination in patients with schizophrenia and present an explicit summary of the available findings up to this date.Objectives: To investigate the mirror mechanism in patients with schizophrenia and related disorders (psychosis spectrum disorder) and present an explicit view of available findings regarding this manner up to the date.Data sources: We will search MEDLINE (through PubMed), Embase, Science Citation Index – Expanded (Web of Science), and Conference Proceedings Citation Index – Science (Web of Science). We won’t consider any timeframe, language, or geographical restrictions.Methods: Standard systematic review protocol methodology is employed. Eligibility criteria is reported in line with SPIDER guideline. Sample is limited to Adults of any age and sex with the diagnosis of schizophrenia, schizoaffective disorder, and psychosis spectrum disorders in general confirmed by a physician according to International Classification of Diseases (ICD) or Diagnostic and Statistical Manual of Mental Disorders (DSM) guidelines, irrespective of the severity of disease and duration of illness. Participants with any other confirmed structural or functional neurologic disorders will be excluded. Phenomenon of interest is the mirror neuron system (MNS) functional integrity. Study designs will be restricted to observational cohort and cross-sectional studies. Means of evaluation will be Electroencephalography (EEG), Magnetoencephalography (MEG), Transcranial magnetic stimulation (TMS), Functional magnetic resonance imaging (fMRI), near-infrared spectroscopy (NIRS), Eye-tracking, and muscle activation (EMG). Research types of interest will be qualitative, quantitative, and mixed-methods researches. All included studies will be assessed for the risk of bias using NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. We will perform a meta-synthesis based on vote counting methods on the included studies. We will also evaluate the publication bias using Funnel plots and assess the confidence in cumulative evidence using CERQual.