NEURO-COGS: Neurometabolic Mechanisms of Cognitive Training in Schizophrenia

Schizophrenia is associated with cognitive and visual impairments that can persist across the lifespan and are not fully addressed by current antipsychotic treatments. These impairments may be related to disruptions in brain metabolism and excitatory/inhibitory balance. This study is designed to better understand neurochemical and neurophysiological mechanisms of cognitive and visual functioning in schizophrenia and to evaluate whether these mechanisms change following cognitive training. The study will enroll adults with schizophrenia or schizoaffective disorder and demographically similar healthy control participants. Participants will complete baseline clinical assessments, cognitive and visual tasks, electroencephalography, structural magnetic resonance imaging, and magnetic resonance spectroscopy. Magnetic resonance spectroscopy will be used to measure brain metabolite concentrations, including metabolites related to brain metabolism and excitatory/inhibitory function. After baseline assessments, participants will be randomly assigned to one of two computerized cognitive training programs: perceptual discrimination training or cognitive control training. Both training programs are delivered through the BrainHQ platform and include approximately 10 hours of training over a 2- to 6-week period. Perceptual discrimination training focuses on visual stimulus discrimination, signal-to-noise resolution, and attentional control. Cognitive control training focuses on maintaining cognitive context in working memory during response selection. After completing cognitive training, participants will return for follow-up assessments, including repeat clinical assessments, cognitive and visual tasks, EEG, MRI, and magnetic resonance spectroscopy. Participants may also choose to complete an optional extended baseline component with additional baseline scanning visits before cognitive training. The primary outcomes include behavioral performance on the DPX task variant, EEG variables related to excitatory/inhibitory balance, and magnetic resonance spectroscopy measures of neurometabolite concentrations. Secondary outcomes include symptom and functioning measures such as the Brief Psychiatric Rating Scale, Scale for the Assessment of Negative Symptoms, Scale for the Assessment of Positive Symptoms, World Health Organization Disability Assessment Schedule, and Global Functioning Social/Role scales.