The purpose of this study is to better understand the neural correlates of cognitive control (CC) deficits in schizophrenia and determine how these mechanisms can be modulated by transcranial direct current stimulation (tDCS). CC is a critical neurocognitive process that is required for flexible, directed thought and action based on goals and intentions. Identifying and developing paradigms to improve CC is therefore a mental health priority. Current theories of CC postulate that recruitment of the dorsolateral prefrontal cortex (DLPFC) is essential for this process by maintaining high-level information that it can then use to orchestrate patterns of activation in other brain networks to support optimal performance. tDCS is a safe, noninvasive method of modulating regional brain excitability via brief (15-20 m) application of a weak (1-2 mA) current. The goal of the proposed experiments is to combine tDCS with functional magnetic resonance imaging (fMRI) to test the hypotheses that 1) acute tDCS over the DLPFC can improve performance during a CC task (the dot pattern expectancy (DPX) variant of the AX-CPT) in schizophrenia, and 2) acute tDCS over the DLPFC can increase recruitment of the DLPFC during the DPX. The current study will be the first to use fMRI to examine the effects of tDCS on the neuronal mechanisms of CC in schizophrenia, and has potentially important implications for therapeutic development for this treatment refractory yet disabling aspect of the illness. Through completion of this research, in combination with additional activities including coursework, participation in an active clinical research group, and the University of California, Davis neuroscience community, the NRSA will enable Dr. Smucny to achieve the following goals of his postdoctoral training: 1) Research and Expertise in tDCS, 2) Continued Training in Neuroimaging Methods, 3) Additional Clinical Research and Data Analysis Training, and 4) Developing Skills Necessary to Become an Independent Researcher (Including Writing Grants, Mentoring, Networking, and Presenting). Achievement of these goals is an important step towards Dr. Smucny's long-term goal of becoming a productive independent researcher in the mental health field with a focus on using neuroimaging to better understand the neurobiology of and development novel treatments for schizophrenia.
Although cognitive symptoms (such as cognitive control deficits) are the greatest predictor of poor quality of life in schizophrenia, they are not clinically well-managed. The aim of this study is to use neuroimaging to examine brain function during a cognitive control task, and to determine if atypical brain activity and performance in patients during the task can be improved with transcranial direct current stimulation. The study is expected to yield knowledge that can be used help develop novel ways to treat cognitive symptoms of schizophrenia.
|Smucny, Jason; Lesh, Tyler A; Newton, Keith et al. (2018) Levels of Cognitive Control: A Functional Magnetic Resonance Imaging-Based Test of an RDoC Domain Across Bipolar Disorder and Schizophrenia. Neuropsychopharmacology 43:598-606|
|Smucny, Jason; Lesh, Tyler A; Iosif, Ana-Maria et al. (2018) Longitudinal stability of cognitive control in early psychosis: Nondegenerative deficits across diagnoses. J Abnorm Psychol 127:781-788|
|Smucny, Jason (2018) Cognitive Control, the Anterior Cingulate, and Nicotinic Receptors: A Case of Heterozygote Advantage. J Neurosci 38:257-259|