Based on incoming sensory signal, the brain makes many different moment-to-moment perceptual decisions, ranging from the identity of single objects to the relative timing of multiple external events. How exactly does the brain integrate sensory information to arrive at these decisions? What are the brain mechanisms for making decisions when incoming sensory signals are weak, variable or ambiguous? With funding from the National Science Foundation, Mukesh Dhamala of the Georgia State University is providing new insights into these questions by analyzing the brain activity and networks during easy and difficult perceptual decision-making. Previous research has identified the prefrontal cerebral cortex as a decision-making hub that gauges the strength of competing signals from lower-order sensory areas and plays a key role in the implementation of perceptual decisions. But the way the prefrontal cortex interacts with these lower-order regions forming a dynamic network for information flow remains largely unknown. Using perceptual categorization tasks during simultaneous electroencephalography (EEG) functional magnetic resonance imaging (fMRI) experiments, this project has the goal to provide a more comprehensive understanding of the neural information flow patterns and the hierarchy of brain structures associated with perceptual decision-making processes.
The results of this research will advance our understanding of the interactions between bottom-up visual sensory signals and top-down control signals with varying perceptual task difficulty and will have a broad impact in the field of cognitive neuroscience. This research and integrated education plan will promote undergraduate and graduate biophysics and neuroscience education in the Atlanta, Georgia area. The research provides participating students with advanced multidisciplinary skills from EEG-fMRI data recordings, and multivariate data analysis, using analytical tools in tackling challenging neurobiological questions. Neuroimaging coursework and neuroscience workshops aim to train a diverse group of students with necessary skills for research and educational opportunities in the fields of neuroscience and biomedical science. The course materials and computer software developed during this project are intended to be freely available to the community.
