Understanding the mechanistic underpinnings of cognition is highly dependent on technologies that allow monitoring brain activity in behaving animals. The recent progress in functional ultrasonic imaging (fUSi) provides this ability by enabling imaging both cortical and subcortical brain structures simultaneously in freely moving animals. The long term goal of this line of research is to unravel the brain wide networks underlying cognitive tasks such as decision making and working memory. This lab has succeeded in training rats on sophisticated cognitive tasks with a special focus on evidence accumulation. Moreover, work from this lab has focused on studying one brain area at a time during evidence accumulation finding that frontal orbital field (FOF), posterior parietal cortex (PPC) and dorsal striatum are part of an integration circuit. The remaining nodes of this circuit are largely unknown and how activity is flowing from one brain area to another, in the context of evidence accumulation, remains to be elucidated. The proposed experiments will study the contribution of cortical and sub-cortical areas in the evidence accumulation process and pave the way for obtaining a circuit diagram for the neural mechanisms underlying this behavior. The overall objective of this project is to advance functional ultrasound imaging (fUSi) technology to measure cortical and subcortical brain activity during cognitive tasks and apply it to an evidence accumulation task as a test case. In the evidence accumulation context, fUSi will help us understand how decision related information is routed in the brain and which specific brains areas are involved in multiple aspects of the task. The contribution is significant because it will resolve several important questions about the flow of information across time and space in the brain during decision making. The approach is innovative because this laboratory has advanced tools that allow imaging both cortical and subcortical brain areas in a freely moving animal preforming cognitive tasks. The work proposed in this application will therefore advance our knowledge of how the encoding of information and interactions among brain regions lead to cognition with a special emphasis on decision making. In the long run, we expect this research to produce mechanistic models of cognition.
The proposed research is relevant to public health because our ability to diagnose and treat conditions that impair decision-making, including aging and addiction, is currently limited by a lack of information about the detailed function of brain circuits that control decisions driven by the accumulation of evidence. It is also limited by the availability of imaging technologies that allow us to observe brain wide activity in freely moving animals performing cognitive tasks such as decision making. Because of the evolutionary conservation of brain structure and function, the study of model organisms such as the rat should yield fundamental concepts that contribute to understanding the human brain.