I. Components of higher cognition
In our research involving healthy young adults, we examine various cognitive processes that underlie complex human behaviors, like goal-directed behavior, learning and memory, and reasoning. In particular, the lab has studied how we 1) use rules to select appropriate responses under different circumstances, 2) exert control over our behavioral responses, 3) retrieve and use relevant information from long-term memory, 4) manipulate, compare, and integrate mental representations in the service of reasoning, and 5) use prior knowledge to scaffold learning. We also examine how education shapes cognitive abilities and the brain. To investigate these phenomena, we design cognitive measures and conduct behavioral, neuroimaging, and eyetracking studies.
CURRENT PROJECTS:
1. How does the brain represent abstract concepts?
The ability to reason about the relations between sets of concepts — relational reasoning — gives rise to abstract thought, and has fueled some of humanity?s greatest achievements in science and technology. Although prior research has identified where in the brain relational reasoning takes place, this project pushes the research field by addressing how the brain represents abstract relations. Specifically, the project aims to address three key questions: (1) Can the brain represent an abstract idea independently of the concrete entities that comprise the content of the idea? (2) Do people represent concepts in an abstract manner only when explicitly required to do so, or are abstract relations also retrieved spontaneously? (3) What neural markers reliably predict differences in reasoning capacity between individuals? That is, do individuals whose brains represent abstract relations more readily also tend to have stronger reasoning skills, and/or to perceive meaningful connections that others miss?
This project was funded by the National Science Foundation (PIs: Silvia Bunge, David Kraemer, Keith Holyoak, and Hongjing Lu), and analyses are ongoing.
2. Narrowing the mechanistic gap for anterior prefrontal cortex function. — This project is the major focus of our lab currently.
Prefrontal cortex (PFC) is a large and heterogeneous brain area comprising the front third of the human brain that has been implicated in numerous mental health disorders. One of the least-studied subregions of PFC is anterior lateral PFC (aLPFC). This region, whose functioning is impacted in disorders like schizophrenia, has been implicated in reasoning, multi-tasking, planning, memory monitoring, decision-making, and more. It behooves us to reach a mechanistic understanding of the fundamental processes subserved by this region; however, there are numerous challenges, including the absence of a precise animal model, inconsistencies regarding terminology and anatomical boundaries, lack of attention to individual variability in anatomy, lack of high resolution imaging in living participants, and limited evaluation of the generalizability of its function. In response to these challenges, we seek to do a deep dive on its anatomy and function at the individual level in neurotypical adults, using cutting-edge MRI technology. Leading theories presuppose that aLPFC has a domain-general function, processing abstracted representations that are far removed from initial inputs to the brain. However, this assumption has yet to be carefully tested. Here, we capitalize on a body of work implicating a portion of aLPFC in relational reasoning, or the ability to reason about information by jointly consider several sets of mental representations. First, we seek to evaluate the claim of domain-generality by assessing aLPFC’s activation and interactions with other brain regions during performance of four relational reasoning tasks; these tasks involve both visual and—for the first time—auditory domains, as well as visuospatial and semantic (or “where” and “what”) stimuli processed by different posterior brain regions. Second, to better localize aLPFC activation during reasoning at the single subject level, we seek to assess whether small sulci (grooves) serve as functional landmarks, predicting the location of this functionally defined region. Third, we seek to leverage the exquisite spatial resolution of our NexGen 7 Tesla MR scanner and a combination of two fMRI methods to test whether aLPFC activation during reasoning is predominantly localized to superficial cortical layers, consistent with involvement in local recurrent connectivity that supports integration of high-level mental representations. Fourth, theories of PFC organization either presuppose that aLPFC receives inputs exclusively from other PFC regions or that it also has long-range connections to more domain-sensitive regions in parietal and temporal cortices. Thus, we seek to use high-resolution diffusion-weighted imaging at 7 Tesla to shed light on the provenance of inputs to aLPFC. With strong expertise in PFC function, neuroanatomy, high-field MR imaging technology, and MRI analytic approaches, our team is poised to yield novel insights about PFC function. This study is both theoretically and technologically innovative and will yield a valuable shared dataset. Better characterizing aLPFC structure and function could yield insights for early identification of disordered thinking in neurodevelopmental conditions such as schizophrenia.
This project is funded by the National Institute on Mental Health.
II. Development and plasticity of higher cognition
In our research involving children and adolescents, we study how and why the high-level cognitive abilities outlined above change over development, how they are shaped by experiences such as education and home environment, and why some individuals develop stronger cognitive skills than others. To this end, we relate changes in higher-level cognitive abilities to brain structure and function. We also use eye gaze metrics to track thought processes on a moment-by-moment basis, so as to more carefully pinpoint the processes of change.
In collaboration with professors Keanan Joyner and Fei Xu at UC Berkeley, we have recently established a new shared facility for functional near-infrared spectroscopy research. Our lab’s goals are to (1) extend our research downward in age, studying the foundations of higher-level cognition from ages 4 onward, (2) investigate how education and other experiences affect brain functioning at these earlier ages, and 3) broaden participation to children and families who are not typically included in neuroscience research.
To sign up for a current study, please look under “Participate”.