Research Themes
Social Cognition & Social Neuroscience
The opacity of minds poses a major hurdle in accessing other minds. Therefore, people constantly make inferences and theories about the thoughts, beliefs, and desires of others. This ability is known as Theory-of-Mind (ToM). One of the primary interests of our lab is to study the neural underpinnings of human social cognition in general, and ToM in particular. Socially relevant cognitive and neural processes are explored by focusing on three main avenues: 1) how do people understand the actions of others? 2) how do people infer the emotional and/or mental state of a protagonist involved in an action? and 3) how do people grasp the intentions behind those actions? In any given social interaction, people process the “what”, “how,” and “why” of the actions. We aim to gain a better knowledge of the interrelationship among these constructs and their function in social cognition. We look at the specialized brain activity in core brain regions, and the coordinated functioning of these regions in accomplishing a given task. In this quest, we target two brain systems that are hypothesized to be involved in action understanding and social cognition: the mirror neuron system (MNS) and the ToM system. While the MNS has been found to play a key role in action execution and action observation, it also may mediate understanding and making inferences about other minds. Therefore, the interplay between the MNS and ToM systems may be critical in accomplishing tasks of mind reading. In brief, these investigations target neuroscience questions pertaining to the structure and function of the social brain in typical individuals and in autism.
Autism Spectrum Disorders (ASD)
ASD is a pediatric health issue of growing urgency and is characterized by impairments in social communication, and repetitive behavior and restricted interests. Considering our lab’s interest in asking questions related to social cognition and social neuroscience, autism provides an appropriate arena to study the function and dysfunction of the “social brain.” In addition, in light of the recent findings of aberrant functional connections in the brains of people with autism, our projects on autism further investigate such connections in the “social brain” and extend that to translational level attempting to mend altered connections. By applying our research questions related to social cognition and connectivity to autism, we aim to gain insight into the neural deficits and strengths associated with autism, as well as a better understanding of the overall functioning of the social brain. Our functional MRI studies span different domains of cognitive and social functioning, such as emotion recognition, ToM, anthropomorphism, self-other representation, causal attribution, and implicit learning. The findings from some of these studies provide important insights into the inner workings of the brain in people with autism. Research studies pertaining to disorders in general should ultimately lead to helping the individuals affected by it. Since the lab’s main focus is autism research, clinical and translational implications are close to us in our research questions.
Language Comprehension
Our interest and focus on language research is in three primary directions: 1) understanding the neural and cognitive mechanisms underlying language and action. We try to address this question through a series of fMRI studies testing the role of motor cortex and action-related brain areas in comprehending words and sentences involving action scenarios; 2) examining the neural underpinnings of the social use of language in children and adults with autism spectrum disorders. Since pragmatics of language entails an understanding of the speakers’ intentions, the social difficulties in people with ASD may come to the fore in tasks that involve figurative speech. Studies in this domain show altered pattern of brain responses in ASD; and 3) evaluating the impact of intense language intervention on changing brain activation and connectivity in children with autism. One of our recently completed studies in collaboration with the Lindamood-Bell Learning Processes tested the change in brain responses in language-impaired children with autism after a visualizing and verbalizing reading intervention. The goal here is to characterize the language areas in the brain in autism and to assess how a clinical intervention can improve language skills in children with autism at an early stage in order to ameliorate their language impairment.
Multimodal Neuroimaging
It may be difficult to conceptualize the complexity of cognitive and biological processes in the autistic brain given its wide heterogeneity by relying on a single approach. Considering the phenotypic complexity of ASD, multivariate approaches can provide better characterization and higher discriminative power than single brain measures. For example, brain activation and functional connectivity measures provide two different but complementary indices of neural functioning. Functional connectivity MRI (fcMRI) can measure the functional integration involving the coordination among different brain areas by measuring the synchronization of the time-series of the activated brain areas during a certain task or during rest. FcMRI is a method for assessing observed cross-talk between active brain areas; but it does not have directional information of connectivity which can be gained from effective connectivity. However, none of these measures provide insight into the physical attributes of these putative connections. We use diffusion-weighted MRI (DW-MRI) to measure these physical attributes (anatomical connectivity) by examining the diffusion of water in brain tissue and get a measure of white matter integrity. Another technique we use to supplement functional and neuroanatomical knowledge is proton magnetic resonance spectroscopy (1H-MRS), which estimates the concentration of brain metabolites based on chemical resonance shift and provides an index of overall neuronal health. Finally, we also compute specific neuroanatomical measures by cortical thickness, volume, surface area, and gyrification. These diverse neuroimaging methods, along with sophisticated data analysis techniques like data-driven methods, pattern/statistical classification, Independent Component Analysis (ICA), regional homogeneity (ReHo), and Activation Likelihood Estimation (ALE), provide a converging and comprehensive characterization of the brain in autism.
