Social situations are often complex and dynamic, requiring a human brain to constantly scan and rescan the scene to pick up the social cues—such as facial expression of emotion—necessary to understand what each person in the scene is feeling, thinking, or doing. An inability to do one or more of these things would then lead to poor socialization, which in turn would lead to less friends, poor job prospects, and an overall inability to participate in society. This is often the fate of individuals suffering from schizophrenia and other neuropsychiatric disorders.
Our lab, at Columbia University and the New York State Psychiatric Institute, uses brain imaging and behavioral measures to study social functioning and its deficits in neuropsychiatric disorders. We combine cutting-edge functional magnetic resonance imaging (fMRI) methods combined with eye-tracking to measure a subject’s visual scanning of movies of social situations simultaneously with the brain activity and structure that underlies this behavior. The movies more closely mimic real social situations as compared to static pictures, and will therefore more readily translate to neuropsychiatric populations. With the results we hope to not only reveal the mechanisms underlying this basic human function, but also design treatments for individuals with neuropsychiatric disorders that interfere with social functioning.
Visual Scanning: We have recently discovered that schizophrenia patients oftendo not look at the same features of a social situation as
healthy controls, and that the more features they miss the worse their comprehension of that social situation. We are now quantifying which visual features drive the attention of healthy controls and which ones are most often missed by schizphrenia patients. This study is in collaboration with David Leopold at the NIMH.
Network Architecture of Social Functioning: Using a combination of tasks designed to localize the brain areas involved in the various components of social functioning, we have recently mapped the architecture of the brain networks underlying visual scanning using resting state fMRI (rs-fMRI). In schizophrenia, we found major deficits in the connectivity of areas in the temporoparietal junction/posterior superior temporal sulcus (TPJ-pSTS) in the right hemisphere, an area that undergone dramatic reorganization in the course of evolution in humans versus other primate species. We are now investigating the functioning of these areas during the viewing of movies of social situations and their connection to the deficits in visual scanning.
Development of TPJ-pSTS in Social Functioning: We are now extending both of the abovefindings to individuals who are at high risk of developing schizophrenia. Schizophrenia is a neurodevelopmental disorder, with full manifestation usually taking place in early adulthood. The TPJ-pSTS matures at about the same time, and so we are studying whether the disconnections observed precede or are the result of the onset of schizophrenia using the same imaging and eye-tracking techniques used in our studies of chronic schizophrenia.
Retinotopic Organization of Attention Networks in Schizophrenia: We have recently found that the attention networks are grossly normal in schizophrenia patients, and that the patient that are unable to use their attention networks to overcome their visual processing deficits are the ones who do not look at the socially relevant cues in the social movies. In collaboration with Clay Curtis at NYU, we plan to examine how well does the organization of these areas mirror that of the retina (retinotopic organization), and whether activity in these retinotopic maps during movie watching can be used to decode where healthy volunteers and schizophrenia patients decide to visually scan.
Neuromodulation of TPJ-pSTS in Visual Scanning: Based on the finding that the TPJ-pSTS connectivity and activity underlies visual scanning, we plan to use transcranial direct current stimulation (tDCS) to causally change the activity in this region to determine its effects on both visual scanning behavior and the neural activity evoked by movie watching.