Dr. Bruce Luber of the Division of Brain Stimulation will present a talk on "What Transcranial Magnetic Stimulation Can Say About Self and Self-Awareness" on Saturday, December 6 at 10:00 a.m. as part of the Neuropsychoanalysis Lecture Series:
The self is a rather elusive concept and the psychobiology of self is even more so. A large number of neuroimaging studies have attempted to find regions in the brain specific to processing the self, primarily by contrasting self-related stimuli with non-self-related stimuli (i.e., self vs. other). Across a wide variety of self-related tasks, a consistent cortical network has been activated. Criticism has arisen that this network can not be related to self-specific processing. For example, it is almost identical to the active network of the resting state, the "default" mode, when the subject is free to think about anything at all. However, while neuroimaging techniques can only reveal correlations between brain states and behaviors, the new technique of transcranial magnetic stimulation (TMS), a harmless means of temporarily changing the function of precise regions of the brain, can demonstrate causal links between brain and behavior. We have tested the proposed self-specific network by using TMS to briefly disrupt local cortical processing while subjects rated adjectives as like or unlike themselves or their best friend. We found that while judgments about the best friend were never affected by TMS, it did dynamically influence self judgments. Our TMS program of experiments may reveal the neural basis of self-specific processing, leads to speculation as to what the "default" brain network does, and ultimately may provide a key technology to understanding the biology of the self.