Understanding the nature of self is central to many areas of psychology, and evidence from multiple domains suggests that information about one's self is processed in a substantially different manner than information about others. For example, information about the perceiver receives preferential attention, such as when people hear their names across noisy rooms. There is also a selective memory advantage for stimuli evaluated with reference to the self, as when a listener remembers words better if asked about how well the words described him or herself as compared to someone else. Initial studies have identified a number of central midline brain structures, notably the medial prefrontal cortex, posterior cingulate cortex, and ventral anterior cingulate cortex that are active in various aspects of self-representation. For instance, people differ in how they view themselves, with some people generally favorable (i.e., those with high self-esteem) and others generally more negative (low self-esteem). With support from the National Science Foundation, Dr. William Kelley and colleagues at Dartmouth College will use functional magnetic resonance imaging (fMRI) and anatomy-based diffusion tensor imaging (DTI) to examine individual differences in how people process information about the self. An innovative feature of this research is the use of a hybrid state-item brain imaging design that allows for an independent assessment of how temporary changes in mood influence the way that individuals evaluate themselves on a moment-to-moment basis. Individual differences in brain patterns for well-known perceptual effects (e.g., flicker fusion for visually presented checker-board patterns) will be compared with more self-related tasks (e.g., judging the relevance of words to describe a person). Here, there must be individual differences, so contrasting those differences with what should be fairly stable patterns will allow a better sense of what the imaging results can tell us.
This line of inquiry will provide insights into the brain regions that support a unified representation of self. A better understanding of the specific roles of brain regions involved in the mental representation of self should aid in understanding variations in self, such as age-related changes in self-awareness and how various disease processes might affect how people process information about the self. This research will also explore the effectiveness of hybrid brain imaging designs for studying the beneficial effects of social and affective components of human cognition. The current project helps to enhance and sustain an interdisciplinary collaboration between social psychology, affective neuroscience, and cognitive neuroscience that has been developing at Dartmouth College. It does so by a training program in which undergraduate and graduate students in the laboratories of the investigators receive training in multiple domains: social psychology, emotion, cognition, and neuroscience.
