Abstract:
When we interact with others, we use their nonverbal gestures to predict what they are going to do next. This process, termed mentalizing, allows us to engage in successful social interaction where responses to gestures are appropriate. For example, you can predict that someone is hungry when you see them looking at an apple pie. Mentalizing processes are associated with activity in a network in the brain that is responsible for processing social interactions. Although humans generally mentalize with only other humans, humans can also mentalize with inanimate objects (i.e., robots) when the objects are perceived to have thoughts and intentions of their own (i.e., perceiving a mind to them). This mind perception process has been well understood and although neural substrates have implicated the mentalizing brain network for mind perception processes in the brain, little is known about how engaging the mentalizing network through mind perception is related to socio-cognitive processes. In this thesis we use a social attention task, the gaze-cueing task, to examine subjects’ performance on social attention when they encounter agents that have varying degrees of physical humanness. The first study in this proposal examined how physical appearance can influence gaze-cueing performance and subjective mind ratings separately. Results showed that physical appearance only influenced mind ratings but not gaze-cueing performance. In the second study, we illustrated how physical humanness (i.e., a mind trigger) influences gaze-cueing performance as a function of brain activity related to mind ratings (i.e., BOLD response as it relates to subjective mind ratings) and subjective mind ratings. In the last study, we used tDCS to establish a causal link between brain activity in regions related to mind perception and gaze-cueing performance in a social attention task and found that only brain stimulation to prefrontal brain regions modulated social attention performance.
