Guest Speaker: Dr. David Rothlein (Post-doctoral research fellow at the Boston University School of Medicine)

Talk Title: Mapping the fidelity and connectivity of visual information using fMRI: Implications for attentional control, valence processing, and PTSD
Abstract: In this talk, I will discuss the two studies using different methods to measure the fidelity and connectivity of fine-grained stimulus information. The first method uses Representational Similarity Analysis to analyze data from a sample of Veterans performing a sustained attention task (gradCPT with scenes) in an fMRI scanner. Results reveal an amygdala-mediated attentional pathway that is associated with increased PTSD symptomology. The second study uses a similar sustained attention task but presents a simultaneous stream of task-irrelevant background images of either positive or negative valence (EmoGradCPT). Using careful manipulations of trial order I discuss a method of disentangling the BOLD signal timecourses, assigning contribution weights to each of the simultaneous and spatially overlapping streams of information (task stimuli and distractor images). I will present preliminary results showing where background distractions compete with task information in the brain and how this competition is mediated by valence and attentional state.