Look at the postings outside Tobin 503 for Undergraduate Research Assistants. Often these turn into successful thesis projects. You can also take Psych 295H, Departmental Honors Seminar (offered in the Fall only) to learn about research programs going on within the department. Another option is to look at the listing of faculty research interests and contact a faculty member who is conducting work that is of interest to you, and see that person in his or her office hours.