Students form their thesis committees at the beginning of their second year. A standard thesis committee includes the student’s advisor, a committee chairperson and two additional members. All committee members should be drawn from the neurobiology training faculty. At least one member must represent a minor area in relation to the student’s research. To ensure consistency in mentoring and advising, we discourage students from seeking outside expertise unless they can demonstrate its necessity.
The thesis committee advises the student on selecting a thesis research topic, deciding the scope and feasibility of the student’s aims, and determining the suitability of the project as a Ph.D. thesis. The thesis committee meets at least once a year. Committee members begin each meeting with a brief discussion without the student present. Each meeting ends with a discussion between committee members and the student without the thesis advisor present.
Students are responsible for scheduling thesis committee meeting and filing a Report of the Thesis Committee that documents and summarizes each meeting.
The Preliminary Examination
By May 31 of the student’s second year, the thesis committee conducts a preliminary examination. Students must complete and submit a committee approval form to the department’s Director of Graduate Studies Assistant (DGSA) no later than 30 days before the preliminary exam. Students who fail to meet this deadline will require additional approval from the Associate Dean of Academic Affairs.
The preliminary exam is based on a research proposal the student has written. It is modeled after an NIH application for a National Research Service Award (NRSA) training fellowship and often serves as such after successful completion of the exam. It includes:
- Specific aims (1 page)
- Background, significance and innovation (3 pages)
- Research design and methods (4 pages)
Student are not allowed to include preliminary data they have collected; although, they may use properly cited published data to inform project feasibility. Students must give the proposal to the thesis committee members at least two weeks prior to the preliminary exam.
A successfully written proposal formulates specific research aims that seek to answer an important scientific question the student has identified through studying neuroscience literature. The student should then conceptualize how to answer this question using a range of scientific methods, including those that may not yet be in the student’s technical grasp. Although not required, the proposal topic is typically closely related to the student’s current or planned laboratory research.
The committee also conducts a 90-minute oral examination following the student’s public thesis seminar. The oral exam has four parts:
- A 10-minute meeting for committee members to assess the student's progress, identify issues to address, and determine who will address these issue and in what order. The student is not present during this time.
- A 20-minute presentation by the student. Students should use slides or other visual aids to help communicate the main points of the proposal.
- A question and answer session in which the student responds to questions from committee members. Questions may relate to the proposal or to general neuroscience knowledge suitable for a student entering doctoral candidacy in neurobiology. Some questions may not yet have answers; part of this exercise is to determine the limits of the student’s knowledge. A successful oral presentation does not hinge on answering every question or demonstrating omniscience.
- Deliberation and blind vote by the committee on the quality of the student’s performance. Two negative votes (or one negative vote by the chair) constitute a failure. In accordance with the policies of the Graduate School, the student may retake the examination once.
For additional information about the preliminary exam, consult the Duke Graduate School.
After the preliminary exam, the candidate enters into full-time research with few obligations other than to expand the frontiers of human knowledge in neuroscience, as guided by his or her advisor and thesis committee. The research phase lasts two to four years. Students are encouraged to develop into independent scientists, advancing their research while also taking advantage of relevant courses, journal clubs, and seminars on Duke campus. Candidates may choose to take additional advanced coursework with approval of their advisor and the Director of Graduate Studies. Candidates continue to meet at least annually with the thesis committee to report progress and seek advice on successfully completing the thesis project.
To receive a doctoral degree, the student must write a cogent doctoral dissertation, present the major findings of this dissertation in a public seminar and satisfactorily defend the dissertation in an oral examination conducted by the thesis committee. The written dissertation includes a scholarly introduction to the scientific questions tackled by the student; experimental chapters that move scientific concept and knowledge forward by answering these questions; and a concluding chapter that discusses the significance of the experimental findings, especially as they relate more broadly to neuroscience. There are no length limits, but most theses are 100-200 pages, formatted to guidelines provided by the Graduate School of Duke University. Thesis examples can be found in the Duke Thesis Archive.
The thesis is a published document, so the student does not need to publish experimental findings prior to the thesis defense. However, timely publication is strongly encouraged and is common in the fast moving field of neuroscience research. Thesis chapters may include published papers or submitted manuscripts. The advisor and student may also consider using the introductory chapter as the framework for a review article.
The thesis defense consists of a 45-minute public seminar delivered at Duke University, followed by a question and answer session with the audience. After the public seminar, the thesis committee conducts a closed-door oral examination lasting 30-90 minutes. Like the preliminary examination, committee members ask questions while the advisor silently observes, unless invited by the chair to pose questions to the candidate. When the committee completes their questioning, the candidate is asked to leave the room while the committee members deliberate and cast votes awarding the doctoral degree. In some cases, the committee may request revisions or slight editing changes to the written document.
It is vital that all students follow the Graduate School’s policies and procedures to ensure that the publication of their research adheres to Duke University Guidelines.