Your thesis is like your first love. It will be difficult to forget.
—Umberto Eco, How to Write a Thesis
Writing your dissertation may be the hardest, most stressful, and most momentous moment of your entire adult life. It may sweep you away in waves of emotion driving you to question why you ever entered graduate school in the first place, bookended by the most deeply troubling existential thoughts about your place in this feeble world.
It might also be pretty anticlimactic.
In the most likely scenario, your dissertation process will be a few months of writing, punctuated by tough moments of self-doubt and confusion about how margins work. Some people find this period really difficult, but others find it really rewarding. I recommend stepping back and seeing the big picture—you’ve done a lot of really hard work, and you’re almost at the finish line.
It would be incredibly useful if there was some form of tooth fairy that would visit you in your lab and wave her magic pipette and declare you ready to defend, my dear.
Sadly, that’s probably not going to happen.
In most cases, readiness to start writing is quite elusive. Rarely (read: they’re strapped for money), will your advisor say to you, “I think you’re ready to defend!” In which case, your response should probably be to skip out of their office and begin writing immediately.
More likely than not, your advisor won’t tell you that they think you’re ready. You’ll need to decide for yourself. Some people hit the four-year mark and are immediately thinking about their graceful exit from graduate school, others get to year six and just start thinking about it. Hopefully you’ve already given some thought to how long you’d like to be a graduate student. Although Science may not always respect your wishes, this should at least give you a framework for when you can think about defending.
When you defend will largely depend on what you’d like to do after graduate school. If you’d like to stay in research, it will probably be in your best interest to stick around and complete your project to its fullest. You’ll want to have a nice, fairly complete science story to tell during your interviews. But, if you’re thinking you’ll follow a different path, you can likely finish your project to your advisor’s satisfaction and leave.
Here are a few things to consider when you’re determining whether or not you’re ready to leave:
■ Is there anything more you’d still like to learn from this lab? If not, consider moving on to your next adventure.
■ Did you accomplish what you set out to accomplish? It’s likely you (naively) set your goals quite high, but did you get close?
■ Will staying for another year really add more to your skillset or project?
■ Do you have an idea what you’d like to do next? If not, it might be worth spending some time and energy thinking about that.
If you think you’re ready, it’s time to have a conversation with your advisor. Express what you feel you’ve accomplished, what you’d still like to accomplish, and when you’re hoping to graduate. Hopefully, you can both come to a resolution about when a reasonable graduation time would be.
Depending on your program structure, you might also have a committee meeting about six months to a year before your intended graduation quarter, when you have the chance to get your committee on board with you defending. This is your chance to learn their expectations for you and make sure you can achieve those in the time you have left.
Neuroscience dissertations are highly variable in their length and depth. They can be anything from about one hundred pages to over three hundred pages, largely on how many figures and appendices you have.1 Typically, a dissertation will include an introduction, a few chapters that highlight specific research projects you’ve worked on, and some sort of overall discussion or conclusion. It can really help to see a lab mate’s dissertation before writing your own.
Your institution will probably have a very, very specific way that they’d like you to format your dissertation. For example, they’ll want specific page margins, a separate numbering scheme for each chapter, a small, magical elf to translate acronyms, and so on. Wrestling with Microsoft Word may very well be the most frustrating part of writing your dissertation—I’ve seen many graduate students lose their already fragile minds in this manner. You’ll need to be prepared for an administrator to pull out a ruler and measure your margins. Not kidding.
Some people will choose to use LaTeX for their dissertation. You’ll very quickly find out who these people are because, well, they’ll tell you. I wouldn’t use your dissertation as a way to learn LaTex, unless you’re feeling particularly secure and ready for even more learning after your already invested time. Using LaTeX is possible, but it could be more hassle than it’s worth. However, some institutions usefully have a LaTeX template that you can use, in which case you can write your dissertation however you choose and simply plug it in to the template.
Each institution will have its own specifications for the layout of the dissertation, but there are typically a few key pieces:
The introduction
The introduction of your dissertation serves as an overview of all of the applicable background material to support your research. Before really planning it out, I highly recommend sitting down and mind dumping everything you think you’ve learned in graduate school into a document. If you’re anything like me, you’ll find writing this section extremely enjoyable because it will reassure you that yes, you have learned something. Even if that something is the exact spatial resolution of the mouse’s visual system it will make you feel like a neuroscience god.2
Your introductory section should be like the beginning of a scientific paper but even broader. It is your grand motivation for studying your topic. It should provide a comprehensive, understandable background that supports each of your research projects.
In my case, my projects felt pretty different, but they all fell under the umbrella of the cell types and pathways involved in the visual system. My introduction described the anatomy of the visual system and the idea that there were different cell types and circuits within that served different functions. I set the stage for some of the research in my individual chapters but not in depth.
If you find the introduction difficult to scope out, consider a few questions to get started:
■ What does someone need to know to understand your dissertation work?
■ What research did you read when you first started on your project(s)?
■ What do you feel are the most pivotal papers (from your lab, or others) leading up to your research?
The body
For some, a dissertation is a collection of papers that they’ve published (or at least submitted) over the course of their time in graduate school. Most advisors will expect you to write an introduction and possibly a conclusion to tie your papers together, and boom—you’ve got a dissertation. This is informally called a staple dissertation.
In other cases, you may not have any published papers or really any immediately coherent stories to tell. That means writing the body of your dissertation will require a bit more thought and creativity.
One useful way to think about it is as two to four small stories about your research. You might have one big overarching question, for example: How does the structure of a hallucinogen change its effect on receptors and ultimately the brain? Then within this question you’ll have several more specific questions, for example: Does psilocybin differentially bind to 5-HT2A or 5-HT2C receptors? The stories may not immediately flow into one another, but they’ll all provide a different point of view on your bigger question.
Either way, you’ll likely have data and smaller projects that may not have a clear place. For example, there might be experiments you conducted either as a trial or before switching directions on your project. There might be decent data there, but it may not have been enough for a paper on its own. Whether or not you include these data will depend on if you have enough other data for your dissertation and how well they fit into your other projects. It’s nice to give yourself due credit for the work you did as long as it doesn’t distract from the bigger story of your dissertation.
The conclusion
Some advisors or programs will ask that you also write a conclusion to your dissertation, which will serve to pull it all together and draw some broader takeaway messages. This is your chance to reflect on your findings, including their strengths and limitations.
Here are a few questions to consider for your conclusion:
■ Does your data align with the frameworks you presented in the introduction?
■ Do you have any conflicting results, and if so, how can you reconcile them?
■ What are the next steps for your eager, future lab mates, or the field in general?
On the date of your defense, you have one mission: Give a coherent talk that summarizes your hard work to your thesis committee and your colleagues. It’s not an easy task, but after putting the work into writing your dissertation, it’ll be much easier.
Very likely, you’ll have seen a few graduate students before you give their defense talks. These can be really helpful examples of what to do (or not do) in your own presentation, and you may like some people’s approaches more than others.
There isn’t a right or a wrong way to give a defense talk specifically—you should follow the same principles as any other talk. Include limited text on your slides, use a talk roadmap, make sure visuals are clear and labeled.
One tricky thing about the dissertation talk is that you may need to give background information to family, friends, and any other nonscientists in the audience, since they’re typically public talks. A graceful way of doing this is by adding a few extra slides explaining some more fundamental concepts—for example, what neurotransmitters are, or what the main classes of cells are in the brain. Your committee won’t think you’re silly or dumb for doing this—it’s expected in a dissertation talk. That also means you don’t need to qualify why you’re showing such basic information—just do it, and then get to the meat of your work.
A dissertation is a necessary step to getting a PhD, and a PhD is a necessary step to becoming a neuroscience researcher. But in the field of neuroscience, few people will actually read your dissertation. Honestly, you’ll be lucky if your dissertation committee reads it in full. Most likely, they’ll take a breezy look at it and come up with a few questions to ask you during your thesis defense.
Occasionally, I’ll stumble upon someone’s dissertation when I’m looking up a topic. This happens more often when there is data in their dissertation that didn’t end up making it into a paper. The introductions to dissertations can also be really useful reviews of a field, often just as helpful as formally published reviews.
Dissertations are very rarely cited in scientific papers. Because they’re not formally peer reviewed (and because relatively few people have had the chance to comment on them and give feedback), they’re typically not respected as solid scientific reports. The same goes for citing conference posters or preprint papers.
So what does your dissertation stand for in the end? In my opinion, it’s much more about the process than it is about the final product. The process of writing a dissertation will give you a chance to reflect on everything you’ve accomplished and tie together the threads in your own work. The ability to wrangle complicated data into stories and future experiments is an incredibly important skill for researchers and many other careers. Plus, it’s probably collectively the largest project you have ever completed—that in itself is an incredible accomplishment.