Bloggin' from Boot Camp - Day Two

The Neuro Gang's all here! We posed this afternoon
for a group photo on the beautiful Penn campus.

Is it only day two? More than one person asked this today, as we've covered a lot. And everyone I’ve talked to so far is also raving about the program. Comments I’ve heard in the elevator and at lunch are along the lines of “I’m getting so much out of this” and “This is really exciting”. Major kudos to Martha and Leah Fiasca for having things running so smoothly, and to Geoff for his excellent high-energy lectures. For my own part, boot camp is shaping up as I hoped it would. I feel that I’m learning some of the underlying science, and I’m having one great conversation after another. 

It’s also worth noting that research by scholars associated with the MacArthur Law & Neuroscience Program is coming up again and again in discussion. In addition to Stephen Morse, Owen Jones, and Gideon Yaffe, who are all in the audience asking great questions, the following Law & Neuro project members were mentioned today: Kent Kiehl, Adina Roskies, Anthony Wagner, Marc Raichle, Liz Phelps, and Read Montague. Clearly the Law and Neuro project has brought together a group of researchers at the frontiers of the neuro research most relevant for understanding human behavior. Good stuff! (Click below for Day 2 play-by-play, important lessons, and more). 

I. Play-by-Play  

The morning started off with a really useful exercise, a breakout session led by Penn neuro grad students, on how to read through a paper that reported fMRI results. We broke into five groups (my group covered race and empathy as reported in this paper), and it was a very helpful exercise. For those playing along at home, you might also want to check out Owen Jones article, “Brain Imaging for Legal Thinkers”. If you’re new to fMRI, it will help you understand what the terminology means.  

After the break out session, we heard again from Geoff Aguirre. Through a series of morning and afternoon lectures, Geoff walked us through more advanced topics in fMRI. If you want to see what we covered, you can find Geoff’s presentations (both slides and videos) online. I highly recommend checking him out.  

After Geoff’s lecture in the afternoon, we had two hour-long breakout sessions. These afternoon sessions, designed to be informal and a chance to converse, were led by boot camp participants. Along with Hiroko Ide, a political scientist doing fMRI research at the University of Tokyo, I led a small session on neurocampaigning and neurotargeting.

The lineup of breakout sessions (5 were offered each hour) was great, and I wish I could have attended many of them. If you were here you could have attended the following sessions:

• Neuroimaging of Punishment by Owen Jones
• Regulating Neuroimaging by Stacey Tovino
• Neuroimaging: Privacy Considerations by Marc Blitz
• Neuroimaging of Religious Experience by Andrew Newberg
• Neuroimaging in Court by Julie Seaman
• Imaging of Intention by Tom Buller and Deborah Denno
• Marketing and Neuromarketing by Jeff Galak and Gal Zauberman
• Neuroimaging Pain by Adam Kolber   

II. Important Lessons  

Yesterday we learned some fMRI basics, and today Geoff taught us how to be informed consumers of fMRI research. Like any research methodology, fMRI has both promises and limitations. Because it is still new, and because the first round of fMRI studies didn’t do everything they needed to methodologically (e.g. statistical corrections), Geoff has been reminding us that a lot of the stuff currently out there isn’t to be trusted. So how do we know if an fMRI study is solid? What types of questions should we ask? Geoff gave us the answers.   There are three main types of fMRI studies, and each of these has an Achilles heel. Here’s the bullet-point version:  

1. Forward Inference Experiments. These types of experiments are those that tell us “the brain area is for X,” where X may be love, working memory, or any number of other mental operations. When you see these experiments, ask this question: “How did the researchers isolate this mental operation?” For instance, if they’re claiming that this is the brain area for love, how did they isolate love? Remember that we can only isolate a mental process indirectly, through a method neuroscientists call cognitive subtraction. We’re not able to see subject “love” and then track the neurons that fire. Rather, we observe subject during state-1 and during state-2, and we subtract the neuronal activity between the two states. We then call that difference “Love,” but we can only do so if we’ve designed the experiment such that we can credibly claim that the only difference in mental processes between state-1 and state-2 is in fact Love. As you’re probably guessing, such a claim often isn’t valid. This problem is known as the “trouble with cognitive subtraction” and it’s a longstanding problem.
2. Reverse Inference. In a reverse inference experiment, a researcher sees where neuronal activity is in the brain, and then works in reverse to claim that this brain activity is related to the mental process the subject was engaging in at the moment the scan was taken. The problem is that, in the absence of information provided by previous forward inference studies, a researcher doesn’t know a priori which mental processes the subject is actually engaged in. When a brain area is associated with multiple mental processes, it is impossible to know which mental process (or combination of processes) the subject happened to be experiencing. Thus, the question to ask when you see these sorts of studies is, “How strong is the relationship between brain activity and the mental process?” Geoff illustrated this problem with a study he called the “biggest, smelliest pile of garbage you can find”. He also has written a longer critique
3. Distributed Reverse Inference. Distributed reverse inference studies are the closest we get to “mind reading,” as researchers essentially say: Let us see your brain's entire activity and based on the distribution of activation we can accurately predict what you’re thinking about … so long as you’re thinking about one of the things that we’ve trained our computer program to recognize (e.g. a certain face). This caveat sound familiar to social scientists, as it’s another version of the internal/external validity challenge. In the same way that experimental social scientists can’t be sure that the conclusions they reach will be valid outside the laboratory setting, so neuroscientists can’t be sure that their predictive models will work accurately outside the things that the computer has been trained to recognize. This has big implications for lie detection, namely that current technology does not allow for scientifically valid claims about the ability to detect lies. 

The rest of the lectures covered a number of important advanced topics in fMRI. There’s not enough room here to report on them all, so let me make the following three points: (1) fMRI is not a single method, but an umbrella term that refers to a host of methods, many being improved as we speak; (2) both functional and structural information about the brain is important, especially in tandem; and (3) just because you’re making a measurement of the brain doesn’t mean you have a measurement that is better or more accurate than what you can get from behavioral measurements.  

III. Who’s at boot camp with me?  

I went to lunch today with Bombie Salvador, a Management Professor at the University of Washington’s Milgard School of Business, and Hiroko Ide, a graduate student in the Graduate School of Legal and Political Studies at the University of Tokyo. Hiroko is studying the neural correlates of attitude change after exposure to campaign ads, and Bombie studies moral decisionmaking in the workplace. We had a delightful time learning about each other’s work, and Hiroko and I had a fun time leading discussion later in the day on how neuroscience may intersect with political campaigns and political behavior.