By Peter Bandettini
Episode produced by Kevin Sitek and Rachael Stickland
S2 Ep5: Jack Gallant, Strong opinions about fMRI analysis
MRI is ultimately about separating a known but variable signal from highly variable noise. How one does this makes all the difference, and fMRI is particularly challenging since what is signal and what is noise is not always clear as they both vary in time and space. Jack is a huge proponent of fMRI encoding or, more generally, careful model building to probe the time series, and he thinks that more model-free approaches and paradigm-free methods are ultimately limited. The discussion gets technical as well as intense at times. The points he makes are important. While we agreed most of the time, there were some nuanced differences of opinion - mostly when it came to discussing alternative methods for probing fMRI data. Overall, it was a fun and hopefully useful discussion! What does come through is his passion for what he does. Given that we only barely got into my questions, we scheduled a follow-up conversation with him.
S2 Ep6: Jack Gallant, Deriving fundamentals of brain organization with fMRI
The first podcast with Jack delved so deeply into his approach to assessing fMRI data and his philosophy of doing good science that we really didn’t get a chance to talk about either his groundbreaking results or what questions they open up. In this episode, we cover both of these topics in-depth. First, we discuss his fascinating and potentially paradigm shifting results on widely-distributed, semantic maps in the brain that shift and warp depending on the task itself. These results, at least in my opinion, open up new avenues for insight into fundamentals of brain organization. The brain is not just a conglomeration of distinct and static modules, but a shifting landscape of representation, much of which may be shaped primarily by our experience in the world. How our attention shifts these landscapes is an open and potentially profound question. Here we also discuss prospects for layer fMRI as well as the challenges of clinical MRI. It was a rich and engaging discussion with one of the true luminaries in the field.
About the guest:
Jack Gallant, Ph.D. is a neuroscientist and engineer at heart who trained with David Van Essen at Wash U. He is currently a Chancellor’s Professor of Psychology and Class of 1940 Endowed Chair at UC Berkeley and is affiliated with the Department of Electrical Engineering and Computer Science. He is also affiliated with the graduate programs in Bioengineering, Biophysics, Neuroscience and Vision Science. His work spans from single unit recordings, to whole brain fMRI, embracing the whole of computational neuroscience, setting extremely high standards, technical rigor, creativity, and insight.