For more of Nancy's short talks about the brain, click here. This story serves as the introduction to Nancy's new course, "The Human Brain". Lectures from her course will be appearing here over the next few months.
The bare basics on functional MRI, a noninvasive method for measuring neural activity in the human brain with (almost) millimeter resolution.
The bare bones of the design and analysis of a very simple fMRI experiment, and some basic terminology.
Watch my lab tech Jenelle Feather scan me on that very simple experiment while course TA (and MIT graduate student) Hilary Richardson narrates.
Here I describe the basic fMRI evidence for the fusiform face area, how we test alternative hypotheses to face specificity, and the functional region of interest method.
In a paper published in 2001 Jim Haxby made the important point that a region of the brain can contain information about classes of stimuli that it does not respond to above baseline, if the pattern of response across voxels in that region differ stably for one class versus another. In other words, even if the response of...
Nancy discusses how we can use fROIs to explore human cognition, and why it provides unique advantages over other functional imaging methods.
How do we figure out not just what a region likes (i.e., responds to most), but what it does? One way is to measure its response to a lot of other kinds of stimuli, that is measure its "response profile".
How can we tell what information is represented in each voxel or region? Even if the mean response of the voxel is the same to the two kinds of stimuli, different neural populations in the voxel may respond to the two stimuli, and if so those populations of neurons can represent the difference between those stimuli. This...
Multiple voxel pattern analysis (MVPA) is the other method (besdies fMRI adaptation) that enables us to figure out what information is repesented in a given region. If the pattern of response across voxels in that region is stably different for one kind of stimulus, from the pattern for another kind of stimulus, then the...
Here I give a few tips for evaluating published fMRI studies by pointing out three common flaws in imaging studies.