Functional connections within the brain can be revealed through functional magnetic resonance imaging (fMRI), which shows simultaneous activations of blood flow in the brain during response tests. However, fMRI specialists currently do not have a tool for visualizing the complex data that comes from fMRI scans. They work with correlation matrices that table what functional region connections exist, but they have no corresponding visualization.
FMReye is a graph network visualization tool that relies on a technique developed in computer science to support the process of interactive exploration. Using the “brushing” technique, the user can examine the same data from multiple perspectives, and multiple levels of abstraction at the same time.
The Web application loads a correlation matrix of fMRI data and demonstrates three levels of abstraction within a multi-view display. The first level is the exploratory view, which is a representative 3D rotatable model of the connections between functional regions. Anatomical landmarks provide the contextual clues for spatial orientation.
The second level is a view for intuiting meaningful data at a glance. The benefit of this view is to create the ability for sense-making. This view flattens networks onto a single plane, like the spokes on a bicycle hub, so just the interactions are summarized, and extraneous information is abstracted away.
The third level is a way to schematize data. It recognizes nodes according to their functional groupings. Each functional region gets plotted into an atlas of regional groups around a circle, and connections can be viewed according to their categorical relations.
Having the three views appear simultaneously lets users investigate one inquiry about the brain from multiple levels of abstraction. Since the tool is online, any interested individual can access the site and view previously uploaded data or post their own information.
This work was done by Scott Davidoff and Hillary Mushkin of Caltech; Margaret Hendrie of the Art Center College of Design; Abdelwahab Bourai of Carnegie Mellon; Sarah Churng of the University of Washington; and Conrad Egan of the University of Texas at Austin for NASA’s Jet Propulsion Laboratory.