Can an Image Justify a Theory? Weighing the Usefulness of fMRI
by Rebecca Steinberg
Functional magnetic resonance imaging (fMRI) provides a safe method of observing brain activity in a spatial and temporal context. Although its recent use primarily classifies brain activity and localization, it is only logical that neuroimaging be used as a supplemental tool for integrating a variety of existing cognitive theory. For example, fMRI studies reveal that an aging mind declines in certain activity, such as processing speed, but compensates by more heavily activating regions corresponding to task-relevance. The ability to visualize regional stimulation of the brain in response to assorted stimuli strongly correlate with the theory that mechanisms underlying observed thoughts and behaviors are more established in certain parts of the brain and less so in others. The big question on everyone’s mind is what strategy to take in conclusively explaining behavioral response using the information gleaned from neuroimaging.
Mather, Cacioppo, & Kanwisher suggest that neuroimaging can refine and contribute to cognitive theory beyond localization through four fundamental questions. The first question concerns whether a specified mental process is associated with a localized mechanism in the brain. The second examines whether these mechanisms are activated by a given task and might be used as markers for specific functions. The third question serves to reveal the depth of boundaries between different stimuli and tasks. The final question assesses to what extent two distinct tasks engage similar mechanisms of the brain. The focus of these questions is not solely on “where” the brain is stimulated, but when the regions are active and in response to what stimuli.
fMRI can be used to shed light on established cognitive theories not through direct comparison of images to behavior, but through the interpretation of what these images might mean on a behavioral level. The four questions proposed by Mather et al. take a step-by-step approach to connecting observed brain activity in fMRIs to generally observed behavior in mankind.
References:
Mather, M., Cacioppo, J. T., & Kanwisher, N. (2013). How fMRI can inform cognitive theories. Perspectives on Psychological Science, 8(1), 108-113.
Mather, M., Cacioppo, J. T., & Kanwisher, N. (2013). Introduction to the Special Section: 20 years of fMRI – what has it done for understanding cognition? Perspectives on Psychological Science, 8(1), 41-43.
John T. Cacioppo is the director of the Center for Cognitive and Social Neuroscience at the University of Chicago.
Learn more about CCSN.