January 17, 2013
Review Finds Brain Scans Not Completely Persuasive
Connie K. Ho for redOrbit.com — Your Universe Online
A new study published in the January edition of the Perspectives of Psychological Science reveals the impact of functional magnetic resonance imaging (fMRI) over the last 20 years, and argues that there are some issues that remain unclear.To begin, fMRI has been used to evaluate real-time brain activity. The tool can determine changes in blood flow and help researchers better understand the human brain.
Past studies at institutions like the University of California, Berkeley (UCB) have utilized fMRI to track brain responses. For example, a study done in 2011 at UCB focused on picking apart participants´ visual experiences with the help of brain imaging. They believed that the study could, one day, help them better understand the inner workings of individuals who could not communicate verbally in situations related to neurodegenerative disease, stroke, or coma.
“This is a major leap toward reconstructing internal imagery,” explained the study´s co-author Jack Gallant, a professor and neuroscientist at UCB, in a prepared statement. “We are opening a window into the movies in our minds.”
Another study last June at UCB looked at the effect of sleep deprivation with the help of fMRI scans. The researchers found that sleep deprivation was related to natural anxiety that the participants had. The fMRI scans showed how sleep deprivation could elevate the build-up of anticipatory activity in emotional centers of the brain.
"Anticipation is a fundamental brain process, a common survival mechanism across numerous species," commented the study´s lead author Andrea Goldstein, who was a graduate student at UCB´s Sleep and Neuroimaging Laboratory, in the statement.
While some researchers have found fMRI to be helpful, others have stated that the instrument does little to help increase knowledge on the brain and mind.
“Despite the many new methods and results derived from fMRI research, some have argued that fMRI has done very little to advance knowledge about cognition and, in particular, has done little to advance theories about cognitive processes,” noted Mara Mather, Nancy Kanwisher, and John Cacioppo in an article commentary.
Like editors Mather, Kanwisher, and Cacioppo, researchers Martha Farah and Cayce Hook argued in the paper that there is little evidence that supports the idea that fMRI data is “more persuasive than other types of data.”
The special section, which includes 12 articles, discusses whether fMRI results have had any impact on the study of the brain and human psychology. Some authors propose that fMRI has brought innovations to previous theories on the ageing mind. For example researchers Tor Wager and Lauren Atlas state that fMRI could also pave the way for a better method of evaluating pain. Other researchers discuss the role of fMRIs in cognitive operations and whether these operations are modular or distributed over a number of cognitive domains that are related to development of intellectual skills. Some researchers even wrote about the relationship between cognitive theories and fMRI.
Overall, even though fMRI images do provide some new perspective into cognition, there are some questions in which fMRIs have never been able to address.
“The best approach to answering questions about cognition,” concluded Mather, Cacioppo, and Kanwisher in the statement, “is a synergistic combination of behavioral and neuroimaging methods, richly complemented by the wide array of other methods in cognitive neuroscience.”