Other neuroscientists previously have implicated the cingulate in a variety of specialized cognitive tasks, Dosenbach notes, but the new analysis may change their thinking.
"It's a question of whether the cingulate has specific contributions to make in all these tasks, or whether it plays such a very basic role that its participation is almost always required," he explains.
The researchers' theories are reinforced by akinetic mutism, a condition that occurs in patients who suffer a lesion from stroke or surgery that includes the cingulate. To varying degrees, such patients are minimally active.
"If you give them a cup of coffee, they'll drink it, but they'd never ask for a cup of coffee," Petersen explains. "If you ask them how they are, they'll tell you, 'I'm fine,' but they won't tell you a story."
"They seem to have problems voluntarily entering a task state," Dosenbach says. "They can do tasks with very explicit instructions, but are much less proficient at what's called random generation tasks, such as coming up with random words. So there is some other evidence that the cingulate really is an important contributor to task sets."
The analysis was based on data from eight separate functional brain imaging studies conducted over the course of five years. According to Petersen, the volume of data provided by the different studies was essential to making sure that the areas highlighted in the analysis were contributing at a very basic level, rather than at the specialized level of a particular task.
"Some neuroscientists were certain what we should have found with this analysis, and t
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Contact: Michael C. Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
31-May-2006