Neuroscientists at Duke University have mapped the timing and sequence of neural activations that unfold in the brain when people focus their attention on specific locations in their visual fields.
The findings may point the way for clinicians to address attention-related problems, said study team member Marty Woldorff, associate director of the Center for Cognitive Neuroscience and an associate professor in psychiatry.
“There are a number of clinical syndromes where attention is dysfunctional, including schizophrenia, autism and attention deficit-hyperactivity disorder,” Woldorff said. “Moreover, attentional capabilities change during normal and abnormal aging.”
The findings appear in the January 2007 issue of the journal Public Library of Science (PLoS) Biology. The research was supported by the National Institute of Mental Health and the National Institute of Neurological Diseases and Stroke.
In this study, the researchers combined information from two different technologies for measuring brain activity in order to provide insight into the basic mechanisms by which humans orient and focus their visual spatial attention.
“At every moment of our lives, we are deluged with sensory stimuli coming from multiple directions,” Woldorff and study co-investigator Tineke Grent-‘t-Jong wrote in the journal report. Grent-‘t-Jong is a research associate at Duke’s Center for Cognitive Neuroscience and a graduate student in psychopharmacology at the University of Utrecht in the Netherlands.
This sensory deluge encompasses “much more information than we can fully process,” they said. “The critical function of attention allows us at each moment to continuously select and extract the most important information from this flood of sensory inputs.”
An example of the kind of focused visual attention the researchers investigated is what happens as a motorist watches traffic in front of his car while also monitoring out of the corner of his eye the movement of a bicyclist pedaling on the side of the road. This example is illustrated on Woldorff’s laboratory website at http://www.mind.duke.edu/faculty/woldorff/.
“When we direct our attention to such specific locations or events — in this case, the bicyclist off to the side — we tend to more quickly discriminate or detect changes there than at other locations in our visual field that are not so attended,” Woldorff said.