The new study, to be detailed in an upcoming issue of the journal American Journal of Geriatric Psychiatry, looked at the brain activity of 24 neurologically normal volunteers between the ages of 55 and 76 as they searched the Internet. Half of the participants had experience surfing the Web, while the others did not.
The researchers used functional magnetic resonance imaging (fMRI) scans to record subtle brain-circuitry changes in the patients as they performed Web searches and read book passages. fMRI scans track the intensity of cell responses in the brain by measuring the level of blood flow through the brain.
All the study participants showed significant brain activity during the book-reading task, specifically in the temporal, parietal and occipital lobes of the brain, which are involved in controlling language, reading, memory and visual abilities.
But Internet searches revealed differences between the two groups. While all the participants showed the same activity as during the book-reading, the Web-savvy group also registered activity in the frontal, temporal and cingulate areas of the brain, whereas those new to the net did not. (These areas of the brain control decision-making and complex reasoning.)
"Our most striking finding was that Internet searching appears to engage a greater extent of neural circuitry that is not activated during reading - but only in those with prior Internet experience," said study leader Gary Small of the Semel Institute for Neuroscience and Human Behavior at UCLA.