Getting a read on the brain.

Although scientists have long posited that only a few areas of the brain orchestrate human language abilities, brain-imaging studies increasingly challenge that position. A team of researchers reports in the September Journal OF Cognitive Neuroscience for instance, that reading sentences galvanizes several relatively small neural regions in patterns that vary to a surprising extent from one person to another.

Native English speakers reading English sentences, as opposed to strings of consonants, display heightened activity in three regions of the brain's left hemisphere traditionally associated with language--Broca's area, Wernicke's area, and the angular gyrus--assert Daphne Bavelier of Georgetown University in Washington, D.C., and her colleagues. Sentence reading also sparks surges of oxygenated blood--a sign of increased neural exertion-at the top of the temporal lobe (on both sides of the brain) and in part of the prefrontal cortex in the left hemisphere.

Eight adult volunteers who underwent functional magnetic resonance imaging as they read both sentences and consonant strings exhibited large individual differences in the precise location of elevated activity in these regions.

Some temporal lobe areas activated by sentence reading may help to discern grammatical meaning, Bavelier and her colleagues theorize.