Hyperfrontality of regional cerebral blood flow distribution in normals during resting wakefulness: fact or artifact?

Earlier studies with two-dimensional measurement techniques consistently found higher frontal flow in normal subjects during resting wakefulness. However, this finding could not be confirmed by several laboratories with the more modern and technologically more sophisticated three-dimensional measurement techniques. This discrepancy can have strong implications for psychiatric research in which both types of techniques are frequently used. This article reviews the existing literature, discusses possible reasons for the discrepancy, and evaluates evidence from other sources on the activity of the frontal lobe during wakefulness.