A baseline or control state is fundamental to the understanding of most complex systems.
Defining a baseline state in the human brain, arguably our most complex system, poses a�…

The concept of a default mode of brain function arose out of a focused need to explain the
appearance of activity decreases in functional neuroimaging data when the control state�…

At the forefront of cognitive neuroscience research in normal humans are the new
techniques of functional brain imaging: positron emission tomography and magnetic�…

Functional magnetic resonance imaging typically measures signal increases arising from
changes in the transverse relaxation rate over small regions of the brain and associates�…

Remarkably, despite its relatively small size, the brain accounts for about 20% of the oxygen
and, hence, calories consumed by the body (1). This high rate of metabolism is remarkably�…

Introduction 2883. Relationship between neuroenergetics and neurotransmitter flux 2944. A
model of coupling between neuroenergetics and neurotransmission 2965. Relationship�…

Oxygen is essential to maintaining normal brain function. A large body of evidence suggests
that the partial pressure of oxygen (p O 2) in brain tissue is physiologically maintained within�…

Functional brain imaging with positron emission tomography and magnetic resonance
imaging has been used extensively to map regional changes in brain activity. The signal�…

Neuroimaging techniques, such as positron emission tomography and functional magnetic
resonance imaging are essential tools for the analysis of organized neural systems in�…

Over the last 30 years the development of new and exciting techniques has enabled us to
observe the localization of function in the human brain and to discover how the working�…