The brain and somatic integration: Insights into the standard biological rationale for equating "brain death'' with death

The mainstream rationale for equating "brain death'' (BD) with death is tha t the brain confers integrative unity upon the body, transforming it from a mere collection of organs and tissues to an "organism as a whole.'' In sup port of this conclusion, the impressive list of the brain's myriad integrat ive functions is often cited. Upon closer examination, and after operationa l definition of terms, however, one discovers that most integrative functio ns of the brain are actually not somatically integrating, and, conversely, most integrative functions of the body are not brain-mediated. With respect to organism-level vitality, the brain's role is more modulatory than const itutive, enhancing the quality and survival potential of a presupposedly li ving organism. Integrative unity of a complex organism is an inherently non localizable, holistic feature involving the mutual interaction among all th e parts, not a top-down coordination imposed by one part upon a passive mul tiplicity of other parts. Loss of somatic integrative unity is not a physio logically tenable rationale for equating BD with death of the organism as a whole.