In cryonics, we work very hard to use standard terminology rather than any jargon that needs explanation. Most of the terminology on this page is, therefore, used in the standard expected manner. The exceptions are in red.
Preservation of human brains or bodies at low temperature. Sometimes eroneously confused with the term "cryogenics".
Clinical Death: Cessation of circulation and breathing. A person who suffered a heart attack, and was then revived, was clinically dead for a few minutes.
Medical Death (aka Biological Death): An opinion by a physician, based on standards. The definition has changed drastically throughout history and continues to change. Currently based on either irreversible clinical death or brain death. It's actually a statement of prognosis, not a statement of condition. It's frequently an expression of the inability to revive by current medical technology.
Brain Death: Complete and irreversible loss of brain function. The definition is inconsistent, sometimes referring to the cerebrum and sometimes to the brainstem. Usually assessed by EEG as flat-line. A person who is "brain dead" may have a body that is fully alive, a well known fact that transplant surgeons take advantage of.
Legal Death: Government's official recognition of death by issuance of a death certificate. Usually requires a declaration of Medical Death by a doctor.
Cell Death: Different cells in the body die at different rates, even within the same tissue. Brain cells do not die after 5 minutes without oxygen. They actually remain alive for about 6 hours at body/room temperature , and much longer when cooled. This misconception arises because current medical technology has no way to halt the injury cascades and prevent those cells from eventually dying, many of them days later.
Biological life: Organisms with self-sustaining chemistry.
Human life: Existence of a mind or soul. The formation of a human life is gradual during development. The end of a human life is also frequently gradual, declining in old age and with disease.
Cellular life: Cells frequently outlive a dead organism by a few hours.
Viability: This refers to the ability of living cells to recover spontaneously. This could never happen in cryonics because viability is always lost long before the final cooling takes place. Cryonics should not be confused with Suspended Animation.
Dead vs. Alive: This is a frequently-encountered fallacy of false dichotomy. While we do use both of these words in the standard sense, we also recognize that reality is more complex and that there are more states than this; there are gray areas that these two words do not fully capture. Also, neither of these states is necessarily permanent. People have frequently been considered dead, only to later be revived.
We refer to a body or brain that we are trying to preserve as a patient. This is not done in an effort to mislead. We are not claiming that the patient is alive or undergoing medical care. We use this word because it has utility and because, after decades, we have still not found any other word that works better. It correctly emphasizes that we are still actively engaged in preservation.
Merriam-Webster definition 1: head. This is a valid, if somewhat obscure, definition. It is a respectful dispassionate clinical term for an isolated head. Sometimes, the short version, ceph, is used.
Similar to the expected typical definition, but with some very important caveats. First of all, "revival" is unlikely to biological. From an engineering standpoint, it should be far easier to reconstruct the extracted memories on some sort of computer instead of rebuilding a biological brain. Secondly, "revival" is unlikely to be 100%. If it's only a 60% revival, with 40% amnesia or brain damage, then the word doesn't seem to be as appropriate. We prefer, when possible, to instead use words such as:
We avoid certain terms that are pejorative or that imply inaccurate scientific details:
Suspension: We instead use variations of "preservation", because suspension implies suspended animation and also has additional meanings such as hanging and disciplinary action.
Corpse, cadaver: These words are pejorative in the context of memory preservation. Body is more accurate. If corpse or cadaver are used in a news article, it's immediately clear that the writer is hostile toward cryonics for some reason.
Resurrection: A completely inappropriate religious term.
Severed head: This is a somewhat inflammatory term that is frequently used in the media for shock value. The word "severed" improperly implies violence, while there are other perfectly good adjectives available such as isolated, detached, and separated.
1: Garcia JH, Liu KF, Ho KL. Neuronal Necrosis After Middle Cerebral Artery Occlusion in Wistar Rats Progresses at Different Time Intervals in the Caudoputamen and the Cortex. Stroke. 1995 Apr;26(4):636-43. PubMed PMID: 7709411. Stroke
2: Verwer RW, Hermens WT et al. Cells in human postmortem brain tissue slices remain alive for several weeks in culture. The FASEB Journal. 2002 Jan;16(1):54-60. PubMed PMID: 7709411.
3. Viel JJ, McManus DQ, et al. Temperature and time interval for culture of postmortem neurons from adult rat cortex. Journal of Neuroscience Research. 2001 Apr;54(4):311-321. Pubmed PMID: 11340637. JNR