In an article published in the February 18, 2010 edition of The New England Journal of Medicine, Martin Monti et al. reported that functional MRI scanning may detect awareness and cognition in some patients with severe brain injuries who have no other evidence of sustained, reproducible, purposeful, or voluntary behavioral responses to visual, auditory, tactile, or noxious stimuli. Thus, a small proportion of such patients who have severe brain damage and who appear to be unconscious or only minimally conscious (with wakefulness but without awareness) may actually have some level of awareness as detected on functional MRI scanning, and may in fact be able to communicate by willfully modulating their brain activity.1
In an editorial in the same edition of the NEJM, Allan H. Ropper noted that "The unfortunate term 'vegetative' has been used to describe patients whose eyes open after a period of coma but who lack any meaningful responses to stimuli. Open eyes give the impression of normal alertness, but the patient's behavioral repertoire is limited to reflexive actions such as posturing or purposeless movements, roving eye movements, swallowing, and yawning."2
The term "persistent vegetative state" (PVS) has been used to refer to prolonged states of unconsciousness (due to traumatic or non-traumatic brain injuries, degenerative or metabolic brain disorders, or severe congenital malformations of the nervous system) in which the patient is completely unaware of self and of the environment but has sleep-wake cycles, with preservation of hypothalamic and brainstem autonomic functions. Such patients "show no evidence of sustained, reproducible, purposeful or voluntary behavioral responses to visual, auditory, tactile, or noxious stimuli; show no evidence of language comprehension or expression; have bowel and bladder incontinence; and have variably preserved cranial nerve and spinal reflexes."3 They may be able to exhibit such behaviors as blinking, swallowing, groaning, grimacing, breathing spontaneously, and reflex posturing of the limbs, but they are unable to eat, drink, talk, or make purposeful limb movements. As a result of being permanently confined to bed or chair, they also tend to develop such complications as muscle wasting, limb and joint contractures, skin breakdown, pressure sores, recurrent urinary tract infections, and pneumonia.4
However, the term "vegetative" has pejorative connotations, and implies that the patient who is in this state of unconsciousness is merely vegetating or is merely a vegetable. The term diminishes the personhood of the person who is in this condition.
The study by Monti et al. in the Feb. 18, 2010 edition of the NEJM demonstrates that a small proportion of patients who have been previously diagnosed as having entered a "persistent vegetative state" may actually have some awareness and cognition. They may be able to respond to auditory stimuli, and they may be able to voluntarily modify their brain activity in order to perform simple communicational tasks.
Are individuals with depressed levels of consciousness who are minimally aware of their environment but unable to make any behavioral responses able to retain their moral agency? Are individuals who are fully aware of their environment but unable to make any behavioral responses (such as completely paralyzed individuals, or individuals with the "locked-in syndrome," as originally described by Plum and Posner in 1966)5 able to retain their moral agency? Such individuals obviously retain their personhood, but can they still function as moral agents? Are they still responsible for whatever thoughts and feelings they may have?
What are the criteria for moral agency? Moral agency is a contributor to, but not a requirement for, personhood, since some persons (such as small children and the mentally impaired or handicapped) may not have sufficient voluntary control over their actions to be held morally responsible for them. The proper definition of personhood is quite controversial, since legal recognition of personhood conveys various rights and responsibilities upon any being who is legally considered to be a person. Thus, the politics of personhood has complicated the development of consensus regarding such issues as the nature of reproductive health rights, the legitimacy of end-of-life decision making, the nature of corporate personhood, and the nature of animal rights.
Any attempt to establish a definite set of criteria for personhood may be problematic, insofar as any such set of criteria may not be sufficiently inclusive. Every human being is a person. Whether non-humans can also be considered persons is a matter that has been much discussed elsewhere (e.g. Peter Singer, Practical Ethics, 1993; Sarah Chan and John Harris, "Human Animals and Nonhuman Persons," in The Oxford Handbook of Animal Ethics, ed. by Tom L. Beauchamp and R.G. Frey, 2011). Every person has a personality, i.e. a set of physical, cognitive, perceptual, mental, emotional, and social traits or characteristics that define him/her as a distinct individual. The identity of each person is also defined by his/her relations with other persons.
Agency may be defined as the state of acting or of having the capacity to act (independently or in cooperation with other agents). An agent may be defined as an individual or collective entity that acts or is capable of acting. An agent may act autonomously or in cooperation with other agents--in, upon, through, because of, by means of, for the purpose of, or in behalf of some other agent or entity.
Moral agency may be defined as the state of acting or of having the capacity to act, such that the agent is in a position to be held morally responsible for their actions. In order to be held fully responsible for their actions, an agent must have sufficient autonomy (or freedom of choice) to be held fully responsible for their actions, their actions must be voluntary and under their own control, and the actions must be intentional.
There may be many kinds of agency, including physical, moral, human, non-human, rational, legal, and professional agency. Physical agents include biological, chemical, environmental, radiologic, and thermal agents. Legal agents include law enforcement officers, attorneys, legal guardians, legal representatives, executors, contractors, brokers, and lobbyists. Business and professional agents include literary, theatrical, sports, travel, insurance, booking, sales, and real estate agents.
Agents acting jointly or collectively may share a moral responsibility for their joint or collective actions. The nature of the responsibility of each agent for a joint or collective action may depend on whether each agent is a willing participant in the action, whether each agent is aware of the possible consequences of the action, and whether each agent has the ability to promote, prevent, or modify the expected or actual outcome of the action.
1Martin M. Monti, et al. "Willful Modulation of Brain Activity in Disorders of Consciousness." N Eng J Med; 362: 579-589, Feb. 18, 2010.
2Allan H. Ropper. "Cogito Ergo Sum by MRI." N Engl J Med; 362: 648-649, Feb. 18, 2010.
3The Multi-Society Task Force on PVS. "Medical Aspects of the Persistent Vegetative State." N Engl J Med; 330: 1499-1508, May 26, 1994.
4American Hospice Foundation. "Coma and Persistent Vegetative State: An Exploration of Terms." 2005, at http://www.americanhospice.org/articles-mainmenu-8/caregiving-mainmenu-10/50-coma-and-persistent-vegetative-state-an-exploration-of-terms.
5Fred Plum and Jerome B. Posner. The Diagnosis of Stupor and Coma. Philadelphia: F.A. Davis and Company, 1966.