The Anatomy of Informed Consent

March 1, 2005

Applied Clinical Trials

Applied Clinical Trials, Applied Clinical Trials-03-01-2005,

Informed consent takes place in the brain. While that seems obvious, the implications of that statement go much deeper. To a great extent, both bioethics and federal policy are based on 17th century assumptions by philosophers such as Descartes-who knew nothing of the structure and function of the brain.

Informed consent takes place in the brain. While that seems obvious, the implications of that statement go much deeper. To a great extent, both bioethics and federal policy are based on 17th century assumptions by philosophers such as Descartes—who knew nothing of the structure and function of the brain.

The gut "feeling" that prospective subjects have about entering a clinical trial may not be so much a metaphor as a biological reality. Mark Hochhauser, PhD, IRB member, North Memorial Health Care

In his 1994 book Descartes' Error: Emotion, Reasoning and the Human Brain, neurologist Antonio Damasio argues that reasoning is not merely an abstract philosophical concept, but primarily a biological function of the brain. Despite Descartes' widely accepted separation of mind and body—with its implications for the superiority of reason over emotion—Damasio uses data from brain-damaged patients to show how and why Descartes' mind-body separation is wrong.

Emotion and reason in the brain

Emotion and reason exist in specific parts of the brain. The top cortical layer is involved with rational thinking and planning, while the deeper subcortical central area (the limbic system) is involved with emotions and their corresponding feelings. Philosophers may separate emotion from reason, but the brain does not.

Often implied in the emotional-rationality division is the assumption that emotion disrupts reasoning. But Damasio found that patients unable to experience emotion often exhibited irrational behavior—not more rational behavior. Recently, I was asked if I could suggest ways of removing emotion from the informed consent process. I replied that taking emotion out of the consent process could not be done. Even if emotion could be removed, its removal would not guarantee better (more rational) decisions by prospective subjects. In fact, without emotions, subjects would find it harder to make an "informed" decision since they would not have emotions or their associated feelings to guide them.

Emotions, feelings, and reason

In his 2003 book

Looking for Spinoza

, Damasio described emotions as public bodily behaviors that can be seen by other people, and feelings as private, more hidden reactions to those emotions. Based on the brain's evolution, he concluded that emotional reactions occur first, feeling those emotions second, and thinking about those emotions and feelings last. Emotions and reason are not separate, but integrated functions within the human brain. From this perspective, the consent process is first one of basic emotions—anger, fear, disgust, contempt, happiness, sadness, and surprise. Although psychologist Paul Ekman has found that such emotions can be seen in a prospective subject's facial expressions if one knows what to look for, subjects cannot always translate their emotions and feelings to into meaningful conversations with researchers.

Because prospective subjects might be afraid of a clinical trial, or disgusted by aspects of the consent process, or feel contempt (because of the Tuskegee Syphilis Experiment, for example), they will have emotions and the associated feelings that accompany them, but may be unable to put those emotions and feelings into words. While their decision to take part or refuse to take part in a clinical trial may actually be based on emotions, their rational explanation for their decision may make little reference to their emotions and feelings. Because we don't have a very good emotional vocabulary, what people feel and what people say isn't always the same.

Plus, since the brain is connected to other parts of the body via the sympathetic and parasympathetic nervous systems, hormones and peptides, the "gut feeling" that prospective subjects have about clinical trials may not be so much a metaphor as a biological reality. The unique features of each clinical trial, when combined with individual biology and experiences, means that the consent process may be felt in the body as well as analyzed in the mind.

Mark Hochhauser, PhD, IRB member, North Memorial Health Care.