He contacted Steven Laureys, a member of the Coma Science Group at the University Hospital of Liège in Belgium, to explore how the pupil could be used to communicate a choice.
Analyses were restricted to patients who were fully communicating a choice (maximum scores on the ability to express a choice scale of the MacCAT-T).
The concept of 'decision-making capacity' refers to a person's ability to understand, retain and balance information, and communicate a choice [ 1].
Decision-making capacity was seen as dependent on understanding, insight, evaluation, reasoning, and abilities related to making and communicating a choice.
Since it has been demonstrated that neuroimaging can be used to communicate a choice, we will focus our analysis on the remaining elements.
Legal competence in health care requires being able to communicate a choice, understanding information one is given, appreciation of one's circumstances and mental capacities to reason and deliberate [ 3, 4].
The physician thus has to make sure that the patient has the ability to understand the relevant information, to grasp the medical consequences of the situation, to weigh up different treatment options and to communicate a choice [ 1].
Hence, ability to understand information and insight into one's illness, along with ability to reason and ability to communicate a choice were held as key criteria and often mentioned in relation to clinical cases.
In adults, the generally accepted reference standard for competence assessment by clinicians revolves around four relevant criteria: to communicate a choice, to understand the relevant information, to appreciate the medical consequences of the situation, and to reason about treatment choices [ 2].
This was done because we did not want to include participants where the nature of DMC is clearly different between medical and psychiatric patients (for example inability to communicate a choice because of impaired consciousness) or where interpretation of DMC is difficult (for example ambivalence).
