(1) Subject to subsections (2) to (6), for the purposes of this Act, a person's capacity shall be assessed on the basis of his or her ability to understand, at the time that a decision is to be made, the nature and consequences of the decision to be made by him or her in the context of the available choices at that time.

(2) A person lacks the capacity to make a decision if he or she is unable -

(a) to understand the information relevant to the decision,

(b) to retain that information long enough to make a voluntary choice,

(c) to use or weigh that information as part of the process of making the decision, or

(d) to communicate his or her decision (whether by talking, writing, using sign language, assistive technology, or any other means) or, if the implementation of the decision requires the act of a third party, to communicate by any means with that third party.

(3) A person is not to be regarded as unable to understand the information relevant to a decision if he or she is able to understand an explanation of it given to him or her in a way that is appropriate to his or her circumstances (whether using clear language, visual aids or any other means).

(4) The fact that a person is able to retain the information relevant to a decision for a short period only does not prevent him or her from being regarded as having the capacity to make the decision.