For the purposes of section 2, a person is unable to make a decision for himself if he is unable—
to understand the information relevant to the decision,
to retain that information,
to use or weigh that information as part of the process of making the decision, or
to communicate his decision (whether by talking, using sign language or any other means).
A person is not to be regarded as unable to understand the information relevant to a decision if he is able to understand an explanation of it given to him in a way that is appropriate to his circumstances (using simple language, visual aids or any other means).
The fact that a person is able to retain the information relevant to a decision for a short period only does not prevent him from being regarded as able to make the decision.
The information relevant to a decision includes information about the reasonably foreseeable consequences of—
deciding one way or another, or
failing to make the decision.