I think this is the sensate Subject that I recall Carmel Cloran talking about. So to summarise (and add):
- Is the Doer a sensate being?
- Does it seem like a mental (or verbal) process but can't project eg speak and listen
- Is it a process of physiological or psychological behaviour (both conscious and unconscious) eg cough, sneeze etc (but not think Mick – isn't think mental, cos can project)
This exemplifies the widespread and persistent error of classifying verbs in terms of process types. The same verb can serve as different process types, because the Process is a function of the clause. For example, the verb breathe can serve as Process in a behavioural clause, as in she breathed a sigh of relief, where the Range of the clause, a sigh of relief, is a Behaviour, and it can serve as Process in a material clause, as in they breathe oxygen, where the Range of the clause, oxygen, is not a Behaviour, but the Scope of the breathing process. See related analyses here.