Anhedonic

"[P]hysical anhedonics may not pay attention to tone stimuli (and therefore do not give SC [skin conductance] responses) because such subjects are identified on the basis of lacking pleasure and interest in physical events. As such, nonresponding in physical anhedonics may indicate validity for the way physical anhedonia is measured, but may not reflect a factor of etiologic significance."

"Briefly, the anhedonic syndrome is manifested, first, by the disappearance or impairment of the appetite for food and drink and by failure to experience the corresponding satisfactions. [...] Thirdly, the appetite or desire for rest and the satisfaction of recuperation are also involved in the anhedonic syndrome."