"Schizophrenic Grice": Allyssa McCabe notes that some individuals with schizophrenia have difficulty intepreting utterances that violate Grice's conversational maxims -- as did Grice! (He was just joking with Kant when he mentioned Kant in the first place -- he had never mentioned Kant in his earlier lectures on implicature at Oxford!)

Speranza

Allyssa McCabe, ‎Chien-ju Chang - 2013 

Characteristics of schizophrenic speech Schizophrenic language disturbances involve dysfunctions in almost all levels of ... Some individuals with schizophrenia had difficulties interpreting sentences that violated Grice's maxims