Minimal p-morphic Images, Axiomatizations and Coverings in the Modal Logic K4

We define the concepts of minimal p-morphic image and basic p-morphism for transitive Kripke frames. These concepts are used to determine effectively the least number of variables necessary to axiomatize a tabular extension of K4, and to describe the covers and co-covers of such a logic in the lattice of the extensions of K4.     

Th.o.m.a.s.: an exploratory assessment of Theory of Mind in schizophrenic subjects

A large body of literature agrees that persons with schizophrenia suffer from a Theory of Mind (ToM) deficit. However, most empirical studies have focused on third-person, egocentric ToM, underestimating other facets of this complex cognitive skill. Aim of this research is to examine the ToM of schizophrenic persons considering its various aspects (first- vs. second-order, first- vs. third-person, egocentric vs. allocentric, beliefs vs. desires vs. positive emotions vs. negative emotions and how each of these mental state types may be dealt with), to determine whether some components are more impaired than others. We developed a Theory of Mind Assessment Scale (Th.o.m.a.s.) and administered it to 22 persons with a DSM-IV diagnosis of schizophrenia and a matching control group. Th.o.m.a.s. is a semi-structured interview which allows a multi-component measurement of ToM. Both groups were also administered a few existing ToM tasks and the schizophrenic subjects were administered the Positive and Negative Symptoms Scale and the WAIS-R. The schizophrenic persons performed worse than control at all the ToM measurements; however, these deficits appeared to be differently distributed among different components of ToM. Our conclusion is that ToM deficits are not unitary in schizophrenia, which also testifies to the importance of a complete and articulated investigation of ToM.