[Perturbed consciousness in schizophrenia: an evaluation of C.D. Frith's model]

While many neurocognitive models of schizophrenia coexist, a lot of attention has been centered on C.D. Frith's model over the past few years, especially in regard to its parsimony.

The aim of this paper is to examine its validity. The model relies on the assumption that there are two main components: self-monitoring and monitoring. The first permits one to keep consciousness of personal goals and intentions with metarepresentations. Losing consciousness of personal goals would be the source of schizophrenics' avolition and losing consciousness of personal intentions would generate reference ideas. The second component refers to the so-called "theory of mind", which is the monitoring of others' mental content (knowledge and intentions). Disturbing monitoring would cause schizophrenics persecution disillusions, third order persecutions or speech content disorders.

After reviewing the empirical and theoretical bases of Frith's model, strengths and weaknesses are highlighted, in particular by contrasting Hardy-Baylé's and Abu-Akel's theoretical proposals. For explaining the monitoring impairments of schizophrenics, Hardy-Baylé's model emphasizes the executive functioning defect, while Abu-Akel's model proposes a "hyper theory of mind" where too many hypotheses would lead to misattributions. In addition, several criticisms of Frith's model are examined, particularly those voiced by phenomenologists who underline its reductionism presupposition and argue that the underlying cognitive conception of the "theory of mind" neglects the fundamental intersubjectivity issue. In addition, Gallagher points out that monitoring is a tautological concept and that intention is not like thinking inherent to behaviour.

Frith's model validity is finally discussed at large in the light of these criticisms and competing models, and it is concluded that the self-monitoring part of the model needs to be redefined and that the measurement of the "theory of mind" has to be standardized.