Schizophrenia Research Trends

Schizophrenia: A Cognitive Science Viewpoint 79posturing), and fixing postures that resist to attempts to modify them (catatonic rigidity).Negative SymptomsThere are mainly three negative symptoms: affective flattening, alogia and avolition.Affective flattening is visible through the patient’s face remaining immobile andunresponsive. Patients tell that they feel pleasant or uncomfortable experiences, but thisdoes not appear in their voice tones or corporal expression. In other words, they lose thecapacity to communicate their emotions. Alogia is manifest by evasive, laconic or emptyreplies even to precise questions. Avolition corresponds to the loss of initiation in goaldirectedactivities. Apathy has also been evoked, but its meaning is rather similar to that ofavolition, and it is used in the description of other severe mental diseases.Criteria for DiagnosisAt least two symptoms are required for the diagnosis of an “active phase” ofschizophrenia. The first active phase occurs mostly in late adolescence or early adulthood.It happens statistically earlier in men (17-25 years old) than in women (25-30 years old). Itis preceded by prodromes, correctly interpreted only retrospectively, once the diagnosis hasbecome obvious. Long before the onset of the first active phase, along childhood, there areminor motor skill alterations [48]. Just before active phases, patients express a variety ofodd beliefs and unusual perceptual experiences. Their scholar performances decreaseprogressively. They tend to withdraw from social interaction and express their affects lessthan other persons. In other words, they “gradually slip away”. Another point of interest istheir tendency to become drug addicts, which raises the question of the contribution of theaddiction to the disease, or its relation with the disease (self-medication theory). Mostpatients are heavy smokers and they drink huge amounts of coffee (search of psychostimulantdrugs). The active phase lasts over one month (this duration criterion has nowbeen challenged by an efficient treatment). Such an active phase tends to recur and,between recurrences, some behavioral disturbances persist. This phase is sometimesreported as stabilized phase of schizophrenia. In this report of the time course of thedisease, loss of social interaction has been mentioned. It is, per se, a diagnosis criterion.Rather than a mere consequence of negative symptoms, it is now believed to be the resultfrom the loss of some specific cognitive functions that will be considered in a specificsection.