Assumption: mental disorders including schizophrenia are caused by “faulty” thinking.
We are normally able to filter incoming stimuli and process them to extract meaning it is thought that these filtering mechanisms and processing systems are defective in the brains of schizophrenics
Cognitive theorists assume that these cognitive deficits are due to underlying physiological abnormalities
Frith distinguishes between conscious and preconscious processing.
Conscious processing is where the highest level of cognitive functioning takes place, we are aware of this level. This has a limited capacity so we can only carry out one task at a time.
The preconscious processing takes place without our awareness, this an automatic process and we can carry out many tasks at any one time
Usually only important information arrives into conscious awareness, in schizophrenics, Frith proposes that the attentional filter breaks down and the unimportant information also gets in the conscious so it is seen as something important which needs to be acted upon.
Frith believes that it is how delusions happen
Frith explains auditory hallucinations in a similar way.
We are bombarded with sounds constantly and preconscious mechanisms interpret these sounds and only the significant sound reach the conscious level of processing. If the conscious/preconscious filter is defective, it is possible that we misinterpret non-speech sounds as speech and experience them as voices.
Meyer-Lynderberg et al. (2000) found a link between excess level of dopamine in the prefrontal cortex and dysfunctions of the working memory. Working memory dysfunction is associated with cognitive disorganisation typical of schizophrenics. This supports the idea that underlying biological factors are involved in schizophrenia.
The models cannot explain why the voices heard are so negative and abusive or suggest reprehensible acts.
The cognitive approach explains mainly positive symptoms.
Bentall et al. (1991) found that Szs struggled to identify words belonging to a certain category, such as birds, that they had seen before, created themselves or had not seen before , supporting Frith’s theory that people with Sz had metarepresentation problems.
It could explain why delusions are often influenced by cultural factors i.e. a French schizophrenic might think he is Napoleon whereas a British one might think he is Nelson.
It is reductionist because despite the fact that it takes into account physiological factors, it does not take into account the influence of early childhood conflicts (psychodynamic explanation) or social factors such as stress or urbanicity
It has given rise to CBT which seems to improve the outcome for many schizophrenics (see therapy) and has no side-effects.