Cognitive explanations, including dysfunctional thought processing.

A01 THEORY: BREAKDOWN OF PERPETUAL FILTERING

Many different cognitive explanations for the development of schizophrenia have been put forward. However, they all assume that the various cognitive impairments shown by people with schizophrenia, e.g., poor memory control, language deficits, and disorganised thinking, play an important role in the development and maintenance of schizophrenia.

As profound thought disturbances characterise schizophrenia, cognitive psychologists suggest that disturbed thinking processes are the cause rather than the consequence of schizophrenia. Schizophrenics have difficulty concentrating, impaired ability to sort relevant from irrelevant stimuli and to maintain order in the association of thoughts, and a marked reduction in problem-solving and decision-making ability. As a result, most research has concentrated on the role of attention in schizophrenia. It is thought that the mechanisms that operate in neurotypical brains to filter and process income stimuli are somehow defective in the brains of schizophrenics.

Schizophrenics, by contrast, are unable to screen out distractions or to discriminate between relevant and irrelevant input. They are highly sensitive to stimuli of all kinds- from both internal and external sources- and cannot integrate their perceptions into a meaningful pattern, in other words, they can’t sustain focus, filter, or prioritise incoming and outgoing information. This leads to overwhelming and unintegrated ideas and sensations, affecting their concentration. As a result, schizophrenics are distracted by anything and everything. In turn, this is reflected in their language and their behaviour. For the schizophrenic, then, their brain’s filtering system is effectively broken.

A01 RESEARCH BREAKDOWN OF PERPETUAL FILTERING

• Research shows that schizophrenics were worse at laboratory tasks that required them to pay attention to some stimuli but not others.

A03 RESEARCH ANALYSIS: BREAKDOWN OF PERPETUAL FILTERING

• Cognitive theories of attention and perception are well-established and backed by scientific research.

• There is evidence contradicting the breakdown of the filtering explanation. Studies of brain-damaged patients have shown that they often experience similar cognitive deficits to schizophrenics, such as problems with attention or with the relationship between memory and perception—for example, H.M. and the patients studied by Schmolck et al.. However, although these patients have cognitive deficits, they don't show the symptoms of schizophrenia. This challenges the cognitive explanation. This means that the cognitive explanation alone is unlikely to be valid as if it was these brain-damaged patients would develop schizophrenic symptoms. Therefore, other factors, such as biochemistry, must play a role in the cause of schizophrenia.

• The faulty attention system and self-monitoring explanation account for the positive symptoms of schizophrenia but not the negative symptoms.

FRITHS’S THEORY A01

Frith (1992) suggested that the theory of mind (ToM) in schizophrenia patients is compromised because of their failure to monitor their own and other people's mental states and behaviour, which may account for many positive and negative symptoms in schizophrenic disorders.

A03 RESEARCH ANALYSIS FRITHS’S THEORY

There is evidence to support the Frith’s explanation. For example, Drury, Robinson and Birchwood showed that schizophrenics experience difficulties interpreting the beliefs and intentions of others. This adds weight to Frith’s theory that schizophrenics suffer deficits in meta-representation and ToM.

• There are alternative interpretations of Drury, Robinsons and Birchwood’s findings; poor performance of schizophrenics may not have been due to a lack of Theory of Mind but due to information processing overload in dealing with the complex nature of the task. This suggests that schizophrenia is not due to problems with meta-representation, as Frith suggested, but due to difficulty filtering information and attending to relevant information, as suggested by Frith.

FRISTON’S THEORY A01

Since cognitive processes strongly influence emotions it is not surprising that distortions in affective responses and language accompany the disorganisation of thought. In the case of auditory hallucinations, Friston hypothesised that in normal people, thoughts progress via internal language into a form in which they can be articulated and, if desired, spoken. This progression of thought to speech involves a feedback loop which warns us that the inner speech is our own. In auditory hallucinations, the feedback loop is broken. Friston believes causes Schizophrenics to talk to themselves and not realise it.

Friston proposes that key processes in the brains of schizophrenics are not working in unison, and as a result, their perceptions, thoughts and language are fragmented and random. Thus, sensations are felt but not identified as from the self. For example, most of us recognise our inner voice as our consciousness, but with the schizophrenic, the internal voice has disconnected from self-awareness. The world of the schizophrenic is, therefore, bewildering; this explains paranoid schizophrenia, where the person believes he/she hears voices in his/her head. As our culture designates supernatural experiences to a God this could explain why many schizophrenics have deep connections to religions.

Friston believes there is a breakdown in dialogue between the frontal regions of the brain (which deal with our intentions) and the temporal lobes (which are responsible for language processing and registering the consequences of our actions. This fails to integrate our behaviours in the world with our perception of the consequences of those behaviours.

A01: RESEARCH FRISTON’S THEORY

• There is evidence to support Friston’s explanation. For example, McGuigan (1966) showed that schizophrenics mistook their inner speech for that of someone else, showing Hemsley’s theory of poor integration of memory and perception could be valid.

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  Much of the research into cognitive explanations is scientific and replicable. For example, McGuigan (1966) found that the vocal cords of patients with schizophrenia were tense during the time they experienced auditory hallucinations. This suggests that they were mistaking their inner speech for someone else's voice.

A03: GENERAL ANALYSIS AND EVALUATION OF THE COGNITIVE APPROACH

Unlike many of the other psychological explanations, cognitive explanations account for both the positive and negative symptoms of schizophrenia; this is a strength of the approach.

Cognitive explanations explain how seemingly unconnected symptoms might be due to underlying problems in particular cognitive systems. This gives a more thorough understanding of why certain behaviours in schizophrenia occur. By comparison, Freudian theories are less logical, scientific and more controversial.

Cognitive psychologists suggest that disturbed thinking processes are the cause rather than the consequence of schizophrenia; however, although the cognitive explanation describes the cognitive deficits of schizophrenia in great detail, by itself isn't a complete explanation as it never attempts to expand on the cause. So, it is unclear whether cognitive dysfunction is a cause or effect of the disorder. Or why some people have certain problems but others don't. This is another case of building a theory based on a correlation between thought processes and symptoms. But correlations do not prove cause, a similar criticism applies to the dopamine Hypothesis.

On the other hand, the cognitive explanation explains deficiencies in the dopamine hypothesis. For example, pharmacologists notice that even if dopamine levels are corrected by using drugs, it still takes days or weeks for positive symptoms to fade. This could be because faulty self-monitoring and poor attention are a "bad habit" even when dopamine is normal.

Other factors that influence the development of schizophrenia that don't have anything to do with cognitive deficits, such as genetic factors, stressful life events, and poverty, play a part in the disorder. Still, it's not clear how these link to cognitions. However, cognitive explanations aren't offered as an alternative to biological explanations of schizophrenia. The two types of explanations are complementary- they work together. For example, Frith (1992) found that cognitive deficits are linked to abnormalities in areas of the brain that use dopamine, especially the prefrontal cortex. He showed that people with schizophrenia have reduced blood flow to these areas (indicating reduced brain activity) during certain cognitive tasks. Since the prefrontal cortex handles attention and self-monitoring, this evidence supports biological AND cognitive explanations.

The appeal of cognitive therapy is that it can be used by patients who want to reduce or refuse antipsychotic medication. Morrison et al. (2014) found that drop-out rates for cognitive therapy were lower than for drug therapy. Cognitive therapy was just as effective at reducing the symptoms of psychosis.

The cognitive explanation is often used by people who advocate the Recovery Model. This perspective encourages people who hear voices not to think of themselves as "sick" and silence their troubling thoughts with drugs but instead to understand the voices better and learn coping strategies to live with them. An example of this is the "Hearing Voices Movement" supported by Eleanor Longden (see the TED video):