(9) Cognitive explanations of sz

Dysfunctional Thought Processing

• SZ is characterised by disruption to normal thought processing

• Reduced thought processing in the ventral striatum is associated with negative symptoms, whilst reduced processing of information in the temporal gyrus is associated with hallucinations

• This lower than usual level of information processing suggests that cognition is likely to be impaired

Metarepresentation

• Metarepresentation is the ability to reflect on thoughts and behaviour

• This allows us insight into our own intentions and goals

• It also allows us to interpret the actions of others

• Dysfunction disrupts our ability to recognise our own actions and thoughts as being carried out by ourselves rather than someone else

• This would explain hallucinations of hearing voices and delusions like thought insertion

Lack of central control leads to speech poverty

• Issues have also been identified with the cognitive ability to suppress automatic responses while we perform deliberate actions

• Speech poverty could result from the inability to suppress automatic thoughts and speech triggered by other thoughts

Evaluation of Cognitive Explanations: research support

Stirling compared performance on a range of cognitive tasks in 30 people with sz and a control group of 30. Tasks included the Stroop task/ People with sz took longer to complete the task - supports theories of central control (have to suppress automatic responses in the task).

This suggests the cognitive processes of people with sz are impaired.

Evaluation of Cognitive Explanations: reductionist

• Cognitive explanations only explain the proximal origins of sz

• They explain what is happening now to produce symptoms (not what initially caused the condition - distal explanations)

• Distal explanations include genes and family dysfunction

• Therefore cognitive explanations alone only provide partial explanations of sz