Specification details: Schizophrenia Pages 201-204 of Year 2 book Specification details: Biological explanations for schizophrenia: genetics, the dopamine hypothesis and neural correlates.

Biological Explanations Genetics Biochemistry Brain Structure

Neural correlates of schizophrenia Neural correlates are measurements of the structure or function of the brain that occur in conjunction with an experience, in this case schizophrenia. There is growing evidence that schizophrenia is down to structural abnormalities in the brain Brain scanning techniques have made it possible to investigate living brain images. Both positive and negative symptoms have correlates     

Neural correlates of schizophrenia Neural correlates of negative symptoms Activity in the ventral striatum has been linked to the development of avolition (loss of motivation) The ventral striatum are believed to be particularly involved in the anticipation of a reward for certain actions Therefore, if there is abnormality in areas such as the ventral striatum, then this would result in a lack of motivation (avolition)     

Neural correlates of schizophrenia Neural correlates of positive symptoms Reduced activity in the superior temporal gyrus and anterior cingulate gyrus have been linked to the development of auditory hallucinations Patients experiencing auditory hallucinations showed lower activation levels in these areas than controls Therefore, reduced activity in these areas of the brain is a neural correlate of auditory hallucinations     

Neural correlates of schizophrenia People with schizophrenia have abnormally large ventricles in the brain. Ventricles are fluid filled cavities. This means that the brains of schizophrenics are lighter than normal.

Neural correlates of schizophrenia

Complete worksheet 8.5 in your pack Worksheet task Complete worksheet 8.5 in your pack

Neural correlates of schizophrenia - evaluation Findings are inconsistent and therefore inconclusive MRIs have made it possible to investigate living brain images which is an advance on merely having to rely on post mortems There are, however issues of causality. Cause and effect can not be established with brain abnormalities - it is still uncertain whether structural abnormalities/reduced functioning predispose to schizophrenia, or whether the onset of the clinical symptoms causes these changes.

Evaluation Summary Biological explanations do account for schizophrenia, however the fact that there is no conclusive explanation that accounts for all schizophrenics - research is difficult to interpret and there have been contradictory findings. It is difficult to establish cause and effect – as many participants have suffered from schizophrenia for a while and have been undergoing treatment. Enlarged ventricles may be the result of taking anti-psychotic medication for example Biological explanations are reductionist in attempting to explain a complex multi- faceted disorder at the level of cells, genes and chemicals

Evaluation Summary Biological explanations are deterministic in the assumption that the disorder can be inherited and unavoidable Biological explanations do account for schizophrenia, however the fact that there is no conclusive explanation that accounts for all schizophrenics means that psychological explanations need to be considered. A ‘diathesis-stress’ relationship may be at work – an individual may have a genetic predisposition for schizophrenia but it may be due to environmental factors that lead to the onset of the condition

Exam Question Prepare for this timed question for next lesson Discuss biological explanations for schizophrenia. (16 marks)

Ensure you have written up your class notes to include the following: Homework Ensure you have written up your class notes to include the following: How a genetic explanation for schizophrenia is investigated Explanation of the dopamine hypothesis Explanation of neural correlates, including neural correlates of both negative symptoms and positive symptoms Evaluation of biological explanations for schizophrenia