Neural correlates

• The dopamine hypothesis


  The brain of patients with schizophrenia produce more dopamine - positive symptoms are caused by excess dopamine and negative symptoms are caused by a deficit of dopamine
• Seidman (1990)

  Conducted post mortems and found that people with SZ have a larger than usual number of dopamine receptors
• Lindstroem et al

  Found that L-Dopa is taken up more quickly in patients with schizophrenia
• Link between dopamine and amphetamines

  Amphetamines lead to an increase in dopamine levels and large quantities lead to symptoms of schizophrenia such as delusions and hallucinations
• Chlorphromazine

  Used to treat schizophrenia by blocking dopamine receptors
• Positive evaluation of dopamine explanation

  Application to treatment e.g. drugs and medication which can allow people to live and work outside of a hospital environment
• Negative evaluations of dopamine explanation

  We don't know whether higher levels of dopamine are a cause or symptom of schizophrenia

  Methodological problems with research
• 2 areas of the brain associated with negative symptoms

  Ventral striatum

  Cerebral ventricles
• 2 areas of the brain associated with positive symptoms

  Anterior cingulate gyrus

  Superior temporal gyrus
• Ventral striatum

  Associated with anticipating a reward

  Lower levels in SZ patients which may be associated with avolition
• Cerebral ventricles

  Filled with cerebrospinal fluid which provides pressure on the inside of the brain. If grey matter is damaged, the ventricles enlarge to fill the space left
• Vita et al

  Conducted a review study and found that patients with SZ showed a reduction in grey matter in their cerebral ventricles over time
• Anterior cingulate and superior temporal gyrus

  Associated with hallucinations
• Allen et al

  Took fMRI scans while ppts listened to recorded voices, which were either their own or someone else's, and found that people with schizophrenia made more errors and showed different activation of the gyrus's
• Positive evaluation of neural correlates explanation

  Supporting evidence e.g. fMRI scanning
• Negative evaluations of neural correlates explanation

  Based on correlational research so can't establish cause and effect

  Lack of application to treatment as we are only trying to understand the roles of areas of the brain