neuroanatomy

• what are neural correlates?

  measurements of the structure or function of the brain, that correlate with an experience. the idea that abnormalities within specific areas of the brain, may be associated with the development of schizophrenia
• how are the brains of schizophrenia sufferers studied?

  previously, research relied on postmortem examinations of dead schizophrenics, but modern technology allows for brain scanning.

  this involves schizophrenics are given tasks to complete whilst their brains are scanned and then brain abnormalities can be identified
• what are enlarged ventricles?

  fluid filled gaps between areas of brain tissue. schizophrenic brains would appear lighter, smaller, less dense and have gaps
• Johnstone

  found that schizophrenics have enlarged ventricles while non sufferers did not, suggesting that schizophrenia is related to a loss of brain tissue
• evaluation of enlarged ventricles

  cause and effect is difficult to establish as its unsure whether the structural abnormalities are due to genetics, caused by environmental factors, or by the illness. brain scanning attempts to answer this by scanning the brains of family members who aren't affected so if they have enlarged ventricles its clear its genetic
• evaluation of enlarged ventricles

  some non-schizophrenics have enlarged ventricles, while not all schizophrenics do, which suggests there must be another cause
• evaluation of enlarged ventricles

  the schizophrenics who do not respond to medication are often the ones with enlarged ventricles. therefore, the brain damage may be due to suffering from the illness for a long period of time
• evaluation of enlarged ventricles

  brain damage may be due to the environmental factors such as substance abuse and stress levels, rather than just schizophrenia. both of these are strongly linked to the development of schizophrenia
• Negative symptoms

  research has shown a negative correlation between the level of activity in the Wernickes area that is responsible for understanding language and processing speech, and the severity of negative symptoms in sufferers. this suggests that a lack of activity in this area causes symptoms such as disorganised speech or poverty of speech [alogia]
• ventral striatum

  this are of the brain is linked to avolition. schizophrenics tend to have less activity in this area than non-sufferers. there is a negative correlation between activity levels in the ventral stratium and the severity of negative symptoms. therefore this is a neural correlate for negative symptoms
• positive symptoms

  lower activation levels in the superior temporal gyrus and anterior cingulate gyrus were found to be correlated with positive symptoms such as auditory hallucinations

  the superior temporal gyrus contains the auditory cortex - the part of the brain responsible for processing sounds

  the anterior cingulate gyrus is part of the limbic system and is responsible for processing sensory information, processing emotions and regulating behaviour. it also helps to regulate motor function
• evaluation

  research is not clear on whether the brain damage is the cause of the symptoms or whether the symptoms are causing the lack of brain activity in certain areas
• Crow

  suggested two types of schizophrenia with two biological causes

  1. type one- genetically inherited associated with dopamine - characterised by positive symptoms
  2. type two- neuro-developmental disorder - characterised by negative symptoms