Structural Abnormalities Flashcards
(28 cards)
What are the 3 main focuses in structural abnormalities?
Enlarged ventricles,
Cortical atrophy,
Reversed cerebral asymmetry.
What are ventricles?
Cavities that produce and transport cerebrospinal fluid.
Why is cerebrospinal fluid important?
It provides protection, buoyancy, and chemical stability to the brain and spine.
How many ventricles are in the brain?
4
Where are the 4 ventricles situated in the brain?
The left and right lateral ventricles - in the frontal, occipital, and temporal lobes,
Third ventricle between the left and right thalamus,
Fourth ventricle between the pons and medulla oblongata.
In some individuals with schizophrenia, what are the ventricles like?
The ventricles seem to be larger than those in individuals without schizophrenia.
What did Daniel Weinberger et al. (1979) say?
Ventricular size was greater in a group of 58 individuals with chronic schizophrenia than the 56 in the control group of people with no symptoms of schizophrenia.
What type of scans are used for this explanation?
CAT scans.
What did Nancy Andreasen (1988) study?
MRI scans of individuals with and without schizophrenia and found that those with schizophrenia had ventricles 20% to 50% larger than in control groups.
What does ‘cortical atrophy’ mean?
The loss of neurons in the cerebral cortex.
Where can cortical atrophy occur?
All over the brain, and atrophy can be focused in a limited area.
What does the atrophy affect?
The cognitive functions of the cerebral cortex.
What does the atrophy result in?
Widening the grooves covering the cerebral cortex, this damage characterises the brains of 20% of people with chronic schizophrenia.
What did Antonio Vita et al. (1988) do?
Used CAT scans to assess 124 individuals with schizophrenia and 45 in the control group. They found that 33% of the individuals with schizophrenia showed moderate to severe atrophy. Atrophy was found to be related to sex (male) and ventricular enlargement.
What is cerebral asymmetry?
The left hemisphere is larger than the right hemisphere in most individuals without schizophrenia.
What is reversed cerebral asymmetry?
The right hemisphere is larger than the left hemisphere in most individuals with schizophrenia.
What is found in the left hemisphere, and what could damage to this lead to?
Language function, leading to alogia.
What did Daniel Luchins et al. (1979) do?
Compare, using CAT scans, 80 right handed people without schizophrenia to 57 right handed people with schizophrenia. They found that there was an increase in the frequency of ‘reversals’ in the frontal and occipital lobes of those with schizophrenia with no other form of atrophy
What did Robert McCarley (1999) claim?
The presence of enlarged ventricles is the most reliable finding research using brain scans.
Flashman and Green (2004)
Link between cortical atrophy and schizophrenia has been confirmed.
What did McCarley et al suggest?
Factors such as age and sex have a big influence on the pattern of brain abnormalities, suggesting we need to acknowledge more subtle differences.
Cause or effect issue
Like dopamine hypothesis, it is unclear whether structural abnormalities are a cause or effect.
Kenneth Lyon et al (1981)
As doses of antipsychotics increased, density of brain tissue decreased, suggesting the medication causes some abnormality.
Paul Roy et al (1998)
Individuals with schizophrenia and bipolar have enlarged ventricles, both having overlapping symptoms and similar structural abnormalities.
