Structual Abnormalities

Question 1

What are the three main focuses in the structural abnormalities explanation?

Answer 1

Enlarged ventricles
Cortical atrophy
Reversed cerebal asymmetry

Question 2

What are ventricles?

Answer 2

Cavities that transport cerebrospinal fluid (providing protection and stability for the brain and spine)

Question 3

What are the four ventricles?

Answer 3

1. The left lateral ventricle
2. The right lateral ventricle
3. The third ventricle (between left and right thalamus)
4. The fourth ventricle (between the pons and medulla oblongata)

Question 4

Explain a supporting piece of evidence for the theory of enlarged ventricles in schizophrenia sufferers?

Answer 4

Weinberger used CAT scans finding ventricular size was greater in a group of 58 individuals with chronic schizophrenia compared to 56 in the control group

Question 5

What is a weakness of Weinbergers research?

Answer 5

Small sample size - low external validity
Inability to establish cause and effect - only correlation
Not for every schizophrenia sufferer

Question 6

What is cortical atrophy?

Answer 6

The loss of neurons in the cerebral cortex, it can occur all over the brain making it look as though it has shrunk OR in one particular area affecting the function linked to the area
Atrophy widens the grooves covering the cerebral cortex

Question 7

Why do we need to be careful making assumptions surrounding cortical atrophy?

Answer 7

Damage only appears in 20%-30% of sufferers

Question 8

Vita used CAT scans to assess 124 individuals with schizophrenia and 45 controls. What did Vita find?

Answer 8

33% of people with schizophrenia had severe atrophy - not related to age or family history but appeared to be related to gender (mainly males)

Question 9

Why is Vitas research only considered a partial explanation?

Answer 9

Because the statistic is moderate indicating that atrophy is not the only cause of schizophrenia - may be an effect rather than casual factor

Question 10

What is the theory of reversed cerebral asymmetry?

Answer 10

Most people without schizophrenia have a left hemisphere slightly larger than the right. In some individuals with schizophrenia this is reversed

Question 11

Why is the idea of reversed cerebral symmetry relevant to schizophrenia?

Answer 11

Language formation is often linked to the left hemisphere so the damage here could lead to the poverty of language (ALOGIA)

Question 12

Where did support for reversed cerebral asymmetry come from?

Answer 12

Luchins
Compared CAT scans of right and left handed people with schizophrenia to controls and found an increase in the frequency of reversals in both frontal and occipital ones of those with schizophrenia when there was no other form of atrophy

Question 13

Why is cause and effect an issue for this explanation?

Answer 13

Because it’s possible the brain adapts to try and cope with schizophrenic symptoms therefore structural abnormalities are an effect rather than a cause of the illness

Question 14

What did Lyon et al find?

Answer 14

That as antipsychotic medication dosage increased - so did the density of brain tissue indicating medication may in fact cause abnormalities therefore is an effect

Question 15

Why is cause and effect of schizophrenia nearly impossible to establish?

Answer 15

We live in a society mindful of human rights so cannot test and study all individuals e.g. scanning brains of babies is unethical as it could lead to isolation and discrimination

Question 16

What did Roy et al find?

Answer 16

Individuals diagnosed with bipolar disorder and schizoaffective disorder also have enlarged ventricles - could be down to overlapping symptoms within the DSM-5

Question 17

Why does diagnostic criteria need to be reviewed?

Answer 17

Suggest disorders have a similar cause and the differences between cultures and diagnosis is worrying due to overlapping symptoms

Question 18

Why would brain scanning techniques becoming more refined be a strength of diagnostic criteria?

Answer 18

Diagnosis could be based in a scan rather than observation of subjective behaviour

Question 19

Are the findings of structural abnormalities reliable?

Answer 19

McCarley and colleagues claim the presence of large ventricles in schizophrenia sufferers is the most reliable finding in research using brain scanning
The link between atrophy and schizophrenia has also been confirmed
HOWEVER
Structural abnormalities are not found in every sufferer leading to questions about the reliability of these findings

Question 20

Why should brain scanning techniques focus on more subtle differences?

Answer 20

Would improve reliability as factors such as age and gender can affect the pattern of observed abnormalities e.g. if structural abnormalities are an effect than a 70 year old sufferer would have a much different scan to a 15 year old sufferer
The assessment should remain consistent for all researchers

Question 21

Why might structural abnormalities be linked to neurodevelopment?

Answer 21

exposure to noxious agents or events in utero, childhood or adolescence hindering healthy brain development

Question 22

What did Distantos research of 60,000 patients find?

Answer 22

That schizophrenia was more prevalent in people born in January - could be due to mothers exposed to the flu virus or suffering from vitamin D deficiency in later stages of pregnancy

Question 23

Why is Distantos research important?

Answer 23

Shows that environmental factors can influence the prevalence of the disorder

Question 24

What is a weakness of Distantos research?

Answer 24

Only correlational

Most people born in January do not develop schizophrenia - limiting the usefulness of the supporting evidence

Question 25

When it comes to a combination of neurodevelopmental and neurodegenerative disorders being linked to schizophrenia, what is the most likely explanation of this?

Answer 25

Neurodevelopmental factors may cause cortical impairment and may make the individual more susceptible to neurodegenerative disorders

Question 26

What did Andreasen find when studying MRI scans?

Answer 26

Those with schizophrenia had ventricles 20%-50% larger than those who do not suffer with schizophrenia