Neural explanation (biological)

Question 1

What is the neural explanation?

Answer 1

A further biological explanation for Sz regarding the structure of the brain and levels of neurotransmitters
One of the most heavily researched and supported neural correlates is dopamine

Question 2

What is the original dopamine hypothesis v updates?

Answer 2

Subcortical hyperdopaminergia= HIGH levels of dopamine found beneath the cortex
Cortical hypodopaminergia= LOW levels of dopamine found in the cortical area

Question 3

What is the original dopamine hypothesis?

Answer 3

Based on antipsychotic meds to treat Sz as some side effects were similar to Parkinson’s disease
Parkinson’s was associated with low levels of dopamine
Concluded that if the drugs are treating Sz by lowering levels of dopamine, so the levels of dopamine must be high in the first place to cause Sz
Hyperdopaminergia in Broca’s area and is typically associated with positive symptoms e.g., delusions and hallucinations

Question 4

What is the revised dopamine hypothesis?

Answer 4

original seen to be too simplistic as it only explains/ treats positive symptoms
Davis et al: suggested hypodopaminergia can explain negative symptoms of Sz
Revised suggests that hypodopaminergia in the cortex can cause hyperdopaminergia in the subcortex
This means that we can both have high and low levels of dopamine explaining why Sz has both positive and negative symptoms

Question 5

Limitation of neural (determinism)

Answer 5

It’s deterministic/ too simplistic
Ignores external factors which may affect a person’s risk to developing Sz e.g., trauma
Morkvet- 68% of people who experienced childhood trauma had a psychotic break showing how the environment plays a role in the development of Sz

Question 6

Limitation of neural (not always dopmaine)

Answer 6

there may be other neurotransmitters that cause Sz
post-mortem and live scanning have found raised levels of glutamate in several brain regions of people with Sz
also several candidate genes are believed to be involved i glutamate production or processing
so cause and effect can’t be established and it questions the validity of these theories

Question 7

Strength of neural (research support)

Answer 7

amphetamines increase dopamine and worsen symptoms of Sz whilst inducing symptoms for those without
Also, antipsychs reduce the activity of dopamine which is found to reduce the intensity of Sz symptoms
increases the validity of the dopamine hypothesis