Psychology 11 (Biology) - Psychological Problems - Schizophrenia - Biological theory/Brain structure theory

Dendrites

Receive info from other neurons through chemicals

Cell body

Processes the info needed

Axon

Long cable where the electrical impulse travels down

Myelin Sheath

Insulation of the axon which speeds up the impulse travelling down the axon

Axon terminals

Releases electrical impulse to trigger release of neurotransmitters

Synapse (Synaptic Gap)

Gap between 2 neurons

Neurotransmitters

Chemical form of electrical impulses that transmit messages from the pre synaptic neuron to the post synaptic neuron

Receptors

Where the neurotransmitters gets absorbed (On the post synaptic neuron)

Synaptic transmission

Axon terminals contains vesicles which store the neurotransmitters. Electrical charge causes vesicles to move to the end of the axon terminals. Vesicles then release the neurotransmitters into the synapse. Then they diffuse across the gap where they meet the receptors at the end. Neurotransmitters bind to specific receptors.

After that, the message is passed along that neuron the same way

Biological theory

Dopamine Hypothesis

Dopamine

Neurotransmitter which is responsible for perception/attention/mood

Perception linked with schizophrenia

Hallucinations

Attention linked with schizophrenia

Word salad

Mood linked with schizophrenia

Avolition

Dopamine hypothesis

People with schizophrenia have abnormal amounts of dopamine which cause the symptoms because dopaminergic neurons fire too often. Schizophrenics also have too much dopamine receptors leading to too much dopamine neurotransmitters being absorbed.

Hippocampus link with schizophrenia

Responsible for memory/emotion so smaller hippocampus may explain negative symptoms such as lack of emotion

Temporal lobe link with schizophrenia

Responsible for processing auditory information so if the lobe has a lack of grey matter (lower in volume), it may explain the symptom of hallucinations

Prefrontal cortex (Frontal cortex) link with schizophrenia

It is the control centre so having a restricted blood flow in that area could mean that schizophrenics struggle with being organised and lose control of psychological functioning.

Blood

Contains nutrients/glucose/oxygen to help brain function properly.

Criticism of the Biological theory #1

Brain function is an effect of schizophrenia but no the cause.

Evidence comes from analysing the brain using post mortems/scans after the diagnosis.

Therefore, brain function/structure could change after something else triggered the disorder

Determinism

Idea that behaviour is determined by outside forces such as genetics or upbringing. Ignores role of free will

Reductionism

Viewing human behaviour from a simplistic view such as explaining behaviour by focusing on their biology

Criticism of the Biological theory #2

Theory is too reductionist.

Argued that it's too simple to explain a complex disorder by looking at a part of their brain.

This means that there are other psychological factors that work together to cause schizophrenia.

Criticism of the Biological theory #3

Nurture effects of the disorder have been ignored.

Evidence of how schizophrenics brains look and work differently is not enough to cause the disorder by itself.

Therefore, the brain needs to surround itself with the environment to produce the symptoms.