Biopsychology and the Brain
What this domain tests
Biopsychology and the brain tests how biological systems produce behaviour and mental processes. You must explain neural transmission, link brain structures to functions, evaluate methods such as lesions, EEG, fMRI, PET and TMS, and use evidence from patients and animals carefully.
Core rules and concepts
- Neuron and synapse: dendrites receive, axons transmit, myelin speeds conduction, and axon terminals release neurotransmitters across the synaptic gap. Action potentials are all-or-none once threshold is reached.
- Neurotransmitters: glutamate is mainly excitatory, GABA mainly inhibitory; dopamine is involved in reward and motor control; serotonin in mood; acetylcholine in memory and muscle action. Agonists mimic, antagonists block, and reuptake inhibitors prolong transmitter action.
- Brain organisation: frontal lobes support executive function and movement; parietal lobes somatosensation; temporal lobes hearing and memory; occipital lobes vision; cerebellum coordination; amygdala emotion; hippocampus declarative memory; corpus callosum connects hemispheres.
- Methods: fMRI measures BOLD signal correlated with activity; EEG has good temporal resolution; PET measures metabolism; lesions can suggest causal roles but plasticity may compensate; TMS can temporarily disrupt processing.
- Plasticity: experience shapes connections, especially in sensitive periods, and recovery after injury is variable.
Worked example
A patient with bilateral hippocampal damage cannot form new declarative memories but can learn a mirror-tracing skill. Reasoning: anterograde amnesia with spared procedural learning suggests separate memory systems; the medial temporal lobes are necessary for declarative consolidation, not all learning. Caution: this is a single case, and pre-existing damage limits generalisation.
Traps
Avoid “region X causes behaviour” oversimplification; fMRI activation is correlational, so reverse inference is risky; lesion patients may compensate; animal findings may not generalise; neurotransmitters are not “happy chemicals” with one simple role.