AQA A-level Psychology (7182): Paper 2 – Biopsychology – Revision Notes

Biopsychology in AQA A-level Psychology (7182) covers how the nervous system, hormones and brain produce behaviour, and how the brain is studied. It is section 4.2.2 and topic 6 of the AQA AS and A-level Psychology (7181, 7182) specification, Version 1.4 (1 September 2025), and is assessed on Paper 2: Psychology in Context (2 hours, 96 marks, 33.3% of the A-level). These notes give you the facts, the studies and the evaluation points in a form you can test yourself on.

For full explanations, read the Biopsychology study guide first. When you are ready, try the Biopsychology practice questions.

What the specification lists

1. The divisions of the nervous system: central and peripheral (somatic and autonomic).
2. The structure and function of sensory, relay and motor neurons; synaptic transmission, neurotransmitters, excitation and inhibition.
3. The function of the endocrine system: glands and hormones.
4. The fight or flight response, including the role of adrenaline.
5. Localisation of function and hemispheric lateralisation: motor, somatosensory, visual, auditory and language centres; Broca’s and Wernicke’s areas; split-brain research. Plasticity and functional recovery after trauma.
6. Ways of studying the brain: fMRI; EEG and ERPs; post-mortem examinations. Biological rhythms (circadian, infradian and ultradian rhythms, pacemakers and zeitgebers) were in earlier editions but are not in section 4.2.2 of Version 1.4, so they are not examined.

Key terms

Term	Definition
CNS	Brain and spinal cord
Somatic nervous system	Voluntary movement and sensory information
Autonomic nervous system	Involuntary functions; sympathetic (arousal) and parasympathetic (rest)
Sensory / relay / motor neuron	Receptor to CNS / within CNS / CNS to effector
Synapse	Gap between neurons where neurotransmitters carry the signal
Excitation / inhibition	Neurotransmitter makes postsynaptic firing more / less likely
Summation	Combined effect of excitatory and inhibitory inputs decides firing
Hormone	Chemical messenger carried in the blood
Adrenaline	Hormone from the adrenal medulla that drives fight or flight
Localisation of function	Specific brain areas have specific functions
Lateralisation	The two hemispheres specialise in different functions
Plasticity	The brain’s ability to change with experience
Functional recovery	Undamaged areas take over functions after trauma
Spatial resolution	How precisely a method shows where activity happens
Temporal resolution	How precisely a method shows when activity happens

Neuron types compared

Neuron	Location	Dendrites	Axon	Function
Sensory	PNS, receptors to CNS	Long	Short	Carries sensory information to the CNS
Relay	CNS	Short	Short	Links sensory and motor neurons
Motor	CNS to effectors	Short	Long	Carries commands to muscles and glands

Synaptic transmission in six steps

1. Action potential reaches the presynaptic terminal.
2. Synaptic vesicles release neurotransmitter into the cleft.
3. Neurotransmitter diffuses across the synapse.
4. It binds to receptors on the postsynaptic neuron.
5. The postsynaptic effect is excitatory or inhibitory; summation decides whether it fires.
6. Neurotransmitter is broken down or reabsorbed (reuptake).

Fight or flight in five steps

1. Amygdala detects threat.
2. Hypothalamus activates the sympathetic nervous system.
3. Adrenal medulla releases adrenaline.
4. Heart rate, breathing and blood glucose rise; digestion slows; pupils dilate.
5. Parasympathetic system restores rest when the threat has gone.

Studies at a glance

Study	Finding	Use it for
Broca (Tan)	Damage to left frontal area; could not produce speech	Localisation of speech production
Petersen et al. (1988)	PET: Wernicke’s area active when listening, Broca’s when reading	Scan evidence for localisation
Lashley (1950)	Rats’ learning not lost by removing any single cortical area	Equipotentiality, challenges localisation
Sperry (1968)	Split-brain patients named objects shown to the right visual field only	Lateralisation of language
Maguire et al. (2000)	Taxi drivers had more posterior hippocampal grey matter	Plasticity
Taylor et al. (2000)	Females may “tend and befriend”	Gender bias in fight or flight
Dement and Kleitman (1957)	EEG showed REM sleep linked to dreaming	EEG as a way of studying the brain

Brain-study methods compared

Method	Spatial resolution	Temporal resolution	Invasive?	Key limit
fMRI	High	Low (seconds)	No	Correlational; costly
EEG	Low	High (milliseconds)	No	Cannot locate deep activity
ERP	Low	High	No	Needs many trials to average out noise
Post-mortem	Very high (direct)	None	After death	Cause of damage unclear; no live behaviour

Must-know distinctions

• Somatic vs autonomic: voluntary vs involuntary.
• Sympathetic vs parasympathetic: arousal vs rest.
• Nervous vs endocrine: fast, short-lived electrical/chemical signals vs slower, longer-lasting hormones in the blood.
• Localisation vs lateralisation: a function in a specific area vs a function in one hemisphere.
• Plasticity vs functional recovery: general change with learning vs change to compensate for damage.
• Spatial vs temporal resolution: how precisely a method locates activity vs how precisely it times it.

Mini essay plan: “Discuss localisation of function in the brain” [16]

1. AO1: motor, somatosensory, visual, auditory areas; Broca’s (production) and Wernicke’s (comprehension) areas.
2. AO3 support: Broca’s Tan; Petersen et al. (1988) scans.
3. AO3 challenge: Lashley (1950) equipotentiality; plasticity shows functions can move.
4. AO3 method: case studies of brain damage are unique and may not generalise; scans show correlation, not cause.
5. Issue: localisation is reductionist; complex behaviours involve networks across the brain.
6. Conclusion: basic functions are localised; higher functions are more distributed.

Frequently asked questions

Which paper assesses biopsychology? Paper 2, Psychology in Context, together with approaches and research methods: 2 hours, 96 marks, 33.3% of the A-level.

What is the difference between localisation and lateralisation? Localisation means specific areas of the brain have specific functions; lateralisation means some functions are processed mainly in one hemisphere, such as language in the left in most people.

Do I need to know scanning techniques in detail? You need fMRI, EEG, ERPs and post-mortem examinations: how each works, what it shows, and its main strengths and limitations, especially spatial and temporal resolution.

Quick self-test

1. Which division of the nervous system controls voluntary movement?
2. Which neuron has a long axon and short dendrites?
3. Why is synaptic transmission one-directional?
4. Which gland releases adrenaline?
5. Which hemisphere usually controls language?
6. In split-brain research, which visual field’s objects could be named?
7. Which brain method has the best temporal resolution?
8. Which gland releases melatonin, and which part of the adrenal gland releases cortisol?

Answers: (1) somatic; (2) motor neuron; (3) vesicles are only presynaptic and receptors only postsynaptic; (4) adrenal medulla; (5) left; (6) right visual field; (7) EEG (or ERP); (8) the pineal gland; the adrenal cortex.

Where marks are usually lost

• Labelling diagrams of neurons wrongly; learn the dendrite and axon lengths.
• Writing “adrenaline is a neurotransmitter released by the hypothalamus” in a fight-or-flight answer; it is a hormone from the adrenal medulla.
• Giving “fMRI is expensive” as the only evaluation; compare spatial and temporal resolution.
• Revising biological rhythms from an older textbook; they are not in Version 1.4.

Official syllabus

AQA AS and A-level Psychology (7181, 7182) specification, Version 1.4 (1 September 2025), section 4.2.2 Biopsychology — aqa.org.uk. For other topics, see the AQA A-level Psychology hub.