AQA Psychology A-Level Notes

Topic 6: Biopsychology

Part 1: The Nervous System and the Endocrine System

• Nervous System: Composed of CNS (brain and spinal cord) and PNS.
  • PNS relays messages via sensory and motor neurons.
  • Divided into autonomic (involuntary functions) and somatic (voluntary movements) systems.
  • The autonomic system has sympathetic (arousal) and parasympathetic (relaxation) branches.
• Endocrine System: Chemical messenger system using hormones.
  • Pituitary gland controls hormone release.
  • Hormones like adrenaline prepare the body for fight or flight.

Part 2: Neurons and Synaptic Transmission

• Synaptic Transmission: Communication between neurons.
  • Action potential prompts neurotransmitter release.
  • Neurotransmitters bind to receptors, influencing neuron activity.
  • Inhibitory (e.g., serotonin) vs. excitatory (e.g., dopamine) neurotransmitters.

Part 3: Localisation of Function in the Brain

• Theory: Specific brain areas manage specific functions.
• Key Areas:
  • Motor: Movement control, located in frontal lobe.
  • Auditory: Processes sound, located in temporal lobe.
  • Visual: Processes visual info, located in occipital lobe.
  • Somatosensory: Processes sensory info, located in parietal lobe.
• Language Areas:
  • Wernicke’s: Language comprehension.
  • Broca’s: Speech production.
• Support: Case studies like Phineas Gage and research on memory.
• Criticism: Holistic perspective on brain function.

Part 4: Plasticity and Functional Recovery

• Plasticity: Brain's ability to change.
  • Supported by studies like Maguire et al. (taxi drivers).
  • Involves synaptic pruning and axonal sprouting.
• Functional Recovery: Brain's ability to reorganize after damage.
  • Includes neuroplasticity research (e.g., Jodi Miller case).
• Research: Studies on phantom limb syndrome and cognitive reserve.

Part 5: Split-Brain Research

• Hemispheric Lateralisation: Each hemisphere specializes in certain functions.
  • Left: Language.
  • Right: Visuo-spatial tasks.
• Studies: Sperry and Gazzaniga's research on split-brain patients.
• Critique: Variability in brain function between individuals.

Part 6: Investigating the Brain

• Methods:
  • ERPs: Measure brain response to stimuli.
  • fMRI: Images brain activity via blood flow.
  • EEG: Monitors electrical brain activity.
  • Post-mortem: Examines brain structures after death.
• Advantages/Disadvantages:
  • fMRI: High spatial resolution but low temporal.
  • EEG: Good for monitoring ongoing activity.

Part 7: Biological Rhythms: Circadian

• Circadian Rhythms: 24-hour cycles like the sleep-wake cycle.
  • Influenced by endogenous pacemakers and exogenous zeitgebers.
• Studies: Siffre's cave study demonstrating endogenous rhythms.
• Application: Impact on shift workers' health.

Part 8: Infradian and Ultradian Rhythms

• Infradian Rhythms: Less than one cycle per 24 hours (e.g., menstrual cycle).
  • Examples like SAD and menstrual synchronisation.
• Ultradian Rhythms: More than one cycle per 24 hours (e.g., sleep stages).
  • Sleep stages research by Dement and Kleitman.

Part 9: Endogenous Pacemakers and Exogenous Zeitgebers

• Endogenous Pacemakers: Internal biological clocks like the SCN.
  • Regulate rhythms like the sleep-wake cycle.
• Exogenous Zeitgebers: External cues like light affecting rhythms.
• Research: Studies on SCN (e.g., DeCoursey et al.) and light's effect on sleep cycles.
• Ethics: Concerns about animal studies and generalizability to humans.