Biological psychology

• Central Nervous System is the brain and spinal cord
• Central Nervous System


  • Central processing and control point for all human behaviour
• Brain


  • Processes incoming information from all senses
  • Responsible for controlling behaviour
• Spinal Cord


  • Connects brain to rest of body
  • Allows messages to be passed from body to brain
• Neurons


  Cells within the Central Nervous System that communicate with lots of other cells in huge networks
• We focus on motor neurons
• Myelin Sheath


  • Insulating layer that speeds up rate of transmission
  • Breaks between cells along the myelin sheath are nodes of Ranvier
• Cell Body


  • Contains nucleus and houses genetic material
  • Contains mitochondria to provide energy
• Dendrites


  Attached to cell body and receive messages from other neurons
• Axon


  • Passes electrical impulse towards the axon terminals
  • Where the nerve impulse is triggered from
• Axon Terminals


  • Pass nerve impulses from cell body to the parts of the body they can control/activate
  • Terminal boutons store neurotransmitters for synaptic transmission
• Action Potential


  • The method the nerve impulse passes down the neuron axon
  • A tiny electrical impulse triggered by a change in the electrical 'potential' of the neuron
• Resting Membrane Potential


  Slight negative charge (in relation to outside of the neuron)
• Excitatory Postsynaptic Potential


  Depolarises the neuron by reducing the charge
• Inhibitory Postsynaptic Potential

  Hyperpolarises the neuron by increasing the charge
• Synaptic Transmission


  1. Electrical message reaches axon terminal

  2. Turns into a chemical message

  3. Neuron passes message to other neurons across the synaptic gap
• Neurotransmitters


  Chemicals produced by neurons to pass messages to other neurons
• Key Neurotransmitters


  • Dopamine
  • Serotonin
  • Acetylcholine
• Dopamine


  Related to emotion, cognitive function, posture control of movement, reinforcement in learning, dependency/addictions, hormonal regulation
• Serotonin


  Involved in mood control, pain regulation, body temperature, hunger, sleep
• Acetylcholine


  Stimulates muscle contractions, necessary for memory and other cognitive functions, involved in expression of some emotions
• Recreational Drugs


  Psychoactive drugs that alter brain function and are taken for personal enjoyment
• Reward Pathway


  When activated gives a pleasant and rewarding feeling, encouraging us to repeat the behaviour, can become maladaptive when hijacked by drugs
• Drugs act by


  Changing the way neurotransmitters work in the brain
• Nicotine


  Targets parts of the dopamine pathway, increases amount and transmission of dopamine by blocking enzyme that breaks it down, mimics acetylcholine
• Cocaine


  Increases activity in dopamine pathways by blocking reuptake of dopamine
• How drugs lead to addiction

  1. Withdrawal occurs when drug is no longer active

  2. Brain adapts to changes caused by drug so no longer operates normally without it

  3. Can also lead to tolerance, requiring bigger doses to get the same effect
• Trepanning was used to treat migraines and epilepsy
• Hippocrates believed each hemisphere of the brain has a different function
• Phrenology attempted to map character by mapping bumps on the head
• Phineas Gage's case showed behaviour was linked to the brain
• Paul Broca identified an area of the brain involved in speech production
• Carl Wernicke identified an area of the brain involved in speech comprehension
• Main Lobes of the Brain

  • Frontal Lobe
  • Parietal Lobe
  • Occipital Lobe
  • Temporal Lobe
• Types of Aggression


  • Person-oriented
  • Instrumental
  • Reactive
  • Sanctioned
• Animal Types of Aggression


  • Offensive attack on another animal
  • Defensive response to threat of attack
  • Predatory action to gain food
• Hypothalamus


  Lesion/stimulation causes different types of aggression in cats
• Pre-frontal Cortex


  Regulates emotions, lack of regulation leads to aggression
• Limbic System/Amygdala


  • Linked to autonomic nervous system, self-preservation, fight/flight
  • Amygdala is the centre for emotions, motivation and emotional behaviour
• Lack of communication between Pre-Frontal Cortex and Amygdala means psychopaths can't regulate social and emotional behaviour