bio psychology

• Divisions of the Nervous System

  • The CNS
  • The PNS
• The CNS


  Consists of the brain and the spinal cord
• The brain


  • Provides conscious awareness and is involved in all psychological processes
  • Consists of four main lobes: frontal lobe, parietal lobe, occipital lobe, temporal lobe
• Frontal lobe


  Associated with higher-order functions, including planning, abstract reasoning and logic
• Parietal lobe


  Integrates information from the different senses and therefore plays an important role in spatial navigation
• Occipital lobe


  Processes visual information
• Temporal lobe


  Processes auditory information
• Brain stem


  Connects the brain and spinal cord and controls involuntary processes, including our heartbeat, breathing and consciousness
• Spinal cord


  • Transfers messages to and from the brain, and the rest of the body
  • Responsible for simple reflex actions that do not involve the brain
• Components of the PNS

  • Somatic nervous system
  • Autonomic nervous system
• Somatic nervous system


  • Facilitates communication between the CNS and the outside world
  • Carries sensory information from the outside world to the brain and provide muscle responses via the motor pathways
• Autonomic nervous system


  • Plays an important role in homeostasis, which maintains internal processes like body temperature, heart rate and blood pressure
  • Controls automatic responses
• Components of the autonomic nervous system

  • Sympathetic nervous system
  • Parasympathetic nervous system
• Sympathetic nervous system


  Involved in responses that prepare the body for fight or flight
• Parasympathetic nervous system


  Relaxes the body, and returns us to our 'normal' resting state: rest and digest
• Types of neurons


  • Sensory neurons
  • Relay neurons
  • Motor neurons
• Sensory neurons


  Found in receptors such as the eyes, ears, tongue and skin, and carry nerve impulses to the spinal cord and brain
• Relay neurons


  Found in the brain and spinal cord and allow sensory and motor neurons to communicate
• Motor neurons


  Found in the central nervous system (CNS) and control muscle movements
• Neurons


  • Dendrites receive signals
  • Cell body is the 'control centre'
  • Axon carries nerve impulses
  • Axon terminal connects the neuron to other neurons or organs
• Myelin sheath


  Insulates the axon so that the electrical impulses travel faster along the axon
• Synaptic transmission


  1. Action potential travels down the axon

  2. Crosses the synaptic gap

  3. Neurotransmitters are released

  4. Bind to receptor sites on the post-synaptic cell
• Excitatory neurotransmitter


  Causes a positive electrical charge in the cell membrane which makes the post-synaptic cell more likely to fire
• Inhibitory neurotransmitter


  Results in a negative charge, which makes the post-synaptic cell less likely to fire
• Summation


  1. Addition of positive and negative post-synaptic potentials

  2. If the net effect is inhibitory, the neuron will be less likely to fire

  3. If the net effect is excitatory, the neuron will be more likely to fire
• Endocrine system


  • Works alongside the nervous system
  • Network of glands that secrete hormones into the blood
• Fight or flight response

  1. Amygdala sends distress signal to hypothalamus

  2. Hypothalamus communicates with body through sympathetic nervous system

  3. Sympathomedullary pathway activates physiological arousal
• Parasympathetic nervous system activation

  1. Slows down heart rate and breathing rate

  2. Reduces blood pressure

  3. Restarts functions previously slowed down (e.g. digestion)
• Freeze response is the first response to danger
• Females adopt a 'tend and befriend' response in stressful/dangerous situations
• Early research on fight or flight was conducted on males and assumed to generalise to females (androcentrism and beta bias)
• Fight or flight response is maladaptive in modern life and can have negative health consequences
• Motor area


  Located in the frontal lobe, responsible for voluntary movements
• Somatosensory area


  Located in the parietal lobe, receives incoming sensory information from the skin
• Visual area


  Located in the occipital lobe, receives and processes visual information
• Auditory area


  Located in the temporal lobe, responsible for analysing and processing acoustic information
• Broca's area


  Located in the frontal lobe, controls language production
• Wernicke's area


  Located in the temporal lobe, controls language comprehension
• Phineas Gage case study provided early evidence for localisation of function
• Case studies on Broca's and Wernicke's aphasia support localisation of language functions