Memory Formation

• The case study of Henry Molaison and his memory loss
• Short term memory was fine but long-term memory was destroyed
• Hippocampus


  A medial temporal lobe structure that is crucial for LTM formation (but not all types of LTM)
• Hippocampus


  • Tubular and curved like a seahorse
  • Connected directly to the frontal lobe, thalamus, and amygdala
• The hippocampus is involved in


  Establishing the background or context for each new memory, such as location, situation, and memory of places
• Declarative memories


  Are not permanently stored in the hippocampus, they are sent elsewhere for further processing
• Encoding and storage process of declarative memories

  1. In the hippocampus

  2. Transferred for more permanent storage in relevant parts of the cerebral cortex
• Unlike other cells in the structure of the brain, the cells in the hippocampus can reproduce and enable new memories to be formed
• Hippocampus


  • Important for forming explicit memory
  • Important for memory for complex tasks that require declarative memory
• Explicit memory tasks


  • A child learning to spell unfamiliar words
  • The hippocampi of London taxi drivers are larger than people who worked in other professions
• Consolidation of declarative memory


  Takes place in the hippocampus
• Transferring new memory for storage

  The hippocampus transfers declarative information to other relevant parts of the brain for permanent storage as LTM
• Spatial memory


  An explicit memory for the physical location of objects in space
• The hippocampus acts like your brain’s own in-built GPS
• Linking emotion to memory
• Factors affecting the functioning of the hippocampus

  • Stress
  • Anxiety
  • Depression
  • PTSD
  • Brain trauma
  • Alzheimer’s
  • Herpes
  • Encephalitis
  • Other dementia-related diseases
• Cerebellum


  Has a role in the memory of how to perform a motor skill
• Cerebellum


  • Works with the motor cortex and frontal lobes
  • Encodes, processes, and stores procedural memories
• Procedural memory


  A type of implicit memory (unconscious) that helps you to perform tasks without conscious awareness of the previous experience
• Procedural memory tasks


  • Tying a shoelace
• The cerebellum activates the relevant neural systems to retrieve a procedural memory
• Patients with anterograde amnesia result from brain damage where there has been an injury to the hippocampus
• Patients with anterograde amnesia can only remember information up until the time of the head injury
• Patients with anterograde amnesia can still carry out many procedures learnt before the brain damage
• Patients with anterograde amnesia are unable to form new declarative memories
• Cerebellum


  Also has a role in classical conditioning
• Classically conditioned response


  • Rats with damage to their cerebellum do not blink in response to a puff of air in the eyes
• Amygdala


  A small structure located just above the hippocampus in the medial temporal lobe
• Amygdala


  • Connected with many other brain areas and structures
  • Important in processing and regulating emotional reactions
• Amygdala


  Important in processing and regulating emotional reactions, particularly fear, anger, and aggression
• People with a damaged amygdala are incapable of fear conditioning
• Fear conditioning


  • A monkey with a damaged amygdala will not fear a snake
• Amygdala


  • Involved in the formation and consolidation of a wide range of emotional memories
  • Involved in classically conditioned fear responses
• We are more likely to remember events that produce strong emotional reactions than events that do not
• The level of emotional arousal at the time of encoding


  Influences the strength of the LTM of that event
• Noradrenaline


  Increased amount in the amygdala during times of heightened arousal
• Amygdala


  • Contributes to the formation and storage of long-term explicit memories
  • Involved in flashbulb memory
• Flashbulb memory


  A highly detailed and long-lasting memory of an event that is very surprising, consequential, or emotionally arousing
• Flashbulb memory


  • Hearing about the death of a loved one
• Many years later people can remember details about where they were, what they were doing, and who they were with