07. Learning and Memory

• learning = acquisition of new information
• memory = retention of learned information
• non declarative memory is not available for recollection and requires repetition over a long time

  • less likely to be forgotten
  • skills, habits, emotional responses
• declarative memory is available for conscious recollection, easy to learn and forget

  • LTM, STM
• we are unsure of whether LTM is formed from STM or if they are formed separately
• amnesia = loss of memory and learning ability

  • dissociated amnesia is associated with no other deficits like movement disorders
  • reterograde (before event) and anterograde (after event)
• transient global amnesia is where you forget everything but this resolves over time
• lashley experiments showed that all cortical areas are involved equally in memory storage in rats, but this is not true in humans
• declarative memory is found in medial temporal lobe and cortex

  • medial temporal lobe is involved in memory processing
• learning occurs in the hippocampus
• hebbs theory = strength and effectiveness of synapses is not predetermined, and can be altered by experience
• coincidence of pre and post synaptic firing leads to Ca2+ influx through NMDA -> Mg2+ block is removed when the membrane depolarises

  • Ca2+ activates calmodulin which phosphorylates the AMPA receptor and increases conductivity
  • leads to insertion of AMPA receptors to increase signalling strength
• long term depression = no NMDA leads to decreased AMPA receptors
• neurotrophins increase membrane excitability and post synaptic responsiveness

  • anything that increases these could increase learning
  • limited effect on healthy people