Chapter 5 - The psychological processes of memory

• Episodic memory


  Memories of autobiographical events that have occurred at some time in our own lives
• Semantic memory


  General knowledge and facts about the world
• Role of episodic and semantic memory


  • Retrieving autobiographical events
  • Constructing possible imagined futures
• Evidence for role of episodic and semantic memory


  • Brain imaging studies
  • Post-mortem studies of brain lesions in people with Alzheimer's disease
• Aphantasia


  Absence of mental imagery
• Mnemonic


  Any technique used to assist memory
• Examples of mnemonics


  • Method of loci
  • Acronym
  • Acrostic
  • Songlines
• Alzheimer's disease is a neurodegenerative disease characterised by the gradual widespread degeneration of brain neurons, causing memory loss, a decline in cognitive & social skills & personality changes
• Alzheimer's disease


  • Physical breakdown of neurons causes plaques in the brain
  • Often have low concentrations of neurotransmitter acetylcholine
• Symptoms of Alzheimer's disease


  • Memory loss is persistent and progressive
  • STM impacted first, then LTM
  • Explicit & semantic memories primarily affected, implicit memories less impacted
  • Forget words, names, personal experiences, story plots, ability to perform everyday skills
  • May not recognize family members/carers/own identity
• Hippocampal damage in Alzheimer's disease leads to significant impairments when patients are asked to imagine a future by mentally constructing a hypothetical event or scenario
• Atkinson-Shiffrin multi-store model of memory


  An explanatory model of the encoding, storage and retrieval of information in sensory, short-term and long-term memory stores
• Memory


  • Not a 'single organ' or a single 'thing', rather it consists of a collection of complex interconnected and interacting systems
• Memory systems


  • Know what is important
  • Store information
  • Retrieve information
  • Process information
• Although the memory systems share a common function of storing & retrieving info, they process & store different types of info in different ways
• Given the amount of info processed by memory over a lifetime, its accuracy & reliability is remarkable
• Human memory is not perfect
• Every moment in our lives is not automatically recorded in our memory as if on a DVD, to be filed away for future reference
• Often we fail to properly process & store info that we need to recall at a later point in time
• At the time of receiving sensory info, our brain must select what info to attend to, process & store in the various memory systems and what will be eliminated and therefore not stored in memory
• This process of storage & retrieval is necessary because our memory systems would be overloaded if they had to retain info about every moment in our lives
• Memory


  The processing, storage and retrieval of information acquired through learning
• Processes of memory


  • Encoding
  • Storage
  • Retrieval
• Encoding


  Converting information to a useable form
• Storage


  Retaining information in memory
• Retrieval


  Information recovered from memory when needed
• Stores (or parts) of memory


  • Sensory memory (SM)
  • Short term memory (STM)
  • Long term memory (LTM)
• Sensory memory (SM)


  Where all the information comes in
• Short term memory (STM)


  The short term store - temporarily work on or rehearse the information
• Long term memory (LTM)


  Holds information in a permanent & organised way
• Sensory memory (SM)


  The entry point of memory where new incoming sensory info is stored for a very brief period of time
• Iconic memory


  Stores visual sensory information
• Echoic memory


  Stores auditory sensory information (sound)
• Short-term memory (STM)


  A memory system with a limited storage capacity in which info is stored for a relatively short period of time, unless renewed in some way
• Short-term memory (STM)


  • Info is stored temporarily but for a longer time than SM
  • Info is no longer an exact replica of the sensory stimulus, but an encoding (representation) of one
  • Info is stored in both verbal & non-verbal forms
• Short-term Memory (STM):Duration


  Peterson & Peterson (1959) demonstrated that info is retained in STM for about 18 sec
• Short-term memory (STM):Capacity


  STM is very limited in storage capacity (amount of info it can hold at any given time)
• Recalling information from LTM can also displace items from STM
• STM as working memory


  It is this 'working memory' that provides a temporary storage facility and mental workspace for information currently being used within a conscious cognitive activity
• STM as working Memory


  • Info only remains in working memory while we are consciously attending to it
  • Once the info is no longer required, it is either processed further & passed into LTM or it is discarded