Memory

• Episodic memory


  A type of long-term memory that involves the ability to recall specific events, experiences and situations from our past
• Episodic memory


  • Holidays, autobiographical memory (including details about what happened, where it occurred, and when it happened)
• Episodic memory


  Unique to the individual, involves conscious recall, associated with the right prefrontal cortex
• Semantic memory


  Our general knowledge and understanding of the world, involves the ability to recall facts, concepts and ideas not tied to a specific event or experience
• Semantic memory


  • Knowing the sky is blue, understanding the meaning of words, knowing historical events
• Semantic memory


  Involves conscious recall, associated with the left prefrontal cortex
• Procedural memory


  Our ability to learn and remember how to perform various motor skills and actions, often referred to as muscle memory
• Procedural memory


  • Riding a bike, typing on a keyboard, playing a musical instrument
• Procedural memory


  Associated with the motor area which controls fine motor skills, comes without conscious recall once encoded into long-term memory
• Encoding and storage of memories


  1. Encoding (transforming sensory input into a form that can be stored in the brain)

  2. Storage (memories stored in different regions depending on type, e.g. episodic in hippocampus, semantic in neocortex, emotional in amygdala)

  3. Retrieval (reactivation of the neural code, can be triggered by cues or reminders)
• Encoding


  The process of transforming sensory input into a form that can be stored in the brain
• Storage


  Memories are stored in different regions of the brain depending on the type of memory
• Retrieval


  The process of accessing stored memories, can be triggered by cues or reminders
• Ways new information can be encoded

  • Visual encoding (thinking through images)
  • Acoustic encoding (remembering how a song or piece of music goes)
  • Semantic encoding (understanding words and placing them in a sentence)
• Multi-store model of memory

  A theoretical framework that describes the process by which information is encoded, stored and retrieved from memory
• Multi-store model of memory

  • Consists of three separate stores: sensory register, short-term memory, and long-term memory
• Sensory register


  1. Immediate and automatic recording of sensory information from the environment

  2. Very short duration (a few hundred milliseconds)

  3. Not stored unless attended to
• Short-term memory


  Temporary storage of information that is currently being attended to or actively processed
• Short-term memory


  • Limited capacity (about 7 +/- 2 items)
  • Short duration (about 20-30 seconds unless rehearsed or transferred to long-term memory)
  • Located in the prefrontal cortex
• Long-term memory


  Storage of information that has been rehearsed or processed in short-term memory
• Long-term memory


  • Unlimited capacity
  • Can store information for an indefinite period of time
  • Located in various regions of the brain including the hippocampus and neocortex
• Information processing in the multi-store model

  1. Sensory information briefly held in sensory register

  2. Transferred to short-term memory

  3. Rehearsed or processed in short-term memory

  4. Transferred to long-term memory for more permanent storage
• The multi-store model has been influential but also criticized for oversimplifying the complex processes involved in memory and failing to account for the role of attention and other factors
• Sensory register


  • Coding: Information represented in the same form as received from the environment
  • Capacity: Very large, can hold vast amount of sensory information simultaneously
  • Duration: Very short, ranging from a few hundred milliseconds to a few seconds
• Short-term memory


  • Coding: Primarily encoded in the form of sound or speech-based representations (acoustic coding), but other forms like visual and semantic coding can also occur
  • Capacity: Limited, can only hold about 7 +/- 2 items
  • Duration: Relatively short, lasting only 20-30 seconds unless rehearsed
• Long-term memory


  • Coding: Encoded in various forms including semantic, visual, and acoustic
  • Capacity: Unlimited
  • Duration: Unlimited, some memories can last a lifetime while others may fade
• Serial position effect


  Tendency for people to remember items at the beginning and end of a sequence better than items in the middle
• Primacy effect


  Superior recall of items that appear at the beginning of a list
• Recency effect


  Superior recall of items that appear at the end of a list
• The Primacy effect is explained by the idea that the first few items in the list were more likely to be transferred into long-term memory due to their extended rehearsal time
• The Recency effect is explained by the fact that the last few items were still fresh in the participants' short-term memory when they were asked to recall them
• Research with amnesiacs has shown that people who can't store new long-term memories do not show a Primacy effect but they do show a Recency effect, demonstrating that the Primacy effect is linked to long-term memory
• A limitation of the research is that it is an artificial task as the participants had to learn a list of words, which is not meaningful to them, so the findings only tell us about the ability to recall lists of words, not information that is meaningful
• Reconstructive memory


  Theory developed by Sir Frederick Bartlett in the 1930s that proposes memory is not an exact recording of past events but rather a construction of what we believe happened based on our previous experiences, beliefs and knowledge
• Reconstructive memory


  • When we recall a past event, we are not simply playing back a recording but rather reconstructing the memory based on our current perspective, knowledge and beliefs
• Effort after meaning


  People have a natural tendency to try and make sense of new information and integrate it with their existing knowledge and beliefs
• Effort after meaning


  Can influence how we remember events
• Schema


  A mental framework or organizational structure that helps us to process and remember information
• Schema


  Can influence what we pay attention to, how we interpret new information, and how we remember events
• Memory is not a passive process of retrieving stored information but an active process of construction that is influenced by our current perspective, beliefs and knowledge