Chapter 5

• Memory

  The process of encoding, storing and retrieving information that has been previously encountered and stored.
• Encoding

  The process of converting information into a useable form which can be manipulated and stored in the brain (due to being neurologically represented)
• Storage

  The retention of (encoded) information over time
• Retrieval

  The process of accessing information that has been stored in long term memory and bringing it into our conscious awareness in short term memory.
• The Atkinson Shiffrin multi-store model of memory

  A model of memory that outlines the three separate stores of memory (sensory, short-term term and long-term) each of which interact through the processes of encoding, storage and retrieval.
• Sensory memory

  A store of memory that very briefly stores raw information detected by the senses
• Function of sensory memory

  -Retain information which been detected by the sensory organs in its raw sensory form

  -If this information is attended to, it is then encoded and transferred to short-term memory for processing; otherwise, the memory is completely lost.
• Capacity of sensory memory

  -Unlimited capacity
• Duration of sensory memory 


  -0.2-4 seconds
• Short term memory

  A store of memory that temporarily holds a limited amount of information that is consciously being attended to and actively manipulated.
• Function of short-term memory

  -Receives information from sensory memory and long-term memory, and transfers information to long-term memory

  -Maintains information in conscious awareness for immediate use
• Capacity of short-term memory

  5-9 pieces of information- can be increased by chunking: grouping smaller 'chunks' of information into larger 'chunks'
• Duration of short-term memory

  Approx 18-30 seconds- can be increased by maintenance rehearsal- repeating information over and over again.
• Long-term memory 


  A store of memory in which a potentially unlimited amount of information is stored for a relatively permanent amount of time
• Function of long-term memory

  Information storage of re-access and use at a later time
• Capacity of long-term memory

  Potentially unlimited
• Duration of long-term memory

  -Relatively permanent

  -Some information may be lost of inaccessible over time
• Strengths of the Atkinson-Shiffrin

  -Distinguishes between the different stores involved in memory

  -Outlines different capacities and duration for different memory stores
• Limitations of the Atkinson-Shiffrin

  -Model of memory may be oversimplified

  -Short-term memory is more complex

  -The model ignores factors

  -The model does not account for individual differences.
• Explicit memory 


  A type of long-term memory that is consciously retrieved
• Semantic memory 


  A type of explicit memory that consists of general knowledge or facts
• Episodic memory


  A type of explicit memory that consists of personal experiences or events
• Implicit memory 


  A type of long-term memory that is unconsciously retrieved
• Procedural memory 


  A type of implicit memory that involves knowing how to carry out tasks that are facilitated by motor skills
• Classically conditioned memory 


  A type of implicit memory that involves an involuntary response (eg. fear, disgust or elation) to a stimulus which has repeatedly been associated with an emotionally-arousing stimulus
• Hippocampus 


  A structure in the medial temporal lobe

  -It encodes explicit memories
• Amygdala 


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

  -It encodes emotional components of memories. These may be the emotional components of classically- conditioned memories or explicit episodic memories
• Neocortex

  The largest and most recently evolved part of the cerebral cortex

  • It stores explicit memories
• Basal gangila and cerebullum 


  Implicit procedural memories are encoded and stored via connections between the basal ganglia and the cerebellum
• Basal Ganglia


  A group of structures deep within the brain that is connected with the various brain structures including the cerebellum

  • It is involved in co-ordinating sequences of motor activity
• Cerebellum 


  Structure at the base of the brain

  • It is involved in fine motor control
• Autobiographical events 


  Personally lived experiencees
• Retrieving autobiographical events 


  Contain information that is semantic as well as episodic components
• Possible imagined futures 


  Hypothetical experiences and situations that an individual has the ability to create and conceptualise in their mind
• Constructing possible imagined futures

  1. Involves semantic memory to envision possible scenarios consistent with what is known

  2. Involves episodic memory to construct a subjective future with richly detailed elements
• Neurodegenerative diseases


  Diseases characterized by the progressive loss of neurons in the brain
• Alzheimer's disease


  A neurodegenerative disease that involves the progressive loss of neurons in the brain and is characterized by memory decline
• Symptoms of Alzheimer's disease


  • Decrease in cognitive function
  • Personality change
  • Changes in mood and emotion
  • Confusion or disorientation
  • Difficulty with language and communication
• Biological markers of Alzheimer's disease


  • Amyloid plaques: fragments of protein beta-amyloid that accumulate into insoluble plaques that inhibit communication between neurons
  • Neurofibrillary tangles: an accumulation of the protein tau that forms insoluble tangles within neurons, which then inhibit the transportation of essential substances and eventually kill the neuron entirely
• Later in Alzheimer's disease, the brain experiences a significantly reduced size due to a loss of brain matter due to the progressive loss of neurons, beginning from the medial temporal lobe and moving outwards