MEMORY

Definition:
“Memory is an internal record or representation of some prior event or experience.”

It can also be defined as
“A set of mental processes that receives, encodes, stores, organizes, alters and retrieves information over time”

Memory models:
There are two Common Memory Models

  1. Traditional three-stage memory model
  2. Encoding, storage and retrieval approach

 

Traditional Three-Stage Model

This Model focuses on storing information for different lengths of time
three stages are sensory, short-term memory and long-term memory.

  1. Sensory Memory
  2. Purpose: to retain exact image of sensory information long enough to focus on important info and transfer it to next stage
  3. All senses have a sensory memory
  4. Duration depends on the sense involved
  5. Capacity is relatively large

 

    1. Short-Term Memory
  1. Purpose - temporarily stores info until it is sent to LTM
  2. Duration - relatively limited
  3. Capacity:  5 to 9 items
  4. Duration and capacity can be increased with maintenance rehearsal and/or chunking
  5. Also known as ≥working memory≤
    1. Long Term Memory
  1. Purpose is to keep info stored for long periods of time
  2. Unlimited capacity and duration

 

Encoding, Storage, Retrieval Model (Memory Process Model)

It focuses on how is info changed as it moves through these operations? This Process can be compared to a computer

  1. Encoding
  2. Process of translating info into neural codes that will be retained in memory

 

    1. Storage
  1. The process of retaining neural coded info over time
    1. Retrieval
  1. The process of recovering info from memory storage

 

Encoding and Three Stage Model:

    1. Rehearsal
    2. STM and shallow processing
    3. LTM and elaborative processing

Storage and the 3 Stage Model
There are two varieties of LTM

    1. Explicit/Declarative
    2. Implicit/nondeclarative
      1. Explicit/Declarative Memory

The properties of this type of memory are

    1. Memories with conscious recall
    2. Appears from facts, ideas and life’s events
    3. Semantic (general knowledge)
    1. Episodic  (personal experiences)
      1. Trip to Hawaii
      1. Implicit/ Nondeclarative/ Procedural Memory

The properties of this type of memory are

    1. This type happens from experience but expressed as a change in behavior, not as a recollection
    2. Memory without awareness
      1. How to ride a bike
      2. How to swim
      3. How to sing
    3. Procedures involved in habits
    4. Benefit from repeated practice
    5. Other types as well, can be hidden from conscious awareness

Retrieval and the 3 Stage Model

    1. Retrieval Cues – trigger the retrieval process
    2. Recognition

Factors that Contribute to Forgetting

    1. Serial Position Effect
    2. Primacy
  1. Recency
    1. Spacing of practice
    2. Massed practice
    3. Distributed practice

Theories of Forgetting

  1. Decay Theory
    1. Interference Theory
    2. Proactive interference
  2. Retroactive interference
  3. Encoding Failure
  4. Retrieval Failure Theory

 

Key Memory Problems

    1. Organic Causes
    2. Injury
  1. Disease
    1. Constructive Processes
    2. Eyewitness Testimony
    3. Repressed Memories

3 fundamental insights into bio nature of memory

  1. Immediate & Long term memory can be dissociated
  2. Restricted lesions in brain disrupt ability to make new conscious memories while other cognitive functions intact
  3. There is more than one kind of memory

Temporal categories of memory

    1. Short-term (STM)
    2. temporary records, (sec/min) w/ cont. rehearsal
    3. small capacity (~7 items)
    4. rapid input & retrieval, but wanes fast
    5. depends on different network of brain structures than long-term
      1. Long-term (LTM)
    6. Permanent
    7. Period of consolidation where it can be fragile
    8. Different types
    9. Enormous capacity
    10. Undergoes consolidation
    11. Function divisions
    12. Conscious
    13. Unconscious
    14. We can answer 100,000’s of dissimilar questions rapidly because LTM is HIGHLY ORGANIZED

“Chunking”
It is a process within short term memory of combining dissimilar terms of information so that they can take up as little as possible of the limited space in short term memory. For example, concentration, activity and recall can be made into “car”.

Priming

  1. Amnesics unable to recognize word lists they have studied
  2. For example, if a normal person is shown a list of different items and asked to remember it, it is highly likely that he would be able to recall most of the items when asked.
  3. But in priming, though the person has seen the lists and he or she retains that list in the mind (retention), but is unable to recall (awareness) it.

 

Why Does the Story Help?

  1. Connecting different items (chosen by you depending on past life experiences) - remembering one, brings up several
  2. What we already know shapes what we select & encode.
  3. Elaboration has a downside; if we don’t carry it out we have poor recall.
  4. You see & handle them all the time! We encode features superficially because use of them requires we notice only general features (shape, color etc). You don’t need to remember many details to distinguish a one rupee from a Five rupee or previously fifty paisa.