Types of Memory

Memory is the generic term, denoting the power by which we reproduce past impressions.

Three memory processes:

Encoding          Storing          Retrieving

Three Types of Memory:

- Sensory memory - is our ability to retain impressions of sensory information after the original stimulus 
has ceased.
- Short-term (working) memory - Capacity (or capacities) for holding in mind, in an active, highly available 
state a small amount of information:
- Long-term memory - the permanent memory store accessed after a considerable gap between the 
presentation of a stimulus and its recall. 

Sensory Memory: Recording

Iconic memory - the temporary persistence of visual impressions after the stimulus has been removed.

Echoic memory - the ability to recapture the exact impression of a sound shortly after the sound has finished.

Functions of sensory memory:

     Gives decision time
     Prevents being overwhelmed
     Provides stability, playback, & recognition
Short-Term Memory: Working

Limited duration - from 2 to 30 seconds, can be prolonged with maintenance rehearsal.

Limited capacity - widely accepted, is that working memory can hold on average seven (7) plus or minus 
two concepts at a time varying with each person (George Miller). A memory span test can show the 
negative effect of interference and the positive effect of chunking on short-term memory.

Functions of short-term memory:

    1. Attending - (selective attention) - to selectively attend to information that is relevant & disregard 
everything else.
    2. Rehearsing (2 types)
         Maintenance rehearsal - refers to simply repeating or rehearsing the information rather than forming 
any new associations. Maintenance rehearsal is not very effective.

         Elaborative rehearsal - deliberate effort to form new associations.
    3. Storing - to store or encode information
Long-Term Memory: Storing

Steps in the memory process:

1. Sensory memory
     2. Attention
         3. Short-term memory
             4. Encoding
                 5. Long-term memory
                     6. Retrieval

Features of long-term memory

     Has infinite capacity & permanence.
         Has retrieval capability & varying accuracy of recall.
                 Primacy versus Recency - what was first & what is most recent
                   is remembered best, the middle gets tromped on.

Primacy 70%, Recency 60%

Declarative Memory

     Declarative memory is the aspect of long term-memory that stores facts & events. It applies to 
standard textbook learning & knowledge. It is based on pairing the stimulus & the correct response, 
e.g. the question "What is the capital of England?" and the answer "London". The name declarative 
comes from the fact that we can explicitly "ask" our brain to make a connection between a pair of 
stimuli. Declarative memory is subject to forgetting & requires repetition to last for years. Declarative 
memories are best established by using active recall combined with mnemonic techniques & spaced 

Long-term declarative memory types:

         Episodic memory - represents our memory of events & experiences in a serial form. It is from this 
memory that we can reconstruct the actual events that took place at a given point in our lives.
        Semantic memory - is a structured record of facts, concepts, words, definitions, language rules & 
skills that we have acquired. The information in semantic memory is derived from that in our own episodic 
memory, such that we can learn new facts or concepts from our experiences.

Procedural or Nondeclarative memory - provides for retention of skills not requiring conscious thought.                   

        While declarative memory involves conscious recollection of information (such as explicit rules of a task), 
nondeclarative (procedural) memory involves the development of familiarity & improved performance 
on a task after repeated exposure or practice. Learning a skill involves a transition from a  task that 
relies on declarative memory to a more automatized task that relies on nondeclarative memory.

Other Memory Concepts
    Eidetic imagery - a person (child) who possesses eidetic imagery is able to "see" and describe an image 
in great detail after that image has been removed from their sight, and can perform this feat for a fairly 
extensive period of time.
     Photographic memory - the ability to mentally photograph a visual scene & then recall it in precise detail.
     Flashbulb memories typically are remarkably vivid & seemingly permanent memories. These memories 
are typically of highly emotional & personal events in one's life. Flashbulb memories can also be of 
personal circumstances during an event that did not affect one personally, such as a leader's assassination 
or a devastating airline crash. 

                 Topics in Psychology
                      Robert C. Gates