Atkinson-Shiffrin Memory Model

• Memory models include William James' primary and secondary memory concept.
• Atkinson and Shiffrin later proposed a three-part model: sensory store, short-term store, and long-term store.
• The three stores are viewed as hypothetical constructs for understanding psychological phenomena, not as distinct physiological structures.

Atkinson and Shiffrin's Memory Model

• This model shows the flow of information: environmental input to sensory registers, then short-term memory, and finally long-term memory.
• The model includes control processes and emphasizes passive storage areas.
• Today, the three stores are commonly referred to as sensory memory, short-term memory, and long-term memory.

Sensory Store

• Sensory store (iconic store) briefly holds much of initial information before it enters short-term or long-term stores.
• The iconic store is a visual sensory register for very short periods, storing information as icons (visual images).
• Visual memory persistence is exemplified by "writing" with a lighted sparkler in the dark.

Sperling's Discovery

• George Sperling (1960) studied how much information we can encode in a single, brief glance.
• Using briefly flashed arrays of letters and numbers, Sperling initially used a whole-report procedure.
• Since the whole-report procedure was an issue, Sperling introduced a partial-report procedure.
• In the partial-report procedure, participants only report part of what they see.
• Sperling presented symbols in three rows and cued participants to recall one row based on tone pitch.
• Sperling manipulated the time between display and tone (0-1.0 seconds) to estimate iconic memory duration.
• Using the partial-report procedure, participants initially had about 9 of 12 symbols available.
• Recall decreased to 4 or 5 items when cued 1 second later.
• This suggests the iconic store holds about nine items and information decays rapidly.
• Sperling's findings on information fading are not subjectively obvious due to seldomly encountering only briefly presented stimuli.
• The lack of awareness is because we cannot distinguish between what we see in iconic memory and what we see in the environment.
• Refinement of Sperling's work showed holding about 12 items in sensory memory (75% of 16).
• The capacity of iconic memory may be more than originally estimated when output interference is reduced.

Averbach & Coriell, 1961

• It revealed iconic memory can be erased, making visual sensations more sensible.
• Backward visual masking is the mental erasure of a stimulus when another appears in the same place.
• Visual information enters memory via an iconic store, holding it briefly.
• Information transfers to another store or is erased, especially if new information is superimposed too quickly.
• Auditory information also experiences erasure or movement into another store (echoic memory).

Short-Term Store

• Short-term memory holds memories briefly, from a few seconds up to a few minutes.
• The Atkinson-Shiffrin model states the short-term store includes control processes for information flow to and from long-term store.
• Material stays in the short-term store for about 30 seconds unless rehearsed.
• Information is stored acoustically rather than visually.
• Our immediate memory capacity is about seven items, plus or minus two (Miller, 1956).
• We can chunk items together to remember more information.
• Chunking a string of 21 numbers into larger units makes it easier to reproduce them.

Long-Term Store

• Long-term memory keeps memories for long periods, perhaps indefinitely.
• How much information can be held in long-term memory is unknown.
• There is no proof that there is an absolute outer limit to how long information can be stored.

Information Storage

• Wilder Penfield found patients sometimes appeared to recall childhood memories when he electrically stimulated their brains.
• Those data suggested to Penfield that long-term memories might be permanent.
• Some researchers dispute Penfield's interpretations for many reasons.
• Memory aspects are hardly ever forgotten after 25 years.
• The term permastore refers to very long-term storage of information.
• Permastore can occur even for passively learned information.
• There is to date no resolution of the thought if Permastore is a separate memory system, or just a part of long-term Memory.

The Levels-of-Processing Model

• The levels-of-processing (LOP) framework poses that memory varies along a continuous dimension in terms of depth of encoding

• There are potentially infinite levels of processing (LOP) achieved through greater understanding of the material.

• Processing is key to storage, and the level of information storage depends on how it's encoded.

• Deeper processing increases the likelihood of remembering an item (Craik & Brown, 2000).

• Experiments supporting the LOP view used questions to encourage item elaboration on physical, phonological, and semantic levels.

• Deeper processing increases recall.

• The levels-of-processing framework applies to nonverbal stimuli, such as faces.

• Deeply processed faces are better recognized than those studied at a lower level.

• Deeper processing helps improve the memory impairments of people suffering from schizophrenia.

• The self-reference effect shows high recall levels when meaningfully relating words to oneself.

• High recall occurs even for non-self-descriptive words due to the assessment process.

• People have more elaborate encoding of information about themselves due to greater knowledge.

• Because encoding is more elaborate, there are more available retrieval pathways to self information.

• The self-schema is an organized system of internal cues about attributes, personal experiences, and oneself.

• People richly encode and elaborate information related to themselves.