Memory serves three major functions:

• Encoding: How is information transformed from sensory energy to something usable?

• Storage: How is this information retained?

• Retrieval: How do we get the information back?

How do we encode perceptual information so that it can be used?

Evidence for an auditory code in STM:

• Conrad (1964): Errors recalling visually presented letters are more likely to be acoustically similar letters (i.e. P for B, F for S, etc.)

• Baddeley (1966): Recall of a list of acoustically similar words is worse than recall of acoustically distinct words.

Interference theory claims that errors of memory are a result similar pieces of information competing with each other, and thus interfering with recall of the information.

Two types of interference:

• Retroactive: Interference that occurs after we learn an item but before we need to recall it.

• Proactive: Interference that occurs before we learn a to-be-remembered item.

Schemas: Memory structures that help organize information about static situations.

Example: Office schema, bathroom schema, bedroom schema, etc.
 

Scripts: Memory structures that help organize information about dynamic situations.

Example: Restaurant script, classroom script, waking up in the morning script, etc.

These schemas and scripts (which are discussed more in Ch. 8) are thought to be primarily responsible for the constructive nature of memory.

Memory is not perfect. Sometimes, we misremember things based upon our expectations, such as remembering a stapler on a desk in an office when no such stapler exists.

Eyewitness testimony:

As a result, eyewitness testimony can be very unreliable.

• Loftus stop-sign experiment.

All of next week’s material deals with the issue of the nature of information storage.

However, we can still ask how information gets stored in LTM, i.e. how does it get moved from STM to LTM?

Consolidation: The process by which we add new memories to our stored set of memories.

Rehearsal:

Some researchers believe that all movement of information from STM to LTM involves rehearsal in some way.

From STM:

Memory scanning:

• Serial vs. parallel?
• Exhaustive vs. self-terminating?

However…..

Corcoran (1971) showed that a parallel model could account for Sternberg’s data.

Furthermore, when the items to be scanned are heterogeneous, it appears that a self-terminating search is used.

Basic findings:

• Cued recall better than free recall of words presented by categories

• Learning words hierarchically better than learning them in random order

What ties these together?

Context matters

We already talked about how scripts and schemas can affect the encoding of information

Flashbulb memory: Where were you when the Challenger exploded? Vividness seems to affect memory.

Encoding specificity: This is a theory that all memories are encoded based, at least in part, on the context in which they were learned.

Thus, information is easier to retrieve in the same context.

Examples: Cued-recall better than free-recall; learning in your dorm room vs. remembering in the exam room.