Memory Part 1

Memory

the nervous system’s capacity to retain and retrieve skills and knowledge

What are the three stages of memory?

Encoding, storage, and retrieval

Encoding

The processing of information so that it can be stored

• information often comes from our surroundings

• brain transforms information into a neural code

Storage

The retention of encoded information over time

• neural connections become stronger

• helps to retrieve information later

Retrieval

Recalling or remembering stored information when needed

• not a perfect system-forgetting can occur

Memory’s Physical Location

Memory involves multiple regions of the brain

• not all brain regions are equally involved

Prefrontal cortex

working memory

Hippocampus

spatial memory

Temporal lobe

declarative memory

Amygdala

fear learning

Cerebellum

motor action learning and memory

Sensory Memory

• Very briefly (<1 sec) stores sensory info close to its original sensory form

• not everything reaches conscious awareness

- requires attention

Sperling (1960)

• participants can remember entire display (iconic memory) for brief time

• limitation of “report all” condition is that iconic memory fades before participants can report it all

Short Term Memory (STM)

• Memory storage that briefly holds small amounts of info

- info lasts here for 20-30 seconds

- holds 7 ± 2 “items”

• requires work to maintain

- rehearsal helps maintain items in STM

Digit Span

Participants hear a series of digits and must immediately repeat them back

• list increases until memory fails

• # of digits the person can report without errors is that person’s digit span

Chunking

• the ability to condense information

- Ex) HOPTRASLU (nine items) = HOP TRA SLU (three chunks)

• requires effort but reduces WM load

• does not increase WM capacity

Working Memory

Active memory system that holds info for current use

• also quite short

• can involve info from STM, or reactivated long-term memory

Operation Span/OSPAN Example

• decide whether equation is true or false

• remember the word

• number of words remembered is the OSPAN

Long-Term Memory

The relatively permanent storage of information

• relatively stable

• nearly limitless

• autobiographical, semantic info

Working Memory (WM) is like what?

It’s like a white erase board

• temporary

• limited in size

Long Term Memory (LTM) is like what?

It’s like a library

• info available for long time

• huge, almost limitless capacity

WM and LTM

• Experiment supporting the modal model

- participants study a long series of words (30 words, 1 word presented per second)

- free-recall memory test

Primacy effect

better memory for first few items relative to middle items

• memory rehearsal

• words later in the list are rehearsed less

• rehearsal increases chance of a transfer of items from WM to LTM

Recency effect

better memory for the last few items

• last few items in the list are still held in working memory

• earlier items are displaced by subsequent items

Maintenance Rehearsal

reciting, thinking in repetitive way

Relational or elaborative rehearsal

linking, relating

Shallow processing

Superficial engagement with the material

• Ex) Is the DOG in capital or lower-case letters?

Depth processing

Requires thinking about the meaning of the material

• Ex) Does the word DOG fit in the sentence, “He walked his __.”?

Which rehearsal is better?

• Relational rehearsal is superior to maintenance rehearsal

• repeated exposure does not guarantee memory

Schemas

cognitive structures in long-term memory that help us perceive, organize, process, and understand information

• these guide our attention as we sort through complex information

Mnemonics

• learning aids or strategies that improve recall through the use of retrieval cues

Peg-word systems

items are “hung” on a system of already well known “pegs”

Visualization strategies

memory palace (method of loci)