Short-Term Working Memory

Chapter 5 of Psych 270

What are sensory stores

Visual sensory memory/iconic memory
Auditory sensory memory/echoic memory

What is short-term memory

Holds information for up to 30 seconds
Limited in capacity

What is long-term memory

Holds information for long periods of time
Unlimited capacity

What is short-term memory

The capacity to hold a small amount of information in mind in an active, readily available state for a period of time

What does short-term memory often refer to

The input and storage of new information
Embodies the notion of a limited-capacity system

What are the different aspects of short-term memory

Where the immediately present moment is held in consciousness
Where active mental effort is expended
Where comprehension takes place

Short term memory is

Older
Input and storage of new information

Working memory is

Newer
Processing and storage
The mental workbench

What are limitations of short-term memory

Cannot encode and hold vast quantities of new information and bottleneck

What is bottleneck

Lots of information, but only some gets in

How do you overcome the bottleneck

Chunking

What is chunking

Grouping information into richer, more complex items or units called chunks

What is recoding

The process of grouping items together and then remembering the newly formed groups (two conditions: time/resources and well-learned)

What are mnemonic devices

Any mental device or strategy that provides a useful rehearsal strategy for storing and remembering material

What is the Brown-Peterson Task

On each trial, the subject sees three letters, followed by three numbers
Subjects must remember the letters while counting backwards by 3s from the number
Plot recall accuracy by time spent counting

What is decay

Loss of a memory trace due to simply to the passage of time

What is interference

The loss of a memory trace due to competition from other stimuli or events

What was the challenge to the Brown-Peterson Task

Waugh and Normans study (1965)

What was Waugh and Normans study (1965)

Participants heard a list of 16 digits read at either 1 or 4 digits per second
Last digit was a repeat of an earlier one. Participant had to remember which digit came after it
E.g., 7, 4, 6, 9 … 4 → remember 6

What were Waugh and Normans predictions

Decay hypothesis and Interference hypothesis

What is decay hypothesis

If forgetting was caused by decay, then the 16 second group (1 word/second) would have lower recall accuracy

What is interference hypothesis

If forgetting was caused by interference the two groups should be similar

What is proactive interference (PI)

When older material interferes forward in time with your recollection of the current stimulus
-Previously presented material interferes with new learning

What is retroactive interference (RI)

Newer material interferes backward in time with your recollection of older items
-Recent material interferes with older learning

-E.g., learning material towards the end of a course can interfere with your ability to remember material from earlier in the course

What is short-term memory retrieval

Bringing knowledge to the foreground of thinking (allows us to manipulate or report the information)

What are the types of recall

Free and serial

What is free recall

Recall the items in any order (grocery list)

What is serial recall

Recall the items in the exact order in which they were presented (phone number)

What are standard explanations

Primacy effects and recency effects

What are primacy effects

Better memory for items in the early positions of the list

-Long-term memory effect

-First items in a list get the best and most rehearsal

What are recency effects

Better memory for items at the end positions of the list

-Short-term memory effect

-Last items in the list are still in the short-term memory at the time of recall

What is the important idea in evidence for the standard explanations

Interference task wipes out the recency effect, but not the primacy effect

What are the two properties of rehearsal

Keeps information in short-term memory (refresh in mind)
Increases the probability that information will be transferred to long-term memory

What are the different models of short-term memory and working memory

Multi-store models and unitary models

What are the multi-store models

Models of memory that have multiple components for how memory works

What are the different types of multi-store models

Atkinson and Shiffrin
Baddeley’s working memory model

What are the different components of working memory

Central executive, phonological loop, episodic buffer and visuo-spatial sketchpad

What does the central executive do

In charge of planning future actions, initiating retrieval and decision processes as necessary, and integrating information coming into the system
Monitors and coordinates subsystems (e.g., visuo-spatial sketch pad and phonological loop)
Has its own pool of resources (for use performing tasks and can supply subsystems)

What is the visuo-spatial sketchpad

One of two subsystems in working memory
A system specialized for visual and spatial information (displays and manipulates information)
May be used in spatial awareness

What is mental rotation

Mentally turning, spinning or rotating objects in the VSSP of working memory

What is boundary extension

People tend to misremember more of a scene than was actually viewed, as if the boundaries of an image were extended further out

What is representational momentum

The phenomenon of misremembering the movement of an object further along its path of travel than where it actually was when it was last seen

What is the phonological loop

The second subsystems in working memory
The speech and sound related component responsible for rehearsal of verbal information and phonological processing (recycles information for immediate recall)
Has two components:

-Phonological store (passive store; “inner ear”

-Articulatory loop (active refreshing of information in the phonological store; “inner voice”

What is the articulatory suppression effect

The finding that people have poorer memory for a set of words if they are asked to say something while trying to remember the words

What is phonological similarity effect

The finding that memory is poorer when people need to remember a set of words that are phonologically similar, compared to a set of words that are phonologically dissimilar

What is episodic buffer

The portion of working memory where information from different modalities and sources is bound together to form new episodic memories

What is the dual task method

Two tasks are done simultaneously (can they be done independently or do they interfere with one another)

What is dissociation evidence

Short-term is compromised, but no major deficits in learning, memory, or comprehension

What are the problems with working memory

Central executive, episodic buffer, limited description of modalities and dissociations

What is central executive in problems with working memory

Vague concept; catch-all
“Little person in the head”

What is episodic buffer in problems with working memory

Vaguely specified
Not in original model

What is limited description of modalities in problems with working memory

Only two are included; what about the others?

What are dissociations in problems with working memory

Further neurological evidence indicates that there are dissociations within the subsystems

What is unitary-store models of memory

One store of memory (no short-term/long-term distinction)
One set of representations that comprise our knowledge store (i.e., short-term memory is long-term memory that has recently been activated beyond a threshold; attentional focus can be directed to activated representations)
Rehearsal strengthens representations
Reevaluation of dissociations

Where is working memory located

There is no specific place in the brain, instead it reflects the currently activated portion of long-term memory

What is the digit span task

Participants are exposed to a set of digits they must repeat back
If successful, they get a longer list, then another…

What is operation span

Different types of tasks for different “operations”
More dynamic measures of working memory

What are the operation span examples

Reading span task and arithmetic task

What is reading span task

Requires the participant to read while holding information in working memory
Participant reads two sentences, and has to repeat the last word in each
If successful, they get three sentences, then four

What is arithmetic task

People see equations and read them out loud
Then indicate if the answer is correct and say the word
They do the same for the next equation and them, at some point, must report all of the words

What does operation span also correlate with

Reading comprehension
Standardized academic tests (SAT)
Attention
Reasoning abilities
General intelligence