Ch 5: STM & LTM

What is memory?

The process of retaining, retrieving, and using information about a stimulus after the original information is no longer present.

What are the three memory stores in Atkinson and Shiffrin's modal model (1968)?

Sensory memory, short-term memory (STM), and long-term memory (LTM).

What is the modal model of memory?

A model proposing that information passes through sensory memory, short-term memory, and long-term memory through processes such as encoding, rehearsal, and retrieval.

What is sensory memory?

A memory store that briefly preserves sensory information in its original form.

What is short-term memory (STM)?

A memory system that holds a small amount of information for a brief period.

What is long-term memory (LTM)?

A memory store that retains information for extended periods, potentially years or decades.

How long does sensory memory last?

Fractions of a second to a few seconds, depending on the sensory modality.

How long does short-term memory last without rehearsal?

Approximately 15–20 seconds, according to the lecture.

How long can long-term memory last?

Years or decades, potentially for a lifetime.

What is the approximate capacity of STM in the traditional modal model?

Approximately 5–9 chunks of information.

What are the three main characteristics of sensory memory?

It preserves sensory information briefly, retains information in its original sensory form, and has separate stores for different sensory modalities.

What is persistence of vision?

The continued perception of a visual stimulus briefly after the stimulus is no longer present.

What did Sperling (1960) investigate?

The capacity and duration of visual sensory memory using briefly presented letter displays.

What is the whole report method?

A procedure in which participants report as many items as possible from a briefly presented display.

What happened in Sperling's whole report experiment?

Participants recalled approximately 4–5 of 12 letters, or about 38%.

Why might participants recall only 4–5 letters in the whole report method?

Visual information fades rapidly while participants attempt to report the letters.

What is the partial report method?

A procedure in which participants report only one specified portion of a briefly presented display.

How did Sperling indicate which row participants should report?

He presented a tone immediately after the letter display, with the tone indicating the target row.

What did Sperling find using the partial report method?

Participants could report approximately 82% of the letters in the cued row when the cue appeared immediately.

What is the delayed partial report method?

A procedure in which participants receive a cue indicating which portion of a display to report after a delay.

What happens to performance in delayed partial report as the delay increases?

Performance declines rapidly because visual sensory information decays.

What did Sperling conclude about visual sensory memory?

Initially, much more information is available than people can report, but it fades very rapidly.

What is iconic memory?

Visual sensory memory that briefly retains visual information.

How long does iconic memory last?

Less than one second.

What is echoic memory?

Auditory sensory memory that briefly retains sounds after they have ended.

How long can echoic memory last?

It can last longer than iconic memory, potentially several seconds and, in some circumstances, up to approximately 20 seconds.

What is the difference between iconic and echoic memory?

Iconic memory briefly retains visual information, whereas echoic memory briefly retains auditory information.

What did Peterson and Peterson (1959) investigate?

The duration of short-term memory when rehearsal is prevented.

How did Peterson and Peterson measure STM duration?

Participants remembered three letters, counted backward by threes from a number to prevent rehearsal, and then recalled the letters after a delay.

Why did Peterson and Peterson have participants count backward?

To prevent rehearsal and examine how quickly information disappears from STM without active maintenance.

What was the main finding of Peterson and Peterson (1959)?

Short-term retention declined substantially over delays of a few seconds when rehearsal was prevented.

Approximately how long can information remain in STM without rehearsal, according to the lecture?

About 18 seconds.

What is a free recall task?

A memory task in which participants report as many previously presented items as they can remember, in any order.

What is the digit span task?

A task that measures memory capacity by asking participants to repeat a sequence of digits in the order presented.

What is backward digit span?

A task in which participants repeat a presented sequence of digits in reverse order.

What does the backward digit span task measure in addition to short-term storage?

Working memory, because participants must maintain the digits and mentally manipulate their order.

What is the chunking hypothesis?

The idea that STM capacity depends on the number of meaningful units or chunks rather than the number of individual pieces of information.

Who proposed the chunking hypothesis?

George A. Miller (1956).

What was the title of George Miller's famous 1956 paper?

The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information.

What is a chunk?

A group of familiar items or stimuli that can be stored as a single meaningful unit.

How does prior knowledge help chunking?

It allows separate items to be grouped into familiar patterns, making them easier to remember as one unit.

What is the traditional STM capacity according to Miller's estimate?

Approximately 5–9 chunks, or seven plus or minus two.

Why might LOL be easier to remember than three unrelated letters?

LOL is a familiar, meaningful unit that can be stored as a single chunk.

What was the main lesson of the letter-chunking demonstration?

The same letters can be easier to remember when organized into familiar words or patterns.

What did Luck and Vogel (1997) investigate?

The capacity of visual short-term memory using a change detection task.

What is a change detection task?

A task in which participants view a visual display and determine whether a later display differs from the original.

What did Luck and Vogel (1997) find about visual STM capacity?

Performance was nearly perfect for displays containing 1–3 squares but declined when displays contained four or more squares.

What did Alvarez and Cavanagh (2004) investigate in relation to visual STM?

How the capacity of visual working memory depends on the complexity of the visual information being remembered.

What does the visual STM capacity of approximately four items suggest?

Some visual short-term memory tasks show a capacity closer to four objects than Miller's traditional estimate of seven plus or minus two chunks.

Why is STM capacity sometimes described as four rather than seven?

Some studies find that visual working memory is limited to approximately three or four objects, depending on the task and how capacity is measured.

What is working memory?

A limited-capacity system that temporarily stores and manipulates information during complex tasks such as comprehension, learning, and reasoning.

Who proposed the working memory model?

Alan Baddeley and Graham Hitch (1974).

How does working memory differ from the traditional concept of STM?

STM emphasizes temporary storage, whereas working memory includes both temporary storage and the manipulation of information.

What is an example of working memory in everyday life?

Remembering a phone number while mentally changing the order of its last two digits.

What is the dual-task paradigm?

A method in which participants perform two tasks simultaneously to investigate whether the tasks share processing resources.

How does the dual-task paradigm test working memory?

Researchers examine how performing a secondary task, such as arithmetic, affects performance on a primary task, such as word recall.

What did Baddeley and Hitch conclude from their dual-task research?

Temporary storage and processing are not a single, undifferentiated system; different components can support different activities, although interference can occur when resources overlap.

What are the three main components of Baddeley's original working memory model?

The phonological loop, visuospatial sketch pad, and central executive.

What is the phonological loop?

The working memory component responsible for temporarily holding and rehearsing verbal and auditory information.

What is the visuospatial sketch pad?

The working memory component responsible for temporarily holding and manipulating visual and spatial information.

What is the central executive?

The attentional control system that coordinates working memory, directs attention, and manages the other components.

What is the episodic buffer?

A component added to Baddeley's working memory model that temporarily integrates information from different modalities and connects working memory with long-term memory.

What does the phonological loop's "inner voice" refer to?

The rehearsal of verbal information through an internal speech-like process.

What does the visuospatial sketch pad's "inner eye" refer to?

The ability to maintain and manipulate visual images and spatial information mentally.

What are the two components of the phonological loop?

The phonological store and the articulatory rehearsal process.

What is the phonological store?

A temporary store that holds verbal and auditory information in an acoustic or sound-based form.

How quickly does information in the phonological store decay without rehearsal?

Approximately two seconds, according to the lecture.

What is the articulatory rehearsal process?

The process of mentally repeating verbal information to maintain it in the phonological store.

What is the phonological similarity effect?

The finding that similar-sounding letters or words are more easily confused during immediate recall.

Why is a sequence such as BBGTCD harder to remember than FKYWMR?

The letters in BBGTCD contain more phonologically similar sounds, which increases confusion during recall.

What is the word length effect?

The finding that short words are generally recalled better than long words in immediate verbal memory tasks.

Why are short words easier to recall than long words?

Short words can generally be rehearsed more quickly, allowing more items to be refreshed before they decay.

What is articulatory suppression?

A task that interferes with verbal rehearsal by requiring a person to repeatedly say something aloud.

How does articulatory suppression affect verbal memory?

It reduces recall by interfering with the rehearsal process that maintains information in the phonological loop.

What happens to the word length effect during articulatory suppression?

The word length effect is reduced or eliminated because rehearsal is disrupted.

What does evidence from phonological similarity, word length, and articulatory suppression support?

The existence of a phonological loop that temporarily stores verbal information and maintains it through rehearsal.

What are the two subcomponents of the visuospatial sketch pad proposed by Logie (1995)?

The visual cache and the inner scribe.

What is the visual cache?

The visuospatial component that temporarily stores visual information, including what objects look like and where they are located.

What is the inner scribe?

The visuospatial component that rehearses spatial information and supports operations such as mental rotation.

What is mental rotation?

The ability to mentally rotate an object to determine whether it matches another object.

Who conducted the classic mental rotation study in 1971?

Roger Shepard and Jacqueline Metzler.

What did Shepard and Metzler's (1971) mental rotation experiment demonstrate?

People take longer to judge whether two three-dimensional objects are the same when the objects differ by a larger rotation angle.

What does increased response time during mental rotation suggest?

People mentally rotate visual representations, with larger rotations generally requiring more time.

What did Della Sala and colleagues (1999) investigate?

Visual pattern memory and the capacity of the visuospatial sketch pad.

What was the average performance in the visual patterns task described in the lecture?

Participants could reproduce patterns consisting of approximately nine shaded squares on average.

What is the central executive responsible for?

Controlling attention, coordinating working memory components, and deciding how to divide or switch attention between tasks.

Is the central executive specific to one sensory modality?

No. It is considered modality-free because it coordinates attention across different types of information.

How does the central executive coordinate working memory?

It allocates attention and coordinates the phonological loop and visuospatial sketch pad.

What can frontal lobe damage reveal about the central executive?

It can produce difficulties with planning, attention, and flexible control of behaviour.

What is perseveration?

The repeated performance of the same action or thought even when it is no longer appropriate or goal-directed.

How is perseveration related to the central executive?

It can reflect impaired executive control, making it difficult to stop a response or switch to a new task or strategy.

What did Baddeley's episodic buffer add to the original working memory model?

A temporary multimodal store that integrates information from verbal, visual, spatial, and long-term memory sources into coherent episodes.

What does multimodal mean in relation to the episodic buffer?

It combines information from different sensory or representational formats, such as auditory and visual information.

How does the episodic buffer connect working memory and long-term memory?

It integrates information held temporarily in working memory with information retrieved from long-term memory.

What is the correct answer to the lecture's knowledge check about STM capacity?

Option A: STM capacity is relatively small, traditionally described as approximately seven items, or more precisely around five to nine chunks.

What are the two main topics in the Short-Term Memory lecture?

The modal model of memory, including sensory and short-term memory, and the working memory model.

How do encoding and retrieval differ?

Encoding involves getting information into memory; retrieval involves accessing stored information.

What is the difference between storage and manipulation in working memory?

Storage maintains information temporarily, while manipulation involves mentally transforming or operating on that information.

What is the difference between sensory memory and STM?

Sensory memory briefly preserves a large amount of raw sensory information, whereas STM maintains a smaller amount of information for a longer period.

What is the difference between STM and working memory?

STM refers mainly to brief storage, while working memory includes temporary storage and active processing or manipulation.