CHAPTER 5 SHORT-TERM AND WORKING MEMORY

Modal model of memory

The model proposed by Atkinson and Shiffrin that describes memory as a mechanism that involves processing information through a series of stages, including short-term memory and long-term memory. It is called the modal model because it contained features of many models that were being proposed in the 1960s.

Structural features

Types of memory indicated by boxes in models of memory. In the modal model, the types are sensory memory, short-term memory, and long-term memory.

Control processes

In Atkinson and Shiffrin's modal model of memory, active processes that can be controlled by the person and that may differ from one task to another. Rehearsal is an example of a control process.

Rehearsal

The process of repeating a stimulus over and over, usually for the purpose of remembering it, that keeps the stimulus active in short-term memory.

Sensory memory

A brief stage of memory that holds information for seconds or fractions of a second. It is the first stage in the modal model of memory.

Persistence of vision

The continued perception of light for a fraction of a second after the original light stimulus has been extinguished. Perceiving a trail of light from a moving sparkler is caused by the persistence of vision.

Whole report method

Procedure used in Sperling's experiment on the properties of the visual icon, in which participants were instructed to report all of the stimuli they saw in a brief presentation.

Partial report method

Procedure used in Sperling's experiment on the properties of the visual icon, in which participants were instructed to report only some of the stimuli in a briefly presented display. A cue tone immediately after the display was extinguished indicated which part of the display to report.

Delayed partial report method

Procedure used in Sperling's experiment on the properties of the visual icon, in which participants were instructed to report only some of the stimuli in a briefly presented display. A cue tone that was delayed for a fraction of a second after the display was extinguished indicated which part of the display to report.

Decays

Process by which information is lost from memory due to the passage of time.

Iconic memory

Brief sensory memory for visual stimuli that lasts for a fraction of a second after a stimulus is extinguished. This corresponds to the sensory memory stage of the modal model of memory.

Visual icon

(icon means “image”), corresponds to the sensory memory stage of Atkinson and Shiffrin’s modal model.

Echoic memory

Brief sensory memory for auditory stimuli that lasts for a few seconds after a stimulus is extinguished.

Short-term memory (STM)

A memory mechanism that can hold a limited amount of information for a brief period of time, usually around 30 seconds, unless there is rehearsal (such as repeating a telephone number) to maintain the information in short-term memory. Short-term memory is one of the stages in the modal model of memory.

Recall

Subjects are asked to report stimuli they have previously seen or heard.

Digit span

The number of digits a person can remember. Digit span is used as a measure of the capacity of short-term memory.

Change detection

Detecting differences between pictures or displays that are presented one after another.

Chunking

Combining small units into larger ones, such as when individual words are combined into a meaningful sentence. Chunking can be used to increase the capacity of memory.

Story mnemonic

A memory strategy that puts random items into a meaningful order within a story that can then be more easily remembered.

Mnemonics

Any memory strategy or technique that improves encoding, retention, and/or retrieval of information.

Chunk

Used in connection with the idea of chunking in memory. A chunk is a collection of elements that are strongly associated with each other but weakly associated with elements in other chunks.

Working memory

A limited-capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning.

Phonological loop

The part of working memory that holds and processes verbal and auditory information.

Phonological store

Component of the phonological loop of working memory that holds a limited amount of verbal and auditory information for a few seconds.

Articulatory rehearsal process

Rehearsal process involved in working memory that keeps items in the phonological store from decaying.

Visuospatial sketch pad

The part of working memory that holds and processes visual and spatial information.

Central executive

The part of working memory that coordinates the activity of the phonological loop and the visuospatial sketch pad. The "traffic cop" of the working memory system.

Phonological similarity effect

An effect that occurs when letters or words that sound similar are confused. For example, T and P are two similar-sounding letters that could be confused.

Word length effect

The notion that it is more difficult to remember a list of long words than a list of short words.

Articulatory suppression

Interference with operation of the phonological loop that occurs when a person repeats an irrelevant word such as "the" while carrying out a task that requires the phonological loop.

Visual imagery

A type of mental imagery involving vision, in which an image is experienced in the absence of a visual stimulus.

Mental rotation

Rotating an image of an object in the mind.

Perseveration

Difficulty in switching from one behavior to another, which can hinder a person's ability to solve problems that require flexible thinking. Perseveration is observed in cases in which the prefrontal cortex has been damaged.

Episodic buffer

A component added to Baddeley's original working memory model that serves as a "backup" store that communicates with both long-term memory and the components of working memory. It holds information longer and has greater capacity than the phonological loop or visuospatial sketch pad.

Delayed-response task

A task in which information is provided, a delay is imposed, and then memory is tested. This task has been used to study short-term memory by testing monkeys' ability to hold information about the location of a food reward during a delay.

Activity-silent working memory

Short-term changes in neural network connectivity have been hypothesized as a mechanism for holding information in working memory.

Reading span test

The test used by Daneman and Carpenter to measure reading span.

Reading span

Measure used by Daneman and Carpenter to determine individual differences in working memory. It is the number of 13- to 16-word sentences that a person can read and then correctly remember the last words of all of the sentences.