Theme 1 – Short-Term Memory
Baddeley et al. (2015). Chapter 3.
Digit span: maximum number of sequentially presented digits that can reliably be recalled in the correct
order. This is still included in the most used intelligence test (Wechsler Adult Intelligence Scale (WAIS)).
In this basic version, the span doesn’t correlate very highly with general intelligence. A somewhat more
complex version, working memory span (a range of complex memory span tasks in which simultaneous
storage and processing is required), does an excellent job at predicting a wide range of cognitive skills.
The digit span test is typically referred to as reflecting short-term memory (STM). It refers to remembering
things over a few hours or days; it’s the sort of capacity that becomes poorer as we get older; and is
dramatically impaired in patients with Alzheimer’s disease. To psychologists, these are long-term memory
problems.
The STM refer to performance on a particular type of task, involving the simple retention of small amounts
of information, tested either immediately or after a short delay. The system(s) responsible for STM form
part of the working memory system. The WM is a system that stores information temporarily and
manipulates it, so people can perform complex activities such as reasoning, learning, and comprehension.
- It’s based on a theoretical assumption, that tasks such as reasoning and learning depend on a
system that is capable of temporarily holding and manipulating information, a system that has
evolved as a mental workspace.
Memory span measures require two things:
1. Remembering what the items are
2. Remembering the order in which they were presented
In a digit span, we already know the items very well, so it becomes a memory task for order. In another
language it would be more difficult, just as with letters in a random order that don’t make a word. Miller
suggested that memory capacity is limited not by the number of items to be recalled, but by the number of
chunks. Chunking is the process of combining a number of items into a single chunk, typically on the
basis of long-term memory. Grouping can be induced by rhythm.
- Memory for sequences of consonants is substantially poorer when they are similar in sound.
By the late 1960s, they wanted to abandon the attempt to explain STM in terms of a unitary system, in
favor of an explanation involving a number of interacting systems, one of which was closely identified
with the extensive evidence accumulated from verbal STM.
Phonological loop: the component responsible for temporary
storage of speech-like information. It’s part of the
multicomponent working memory model by Baddeley and
Hitch (1974). The phonological loop has two subcomponents:
- A short-term store, which is limited in capacity. Items
are registered as memory traces that decay within a
few seconds.
- An articulatory rehearsal process, which refreshes the
memory traces by saying the items to oneself
(subvocal rehearsal) that depends on a vocal or
subvocal articulatory process.
Phonological similarity effect is a tendency for immediate
serial recall of verbal material to be reduced, when the items
are similar in sound. This effect disappears if the lists are
increased in length and participants are allowed several
learning trials, where similarity of meaning becomes much more important. The LTM gains more from
relying on meaning than on sound.
1
Baddeley et al. (2015). Chapter 3.
Digit span: maximum number of sequentially presented digits that can reliably be recalled in the correct
order. This is still included in the most used intelligence test (Wechsler Adult Intelligence Scale (WAIS)).
In this basic version, the span doesn’t correlate very highly with general intelligence. A somewhat more
complex version, working memory span (a range of complex memory span tasks in which simultaneous
storage and processing is required), does an excellent job at predicting a wide range of cognitive skills.
The digit span test is typically referred to as reflecting short-term memory (STM). It refers to remembering
things over a few hours or days; it’s the sort of capacity that becomes poorer as we get older; and is
dramatically impaired in patients with Alzheimer’s disease. To psychologists, these are long-term memory
problems.
The STM refer to performance on a particular type of task, involving the simple retention of small amounts
of information, tested either immediately or after a short delay. The system(s) responsible for STM form
part of the working memory system. The WM is a system that stores information temporarily and
manipulates it, so people can perform complex activities such as reasoning, learning, and comprehension.
- It’s based on a theoretical assumption, that tasks such as reasoning and learning depend on a
system that is capable of temporarily holding and manipulating information, a system that has
evolved as a mental workspace.
Memory span measures require two things:
1. Remembering what the items are
2. Remembering the order in which they were presented
In a digit span, we already know the items very well, so it becomes a memory task for order. In another
language it would be more difficult, just as with letters in a random order that don’t make a word. Miller
suggested that memory capacity is limited not by the number of items to be recalled, but by the number of
chunks. Chunking is the process of combining a number of items into a single chunk, typically on the
basis of long-term memory. Grouping can be induced by rhythm.
- Memory for sequences of consonants is substantially poorer when they are similar in sound.
By the late 1960s, they wanted to abandon the attempt to explain STM in terms of a unitary system, in
favor of an explanation involving a number of interacting systems, one of which was closely identified
with the extensive evidence accumulated from verbal STM.
Phonological loop: the component responsible for temporary
storage of speech-like information. It’s part of the
multicomponent working memory model by Baddeley and
Hitch (1974). The phonological loop has two subcomponents:
- A short-term store, which is limited in capacity. Items
are registered as memory traces that decay within a
few seconds.
- An articulatory rehearsal process, which refreshes the
memory traces by saying the items to oneself
(subvocal rehearsal) that depends on a vocal or
subvocal articulatory process.
Phonological similarity effect is a tendency for immediate
serial recall of verbal material to be reduced, when the items
are similar in sound. This effect disappears if the lists are
increased in length and participants are allowed several
learning trials, where similarity of meaning becomes much more important. The LTM gains more from
relying on meaning than on sound.
1
