Memory 1- Basic of Memory, ,
Short Term Memory (STM), and
Working Memory
PERTEMUAN 4
4.1 Introduction to memory
• Memory refers to our ability to:
– retain information about past experiences
– the processes by which we acquire, record or
encode information
– the processes by which we store information
in an accessible format
– The processes by which we can later retrieve
that information.
Methods of testing memory
• Free recall (also called spontaneous recall)
– you are required to generate the test items from your
own memory without any outside help
• Cued recall
– you are required to generate test items from your own
memory, but with the aid of reminders or ‘retrieval
cues’ which may help to jog your memory
• Recognition
– In a recognition test the original test items are represented at the retrieval stage, and you are merely
required to indicate whether or not you recognise
them.
Multistore models of memory
• William James (1890) put forward theories about two
types of memory store, which he called ‘primary memory’
and ‘secondary memory’. Now replaced by the terms
‘short-term memory’ and ‘long-term memory’
• Short-term memory (STM)
– memories which we are holding in conscious awareness, and
which are currently receiving our attention
• Long-term memory (LTM)
– memories which we are not presently holding in conscious
awareness, butwhich are held in storage ready to be recalled.
4.2 Short-term memory
• Information from our senses enters shortterm memory (STM) via sensory registers
• STM is a temporary store for relatively
unprocessed (sound-based or visual)
information.
– Verbal STM has a limited capacity of 7 ± 2
items, which can be used most efficiently by
chunking the information to be remembered.
Measuring STM performance
Digit span test
• 71504
• 284936
• 8351609
• 25736184
• 940627135
Serial position curves for
immediate and delayed recall
4.3 Working memory
• Working memory refers to the processes that
temporarily store and manipulate information so
that we can use that information to follow a
conversation, solve problems etc.
• Baddeley and Hitch’s model of working
memory comprises the phonological loop (PL),
visuo-spatial sketchpad (VSSP), central
executive and, recently, the episodic buffer
4.4 Forgetting and remembering
• Two main mechanisms of forgetting, from
STM or LTM, have been proposed.
– Decay theory proposes that memory fades
with time
– Interference theory proposes that forgetting
occurs because memories disrupt with each
other.
4.5 Limits and failures of memory
• Case study: Temporal lobe surgery (HM)
4.6 Mental representation
• A representation is a sign, symbol or token
that ‘re-presents’ something in its absence
• analogue representations
– representations bear some physical
resemblance to the object or event they
represent.
– For example, a painting or scale model of a
town may retain the structural features and
spatial layout of the buildings and streets in
that town.
• symbolic representations
– do not resemble the represented object or
scene in any way.
– For example linguistic representations, letters
and words are arbitrary symbols that bear no
physical relation to the phonemes or items
they represent.
– they symbolize rather than mimic the thing
they stand for
Imagery
• Mental imagery provides us with a way of
experiencing novel situations or re-experiencing
past events
• Baddeley (1986) assumed that visual imagery is
a function of the visuo–spatial sketchpad (VSSP)
of working memory.
• Logie, Zucco and Baddeley (1990):
– visual imagery interferes more with visual short-term
memory (STM) than with verbal STM
– whereas mental arithmetic interferes more with verbal
STM than visual STM.
Concepts
• A concept is a unit of knowledge that
allows us to recognize novel stimuli as
types of thing we have encountered before
• typicality effects
Connectionism
• Connectionist models exhibit parallel
distributed processing (PDP).