The Architecture of Human Memory

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The Architecture of Human Memory

• Information Processing Theory

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Epistemic Heritage To The Model

• Memory researcher dates back to 1885 with
  Hermann Ebbinhaus who looked at memory in terms
  of nonsense symbols.
• In the 1950s cognitive scientists began creating
  models that acknowledge the stages of acquisition
  storage and retrieval.
• The increasing influence of computers were
  clearly reflected in these models that came to
  be known as Information Processing Models
• One of the most influential models was the modal
  model proposed by Atkinson and Shiffrin in 1968.

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Modal Model
Long Term Memory Declarative Knowledge Proc
edural Knowledge Conditional Knowledge
Short term Memory
Sensory memory
retrieval
encoding
Rehearsal
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Criticisms of the Modal Model

• Proposes three separate structures in memory
  ,short term, long term and sensory. Critics
  suggest there are many smaller interrelated
  parts.
• Assumes that information only flows one way in a
  linear fashion. It is believed that information
  in long term memory influences short term memory
  and information is processed concurrently in
  short term and long term memory
• Does not correspond to any one area of the brain.
  A newer theory called the connectionist model
  better explains activated portions of the brain.

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Description of Sensory Memory

• Sensory memory-is a system that briefly holds
  stimuli in sensory registers so that perceptual
  analyses can occur before the information is
  lost.

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Two Types of Sensory Registers

• Visual registers are very limited ,visual memory
  can only process 7 to 9 pieces of information at
  any given time. Information is only available
  briefly 0.5 seconds
• Auditory Registers can only process 5 to 7 pieces
  of information and can only be stored for up to 4
  seconds before the information becomes unavailable

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Steps in sensory memory process

• Perception enables us to identify incoming
  perceptual stimuli and direct attention to them
• Pattern recognition enables us to associate
  perceptual information with a recognizable
  pattern then it is forwarded to short term memory

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Description of Short Term Memory

• Short term memory is the place where information
  is stored for meaning. It has limited capacity
  and duration. The current name for short term
  memory is working memory. It can only hold 7
  chunks plus or minus two (Miller). The duration
  is not limited by time so much but by
  interference and capacity overload.

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Postulation about short term and sensory memory

• Memory systems are functionally separate
• Attention is limited
• Process are controlled (constructing inferences
  when reading) and automatic (driving a car)
  Automatic task are much easier to perform and
  require much fewer cognitive resources (e.g.
  strategies)
• Meaning is constructed based on context and prior
  knowledge

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Working Memory

• Baddeley replaced the unitary short term store
  with a working memory system
• Central executive, which is assumed to be an
  attention-controlling system, is important in
  skills such as chess playing
• Visuospatial sketch pad, which manipulates visual
  images
• Phonological loop, which stores and rehearses
  speech-based information and is necessary for the
  acquisition of both native and second-language
  vocabulary.

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Long Term Memory

• It is referred to as a permanent storehouse for
  information. Long term memory is capable of
  storing unlimited amounts of information.
  Anything that you want to remember for a long
  period of time must be transferred for short term
  to long term memory.

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Baddeleys Original Model of Working Memory
Central Executive
Visuospatial Sketchpad
Phonological Loop
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Baddeleys Revised Model of Working Memory 2001
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Central Executive
Visuospatial Sketchpad
Episodic Buffer
Phonological loop
Episodic LTM
Language
Visual Semantics
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The Phonological Loop

• Broken into two components a phonological store
  and an articulatory rehearsal system. It is
  assumed to decay over time unless refreshed by
  rehearsal, It is dependent on the second
  component the articulatory loop.

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Phonological Store

• Similarity effect-the immediate recall of items
  that sound similar (B ,V, G T, C,) is poorer than
  dissimilar items (F ,K ,Y, W, M,R ,)
• Similarity of meaning has little effect in the
  standard immediate recall paradigm
• The opposite is true for the learning of
  multitrial long term learning of ten items, it
  solely depends on semantic rather than acoustic

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Articulatory Rehearsal

• It was proposed to give an account of the
  immediate word length effect, whereby the is the
  immediate serial recall is a direct function of
  the length of items being retained (Baddeley,
  Thomson Buchanan) An example is a sequence such
  as sum, pay, wit, bar, hop is much more likely to
  be recalled correctly than helicopter,
  university, television, alligator, opportunity.
  This reflects the slower rehearsal of longer
  words that allows greater forgetting

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The Visuospatial Sketchpad

• Assumed to capable of temporarily maintaining and
  manipulating visouspatial information
• Forms an interface between visual and spatial
  information accessed either by senses or long
  term memory

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The Central Executive

• In charge of focusing attention
• Also in charge of dividing attention
• Switching attention also happens here
• Forms an interface between long term memory and
  subsystems

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Episodic Buffer

• This is assumed to be capable of combining
  information from LTM with that from the slave
  systems.
• Dedicated to linking information across domains
  to form integrated units of visual, spatial, and
  verbal information (e.g., the memory of a story
  or a movie scene).

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Summary

• Baddeley replaced the unitary short-term store
  with a working memory system consisting of three
  components an attention-like central executive,
  a phonological loop holding speech-based
  information, and a visuo-spatial sketchpad
  specialized for spatial and visual coding.
• This working memory system is of relevance to
  non-memory activities such as comprehension and
  verbal reasoning. The phonological loop and
  visuo-spatial sketchpad have both been
  sub-divided into two-component systems, one
  component for storage and one for processing. The
  central executive fulfils several functions. Many
  of the characteristics of the central executive
  remain unclear.

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