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Cognitive Psychology Winter 2004 -Discussion
Section-
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Memory I. Short term memory
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Cognitive functions

• Perception

Emotion Motivation Action

• Attention

• Memory

• Memory

• Imagery

• Decision-making

• Reasoning, problem-solving

• Language

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Why memory?

• Essentially Temporal integration

• No action without memory

• Improves survival by storage of
• rewarded behaviors.

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Memory

• Big issue in cognitive psychology

• Deals with the mental representation per se

• Big deal because its basically part
• of all cognitions

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Temporal integration

• The time that (sensory) information is summed to
  perform a given cognition/action.

• Example Speech perception. At least 4
  integration-windows

• Why not infinite? One needs to act on the info.

• As long as necessary to do the task, as short as
• possible (to improve temporal resolution).

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Evolutionary issues

• Key to understanding many memory effects
  (context-sensitity, state-dependent learning,
  forgetting, etc.)

• Really simple organisms (particularly simple
  slugs, insects)

Perception ? Action (Reflex)
Stereotypical behavior. Usefulness limited.

• More advanced, but essentially limited organisms

Cognition Selection, modification of action
based on goals, context, etc. Basically trial and
error.
Perception ? Cognition ? Action

• (Most) modern organisms

Memory Influences cognition by previous
experience (learning through punishment and
reward). Storage of best previous response.
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Why forgetting?

• Evolutionary issues Storage and reproduction of
  best response to given previous stimulus type.

• What if reward context changes? ? Useful to limit
  temporal integration for the sake of flexibility.

• Access issues If we store the best response, we
  do good to erase irrelevant ones, or our behavior
  will be polluted by these (now) irrelevant
  issues. Keeping efficiency ? Avoiding
  interference effects.

• Example Interference when learning similar
  material in succession. Resolution Partial
  forgetting.

• Neuropsychological evidence suggests that
  forgetting is indeed an adaptive function
  (Lurija). We only store abstractions of info, not
  depictive details itself. To function.

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Types of memory
Basic classification based on longetivity of
storage, not qualitative aspects (after
Shiffrin Atkinson, 1975)

• Ultra-short term memory (sensory register)

• Short term memory (Working memory)

• Long term memory (Episodic, Semantic, Procedural,
  etc.)

All of them have relatively well established
physiological correlates
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Short term memory

• Demo

.
9 5 0 1 2 3
6 0 6 8 4 8 6
.
.
8 9 1 3 7 6 2 1
.
4 5 6 5 0 1 8 5 8
9 2 1 8 7 3 8 2 1 7
.
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Short term memory

• Demo

9 5 0 1 2 3
6 0 6 8 4 8 6
8 9 1 3 7 6 2 1
4 5 6 5 0 1 8 5 8
9 2 1 8 7 3 8 2 1 7
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? Characteristics of STM

• Information available in absence of the stimulus

• Information is not stored indefinitely. Vanishes.

• There is a capacity limit. The short term storage
• cant keep large amounts of information active.

• The retained information is in a highly sensory-
• Based format. Little abstraction/distortion.

• There are characteristical memory-effects. STM
• profits highly from memorization strategies.

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Capacity of STM

• 7 /- 2 items (G.A. Miller, 1956)

• Improved by chunking. Chunking allows to improve
  the objective capacity of STM

• 7 7 3 8 3 4 3 0 7 2

• 773-834-3072

• Chunking is a form of re-coding of the sensory
• Information. Profits from identification, LTM

• C I A F B I K G B S D I M A D

• C I A F B I K G B S D I M A D

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Retention duration

• Basic retention time is roughly 20 seconds.

• Improved by rehearsal. Continuous rehearsal can
• basically extend the retention duration
  indefinitely.

• Moreover, rehearsal can also facilitate the
  trans-
• tormation of the information from STM to LTM.

• Another strategy to improve retention is sensory
• recoding (Silent) speaking, writing, etc.

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Coding

• Mental representation is sensory, particularly
  acoustic for language material.

• ? Things are encoded in terms of how they
• sound, not what they look like or mean.

• Classical studies People were given material to
• remember and then given confusing material on a
  test
• They were confused by items that sounded similar,
  not by items that mean similar things.

• This effect might be highly material-, task-, and
• strategy-dependent.

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STM effects

• Almost all information that goes into STM is
• subject to the so-called Primacy- and
  Recency-Effect.

• This effect means that information at the
  beginning and at the end of the list has a
  retention advantage

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STM effects

• Interference An alternative explanation for
• forgetting, vs. decay.

• Basic idea Some information displaces others in
  capacity
• limited STM. ? Alternative explanation for
  retention duration, as a side-effect of capacity
  limitations.

• Proactive interference Material learned first
  disrupting
• retention of subsequently learned material.
• Retroactive interference Material learned later
  disrupting
• retention of previously learned material.

Both effects explain why cramming is a bad idea.
Ineffective.
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Information retrieval

• Information retrieval is the complementary step
  to
• Information encoding.

• Saul Sternberg (1966) Information retrieval is
  serial and exhaustive The higher the number the
  distractors there are, the longer it takes the
  whole set is searched.

• Classical effects might be content-dependent ?
  Parallel search possible.

• Homework Watch Brazil (1985).

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Working memory

• Typical inflation of words, in memory field.
  Inspired
• by computer science. Term goes back to Baddeley.

• Means That short term memory has a substructure.

Central executive
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Reasons

• Problems in Exam-design, Format

• My fault...

• Your fault...

• Attitude?

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Come and see me, if...
You scored under 70
You have a question regarding the exam
You have a problem
I will post a sample solution on my website
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In general
QALMRIs much better than the exam. Really, really
good for a hard paper. Good job.