1. Ψ
Cognitive Psychology
Spring 2005
-Discussion Section-

2. Cognitive functions Perception Attention Memory Memory Imagery
Emotion
Motivation
Action
Attention
Memory
Memory
Imagery
Decision-making
Reasoning, problem-solving
Language

3. Memory is becoming popular…
Memento (2000)
Finding Nemo (2003)
Eternal Sunshine of the Spotless mind (2004)
50 first dates (2004) …
A very mixed blessing

4. Memory
I. Short term memory

5. 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

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

7. 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

8.  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
can´t 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.

9. Capacity of STM C I A F B I K G B S D I M A D
7 +/- 2 items (G.A. Miller, 1956)
Improved by chunking. Chunking allows to improve the objective capacity of STM:
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

10. 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.

11. 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.

12. 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:

13. 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.

14. 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).

15. 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
Phonological loop
Visuospatial
sketchpad

16. Memory
II. Long term memory

17. Characteristics of LTM
STM
LTM
Retention duration is very limited
Capacity is limited (7 +/- 2)
Sensory coding
Very long, potentially life-long.
Virtually unlimited, hard to study, hard to quantify.
Semantic, conceptual coding.
Retained is the gist, the meaning of
information that was learnt.

18. Structure of LTM LTM Declarative Procedural Episodic Semantic
The real deal?
Methods matter.
Example: Experimental evidence for decontextualisation.
# of exposures E S
A gradient, vs. categorical

19. Some brain facts about memory...
Declarative vs. Procedural has a brain basis (Neocortex vs. Cerebellum).
Most of the back part of the brain
(posterior part) involved in LTM.
Exact coding principle is unknown. Many theories (holistic, etc.). In general, we know much less about the biological basis than about the biol. basis of STM.
Processing tissue = Storing tissue. Not like in Computers. This has important implications...

20. Basic memory processes
Encoding
Storage
Retrieval

21. Encoding *Information can be encoded on different levels
*Encoding of meaning is usually more stable
Than encoding for physical attributes.
*Levels of Processing theory. Critique:
Highly dependent on retrieval task.
*Encoding into LTM generally by paying
attention, rehearsal.

22. Storage: LTM „Forgetting“ due to
*Decay and/or loss of retrieval cues
*Interference
*OVERWRITING
Each information retrieval is a new encoding.

23. Principles of Information retrieval:
Categorization: Subjects generally recall lists in the order of their internal categories.
Encoding specificity: Retrieval is easier if the context of retrieval matches the context of encoding as close as possible.
 Context effect, mood/state-dependent memory.
Cues: Memory retrieval is best, if as many cues as possible are attached to a given memory (spacing), but as few as possible memories to any given cue.
Good
Bad

24. Eye-witness memory
Elizabeth Loftus, Lady „Eye-witness memory“

25. Eye-witness memory

26. Eye-witness memory
Blue van or red car?

27. Eye-witness memory

28. Eye-witness memory
Red hair or bald?

29. Eye-witness memory

30. Eye-witness memory
Black boots or sandals?

31. Eye-witness memory Not really reliable
Fallible to distortions, information that was introduced later. (due to constructive nature of memory – overwriting).
Likely cause: Source memory failure
Can be offset by paying attention to relevant things.

32. „Flashbulb“ memories Characteristics: Extremely vivid
High personal confidence of accuracy
Usually for rare events of personal significance.
Examples:
9/11
Tschernobyl
Princess Diana
...

33. Flashbulb memories
Surprisingly, they are NOT much more accurate than other memories, just more „memorable“.
They do NOT form a special system, vividness can be explained by basic memory mechanisms:
-Attention (Relevance) -Rehearsal
-Lack of interference -Spacing
No inflation of concepts  Good science.

34. Repressed memories A hot issue since the mid 90s. Number of
Cases exloded.  Into the thousands.
People have been sued and convicted
Of ghastly crimes (often involving relatives)
Usually based on concept of repression (Introduced by Freud).

35. Repressed memories
While it is impossible to tell in an invididual case, some things are very troubling...
Scientific concept of Repression is extremely shaky. No evidence that it can happen. In fact, the opposite seems to be true (PTSD)
It has been shown that very vivid memory can be implanted into the minds of both adults and children. The subjects can´t discriminate real vs. implanted memories.
The process of recovery (recovery therapy) is very similar to the process used for artificial implantation.
Evidently wrong „recovered“ memories seem to be progressive,  the reports of the abuse get more and more severe over time.
People who solidly claim that they were abducted by space aliens and similarly outrageous stories usually have bad source memory.

36. The seven sins of memory by Dan Schacter

37. What are the seven sins? Pride Envy Gluttony Lust Anger Greed Sloth
Transience
Absentmindedness
Blocking
Misattribution
Suggestibility
Bias
Persistence