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Memory:Interference, The Critical Assumption, Limited capacity

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Cognitive Psychology ­ PSY 504
VU
Lesson 30
Memory
Interference
Various factors can affect the amount of activation that is spread to a knowledge structure. From
the previous experiments we can infer that strength of encoding has an effect such that more
strongly encoded information receives greater activation. Another factor is the number of
alternative network paths down which activation can spread.
Encoding is a process of transfer the information from short term memory to long term memory
through codes.
This following figure is showing the activation in a network. The word penguin has two links, one
is bird and other is swimming. Bird and swimming have their links as well. If we think about
swimming the activation model will become active and we can recall penguin because of its
connection with swimming.
The Fan Effect
Anderson (1974) performed an experiment. He had subjects to memorize 26 facts. In these
statements some persons were paired with only one location and some locations with only one
person. Other persons were paired with two locations and other locations were paired with two
persons. Each statements was followed by two numbers, reflecting the number of facts
associated with the subject and the location. For instance, sentence3 is labeled 2-1 because their
subject occurs in two sentences (sentences 3 and 4) and its location occurs in one sentence
(sentence 3). The sentences were;
The doctor is in the bank. (1-1)
The fireman is in the park. (1-2)
The lawyer is in the church. (2-1)
The lawyer is in the park. (2-2)
Number of facts associated with subject and location.
Subjects were drilled on each sentence. Before beginning the reaction time phase, subjects were
able to recall all the locations associated with a particular type of person (e.g. doctor) and all the
people associated with a particular location (e.g. park). Then they began a speeded- recognition
phase of experiment, during which they were presented with sentences and had to judge whether
they recognized them from the study set. Foil sentences were created by repairing of people and
locations from the study set.
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Cognitive Psychology ­ PSY 504
VU
Results
The recognition time for sentences as a function of number facts learned about persons and
location.
Specific Location
Specific Person
1 sentence
2 sentences
1sentence
1.11
1.17
2 sentences
1.17
1.22
Results are showing recognition time increases as a function of both the number of facts studied
about the person and the number of facts studied about the person and the number of facts
studied about the location.
The Fan Effect: Network
The network representation for sentences 1 through4 is given below.
Every node has three parts such as relations, subject, and location. By applying the activation
concept to this representation, we can nicely account for the increase in reaction time. Subject
might recognize such as probe as a lawyer is in the park. First suppose the presentation of terms
lawyer, in and park serves to activate their presentations in memory. Then activation will spread
from these nodes to activate the target proposition and enable it to be recognized. Fireman and
lawyer interfere with park. But there is no interference between doctor and lawyer, so there is no
fan effect.
The Critical Assumption
The amount of activation reaching the proposition is inversely related to the number of links
leading from it.
Subjects should be slower to recognize a fact involving lawyer and park than one connecting
doctor and bank because more paths emanate from the first set of concepts. That is, in the
lawyer and park case two paths point from each of the concepts to the two propositions in which
each was studied, whereas only one path leads from each of the doctor and bank concepts.
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Cognitive Psychology ­ PSY 504
VU
Activation: Limited capacity
This is one experiment among many points to a limited-capacity feature of the spreading-
activation process. The nodes, such as lawyer and park, from which the spread of activation
starts can be called source nodes. One node can has thousands nodes. This one node supply
energy to other nodes the energy of this node is also transfer to other but in a very limited
amount. Like in an example of experiment of last lecture the word dog is also activate other kind
of dogs, meats, bones and other animals.
A source node has a fixed capacity for emitting activation. This capacity is divided among all the
paths emanating from that node. The more paths that exist, the less activation will be assigned to
any one path and the slower will be the rate of activation.
At one time we can make many nodes with one word. Like the word fish has many links. We can
remember many other things, like other kind of fish, water, sea, other sea animals etc.
Another example of Gambler, we can make many links with this word like cards, the pictures on
cards, the figures of cards etc.
Interference
The fan effect is the name given to this increase in reaction time related to an increase in the
number of facts associated with a concept. It is so named because the increase in reaction time
is related to an increase in the fan of facts emanating from the network representation of the
concept. The term conveys the fact that additional information about a concept interferes with
memory for a particular piece of information. Interference affects a wider range of measures than
just recognition time. Fan effect is reserved for interference effects as measured by reaction time.
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Table of Contents:
  1. INTRODUCTION:Historical Background
  2. THE INFORMATION PROCESSING APPROACH
  3. COGNITIVE NEUROPSYCHOLOGY:Brains of Dead People, The Neuron
  4. COGNITIVE NEUROPSYCHOLOGY (CONTINUED):The Eye, The visual pathway
  5. COGNITIVE PSYCHOLOGY (CONTINUED):Hubel & Wiesel, Sensory Memory
  6. VISUAL SENSORY MEMORY EXPERIMENTS (CONTINUED):Psychological Time
  7. ATTENTION:Single-mindedness, In Shadowing Paradigm, Attention and meaning
  8. ATTENTION (continued):Implications, Treisman’s Model, Norman’s Model
  9. ATTENTION (continued):Capacity Models, Arousal, Multimode Theory
  10. ATTENTION:Subsidiary Task, Capacity Theory, Reaction Time & Accuracy, Implications
  11. RECAP OF LAST LESSONS:AUTOMATICITY, Automatic Processing
  12. AUTOMATICITY (continued):Experiment, Implications, Task interference
  13. AUTOMATICITY (continued):Predicting flight performance, Thought suppression
  14. PATTERN RECOGNITION:Template Matching Models, Human flexibility
  15. PATTERN RECOGNITION:Implications, Phonemes, Voicing, Place of articulation
  16. PATTERN RECOGNITION (continued):Adaptation paradigm
  17. PATTERN RECOGNITION (continued):Gestalt Theory of Perception
  18. PATTERN RECOGNITION (continued):Queen Elizabeth’s vase, Palmer (1977)
  19. OBJECT PERCEPTION (continued):Segmentation, Recognition of object
  20. ATTENTION & PATTERN RECOGNITION:Word Superiority Effect
  21. PATTERN RECOGNITION (CONTINUED):Neural Networks, Patterns of connections
  22. PATTERN RECOGNITION (CONTINUED):Effects of Sentence Context
  23. MEMORY:Short Term Working Memory, Atkinson & Shiffrin Model
  24. MEMORY:Rate of forgetting, Size of memory set
  25. Memory:Activation in a network, Magic number 7, Chunking
  26. Memory:Chunking, Individual differences in chunking
  27. MEMORY:THE NATURE OF FORGETTING, Release from PI, Central Executive
  28. Memory:Atkinson & Shiffrin Model, Long Term Memory, Different kinds of LTM
  29. Memory:Spread of Activation, Associative Priming, Implications, More Priming
  30. Memory:Interference, The Critical Assumption, Limited capacity
  31. Memory:Interference, Historical Memories, Recall versus Recognition
  32. Memory:Are forgotten memories lost forever?
  33. Memory:Recognition of lost memories, Representation of knowledge
  34. Memory:Benefits of Categorization, Levels of Categories
  35. Memory:Prototype, Rosch and Colleagues, Experiments of Stephen Read
  36. Memory:Schema Theory, A European Solution, Generalization hierarchies
  37. Memory:Superset Schemas, Part hierarchy, Slots Have More Schemas
  38. MEMORY:Representation of knowledge (continued), Memory for stories
  39. Memory:Representation of knowledge, PQ4R Method, Elaboration
  40. Memory:Study Methods, Analyze Story Structure, Use Multiple Modalities
  41. Memory:Mental Imagery, More evidence, Kosslyn yet again, Image Comparison
  42. Mental Imagery:Eidetic Imagery, Eidetic Psychotherapy, Hot and cold imagery
  43. Language and thought:Productivity & Regularity, Linguistic Intuition
  44. Cognitive development:Assimilation, Accommodation, Stage Theory
  45. Cognitive Development:Gender Identity, Learning Mathematics, Sensory Memory