CHAPTER 14 Memory and Cognition Memory and Behavior Theory

1
CHAPTER 14

• Memory and Cognition

2
Memory and Behavior Theory

• Organisms must often change their behavior to
  adjust to changing events.
• Some events are not now present, but occurred in
  past.
• So, memory is a basic psychological process in
  behavioral adaptation.
• Without ability to remember, it is difficult to
  imagine ability to learn.

3
Memory and Behavior Theory

• Behaviorists have spent great time and energy
  over past 100 years devising suitable laboratory
  paradigms of Pavlovian and operant conditioning.
• But, basic behavioral preparations to study
  memory are not nearly so well-developed.
• Very little effort has been devoted to systematic
  study of memory.

4
Memory and Behavior Theory

• To early behaviorists, it was most important to
  understand learning of associations, not memory.
• Extreme conservatism governed theoretical efforts
  of early behaviorists.
• Delayed response paradigm did not allow
  researchers to study wide range of empirical and
  theoretical issues central to understanding
  memory.

5
Delayed Response Problem

• Hunter (1913)
• Site baiting
• Delay
• Choice

6
Delayed Response Problem
Time 2
7
Delayed Response Mediation

• Central representation
• Behavioral mediation
• Special tests for behavioral mediation
• Disorient animal during delay
• Remove animal during delay

8
Memory and Behavior Theory

• Neglect of memory is coming to an end.
• Learning alone simply cannot explain intelligent
  action other cognitive processes (like memory,
  attention, and conceptualization) also promote
  adaptive behavior.
• Innovative experimental techniques can now
  disclose operation of memory and other cognitive
  processes.

9
Animal Memory

• We will focus on laboratory study of memory in
  animals.
• Research documents unprecedented flexibility in
  remembering past events.
• New memory methods can be also be used to
  illuminate other adaptive behavioral processes
  like attention, timing, counting, and navigation.

10
Animal Memory

• We will focus on study of short-term or working
  memory.
• Memory for changing events, not static rules of
  the game.
• Key method is delayed matching-to-sample and its
  numerous variants.

11
Delayed Matching-to-Sample

• Successive version
• Choice version

12
Successive Matching-to-Sample
13
Choice Matching-to-Sample
14
Delayed Choice Matching
15
Delayed Matching Parameters

• Delay duration
• Sample duration
• Intertrial interval

16
Delay Duration
17
Sample Duration
18
Intertrial Interval
19
Memory Trace Theory

• Trace strength grows during sample.
• Trace strength fades after sample.
• Interfering traces fade during ITI.

20
Inadequacies of Trace Theory

• Effectiveness of cued delay intervals
• Effectiveness of cued test stimuli
• Prospective vs retrospective tasks
• Directed forgetting effect
• Serial position effect

21
Cued Delay Intervals

• Sample and test stimuli two colors.
• Two retention intervals 2 and 8 sec.
• Two tones are presented during sample stimuli
  one signals 2-sec delay interval and other
  signals 8-sec delay interval.
• Do such delay cues have an effect?
• Control group given uncorrelated cues.
• Delay cues were effective.

22
Cued Delay Intervals
23
Miscued Delay Intervals

• After correlated training, miscuing given
• Short delay signalled, but long delay given.
• Long delay signalled, but short delay given.
• Miscuing did affect performance.

24
Miscued Delay Intervals
25
Cued Test Stimuli

• Sample stimuli two colors.
• Two pairs of test stimuli two colors or two
  lines of different orientations.
• Two forms presented on sample stimuli one
  signals color test and other signals line test.
• Do such test dimension cues have an effect?

26
Miscued Test Stimuli

• Test dimensions miscued.
• Got a color test after the line cue.
• Got a line test after the color cue.
• Each miscuing disrupted memory performance.
• Suggests that pigeons learned to anticipate
  particular test stimuli after particular prior
  cues.

27
Prospection vs Retrospection

• Trace theory is backward looking.
• At testing, one reflects back on past for clues
  concerning how to respond now.
• Retrospective memory is common.
• E.g., when two or more students raise their
  hands, a teacher refrains from calling on student
  who has recently answered question and calls on
  another student who has not recently done so.

28
Prospection vs Retrospection

• But, on other occasions, memory is forward
  looking.
• So, when his mother returns home, a son will tell
  her that she has received a phone call, something
  that he has been preparing to do since receiving
  the call.
• In effect, intention to tell his mother the
  message is a prospective memory that he actively
  holds until he conveys the information to her.

29
Prospection vs Retrospection

• Prospection and retrospection seem to be
  different memory processes.
• Prospection may prepare you to perform vital
  activities.
• Retrospection may prevent you from repeating
  them.
• Experimental tasks can be designed that promote
  prospection and retrospection in animal memory.

30
Prospection vs Retrospection
31
Prospection vs Retrospection
32
Directed Forgetting Effect

• Many theorists believe that humans rehearse
  information to prevent its loss.
• Do animals rehearse?
• One way to tell involves the directed forgetting
  paradigm
• Give cues to remember or to forget after the
  sample stimulus.
• Remember cues precede a memory test forget cues
  precede no memory test.

33
Directed Forgetting Effect

• To see if forget cues affect rehearsal, memory
  test follows forget cue.
• Poorer memory after forget cue than remember cue
  suggests discriminative control of rehearsal.
• Animal memory is lower on forget-cued trials than
  on remember-cued trials.
• Memory is not just a passive trace.

34
Serial Position Effect

• Lists of four visual stimuli were given one at a
  time on upper of two screens.
• Probe item shown on lower screen some time after
  fourth list item.
• If probe had been in list, then left key
  response?food.
• If probe had not been in list, then right key
  response?food.
• Otherwise, no food was given.

35
Serial Position Effect

• If probe item had been in list, then accuracy
  depended both on position of item in list and
  time between last list item and choice test.
• Similar patterns were seen for humans, monkeys,
  and pigeons, although exact values of parameters
  differed.
• Results again question completeness of trace
  theory of memory.

36
Serial Position Effect
37
Spatial Memory

• Delayed spatial matching-to-sample
• Olton radial-arm maze
• Naturalistic paradigms

38
Delayed Spatial Matching-to-Sample

• 3 x 3 stimulus array
• 1 position shown as sample
• 2 positions shown as tests
• Match to spatial location

39
Delayed Spatial Matching-to-Sample
40
Delayed Spatial Matching-to-Sample

• Pigeons learned spatial MTS task.
• Sample location memory increased the longer the
  sample was presented.
• Sample location memory decreased the longer the
  delay between sample presentation and choice test.

41
Olton Radial-Arm Maze

• 8 arms
• All baited
• Rat visits arms until all food is found
• Number of visits is behavioral measure
• 8 is minimum
• Pattern of visits is also recorded

42
Olton Radial-Arm Maze
43
Olton Radial-Arm Maze

• Task requires reference memory.
• Rat must learn rules of the game layout of
  maze, return trips to visited arms should be
  avoided, and so on.
• Task also requires working memory.
• Rat must remember where it has been in order not
  to repeat a visit.
• At end of trial, rat can erase working memory and
  retain reference memory.

44
Olton Radial-Arm Maze

• Rats do very well in this task, visiting little
  more than 8 arms on each trial.
• How do they do it?
• Could processes other than spatial learning and
  memory be involved?

45
Olton Radial-Arm Maze

• Rats could visit maze arms in same order.
• This plan would ease working memory requirements,
  because responses could be run off automatically,
  each one triggering next.
• But, rats do not visit same arms in same order
  every day indeed, pattern of arm visits is
  nearly random.

46
Olton Radial-Arm Maze

• Perhaps rats can smell food at end of arms or
  smell scents in visited arms.
• These possibilities have also been eliminated.
• Dousing maze with after-shave lotion does not
  impair performance.
• Also, if after rat has made several choices, arms
  that it has chosen are again baited with food,
  then rat does not return to those arms.

47
Olton Radial-Arm Maze

• If one rotates maze so that spatial cues outside
  maze no longer give accurate information about
  where rat has and has not been, then rats
  performance deteriorates.
• Even though odor cues are available, rat makes
  mistakes by visiting locations that used to
  contain unvisited arms, but now, after maze
  rotation, contain arms that were already visited.

48
Olton Radial-Arm Maze

• It seems as if rat masters task by learning the
  maze perhaps by constructing a cognitive map in
  reference memory.
• Rat then uses its working memory to keep track of
  where it has already been.

49
Olton Radial-Arm Maze

• Unlike results in delayed MTS studies--where
  forgetting is often complete after 30 sec to 1
  min--rats memory for radial maze is remarkably
  durable.
• One can start a trial, and after rats first four
  choices, impose a delay of up to 4 hours spent
  outside maze.
• When rat is returned to maze, it goes to four
  unvisited arms almost as if there had been no
  delay at all.

50
Olton Radial-Arm Maze

• Introducing delays into rats sequential
  selection of maze arms has yielded another
  important discovery
• Rats may use both prospective and retrospective
  memories in radial-maze performance.

51
Olton Radial-Arm Maze

• Rats first trained on 12-arm radial maze.
• Then, rats received testing trials on which they
  chose among 12 arms until they made 2, 4, 6, 8,
  or 10 selections.
• Rats then removed from maze and put into small
  holding cage for 15 min.
• Finally, rats returned to maze and allowed to
  make remaining choices.

52
Olton Radial-Arm Maze

• As choices before delay rose from 2 to 4 to 6,
  number of choices to complete maze increased.
• Suggests use of retrospective memory.
• But, as choices before delay rose from 6 to 8 to
  10, number of choices to complete maze fell.
• Suggests use of prospective memory more arms
  visited, fewer remaining arms need to be
  remembered.

53
Olton Radial-Arm Maze
54
Olton Radial-Arm Maze

• Rats may be able to switch memory codes due to
  difficulty of memory load.
• As visits accumulate, rat remembers each until 6
  arms have been visited.
• Then prospective load (which starts at 12) falls
  below 6 items and continues to fall as more arms
  are visited.
• After 6 visits, it becomes easier for rat to
  switch to prospective code than to use more
  burdensome retrospective code.

55
More on Cognitive Maps Chimpanzee Behavior
56
More on Cognitive Maps Chimpanzee Behavior

• Chimpanzee on experimenters back
• Watched site bating 18 locations
• Later released to retrieve food
• Most food found
• Retrieval route differed from baiting route
• Traveling distance was very efficient

57
More on Cognitive Maps Chimpanzee Behavior

• Second experiment
• Same general plan
• 18 locations 9 fruits and 9 vegetables
• First retrieval visits were to retrieve fruits,
  according with food preferences

58
More on Cognitive Maps Chimpanzee Behavior

• Results suggest that chimpanzees have something
  like a cognitive map of compound.
• As they are carried around, chimpanzees store
  information about food locations not on the basis
  of the particular path that they are traveling,
  but on the basis of their cognitive map.

59
More on Cognitive Maps Chimpanzee Behavior

• Chimpanzees work with this cognitive
  representation to determine most efficient route
  to travel in gathering food.
• This solution depends on cognitive mediation
  between inputs and behavior that transforms and
  organizes inputs.
• To explain chimpanzees behavior without appeal
  to mediating processes would provide an
  impoverished view of what animal does.

60
Master Mnemonist Clarks Nutcracker
61
Master Mnemonist Clarks Nutcracker

• Nutcrackers collect pine seeds in small pouch
  under tongue.
• They drive seeds into soil with beak.
• Nutcrackers return to small feeding caches months
  later to retrieve seeds--even under cover of
  snow.
• In autumn, 33,000 seeds may be stored in 2,500
  caches for later recovery in winter and spring.

62
Master Mnemonist Clarks Nutcracker

• This is truly a remarkable feat of spatial
  memory.
• But, what does it imply about general memory
  ability of this species?

63
Master Mnemonist Clarks Nutcracker

• Laboratory experiments studied this bird species
  and three others that do not store and recover
  food.
• Birds received two types of memory tasks one
  for location of a stimulus and other for color of
  a stimulus.
• Clarks nutcrackers won contest for spatial
  memory, but were in middle of pack in contest for
  color memory.

64
Master Mnemonist Clarks Nutcracker

• Data suggest that Clarks nutcrackers do not have
  generally exceptional memory.
• Rather, they possess a more highly advanced
  spatial memory that may be a special adaptation
  to their particular evolutionary niche.
• Idea related to Seligmans (1971) notion of
  preparedness.

65
Temporal Memory

• Uses a delayed discrimination task.
• Temporal discrimination also uses a peak
  procedure.
• Former technique is better suited to working
  memory latter technique is better suited to
  reference memory.

66
Delayed Discrimination Procedure

• Animals can discriminate and remember duration of
  a stimulus.
• Delayed discrimination procedure is well-suited
  to documenting these facts.

67
Go/No Go Matching-To-Sample with Temporal Samples
and Line Orientation Test Stimuli
68
Temporal Discrimination Learning

• Pigeons can remember different durations of a red
  sample stimulus and report that memory during
  test stimuli of different line orientations.

69
Temporal Discrimination Learning
70
Temporal Discrimination Behavior

• Birds not only remember two very different
  stimulus durations (2 sec versus 16 seconds), but
  a whole range of more or less different durations
  (2, 4, 6, 8, 10, 12, 14, and 16 sec).

71
Temporal Discrimination Behavior
72
Temporal Discrimination Memory

• Pigeons even remember sample stimulus durations
  over sample-test delays as long as 16 sec.

73
Temporal Discrimination Memory
74
Delayed Discrimination Procedure

• Beyond attributes of single stimuli, pigeons also
  remember temporal order (e.g., red-green) of two
  differently-colored stimuli.
• Spatial order (e.g., left-right) of two
  identically-colored stimuli.
• Relative duration (e.g., short-long) of two
  differently-colored stimuli.

75
Number Discrimination

• Delayed discrimination procedure.
• Other discrimination techniques.

76
Delayed Discrimination Task

• After two noise bursts, a left lever press
  produced food, but a right lever press did not.
• After four noise bursts, a right lever press
  produced food, but a left lever press did not.
• Rats learned.

77
Delayed Discrimination Task

• What about abstractness of rats number
  discrimination?
• Trained with two or four auditory stimuli.
• Tested with two or four visual stimuli.
• Although there was some decrement in
  discrimination accuracy, rats showed transfer
  from auditory to visual stimuli.

78
Delayed Discrimination Task

• Pigeons can be taught to discriminate number of
  their own key pecks.
• After 35 center key responses, pecks to left key
  led to immediate food, but pecks to right key led
  to food after 1-min delay.
• After 50 center key responses, pecks to right key
  led to immediate food, but pecks to left key led
  to food after 1-min delay.

79
Delayed Discrimination Task

• Pigeons learned this task.
• As smaller response requirement was increased,
  accuracy of pigeons discrimination steadily
  decreased.
• It takes longer for pigeons to peck 35 times than
  to peck 50 times.
• Perhaps true discriminative stimulus was duration
  of center key light rather than number of times
  it was pecked.

80
Delayed Discrimination Task

• Later work suggests that number rather than time
  controlled behavior.
• Critical results came from a statistical analysis
  that separated trials where time to complete
  required number of pecks was lower than average
  from trials where time to complete required
  number of pecks was higher than average.

81
Delayed Discrimination Task

• This temporal segregation had little effect on
  strength of discriminative behavior.
• So, it was number of pecks that were made in a
  trial and not total time that it took to complete
  those pecks that controlled pigeons choice
  behavior.

82
Delayed Discrimination Task

• Another kind of study.
• Here, discriminative stimuli presented number and
  time as redundant stimuli--either or both could
  be used to solve the discrimination.
• Rats received two noise bursts in 2 sec and eight
  noise bursts in 8 sec either number or time or
  both could then serve as discriminative stimulus.
  

83
Delayed Discrimination Task

• Tests followed in which number and time were
  uncorrelated.
• E.g., rats received two noise bursts in 8 sec and
  eight noise bursts in 2 sec.
• Data showed that rats discriminated both number
  and time cues.
• Similar results were found for pigeons similarly
  trained and tested with visual stimuli.

84
Complex Number Use

• In order to use numbers in mathematics requires
• Cardinality symbols stand for different numbers
  of items.
• Ordinality different numbers of items can be
  placed along a continuous scale.
• Can animals use cardinality and ordinality?

85
Cardinality

• Arabic number control
• Involves association of arbitrary symbols with
  different numbers of items
• Chimpanzees were given an extended training
  regimen en route to final performance.

86
Cardinality
87
Cardinality
88
Ordinality

• Response order maps to numerical order.
• Does mapping imply appreciation of serial order
  in numerosity?
• Test involves transfer to larger numbers of
  paired items.
• Monkeys were successful in learning and
  transferring ordinality task.

89
Ordinality
90
Summary

• Animals are adept processors of a rich and varied
  world.
• Many attributes of single and multiple stimuli
  can be discriminated and remembered.
• Laboratory tests document those discrimination
  and memory abilities.
• Biological mechanisms can now be studied.