Chapter 7: Getting Around

1
Chapter 7 Getting Around

• Spatial Learning by
• Helen Larzleer,
• Scott McGrath and
• Valerie Stinson

2
Outline

• 7.1 Mechanisms for Spatial Orientation
• 7.2 How is Spatial Information Integrated?
• 7.3 Do Animals Have Cognitive Maps?
• 7.4 Acquiring Spatial Knowledge The Conditions
  for Learning
• Current Research
• Discussion

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Dead Reckoning

• Dead reckoning an internal sense of the
  direction and distance of the goal from the
  animals current position.
• Path integration continuously integrating (in
  the mathematical sense) information about the
  animals changes in distance and direction to keep
  track of its location with respect to the
  predicted location of the nest.

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Dead Reckoning

• Dead reckoning allows egocentric spatial location
  animal is localizing things in the environment
  with respect to itself
• Allocentric or geocentric mechanisms locate the
  animal with respect to some external cues
  (landmarks, the sun, the earths magnetic field).

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Dead Reckoning

• Fig 7.2

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Dead Reckoning

• Disadvantages 1) if the animal is slowly blown
  off course path integration does not compensate.
  2) path integration accumulates error
• To compensate the farther an ant has traveled
  from the nest, the wider its spiraling loops when
  it returns. Ant turns left and right equally
  often, so errors tend to cancel out.
• Ants make less large turns -gt these produce the
  greatest errors.

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Beacons

• Beacons (proximal cues)

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Beacons

• Beacons are cues close to a goal, whereas
  landmarks (distal cues) do not have to be
• Animals can use both proximal and distal cues, as
  illustrated by Morris (1981)

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Beacons

• Figure 7.4
• Morris water maze

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Beacons

• Distal and proximal cues are utilized by
  different areas of the brain, with distal cues
  being more complicated to employ
• Evidence? Hippocampal lesion in rats stops the
  use of distal cues, but proximal cues are still
  utilized
• Why not only use proximal cues? Because you must
  be within range of your target to use them

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Landmarks

• Landmarks (Distal cues)

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Landmarks

• Classic demonstration by Tinbergen and Kruyt
  (1938/1952) in digger wasps
• Figure 7.5

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Landmarks

• Further research demonstrated that digger wasps
  prefer large, nearby and 3-d objects as
  landmarks, which makes sense as these are easiest
  to see
• This finding has been replicated with blue jays
  and honeybees

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Landmarks

• Two distinguishable landmarks are needed to
  specify a single position
• Question how is information processed? Is there
  a continuum between competition and perfect
  averaging?

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Landmarks

• Gerbils use winner takes all, while pigeons use a
  form of averaging
• Figure 7.6

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Landmarks

• Pigeons compute vector and directional
  information separately, in different modules, and
  then combine output of these modules
• Pigeons -gt

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Landmarks

• Fig 7.7

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Landmarks

• Bees trained in 2 featureless huts demonstrate
  ability to distinguish between landmarkspractical
  application evident (must know which landmark is
  which)
• Bee -gt

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Landmarks

• Bees use template matching, in which they move in
  their current environment to reduce the
  discrepancy with a stored template
• Fig.7.8

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Routes

• Learning a route can refer to a mechanism of
  egocentric orientation in which an animal records
  the movements it makes in traveling between two
  places. Usually referred to response learning vs.
  place learning. So, run straight for a certain
  distance then go left vs. go to goal box
• Lorenzs (1952) water shrews

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Routes

• Advantages can travel exceedingly fast without
  wasting a minute on orientation
• Disadvantages change in the environment is not
  detected immediately.
• If an animal has learned a route based on
  landmarks, altering the features of the route
  should disorient it
• Water shrew -gt

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Environmental Shape
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Environmental Shape

• Animals will use geometric information about
  their environment as a spatial cue, such as the
  geometric relationship between objects or the
  shape of an enclosed space
• Closely related to landmarks - the arrangement of
  landmarks and the geometric relationship between
  them form the environmental shape in natural
  settings

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Environmental Shape

• Studies
• Cheng (1986) Rats trained to find food hidden in
  the corner of a rectangular box will dig almost
  as often in the diagonal corner (geometrically
  identical), even in the presence of secondary
  cues such as colored or patterned walls and
  scents.
• Hermer Spelke (1994, 1996) College students
  and 20 month old children tested in featureless
  room, made diagonal errors. When one wall
  colored blue, college students stopped making
  diagonal errors, but babies did not improve.

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Environmental Shape

• Figure 7.9

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Environmental Shape

• Implications Both rats and people appear to have
  a separate cognitive module to process
  environmental shape. Throughout development,
  people overcome the reliance on environmental
  shape and can make better use of other available
  cues.
• Rozin (1976) refers to this change in cue
  dependency throughout development as increasing
  accessibility of modular processing.

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Environmental Shape

• Landmarks and environmental shape
• Studies
• Cartwright Collett (1983) In studies in which
  2 landmarks are separated or compressed, bees
  will search in the middle of the moved landmarks,
  a distance proportional to the amount the
  landmarks are moved. These results are
  consistent with snapshot or template matching
  model.

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Environmental Shape

• Spetch et al (1997) Pigeons and people were
  trained to search in the middle of 4 identical
  landmarks, and then the landmarks were separated.
  People still searched in the middle, while
  pigeons chose one or two landmarks and maintained
  the same distance to them.
• In other research with Clarks nutcrackers, the
  birds searched in the middle (Kamil Jones
  1997).

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Environmental Shape

• Figure 7.10

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The Sun Compass
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The Sun Compass

• Using the sun for direction is inherently
  complex. Why?

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The Sun Compass

• The sun is constantly moving relative to the
  earth, so it is useless as a landmark.
• The movement of the sun through the sky is
  different depending on both location on the
  earths surface and time of year.
• So how do they do it?

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The Sun Compass

• The ability to use the sun for directional
  information requires two things an ephemeris
  function and an internal clock or time sense.
• Ephemeris function A stored representation of
  how the sun, or some correlate of it, moves
  across the sky at the current location and
  season.

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The Sun Compass

• The compass direction of the sun relative to the
  north is called the suns azimuth.
• Figure 7.11

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The Sun Compass

• Studies
• Wehner Lanfranconi (1981) Desert ants get lost
  when they cant see landmarks or the sun, but
  when they can see the proper position of the sun
  for the time of day they head straight home.
• Papi Wallraff (1992) When homing pigeons have
  their internal clocks either pushed forward or
  back by about 3 hours, they will head off in the
  wrong direction (about 45 degrees) when released.

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The Sun Compass

• Dyer (1987) Bees trained to find feeder based on
  sun compass and landmarks, and then the landmarks
  are moved. If released on a cloudy day, bees
  will use landmark cues alone to find the new
  location of the feeder. When back at the hive,
  their dance reflects the previous compass
  direction of the original feeder. However when
  the sun comes out, they immediately change their
  dance to reflect the actual new compass direction
  of the feeder.
• Dyer Dickinson (1994)Young bees raised with
  their only experience in the sun being in late
  afternoon are then released in the morning of a
  cloudy day. Their dances after returning to the
  hive are reversed from the afternoon, however the
  dance did not change gradually but very abruptly
  at noon they changed 180 degrees.

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Combining Outputs

• Information Integration When do I use what?

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Combining Outputs

• Modularity of spatial processing evidenced by
  apparently stupid behaviour by animals i.e. ant
  runs past nest, gerbil ignores cries of babies,
  shrew jumps over nonexistent stone
• Why?

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Rules for Combining

• If all cues will lead to the same goal, why not
  just use one instead of processing them all?
• Evolution? New modules developed that are more
  flexible, instead of modifying old modules.

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Rules for Combining

• Figure 7.13

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Rules for Combining

• Fig 7.14

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What is a Cognitive Map?

• Representations have three essential parts a
  represented system (eg distance and direction) a
  representing system (eg an animals nervous
  system), and rules for correspondence between
  them.
• So, do animals have cognitive representations of
  the world in mind when they travel?

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What is a Cognitive Map?

• Figure 7.16

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Cognitive Maps

• E.C. Tolman (1948) introduced the cognitive
  map. Claimed rats in mazes learn about places.
• Rat -gt

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Cognitive Maps

• OKeefe and Nadel properties of cognitive maps
  and how they might be acquired. Acquisition and
  use of the cognitive map is supported by the
  locale system, a cognitive module located in the
  hippocampus of vertebrates. Contrasts the taxon
  system which supports route learning.
• Gallistel definition of cognitive map is
  considerably looser any orientation based on
  implicitly computing distances and directions
  rather than responding to a beacon is evidence of
  a cognitive map.

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Alternatives to the cognitive map

• The local view hypothesis
• (Leonard McNaughton 1990), (McNaughton, Knierim
  Wilson 1995)
• There are no cognitive maps
• The animal has a set of memories of local views
  of the environment which are associatively linked
  to each other by the memories of how to get from
  one to another.
• Supported by neural net models functions of
  certain populations of cells used in spatial
  learning
• Behaviorally difficult to distinguish from
  cognitive maps

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Alternatives to the cognitive map

• Bennett (1996)
• There is no good evidence for cognitive maps
• Research in this area should be abandoned and
  instead focused on operational discussions of how
  animals get around
• Researchers dont always mean the same thing by
  cognitive map
• The only agreed upon behavioral test for
  cognitive mapping is an animals ability to take
  a novel route without dead reckoning or
  generalization of local views

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Do bees have cognitive maps?

• Experiment Goulds bees

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Do bees have cognitive maps?

• Butis there a problem with this interpretation?

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Do bees have cognitive maps?

• When bees fly up to orient themselves, can they
  get a visual representation of the situation and
  move to feeder A in order to reduce the
  discrepancy between their stored template and
  current situation?
• How can we know?

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Do bees have cognitive maps?

• Dyer replicated study, but feeder B was placed in
  a quarry
• Bees trained at A, but placed at B, could not
  orient themselves, and flew in same direction
  they would as if they were leaving the hive

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Do Rats Have Cognitive Maps?

• Morris swim task rats experienced in the
  swimming task rapidly approached the hidden
  platform. However rats typically swim all over
  the tank in early training no location, view or
  route is completely novel?
• When rats experience of different routes has been
  restricted they are sometimes unable to navigate
  successfully.
• Keith McVety (1988)

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Do Rats Have Cognitive Maps?

• If an animals travels are controlled by
  reference to a single overall allocentric
  representation of space, it should not matter if
  information about different parts of a journey is
  obtained in different ways.

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Do Rats Have Cognitive Maps?

• Disadvantages with rat research almost all done
  in labs and makes little or no reference to what
  the animals might be doing in nature.

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Do other animals have cognitive maps?
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Do other animals have cognitive maps?

• Studies
• Menzel (1978) Chimps were shown the locations of
  multiple items hidden in various locations and
  then allowed to retrieve them. Their routes did
  appear to be efficient and novel in many cases,
  but the results were not significantly different
  from chance.
• Fig. 7.17 a

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Do other animals have cognitive maps?

• Shettleworth Krebs (1982) Marsh tits take
  novel routes to retrieve stored seeds.

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Do other animals have cognitive maps?

• Sherry (1984) Black-capped chickadees remember
  not only the locations of stored seeds but their
  relative value.
• Cramer Gallistel (1996) In research with
  vervet monkeys, the monkeys appear to be planning
  ahead to take the most efficient route depending
  on whether or not they are returning to the
  starting point.
• Fig. 7.17b

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Do other animals have cognitive maps?

• Clutton-Brock Harvey (1977) Larger brain size
  is correlated with fruit-eating species as
  opposed to leaf-eating species of primates.

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Exploration

• What is the purpose of exploration?

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Exploration
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Exploration

• Rats allowed to get reward on one table, removed
  for a period, then placed on another table and
  allowed free travel to get back to reward table
• If only allowed to explore one track, rats do not
  move to reward table above chanceseeing the
  connection does not indicate that it can be
  travelled
• If allowed to explore all tracks, rats perform
  well above chance
• If allowed to explore two tracks, performance is
  intermediate

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Latent Inhibition, Perceptual Learning, and
Cognitive Mapping

• OKeefe and Nadel place learning is subserved by
  a special learning and memory system, the local
  system, whereas response leaning, route learning
  and classical conditioning are part of the taxon
  system.

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Latent Inhibition, Perceptual Learning, and
Cognitive Mapping
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Latent Inhibition, Perceptual Learning, and
Cognitive Mapping

• In associative learning, exposure to a situation
  may retard acquisition that is, it can lead to
  latent inhibition. In contrast, exploring novel
  items in a familiar space is assumed to allow an
  animal to update its cognitive map.
• pre-exposure enhances discrimination (ie
  perceptual learning occurs) when the locations to
  be learned are similar, while latent inhibition
  occurs when they are very different.

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Learning About Redundant Cues Competition or
Parallel Processing

• Does overshadowing and blocking occur in spatial
  learning?
• Rescorla-Wager model describes trade-off among
  potential cues, but redundancy makes more sense
  for important tasks like getting home redundant
  cues could be used as backup if the primary cues
  were unavailable. Eg experience homing pigeons

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Calibration
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Calibration

• The act of checking or adjusting (by comparison
  with a standard) the accuracy of a measuring
  instrument.
• Many species of animals appear to calibrate
  orientation methods against one another.
• Most commonly seen in migratory birds who adjust
  their magnetic compass against the sun compass or
  celestial cues.
• Why would they adjust a magnetic compass to the
  sun compass or celestial cues?

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Calibration

• Because the earths magnetic field changes in
  strength from one place to another (the sun
  compass and celestial cues are more accurate).

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Calibration

• Studies
• Able (1991), Able Able (1990) Savannah
  sparrows raised indoors would orient based
  entirely upon magnetic cues. After different
  groups of the birds were subjected to different
  directional cues (sun, celestial, and
  artificially altered magnetic field), the birds
  adjusted (calibrated) their magnetic compasses to
  a different extent depending on which cues they
  had been exposed to.

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Calibration

• Fig 7.21

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Calibration

• Emlen (1970) Raised 3 groups of indigo buntings
  indoors with no view of the sky. 2 of the groups
  were then exposed to the sky in a planetarium
  One group an accurate representation of it, the
  other an altered view in which the axis of
  rotation centered on Betelgeuse.
• All 3 groups were later tested under a stationary
  sky.
• The group with no experience did not use
  celestial cues to orient
• The group with accurate experience oriented
  properly based on the position of the North Star
• The 3rd group oriented as if Betelgeuse was the
  North Star

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Current Research
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Discussion