Spatial Cognition

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Spatial Cognition

• Navigation Finding the way to a goal
• Discriminate different headings (need a sense of
  direction)
• External directional reference sun, magnetic
  field, landmarks
• Internal directional reference
  vestibular/inertial cues
• Determine the correct heading (need a sense of
  position)
• Path integration
• Knowledge of familiar landmarks in home range
• Geographical positioning system (e.g., position
  relative to large-scale coordinate system defined
  by global geophysical features)--migratory birds,
  whales, turtles

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Spatial Cognition and Navigation

• Navigational Processes That Use Internally
  Represented Spatial Knowledge
• Path integration
• Sun compass
• Landmarks cognitive maps

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Path integration a sense of position

• Ants travel straight path home after circuitous
  outward path
• We can exclude use of odor trails, visual
  beacons, or memory of outward path
• Instead, ants compute direct homeward path based
  on measurements of directions and distances
  traveled on outward path (Wehner et al.)

Food
Homeward path
Nest
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More on PI
5
Sun Compass and Memory in Bees
The basic task
http//www.scottcamazine.com/photos/ BeeBehavior/i
mages/06waggleDance_jpg.jpg

• Bees encode (allocentric?) flight direction in
  dances
• As sun moves, dances change
• Dances change even when bees cant see sun (thus
  compensate by memory)
• Reference for memory landmarks (Dyer Gould
  1981 Dyer Dickinson 1996)

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Celestial compasses birds and bees

• Pattern of solar movement
• Non-linear over day
• Varies with season and latitude
• Animals learn current, local pattern of solar
  movement
• Learning not just a list of time-linked solar
  positions, but a function that can be used to
  find unknown positions of the sun.

Training
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Landmarks Cognitive Maps
From Tolman, EC 1948 Cognitive maps of rats and
men. Psychol Rev 40 40-60.
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What does it mean to have a cognitive map?

• One operational definition a representation of
  spatial relationships that enables computation of
  novel shortcuts between known locations (O'Keefe
  Nadel 1978. The hippocampus as a cognitive map)
• Alternative hypotheses
• Route memory (A--gt B already familiar)
• Recognize familiar landmarks associated with
  goal, even if from novel vantage point

Task get from A to B, having experienced routes
to A and B separately
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Learning local landmarks
Insects can pinpoint locations they need to find
again by learning arrangement of surrounding
landmarks HOW?
Niko Tinbergen (1938)
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Learning local landmarks
Bees match visual image learned on previous
trips Find best match given all available
information
But bees have some flexibility in approach path.
They dont follow stereotyped route, which
Gallistel takes as evidence of generalized map
Landmark
Enlarge single landmark to match view, bees have
to move back
(Bartlett Dyer in prep)
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Algorithm snapshot model
Insect records image of landmarks seen at goal
(after Cartwright and Collett 1983)
Is this evidence for a map?
Vardy www.scs.carleton.ca/avardy/
misc/engrSeminar/engrSeminar.pd
12
Robotic simulations
Source Möller, R., Universität Bielefeld
http//www.ti.uni-bielefeld.de/html/people/moeller
/analog.html
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But is this really what bees do?
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A simpler model?

• Bees encode angles (and distances) of landmarks
  may be encoded in egocentric, not allocentric,
  reference frame
• Weak evidence for a highly flexible computational
  strategy for using landmarks to fly to goal
• Nevertheless, bees do behave as if they can
  recognize familiar landmarks from novel vantage
  points
• Also, bees can use familiar landmarks encountered
  in unexpected context

15
What does it mean to have a cognitive map?

• One operational definition a representation of
  spatial relationships that enables computation of
  novel shortcuts between known locations (O'Keefe
  Nadel 1978. The hippocampus as a cognitive map)
• Alternative hypotheses
• Route memory (A--gt B already familiar)
• Recognize familiar landmarks associated with
  goal, even if from novel vantage point

Task get from A to B, having experienced routes
to A and B separately
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Do insects have cognitive map or something else?
From Dyer 1991
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Varieties of cognitive maps? (Gallistel 1990)
Broader Definition (Gallistel 1990) A cognitive
map is a record in the central nervous system of
macroscopic geometric relations among surfaces in
the environment used to plan movements through
the environment. A central question is what type
of geometric relations a map encodes.

• Specific issues
• Spatial scale (local vs. home-range)
• Geometric content (metric, topological)
• Reference frame (egocentric/view-dependent vs.
  allocentric/view-independent)
• Evidence
• People short cuts in cities and VR (errors)
  mixed evidence contents of underlying map
• Rodents most studies on local scale mixed
  evidence on contents
• Insects on local and home-range scale--metric,
  egocentric

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Varieties of cognitive maps?
Type 1
Type 2
Type 3
Most rodent research

• Computational models of cognitive maps need to
  specify geometric contents (angles, distances,
  routes, nodes), reference frames, and operations
  performed on stored information?
• Humans, but not insects, form Type 3 maps, but
  insects can flexibly use snapshots and route maps
• Big question is whether map-learning is
  viewpoint-dependent or viewpoint-independent

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Toward the implementational level
Is the hippocampus the locus of the cognitive map
of mammals?

• Some evidence
• Input from integrative sensory areas
• Output to neocortex
• Lesion studies suggest role in memory

Rat brain
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Hippocampus and spatial cognition
1. Lesion experiments (rats birds) selective
effect on spatial memory
2. Comparisons of hippocampus size correlation
between HC size and reliance on spatial memory
3. Functional neuroimaging (humans)
4. Place cells
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Place Cells
Rat with recording apparatus
Rat in arena
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Place Cells (cont'd)
Rat put in dark and then rotated slowly relative
to featureless arena causes shift in place field
Conspicuous landmark is rotated, causing shift in
place field
Place fields are referenced to internal and
external coordinates
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Some properties of hippocampal place cells that
imply role in spatial cognition

• Highly stable firing fields in constant
  environment
• Can be established in total darkness (referenced
  to vestibular cues)
• Can be linked to visual cues, and then track
  visual cues
• Individual cells can have different place fields
  in different environments
• Ensemble of cells encodes map of familiar
  environment
• BUT there is no obvious way in which this system
  corresponds to computational models of cognitive
  map based on behavioral evidence. For example..

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Problems with the "hippocampus-as-cognitive-map"
hypothesis

• May not generalize to humans, because hippocampus
  is known to play role in non-spatial episodic
  memory in humans (but see OKeefe)
• Place cell ensemble in hippocampus is not enough
  to account for spatial behavior.encodes current
  location, but not goals, for example (Andre
  Fenton)
• Even in animals, hippocampus is involved in
  non-spatial tasks (e.g., transitive inference)
• Place cells seem to encode something more than
  just "place"

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Transitive inference non-spatial function of
hippocampus in rats

• Rat chooses one odor over another

IF A gt B gt C gt D gt E, then. A gt C
(or D or E) B gt D (or E)
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Place cells encode more than just placerole for
hippocampus in episodic memory?
Rats are trained on alternating T-maze
Wood ER, Dudchenko PA, Robitsek RJ, Eichenbaum H
Hippocampal neurons encode information about
different types of memory episodes occurring in
the same location. Neuron 2000 27 623-633
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Context-specific activity of place cells
A cell that fires in a particular place, but much
more rapidly when a right turn is coming up
Wood ER, Dudchenko PA, Robitsek RJ, Eichenbaum H
Hippocampal neurons encode information about
different types of memory episodes occurring in
the same location. Neuron 2000 27 623-633
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Episodic Memory in Animals?
Episodic Memory in Birds where did I put that
worm and when did I put it there?
http//freespace.virgin.net/cliff.buckton/Birding/
California/Calif17.jpg
Clayton Dickinson 1998
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Interpretations for role of hippocampus in
spatial cognition and memory generally

• Spatial and non-spatial episodic memories involve
  different processes hippocampus does them both,
  and has evolved to become more specialized for
  episodic memory in primates compared with rodents
  (Jacobs Schwenk)
• All experience has a spatial component, and
  hippocampus participates in formation/use of
  episodic memory because of its role in processing
  spatial information processing (O'Keefe)
• Spatial cognition involves processes that are
  also required in encoding certain other kinds of
  relations among stimuli hippocampus plays a more
  general role that leads it to participate in
  spatial as well as certain non-spatial tasks
  (Eichenbaum)

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Where does this leave the search for neural
implementation of cognitive map?

• Hypotheses
• Hippocampus is the cognitive map (OKeefe)
• Cognitive map (sensu Tolman and O'Keefe Nadel)
  is elsewhere, but uses output from hippocampus
• Cognitive map is indeed an important function of
  hippocampus, but computations that hippocampus
  carries out are very different from those
  developed on the basis of behavioral
  observations these computations support
  functions other than spatial encoding (Eichenbaum
  and colleagues)