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Title: Communication Theory


1
Communication Theory
  • Lecture 2
  • Designing tools for interaction with the
    environment (2)
  • Dr. DanaĆ« Stanton Fraser

2
Cognition and Space
  • Distributed cognition challenges us to
    investigate the relationship between space and
    the mind
  • It is therefore important for us to understand
    how space features in cognition both in the
    laboratory and in the wild
  • Fortunately, technologies have begun to provide
    ideal control test beds for understanding the
    cognitive properties of space

3
Humans and animals must adopt strategies to gauge
their constantly altering position within the
environment if they are to successfully negotiate
that great God-given maze which is our human
world (Tolman, 1948, p. 208).
4
The Cognitive Map
  • McGee (1982) defined spatial orientation as
  • the comprehension of the arrangement of
    elements within a visual stimulus pattern, the
    aptitude for remaining unconfused by the changing
    orientations in which a configuration may be
    presented and the ability to determine spatial
    relations in which the body orientation of the
    observer is an essential part of the problem
    (p.4).

5
3D
  • We see our world in three dimensions. Although
    the retina in the eye is a flat surface and
    therefore the images it receives are two
    dimensional, distance cues enable some two
    dimensional images to be perceived as distant in
    a three dimensional world.
  • Monocular depth cues include relative size,
    superposition/occlusion and relative height.
    Relative size refers to smaller objects being
    interpreted as further away than larger objects.
    Occlusion is the effect when one object obstructs
    another, causing the overlapping object to be
    perceived as being nearer. The relative height of
    similar objects can enable distance perception,
    for example, objects that are seen as higher in
    the image are perceived as more distant.

6
3D
  • The use of two eyes (binocular vision) has
    advantages for depth perception. Our two eyes
    enable us to see two slightly different images of
    an object and we use this disparity to calculate
    the objects orientation in space. The term
    stereopsis is used to explain how the brain adds
    depth from this disparity between the different
    images from the two eyes.

7
3D
  • Another type of depth cue arises from autonomous
    movement in space which appears to be crucial to
    the development of an effective internal spatial
    representation. Gibson (1966) stated that as the
    observer moves through space, there is a flow of
    stimulation on the retinas, which leads to a
    better understanding of the three dimensionality
    of our world. When the observer moves....the
    optic array becomes alive with motion (Haber and
    Hershenson, 1973, p.332).

8
Theories of Space
  • Kant claims that space and time are the very
    form of the human mind (Ellis, 1991, p.xiii).
    Indeed everyday navigation and technological
    advances aiding exploration (flying, driving)
    involve complex spatial skill.

9
Space
  • Psychological space refers to the space of our
    perceptual experience, any space which is
    attributed to the mind...and which would not
    exist if minds did not exist (OKeefe and Nadel,
    1978, p.6-7).
  • Physical space refers to the three dimensional,
    Euclidean world in which we live.
  • These two types of space overlap and interact
    with one another.
  • We can also distinguish between virtual space and
    physical space, as virtual environments do not
    exist in the physical world.
  • The focus here is psychological space and
    investigates whether experience of virtual space,
    can be used to supplement physical space.

10
The form of the Cognitive Map
  • Tolman (1948) describes a map control room in
    the brain which stimuli enter and are worked
    over and elaborated into a tentative,
    cognitive-like map of the environment (p.192).
  • This cognitive map contains routes, paths and
    environmental relationships which are stored and
    can be used when responding to the environment.
    Thus accuracy of response to ones environment is
    intricately linked to the quality of the
    cognitive map formed.

11
The form of the Cognitive Map
  • OKeefe and Nadel (1978) drew a distinction
    between the Taxon system (routes) and the
    Locale system (places) in the build up of
    spatial knowledge.
  • The Taxon system involves using a series of
    S-R-S (stimulus-response-stimulus) instructions.
    Navigation involves moving from one landmark to
    the next by aligning oneself in relation to the
    landmarks.
  • The Locale system is a highly flexible system,
    based on the development and use of internal
    maps.
  • OKeefe and Nadel (1978) state that exploration
    is essential for the creation of internal spatial
    cognitive maps and in constantly up-dating them.

12
The form of the Cognitive Map
  • Animal behavioural studies
  • Most authors agree that humans carry spatial
    representations of their environment in their
    heads, yet there is constant debate concerning
    the type and content of these representations.
  • Siegel and White (1975) suggest a three tiered
    process in the development of spatial knowledge
    the use of landmarks, then the adoption of route
    knowledge allowing fairly simple wayfinding, and
    finally internal representations of space,
    allowing more sophisticated methods of
    navigation.

13
Landmarks, routes and maps
  • Siegel and White suggest that landmarks may
    constitute meaningful events and the nervous
    system may be continually taking pictures of
    them.
  • Routes are built up by connecting a series of
    landmarks. This strategy is egocentric (dependent
    on the bodys location and direction of pointing
    in space) and is efficient as long as the links
    between successive turns are accurate.
  • A cognitive map applies to the mental images that
    individuals build up as they become more familiar
    with their surroundings. This type of
    representation is allocentric (not dependent on
    the bodys position in space or direction of
    regard) and thus is extremely flexible

14
Properties of cognitive map
  • Pick and Lockman (1981) describe three properties
    of spatial maps reversibility, transitivity and
    enabling detours.
  • Lynch (1960) suggests that the cognitive map is a
    product of the number and type of landmarks and
    the number and type of past experiences one has
    had in a particular location.

15
Cognitive Map (contd.)
  • Thorndyke and Hayes-Roth (1982) state three
    important points about spatial cognition.
  • Firstly, people build up their spatial knowledge
    from a variety of different sources navigation
    through the environment, a wide variety of
    different forms of maps, verbal descriptions and
    photographs. The knowledge gained from each of
    these sources is integrated to form spatial
    knowledge.
  • Secondly, dependent on the knowledge they have,
    people use different methods when making spatial
    judgements.
  • Thirdly, the accuracy of any spatial judgement is
    dependent not only on the accuracy of spatial
    knowledge but also on the computations performed
    on this knowledge.

16
Virtual Environment (VE)
  • Virtual environments (VEs) have as their core the
    simulation by computer of three dimensional
    space.
  • The first defining feature of VEs is that they
    can be explored in real time with similar freedom
    to real world exploration.
  • The second defining feature is that the user may
    interact with objects and events in the
    simulation.
  • Virtual Environments are interesting tools for
    psychology research in spatial cognition, because
    they allow some control over testing spatial
    exploration

17
Application of VEs
  • Research using VEs has stemmed from
  • Military
  • Space
  • Aviation
  • VEs are now used in a wide variety of settings,
    including
  • Education
  • Medicine
  • Building design
  • Applications for those with disabilities

18
Presence in VEs
  • VEs consist of three-dimensional, interactive,
    computer generated worlds, running in real time.
  • Often, interacting with these worlds provides a
    feeling of presence as every response has a
    consequence, and the egocentric viewpoint gives
    the illusion of looking from within the virtual
    world.
  • This may be true for more or less realistic
    technologies (e.g. head-mounted displays vs.
    desktop VEs)

19
Example VE
20
Training in VEs
  • Virtual environments are potential useful media
    for training spatial skills
  • Interactions with VEs reproduce similar
    visual-spatial characteristics to interactions
    with the real world
  • Interactions with VEs can preserve the link
    between motor actions and their perceived effects
    (Regian, Shebilske and Monk, 1992). This may be
    primarily due to the three dimensionality of the
    display, which provides all of the
    transformations in the visual appearances of
    objects that would accompany real movements in
    space. In Gibsons (1979) terms, the optical flow
    patterns that would be experienced in the course
    of real movements are maintained in the displayed
    environment.

21
Training in VEs (contd.)
  • VEs enable assessment of the internal spatial
    representations within the same mode as they were
    acquired. A user explores a VE and then can be
    tested on their spatial knowledge within this
    same environment using pointing tasks or route
    tests.
  • easily adaptable, allows repeated viewing, and
    provides tight control of cues.
  • they allow learning to take place without the
    danger of injury
  • a high level of interactivity

22
Training and Education
  • Why use 3D environments for training
  • Take on different perspectives
  • Visualise 3D concepts
  • Interact in real time
  • Explore dangerous situations in safety
  • Independent rehearsal
  • Present realistic or abstract scenarios
  • Promote different learning styles and teaching
    methods
  • possess a high degree of flexibility

23
Training and Education
  • Navigation and wayfinding
  • simulations of buildings
  • spatial orientation measures

24
Example studies
  • Experimental work examining the way people
    encode spatial information from exploration of
    virtual environments
  • A novel paradigm for investigating configural
    learning
  • Transfer of spatial information
  • The effect of repeated exposure to virtual
    environments
  • Evidence for vertical asymmetry in spatial memory
  • Work in progress examining transfer from a
    simulation of a multi-level complex building to
    the equivalent real world environment

25
Developing a Cognitive Map
  • The quality of childrens cognitive maps is
    dependent on familiarity with the environment
    (repeated exposure, provision of landmarks,
    locomotion allowing self initiated exploration).
  • Children with restricted mobility less chance of
    exploration of environment and thus develop
    poorer spatial cognitive maps
  • E.g. Foreman Orencas et al (1989) children with
    physical disabilities significantly worse at
    spatial tasks
  • Kozlowski and Bryant (1977) concluded that for
    people to show a good sense of direction it was
    necessary for them (a) to make a conscious effort
    to orientate themselves, and (b) to provide them
    with repeated exposure to the test environment.

26
Why Virtual Environments?
  • Virtual environments (VEs) have as their core the
    simulation by computer of three dimensional
    space. The first defining feature of VEs is that
    they can be explored in real time with similar
    freedom to real world exploration. The second
    defining feature is that the user may interact
    with objects and events in the simulation.
  • VEs particularly suitable due to Egocentric
    viewpoint, visual flow, safe to explore
    independently..
  • Desktop with tailored interfaces

27
1. Background to Shortcut studies
  • Few studies looking at the development of
    internal spatial representations in disabled
    children (Foreman et al, 1989b Simms 1987).
    Neither of these studies included a shortcut
    task.
  • The ability to take shortcuts demonstrates the
    formation of an effective internal representation
    of space (Chapuis, Durup and Thinus-Blanc, 1987).
  • In the present series of studies the experimental
    environment used by Chapuis et al (1987) was
    created as a 3-D simulation and this was used to
    test human participants.

28
The Shortcut study
  • 24 able-bodied children with a mean age of 13.6
    years
  • 34 physically disabled children, with a mean age
    of 14.1 years, was divided into two sub-groups
    based on their history of mobility (rated by
    their teacher as more mobile when they were
    younger or less mobile when they were younger).

29
  • The environment consisted of five pathways
    connecting four rooms that appeared identical
    from the outside.
  • N.B. A series of pilot studies had established
    that 4 large cues were optimal for spatial
    orientation within this environment

30
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31
  • children explored a simulated "maze" comprising
    four rooms linked by runways. In a subsequent
    test, they were asked to take shortcuts between
    target room locations.
  • For example, they were asked to explore the route
    between room A and room B (all other pathways
    were blocked by no entry barriers). They were
    then asked to explore the path between rooms C
    and D, and then between rooms A and D. In the
    testing phase all the barriers were removed and
    participants were placed in room C and asked to
    find room B by the shortest route available.

32
Results
  • In the first shortcut test the probability of
    choosing a correct path by chance alone was 33,
    while the probability was 50 on the second test.
  • Approximately 70 of the able bodied group
    selected the shortcut correctly on both tests,
    significantly exceeding chance levels.
  • The 'more mobile group,' while not performing
    better than chance on the first test
    (approximately 45 correct), scored better than
    chance on the second test with 80 correct.
  • The 'less mobile' group only scored approximately
    45 correct on both tests and therefore did not
    perform better than chance on either test.

33
Conclusion
  • These results add further weight to the argument
    that early independent exploration is essential
    for the development of cognitive spatial mapping
    ability in children, and suggest that these early
    influences persist at least into the early
    teenage years.

34
2. Studies of Repeated Exposure
  • examining whether repeated exploration of several
    virtual environments promotes better encoding of
    virtual environments in general.
  • A series of studies, including 3D vs 2D training
  • skills disabled children acquired using virtual
    environments improved with exposure to successive
    environments
  • However did not show an improvement in general
    spatial skills (assessed by Money Road test and
    Shepard and Cooper tests adapted for children).

35
3. The AshField study
  • Experimental group were 7 physically disabled
    children, 6 boys and one girl. They had a mean
    age of 12.3 years. The control group consisted of
    7 undergraduate students, 2 female and 5 male
    with a mean age of 25.6 years.
  • The primary section of Ash Field School in
    Leicester was created to-scale. The environment
    consisted of an entrance door with a corridor
    leading into a central area and nine rooms.

36
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37
Procedure
  • Experimental and control groups were subsequently
    taken to the real Ash Field school. Pointing
    accuracy was measured from two relative locations
    from which the children had completed computer
    pointing tasks in the simulation, along with a
    third untrained location. They were asked to
    estimate the direction of target objects from
    each of these locations using a hand operated
    pointing device.
  • Finally, each participant completed two route
    tests. They were taken to a room and were asked
    to move directly to a target room. The first
    route was identical to the one trained within the
    simulation. The second route taken was between
    two different rooms.

38
Results
  • Children were more accurate than controls in
    pointing to landmarks that were not directly
    visible from three separate testing sites
    (F(1,12) 67.54, p lt 0.01). They not only
    completed the tasks previously trained in the
    virtual school, but they also completed spatial
    tests that had not been trained in the virtual
    environment equally well.
  • their way-finding ability (to adopt the shortest
    route between two locations) was also found to be
    more efficient than that of the control group
    (Mann-Whitney U test, z 2.01, p lt 0.05).

39
Conclusions
  • These results support the conclusion that the
    children had acquired flexible, effective
    internal representations of the environment from
    the virtual simulation, enabling them to orient
    themselves from a number of different positions
    within the real environment.
  • They add to the accumulating evidence that VE
    training transfers effectively to the real world
    and that this effect is evident even for people
    with physical disabilities whose spatial
    proficiency may be limited.

40
Key findings
  • We are accumulating evidence of the positive
    effect of exploration of virtual environments on
    spatial navigational skills.
  • We continue to examine whether skills learned in
    virtual environments transfer effectively to real
    world environments.
  • The challenge is not only to examine transfer
    from a simulation to it's real world equivalent,
    but also to examine more generally whether
    spatial skills in the real world improve after
    virtual environment experience.
  • Ultimate goal is to improve quality of life

41
Other issues
  • Active versus passive exploration
  • Drivers cognitive mapping skills
  • Personal digital assistants and cognitive maps

42
References
  • Foreman, N., Stanton, D., Wilson, P and Duffy H.
    (2003). Successful Transfer of Spatial Knowledge
    from a Virtual to a Real School Environment in
    Physically Disabled Children. Journal Of
    Experimental Psychology Applied, Vol. 9, no. 2,
    pp. 67-74
  • Gibson, J. J. (1979). The Ecological Approach to
    Visual Perception. Boston Houghton Mifflin.
  • Haber, R. N., Hershenson, M. (1973). The
    Psychology of Visual Perception. Holt, Rinehart
    and Winston, Inc.
  • Lynch, K. (1960). The Image of the City.
    Cambridge, MA. MIT Press.
  • McGee, M. (1982). Spatial Abilities The
    Influence of Genetic Factors. In M. Potegal (ed.)
    Spatial Abilities-Development and Physiological
    Foundation. New York Academic Press.
  • O'Keefe, J., Nadel L. (1978). The hippocampus
    as a cognitive map. London Oxford University
    Press.
  • Regian, J. W., Shebilske, W. L., Monk, J. M.
    (1992). Virtual Reality An Instructional Medium
    for Visuo-Spatial Tasks. Journal of
    Communication, 4, 136-149.
  • Siegel, A. W., White, S. H. (1975). The
    development of spatial representations of
    large-scale environments. Advances in Child
    Development and Behavior, 10, 9-55.
  • Stanton, D., Wilson, P. and Foreman, N. (2003).
    Human shortcut performance in a
    computer-simulated maze A comparative study.
    Spatial Cognition and Computation. 3(4)315-329.
  • Stanton, D., Wilson, P., and Foreman, N. (2002).
    Effects of early mobility on shortcut performance
    in a simulated maze. Behavioural Brain
    Research.Elsevier, Vol. 136, pp. 61-66
  • Thorndyke, P. W., Hayes-Roth, B. (1982).
    Differences in spatial knowledge acquired from
    maps and navigation. Cognitive Psychology, 14,
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  • Tolman, E. C. (1948). Cognitive maps in rats and
    men. Psychological Review, 55, 189-208.
  • Wilson, P. N., Foreman, N., Gillett, R., and
    Stanton, D. (1997). Active versus passive
    processing of spatial information in a computer
    simulated environment. Ecological Psychology,
    9(3), 207-222.
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