This
research has consisted in the elaboration of a spatial strategy for blind
sailors. With auditory information, they can locate the sound buoys along the
track. Vocal watches allow time measurement during the race. After some
experiments that have isolated these different tools, the conclusion that
tactile maps allow stocking accurate tactile pictured representation of the
race has been drawn. However, these do not allow any adjustment as to the boat
position during action. Even with a limited precision, the auditory feed back
makes turning around the buoys along the track possible for blind people.
Because of a space time relation, they can transform a time value into a
distance value on the map. This strategy implicates an important cognitive
load. That is why we would like to use virtual reality techniques to up-to-date
haptic pieces of information about the position of the boat on a virtual map
during sailing.
Key words:
blind sailors,
spatial representation, haptic modality, auditory localisation, cognitive map.
1.
Preamble
The spatial reality
an organism can have access to fundamentally depends on his sensorial equipment
[1]. Blind people perceive space through vestibular, kinaesthetic, haptic[1],
tactile and auditory modalities. Even if these pieces of information are useful
to build spatial representation, no other modality can be compared with as for
the quality and the quantity of data as concerns spatial properties of the
environment [4]. However, blind people elaborate spatial representation of
their environment. What are their nature? Are they precise? Do non visual maps exist?
Situated cognition
theory is especially useful in the case of non-visual representation. Many
searchers consider that cognition cannot be understood without taking into
account the organism inserted in a particular situation with a specific configuration
that is to say ecologically situated [5]. Only In Situ experiments can
be helpful in our search. In addition, understanding the process used by blind
people to locate themselves in space cannot be separated from motion. Moreover,
important studies of Université de Technologie de Compiègne in
To finish with, we
performed experiments on blind sailors in
After defining the
different components of space, we will study how haptic and auditory modalities
can be useful to build cognitive maps during navigation.
In the end, we will
examine different possibilities about virtual reality in order to extrapolate
our search to the maritime space.
2.
Introduction
2.1.
Spatial representation
2.1.1. Individual space
Through the body
geometry and its motor possibilities we can distinguish two lines which
separate three different spaces: the body space, limited by coetaneous tissues,
the space close-by, defined by all points an individual can touch without
moving, and the distant space which is all the points which cannot be reached
without moving [7].
The body space is
mostly identified through self-sensitive modalities. The space close-by can be
reach through sight and touch. The distant space can be apprehended through vision
and auditory information.
Which are the non visual
pieces of information relevant to understand the distant space? The further is
the space, the more important is the lack of vision in building spatial
representation.
The capacity for
subjects to figure a mathematical or euclidean space is the final result of the
cognitive development of human beings [8]. Until eighteen months old, children
only have a topological active space, as a result they can only perceive the
relationship between objects without being able to perceive distances. This
space is structured through an invariant that is the permanent object.
Cognitive evolution allows the construction of a representative space. This one
is projective, so the subjects can have a mental representation of objects
which are outside their tactile and auditory range. These mental operations which
are interiorised actions will eventually result in constructing new invariants
such as distance, volume… [9].
Finally when the
subject is able to use the metric system in order to measure those invariants, euclidean
space construction is accomplished.
How can these
representations of distant space be defined?
2.1.2. Pictured representations
Thorndike and Hayes-Roth
[10], Byrne [11], Pailhous [12] and Richard [13] draw a distinction between
verbal codes and pictured codes. A graphic coding includes spatial
characteristics whereas verbal coding does not. In other words visual
representation make finding one’s way in space easier thanks to the use of
mathematical data for orientation and distance.
Which pieces of information
coming from haptic and auditory modalities do allow building a distant space
representation with pictured but non-visual properties? How can action and
perception be implied in euclidean spatial operations?
2.2.
Perception–action
Perception consists
in knowing and well using sensory motor contingency laws [14]. These laws are
linking rules between motor actions and sensorial transformations [15].
This approach
insists in the necessity of the subject perceiving action in order constitute
perception. The perception quality is not determined by the implicated kinds of
receptors, but by the structure of sensorial transformations produced during
the action. The important point is the structure of the involved sensory motor
law.
The definition of
the perceived object is not obtained by an invariant in the sensation but by an
invariant in the sensory motor circles. It means that when a subject is not in
the action also he does not perceive anything.
If the spatial
location comes from the sensory motor laws, spatial percepts emerge relations
contained in the subject exploration. For blind people, map exploration brings
the necessity of the kinaesthetic movements in order to obtain tactile
feedbacks. The rules of this sensory motor circle are linked to the haptic
modality. Here, action and perception are strongly linked.
Eventually, we try
to show how sensory motor rules are efficient in order to perceive distant
space without vision but with haptic and auditory modalities.
2.3.
Auditory modality for spatial
location in action
Spatial location
consists in evaluating direction and distance of the sound source. We work in
horizontal plan. The direction is called azimuth. We will explain the location
process. The auditory wave comes first into the nearest ear, after than it
touches the furthest one. The times difference change in function of the
azimuth [16]. In reference of the known sensory motor concept, successive
changes of this time difference allow perceiving spatial location during
action.
Blind sailors
define buoys azimuth with the clock reference in order to get one’s bearing on
the auditory track. If the sound is about twelve o’clock, the sailboat will
reach the sound source. If the sound is at three o’clock, it comes from forty-five
degrees in reference of the axis of the boat. Because of the sound buoys,
auditory organs perceived the azimuths variations of the sound sources during
motion.
A study from
Morrongiello et al. [17] shows that the differences between final position of
the blind subjects and the target position are less important with a sound cue.
These results explain that auditory modality affords feedbacks on sound events.
The sounds of the buoys are essential in order to go all over the regatta track
for blind sailors. Although activity seems to show sufficient information
coming from the sound buoys, we search to associate some others information in
order to increase precision.
Spatial information
demands information about distance. A priori, human does not precisely evaluate
the distance of the sound source, except if source is very familiar. In this
case, the rule is that the intensity decrease with the square of the distance
of the source. Even if the exponentially cue helps the organism, environment
physic variations like wind, are touchy to limit the evaluation’s precision
about distance and orientation of the real sound source. However intensity
variations inform at least about the action proceeding. Although intensity does
not give a precise distance to the subject, a variation’s intensity succession
affords that the sound source is coming closer. If we consider this sensory
motor rule, sound buoys are useful without being precise.
We have been
suggesting the following hypothesis: the spatial auditory representation is
efficient during the action without being precise. This representation affords
an action’s regulation during motion that presents a precision inversely
proportional of the distance of the sound source.
Could haptic
information be efficient where auditory information are not. We mean precision
in non visual spatial representation? Can Tactilo-kinaesthetic constitute a
support for this spatial representation?
2.4.
Pictured haptic perception
The most important
trouble of the haptic spatial treatment in comparison with the visual one is
about the sequential nature [18]. Indeed, vision catches simultaneous the
spatial cues and permits a relative positioning of the different visual
components of the environment. Unlike haptic modality implicates such a successive
perception of the information. This
analytic nature presents major difficulty about tactile mapping. Nevertheless,
little objects can be overall appreciated.
Ballesteros et al. [19] shows a helping effect in using the both
forefingers at the same time in order to build a global space representation.
In addition, symmetric marks can appear during this bi manual exploration.
Actually, the logic of the regatta course requires knowing the symmetric
position in reference of the wind axis (cf. pict.1). In effect tactile map,
instead of abstract tactile referential, is able to give an interesting spatial
pictured representation. In this case, we have to be careful about the limits
of the haptic sense.
In order to better
understand haptic perception of space, we suggest studying the limits of the
haptic modality in building spatial representation for blind people.
In the middle of
the twentieth century, gestaltists extended their studies of visual illusions
into haptic illusions. These works were continued by Hatwell [4] [18] and
Gentaz [20] and explained some haptic illusions. The “Oblique effect”, the “detour
effect” and the consequences of the “speed of exploration” are the most
important illusions in haptic perception of distances and orientations. Haptic
perceptions of orientations are submitted in “oblique effect”. This illusion
consists in a better evaluation of the vertical and horizontal lines than the
oblique lines. [21]. A recent study [20] shows that this effect comes from
using a subjective gravity reference. It means this illusion results from multi
references: external (gravity), and internal mark (the vertical line in
reference of the subject body).
After some
experiences on the “detour effect” [22], results prove an euclidean distances
overvaluation which increases with the quantity of the detours effected with
hand.
Even if the
conditions of the “detour effect” apparition are still discussed by different
searchers [22] [ 23] [24] [3] [20]. It appears important difficulties for blind
people, and mostly the born blind people, to precisely estimate the touched
sinuous distances.
The slower is a
manual exploration, the more important the overvaluation is [25]. When we use
tactile maps, this temporal factor has to be considered in order to build a
precise spatial representation. So a speed haptic exploration is more efficient
than a slow exploration.
These illusions
prove the limits of the spatial precision of the haptic modality.
Nevertheless, some
experiences with « Optacon/TVSS » (Tactile Vision Substitution
System) [26] which transforms luminosity waves in tactile vibrations, show that
the limits of the haptic modality are not the only point. Indeed, blind people
have to look for the relevant informations.
The presence of
these haptic illusions shows the importance of the exploration strategy in
order to precisely estimate distances and orientations. Heller [27] observed
that an adapted exploration allows blind people to obtain a precise haptic
perception. Even if the illusion is important, it can disappear when stimuli
are enough little to be overall touched with one hand. So haptic spatial
representation conserve distances and orientations.
These tactile lines show
the possibilities of motion of the sailboat. Departure line Comity boat Sound buoy far of the wind source Sound buoy Near of the wind source
Picture 1:Tactile
map of the sound track
Haptic spatial
treatment is able to be complementary with auditory non precise information in
order to build an overall euclidean representation. Some studies agree with the
possibility of scanning mental pictured representations in the same manner than
a physic space. This possibility shows the principle and the interest of the
utilisation of a virtual map. The maritime space of a sound track can be
discovered by touch. Moreover, the motions can be virtually operated. Blind
subjects affirm using a spatial haptic representation because of the map.
2.5.
Cartography study
What can we learn
from other studies about tactile maps used by blind people?
In a cognitive
view, the first difficulty, mostly for born blind people which have not built
projective space, is to understand that the paper plane of the maps represents
their three dimensional or bi-dimensional space [24].
A case study of a
five born blind child between the age of two and five concludes that the
capacity to read a tactile map is precocious (as soon as four years old) and
does not require any specific learning” [28]. Nevertheless, this conclusion was
not admitted by Millar [29]. The latter showed that neither sighted persons nor
blind have an innate ability to read a map. A child has to understand that the
move of their hands exploring the map let him know about the real moves he has
to do in his environment [29]. Espinosa and Ochaita [30] observed a better
learning of a new track in a town when subjects used a map rather than through
a real exploration. Map is a virtual world presenting analogies with the physical
world. But these analogies have to be correctly interpreted. As a matter of
fact, the change in scale implied by the passage of tactile space to physical
motion space. This requires cognitive skills which can be different from those
use in narrow space [24]. In other words reducing the scale to the size of the
end is sufficient to make a mental representation as effective as possible. Through
which process can these two spaces of euclidean reference be linked thanks to
the mental use of cognitive maps.
2.6.
Cognitive map
Rieser et al. [31] shows
a learnt correlation between locomotion and progressive changes of distances
and orientations. The relations between extern objects and the subjects
themselves allow to navigate, or to find his way in the physic space. Haptic
and auditory modalities equally permit to build a way, or a space – timing
sequence of rectilinear segments and turns in order to go from a point to
another. Nevertheless, a way only consists in the repetition of a locomotor’s
chain learnt by heart. This does not allow us to create some new ways like
shortcuts or supplementary “detours”. This process is automatic and does not
let any place for comprehension and initiative.
In the opposite,
the constitution of a “cognitive map” is a kind of euclidean aerial
representation. This one is able to help for building spatial cognitive
operations and also imagining shortcuts and new ways [4].
In order to
increase the precision of the blind sailors’ motions on a sound track, we
suggest using the tools that allow to build a track cognitive map in function
of the wind direction.
2.7.
Auditory and haptic complimentarily
We have already
been using a non-visual aerial representation of the regatta track with a
tactile map (cf. pict. 1)
The precise
sailboat position is required in order to allow to the subjects to realize
spatial operations in real time. Now we only use sound buoys that are not
precise enough. That is why we suggest to use others tools to build a strategy
based on a euclidean system.
After some first
experiences, we can say that the sailboat speed is constant when the wind
conditions are stable. Also, in order to answer to our questions we can use the
relation where the distance is equal to the speed multiplied by the time.
The strategy we are
testing is very simple. Subjects are going all over the track using sound
buoys. However, they equally use a vocal watch in order to chronometer time (cf.
pict.2). It is a reference. When they would divide the time, they would
also find a division of the distance. If they would report this division of the
distance on the tactile map of the track, they could find precisely their
position during the next round.
In situated
cognition, we attempt that subjects could make emerging an overall sensation
directly coming from the context. Actually, the time measurement could be
adjust with motor sensory rules coming from the different modalities. For
example, because of the vestibular system, the subjects would be able to
interpret the inclination of the boat like an increase of the sailboat speed.
In this case, the subjects could decrease the expected time. Eventually, this
strategy is support in order to realize spatial and euclidean operations.
The
following experimentations try to verify this hypothesis.
Picture 2. Tactile map and vocal watch using together
3.
Experimentation
The experimentation
part takes place in the maritime environment. We compare situations with wind
(more than ten knots) or not. We are either on the beach by feet or on the sea
with seven meters long sailboat in the
3.1.
Subjects
Six blind sailors
and sailors eye-banded agreed to participate in experiences in order to check
the efficiency of the strategy. We try to increase the precision of the
non-visual representation in the course action [32].
3.2.
The pre experiments
The four first
experiences are not explained in details. However, the experience about the
strategy will be described more precisely.
The first
experience shows that the wind is an orientation aid. The subjects take the
helm of the sailboat in order to follow a rectilinear trajectory. They steer it
in the three following situations: “engine without wind”, then “engine with
wind” and naturally “with wind in the sails”. The trajectories coming from G.P.S.
(Global Positioning System) allow us to validate the first hypothesis: “In a maritime
locomotion task, the presence of the wind gives an orientation mark to the
people without vision”.
The second
experience shows that the wind implicates equally a decrease of the sounds
location precision in distances and orientations. Subjects are on the beach
with wind and then without. The latter are in the middle of three circles
within one, two and three meters radius. Forty sounds are buzzing at random on
the three circles. The role of the subjects consists in indicating the distance
and the azimuth (clock analogy: twelve is in front of the wind) [33]. In
conclusion, results validate the second hypothesis: “without vision, the number
of correct positions with auditory evaluations decreases in presence of the
wind”.
In the third experience,
we compare the efficiency of a tactile map and a sound buoy in a situation of earth
locomotion. The role of the subjects consists in reaching a point somewhere on
a forty meters radian circle. The point is signalized on a tactile map aligned
with the physic world, or with a sound boy, or both. Eventually, the results
validate our third hypothesis: “In a locomotion task with wind and without vision,
tactile information of the tactile map aligned with physic world is efficient
in constructing pictured spatial representation in order to improve the
direction of the initial trajectory, in opposite auditory signals allow blind
people to up-to-date their representation and realize a better final
trajectory.” Furthermore, auditory signals are a sine qua non condition to
reach the arrival point. Taking in account these results, we see that a rule
links the reception of a sound and a sensory motor pattern.
The fourth
experience is a sail situation. We try to show the efficiency of the time mark
with constant speed. After a reference’s round of the track, subjects use vocal
watch or not to determine the moment of the turn in order to reach the sound
point situated in the wind axis. Trajectories are collected with G.P.S. . We
measure the difference between the ideal trajectory and the realized one. In
conclusion, the results show that “in a maritime locomotion task, “constant
speed time unity” corresponds to a division of the reference time and distance
for blind sailors.
3.3.
Strategy experimentation
The correct results
of the four first experiences allow us to test a situation that synthesizes all
the tools and results in one strategy.
The final
experience of this study demands to the blind sailors to realize a defined
trajectory on sound track after a reference round. Then the subjects draw on a
tactile paper. Each subject participates in this test in the four following
situations: first they only hear sound buoys (=condition 1, C1), secondly they
equally use a vocal watch (=C2), then they use sound buoys and a tactile map.
Eventually, they use all the previous tools (=C4). Each condition requires two
trajectories: one with two turns and another one with three turns.
3.4. Experimentation strategy results (cf. tables 1 & 2)
|
Difference between the requested trajectories and the realized one |
C1 : Sound
buoys |
C2 :
Sound
buoys and vocal |
C3 : sound
buoys and tactile map |
C4 :
sound
buoys, vocal watch and tactile map |
|
Trajectory
1 : distance in tacks 1 ; 2 |
4 ; 10 |
2 ; 1 |
2 ; 5 |
3 ; 2 |
|
Trajectory
2 : distance in tacks 1 ; 2 ; 3 |
3 ; 3 ; 1 |
1 ; 1 ; 2 |
5 ; 3 ; 3 |
2 ; 0 ; 2 |
|
Ecarts
type |
3,42 |
0,55 |
1,34 |
1,10 |
|
Difference
Average |
4,2 |
1,4 |
3,6 |
1,8 |
Table 1: Distances (without unity) between realized
tacks (GPS) and asked tacks in C1, C2, C3 and C4.
Trajectories
are produced with G.P.S. for motion but on paper for the subjects’ draws. We
first compare the difference between the requested trajectories and the
realized trajectories, then between the realized trajectories and the drawn
trajectories (cf. tables 1).
On
the second table (cf. table 2), we see better trajectories with
vocal watch (difference (D) =1.4). Unlike the precision of the drawn
trajectories is better with the tactile map (D=1.6) than with the vocal watch
(D=2.2). When these both tools are using together, the results are better
(D=1.8 & 1.5).We also conclude that they are complementary.
|
Difference
between the drawn trajectories and the realized one |
C1 : Sound buoys |
C2 : Sound buoys and vocal |
C3 : Sound buoys and tactile map |
C4 : Sound buoys, vocal watch and tactile map |
|
Trajectory 1 : distance in tacks
1 ; 2 |
5 ;
7 |
3 ;
2 |
2 ;
1 |
3 ;
1 |
|
Trajectory 2 : distance in tacks
1 ; 2 ; 3 |
1 ;
2 ; 3 |
1 ;
2 ; 3 |
2 ;
1 ; 2 |
1 ;
0 ; 2 |
|
Ecarts type |
2,41 |
0,84 |
0,55 |
1,14 |
|
Difference Average |
4 |
2,2 |
1,6 |
1,5 |
Table 2: Distances (without unity) between realized
tacks (GPS) and drawn tacks in C1, C2, C3 and C4.
3.5.
Interpretation
These results demonstrate
to the capacity of the blind sailors to store in long-term memory the pictured
representation resulting from the tactile map. Furthermore, they use
information of the vocal watch after having referred the course, i.e. measured
total times to divide them into units. However, the sound buoys remain
essential for the use of the tools "tactile map" and "vocal
watch" because they provide feedbacks during action. Our opinion is that it is interesting to hear
testimonies of the concerned subjects. Indeed while using information
previously quoted, the subjects explain that they modify the times appointed
according to the feelings speed collected. This demonstrates that many sensory
motor circles emerge from the overall situation.
Here, the subjects
mix with the high level cognitive operations, like the conversion of a time
into division of distance, with the emergence of the feelings speed resulting
from the vestibular system, kinaesthetic, auditory, tactile and haptic [32].
The tactile map provides a support for a precise representation a priori or a
posteriori. However this tool is not usable during action because of the
important time which the cognitive operations of positioning require in
abstract tactile map. Conversely, time give information during the action but
is not easily usable from one regatta to another.
The results show
that the use of the tactile map confers on the blind subjects a precise but too
slow abstract representation in the course of action, whereas the auditory
method is not very precise but effective during motion.
Overall, we can say
that haptic and auditory modalities are able to help blind people to build a
pictured but non visual representation.
4.
Discussion
The previous results
prove the capacity of the blind sailors to build cognitive maps on a sound and
windy maritime space. The cognitive activity uses the tactile map like stable
abstract support in time. This representation is favourable to interpretation
by the subjects of the euclidean values constantly brought up to date announced
by the watch. Only the auditory feed-back of the buoys present a bond between
the physical track and its mental repesentation. The sounds of the buoys and
the feelings of slips mentioned above, offer to the subjects a capacity to act
in a tangible way [34], i.e. capacity to move in a way controlled on the track.
Here tangible means that the subject concretely feels its physical motion
because of the consecutive variations of the auditory signals and of the
feelings of slips. The sound buoys also answer a recent theory of the space
memory [35] according to which an intrinsic reference mark with the collection
is used to learn the position from a whole of objects in a new environment. Here
the sound buoys constitute intrinsic reference marks in the collection "course".
Thus, the subjects build couples perception-action suitable in order to
anticipate the feelings of motion. This anticipation allows the actualization
of this pictured and finally total representation.
In spite of real
progress compared to the situation of reference, we remain moderated on the
system effectiveness of the sound buoys, tactile map and vocal watch for the
space representation of the blind sailors in the course of navigation. Indeed,
the weight of the cognitive operations requested from the subjects and the
relative precision which results bring us to question us on the setting in a
more effective strategy. Theoretical points of Paillard, Honoré and Hatwell [1]
[4] [7] converge towards some limits of the auditory and haptic direction for
the construction of an euclidean distant space. Our results, although in
agreement with work of these authors, let imagine a strategy of location space
founded on the capacity to interact with relevant auditory and haptic
information. In order to improve the construction of pictured but non-visual
representation we have to increase the redundant information with different
modalities. If we would combine the redundant and relevant spatial information,
we could allow blind people to control their motion in a better way. Thus
pieces of haptic and auditory information must be brought up to date in the
course of navigation in order to give further information in real time. Could
we use the tools of virtual reality to immerse the blind people in a haptic
world moving?
5.
Future work in virtual reality
Virtual reality is interesting
for at least one reason. “It can represent data in numerous ways. It is a media
that allows transmission of messages of different types, and in multiple
formats; it can even lead to the creation of new models of perceptive mediation
(p.7)” [36]. In this way, we are trying to set a new auditory and haptic
mediation of GPS position on geographic maps. We also have to mix data from map
and GPS in implementing new haptic software.
The techniques of
virtual reality are founded on the interaction with a virtual world in real
time, using behavioural interfaces allowing the "pseudo-natural"
immersion of the user in this environment [37]. The behavioural interfaces
offer to the user the means of interacting physically, or in a tangible manner,
with the virtual world. The haptic interfaces can immerse the blind subjects
"in" the virtual map. We speak about immersion if the subjects use
these new tools like the prolongation of their body [38].
In order to do
that, which hardware system should we choose?
A recent study
about the tactile flow mechanism in virtual reality shows that sensing
vibrations of 4Hz present a higher spatial resolution when subjects use dynamic
exploratory than when they employed the passive manner [39]. Taking into
account the hurdles to perform, we seek a haptic multi degrees of freedom
interface. Our point is that is important to let blind people the freedom to
explore in the way they like in order to let them linking voluntary action and
perception
During some
previous experiments, “because of the presence of force feedback, the magnitude
of unwanted incursions into a virtual wall were reduced by up to eighty percent,
as compared to the case with no force feed-back” (p.21) [40]. We also have to
choose a haptic interface with force feedback. The most important point is to
make tangible the virtual maps. Different kinds are touchy suitable: The
PHANToM from Sensable Technologies, the 3-DOF OMEGA from Force Dimension; or
force feed back gloves: DATA GLOVE 14
ULTRA (vibromotors in addition) from 5DT and CYBERGRASP from Immersion
Corporation.
With all of these,
we imagine software where blind sailors virtually discover
The virtual world
evokes for us a numerical substitute of the paper tactile map always
corresponding to a symbolic representation (or abstract) two-dimensional (or
three-dimensional) projective, of reduced size, of a real space [24]. An
interesting point is virtual worlds can be animated in the real time. Also,
this dynamism helps to link perception and action.
The difficulty of
this ambition is particular about the interfacing with the users. The
problematic of the perception of distant space in real time for blind people
implies to transform into tangible what it is not. In the field of research in
industrial Design [41], this approach requires to seek the link between the
symbolic system and the tangible one by:
- Identification of the experiments which make
sense for the user, i.e. to define which haptic symbols translate most
intuitively such or such physical object into item cartographic.
- translation of
these subjective values in technical data, that is to say the use of the
vectorial maritime maps and the addition of items haptic and/or auditory
symbolic systems.
- the contribution
of virtual reality in design of product and evaluation of the interactions
produced user in situation of use.
The technology that
we need in order to build a up to date virtual map system for blind people does
already exist. However, experiences are necessary, to define the necessary rules
in order to produce a system really adapted for blind users.
For example, due to
the difficulties of the scale variations without vision [24], the new “bubble
technique” [42] would be suitable. This technique is useful to interact with a
large virtual environment using a haptic device with a limited workspace. Using
this software, blind people might also “feel” the inner surface of the bubble,
since the spherical workspace is “haptically” displayed by applying an elastic
force feedback when crossing the surface of the bubble.
This stage
corresponds to the setting in situation of the system (interface haptic,
software of reading of vectorial map, blind subject). This experimental logic
respects the spatial enaction and the concept of situated cognition [5]. The
image according to which we progressively build our external space with our motions,
answers the various authors previously quoted. Also, we wish to compare the
development process of the cognitive maps of the Iroise sea at the time of
controlled displacements carried out In Situ and In Virtuo.
This last part
means that we will experiment some situations with paper maps and vocal information
only. Then these results will be compared with the collected trajectories
(G.P.S) using haptic hardware and virtual map system.
6.
Conclusion
We have developed a
low technologic strategy of space location for the blind sailors. For this
public, information resulting from the haptic (tactilo kinaesthetic) and auditory
modalities is adapted with the construction of pictured space representations.
We used the haptic modality through tactile maps representing the track. The
auditory method is exploited by sound buoys which mark out the track and a
vocal watch to measure times of regatta. The experiments showed us that the tactile
map makes it possible to store in long-term memory a precise tactile image of
the track and that the sound buoys facilitate the location in the course of
action when the subjects pass in the vicinity. The difficulties of coordination
of these two systems lead us to call upon the techniques of virtual reality to
facilitate these interactions.
However, several
questions arise when about the effectiveness of this future system of virtual
reality for maritime numerical tactile maps. How to explore overall a map with the
haptic modality which transmits analytical feelings? Could we imagine to reduce
the virtual map to the size of the hand? What about the new “bubble technique”?
Does one have rather proud with the interest which Ballesteros [19] carries to bi
manual exploration? How many feelings of different textures can user discriminate
with a producing glove of vibrations? Is it necessary to choose one arm on
standard force feed back? In which measurements is it interesting to create a
spring (attractive field)?
Eventually, we pose
the question how to understand the geographical map in real time for blind
people. In a future work, we hope to show that the virtual realities systems
are suitable about that.
7.
References
- Articles in
journal :
[3]
Faineteau H., Gentaz E. and Viviani P. The kinaesthesic perception of euclidean
distance. In Experimental Brain Research, 152, 166-172, 2003.
[5] Varela
J. Entretien avec Francisco J. Varela par Hervé Kempf. In
[7] Honoré J.,
Richard C. and Mars F. Perception de l’image du corps et action, In Y. Coello and
J. Honoré. Percevoir s’orienter et agir dans l’espace, approche
pluridisciplinaire des relations perception-action. Solal. Marseille, 2002.
[11] Byrne R. N. Memory for Urban Geography. In
Journal of experimental Psychology, 31, 147-156, 1979.
[15] O’Regan J. K. and Noë A. A sensorimotor Account
of vision and Visuel Consciousness. In Behavioral
and Brain Sciences,
[17] Morrongiello B. A., Timney B., Humphrey C. K.,
[19] Ballesteros S., Millar
S. and Reales J. Haptic discrimantion of bilateral symmetry in 2-dimensional and
3-dimensional unfamiliar displays. In Perception and Psychophysics, 59, 37-50, 1998.
[21] Appelle S. Perception and discrimination as a function of stimulus
orientation: The “oblique effect” in man and animals. In Psychological
Bulletin, 78, 266-278, 1972.
[22] Lederman S. J., Klatzky P. and Barber R. L. Spatial an movement based heuristics for
encoding pattern information through touch. In Journal of experimental
psychology : General, 114, 33-49, 1985.
[23] Klatzky R. and Lederman S. J. Relative availability of surface and
object properties during early haptic processing. Journal of Experimental
Psychology : Human perception and performance, 23, 1680-1707, 1997.
[25] Wong T. S. Dynamic properties of radial and tangential movements as determinant of the haptic horizontal-vertical illusion with an L figure. In Journal of Experimental Psychology: Human perception and performance, 3, 151-164, 1977.
[27] Landau
B. Early map use as an unlearned ability. Cognition, 22, 201-223, 1986.
[30] Espinosa
M. A. and Ochaita E. Using tactile maps to improve the practical spatial knowledge
of adulte who are blind. In Journal of Visual Impairment and Blindness, 92, 339-345,
1998.
[31] Rieser J., Ashmead C. R. T., Taylor C.R. &
Youngquist T.A. Visual perception and the guidance of locomotion without vision
to previously seen targets. Perception,
19, 675-689, 1990.
- PhD or books :
[1] J. Paillard. Psychophysiologie du comportement. PUF.
[2] G. Revesz.
The human hand, a psychological study. Routledge and Kegan Paul. London. 1958.
[4] Y.
Hatwell. Psychologie cognitive de la cécité précoce. Dunod. Paris. 2004.
[8] J. Piaget and B. Inhelder. La représentation de l’espace chez l’enfant. PUF. Paris. 1977.
[9] J. Piaget and B. Inhelder.
L’image mentale chez l’enfant. PUF.
[12] J. Pailhous.
La représentation de l’espace urbain. PUF. Paris. 1970.
[13] J.-F. Richard.
Les activités mentales, comprendre, raisonner, trouver des solutions. Armand
Colin.
[16] S. Mac Arthur. Audition :
physiologie, perception et cognition. In M. Richelle, J. Requin and M. Robert. Traité
de psychologie expérimentale. PUF.
[18] Y. Hatwell. Toucher l’espace. Presse Universitaire de Lille. 1986.
[20] E.
Gentaz. Explorer pour percevoir l’espace avec la main. In J. Bullier and C.
Thinus-Blanc. Agir dans l’espace. CNRS. Paris. 2005.
[24] Y. Hatwell, A. Streri and E. Gentaz. Toucher pour connaître. PUF. Paris. 2000.
[26] P. Bach-Y-Rita. Brain mecanism in sensory substitution. Academic
Press, New York, 1972.
[28] M. A. Heller. Les illusions perceptives haptiques. In Y. Hatwell, A.
Streri & E. Gentaz. Toucher pour Connaître. PUF. Paris. 2000.
[29] S.
Millar. Understanding and representing space. Theory and evidence from studies
with blind and sighted children, Clarendon Press. Oxford. 1994.
[32] M. Simonnet. Voile et Cécité, les repères utilisés par un sujet non-voyant tardif pour barrer un voilier au près. Mémoire de Maîtrise S.T.A.P.S. Brest : Université de Bretagne Occidentale. 2002.
[33] D. Mason.. Sailing Blind, an instruction manual of sailing techniques for blind and vision impaired people, their sighted helpers and instructors. New Zealand Council for blind sailors. New Zealand. 2000.
[35] T.P. Mc Namara. How are the locations of objects in the environment represented memory. In Spatial Cognition III, Springer-Verlag. Mifflin. 2003.
[36] D. Mellet-d’Huart. De
l’intention à l’attention. Contributions à une demarche de conception
d’environnements virtuels pour apprendre à partir d’un modèle de l’(én)action.
Thèse de doctorat en informatique. Université du
[37] Ph. Fuchs,
B. Arnaldi and J. Tisseau. La réalité virtuelle et ses applications, Traité de
la réalité virtuelle, 2ème édition, volume 1, chapitre 1, pages 3-52, Les
Presses de l'Ecole des Mines de Paris. 2003.
[38] G. Vigarello. Une histoire culturelle du sport, techniques d'hier
et d'aujourd'hui. Robert Laffont et E.P.S. Paris. 1988.
- Conferences :
[6] Lenay C.
Mouvement et perception : médiation technique et constitution de la
spatialisation in Le mouvement. Des boucles sensori-motrices aux
représentations cognitives et langagières, actes de
[10] Thorndyke, P. W., Hayes-Ross B. Spatial
knowledge acquisition from Maps and Navigation.
[14] Declerck, G. La perception du
tangible comme obstruction: approches expérimentales minimalistes. Actes du
colloque « Le virtuel et le tangible : ce qui résiste ». Compiègne Tech U. 2005.
[34] Lenay, C. 2005. Design of a
tactil prothesis for blind users with a virtual reality system, Actes du
colloque « Le virtuel et le tangible : ce qui résiste ».
[39] Bicchi A., Dente D., Scilingo P.: Haptic Illusions induced by
Tactile Flow. Conference Proceeding, EuroHaptics 2003 314-329
[40] Wagner C.R., Howe R. D. 2005.Mechanisms of Performance Enhancement With Force Feedback. World Haptic conference. CNR. University of Pisa.
[41] Guénand A. Sémantique de l’interaction en design industriel. Actes du colloque « Le virtuel et le tangible : ce qui résiste ». Compiègne Tech U. 2005.
[42] Dominjon L., Lécuyer A., Burkhardt J.-M. Andrade-Barroso G., Simon
R. 2005. The “Bubble” Technique: Interacting with Large Virtual Environments
Using Haptic Devices with Limited Workspace World Haptic conferen