Biomedical Engineering Reference
In-Depth Information
Each of the above studies was designed to investigate specific low-level perceptual
and cognitive processes that are involved in navigation. To do so, participants were
either blindfolded or presented with optic flow visual information. Triangle comple-
tion is trivial to perform accurately in rich visual scenes [
34
] which, together with the
simple (two leg) paths that participants followed, means that the above studies had
little ecological validity with the environments and tasks used in VE applications.
5.4.2.2 Single-Route Acquisition and Large-Scale Environments
Compared with the above studies, investigations of the effect of body-based infor-
mation that used single-route acquisition tasks and large-scale environments have
produced more consistent findings. Whenever the results were statistically signifi-
cant, the Full group performed best, and the worst performing group was either the
Vis group (if such a group was part of the study) or the Rot group (if the study had
no Vis group).
In identifying the above consistency in the findings, a number of caveats should
be noted. First, Witmer et al. [
18
] asked participants to learn a route through either
a real building (Full group) or a high visual fidelity VE model of the building (Rot
group), and then tested training transfer to the real building. The Full group was
superior in both training and testing, but the difference could have been caused by
various factors that were associated with performing the task in the real world, not
just the addition of translational body-based information. Second, Grant and Magee
[
26
] also performed a training transfer study. The Full and Vis groups both trained
in the VE, but there was not a significant difference between the groups' direction
estimate accuracy when tested in that environment. A significant difference only
occurred when navigational performance was tested in the equivalent real-world
environment. Third, although Waller et al. [
27
] found no significant main effect for
the accuracy of direction estimates, for the most complex routes (6-8 turns) the Full
group's estimates were significantly more accurate than the other groups' estimates.
Fourth, in both of Waller's studies [
2
,
27
] the Full group moved actively, but the
Vis group passively viewed movement that had been recorded by a camera worn by
a person who walked. Fifth, Suma et al. [
14
] reported significant effects, but these
were due to the poor performance of participants who used a move-where-pointing
interface (a Vis group). There was not a significant difference for the time taken
between a physical walking (Full) group and another Vis group, who used a move-
where-looking interface, for the number of collisions with the environment's walls,
or in recall and recognition tests about objects that had been in the environment.
That contrasts with another study, where participants who physically walked (a Full
group) were significantly better at both recognizing and correctly recalling the order
of objects that had been in the environment than participants who were in a Rot
group [
15
].
In summary, these large-scale environment studies indicate that navigating a route
with full body-based information improves both the route and survey knowledge of
participants. There is some evidence that rotational body-based information produces
