Biomedical Engineering Reference
In-Depth Information
Fig. 6.7
The CyberWalk platform
a portable eye tracking device, which is of great value to the study of the coordination
of the eye, head, and trunk while making turns [
52
,
53
,
57
,
81
,
98
]. Space has also
been a major limitation to earlier research using tracking technologies. Thus, walkers
have typically been tracked while walking short distances, making predefined turns
(e.g., [
27
,
57
,
81
]), or walking in repetitive artificial patterns like circles [
47
], figure
eights [
52
] or cloverleaf patterns (e.g., [
53
]). Sreenivasa et al. [
98
] had participants
walk along trajectories that consisted of turns of various angles (between 45
◦
and
135
◦
, and 180
◦
turns) interspersed with straight sections, in an attempt to simulate
more closely the series of turns that occur in natural day-to-day walking. With the
help of VE technologies it is also possible to strictly control the amount of visual
information provided about upcoming turns. The effects of head/eye orientation on
veering have only been studied when having participants walk for several meters.
However, as the large scale navigation studies suggest, more complete evaluations are
possible when assessing the effects of head/eye orientation on veering duringwalking
trajectories that occur over longer periods of time, or across longer distances.
The CyberWalk platform also opens up a particularly large potential for human
navigation research. For instance, recall the desert/forest experiments described in
Sect.
6.4
, for which it was necessary to travel to the Sahara desert. Without going
through this level of effort and expense, conducting such experiments would be
extremely difficult to test in the real world because of the need for a completely
sparse environment through which an individual can walk for hours. However, such
large scale experiments are now possible in the lab. VEs allow us to manipulate par-
ticular characteristics of the simulated world (e.g., position of the sun, or time of day)
as a way of evaluating the exact causes of any observed veering behaviors, while still
allowing for limitless walking capabilities in any direction. Other questions are now
possible to address as well. Although, thanks to visual VE development programs,
these large scale environments are relatively easy to create and manipulate, the plat-
form is the first to enable truly unconstrained exploration of these environments. It
thereby also creates much more ecologically valid, multisensory circumstances for
studying questions about spatial cognition. The platform also creates unique oppor-
tunities for studying behavior in unfamiliar environments (e.g., [
55
]).
