Spatial Cues in 3D Visualization - Ambient Intelligence for Scientific Discovery - page 110

Through evolutionary selection, the 'hunter-gatherer' theory maintains that
these male-female predispositions in cognitive abilities persist today. In support
of this theory, there is evidence that contemporary females exhibit superior per-
formance to males on spatial tasks mimicking foraging-related activities, such as
remembering the location of landmarks in their environment [48]. In addition, it
has been shown that women are better than men at keeping track of objects, and
at finding objects that are lost [47, 49]. Moreover, studies report that women re-
member the locations of previously viewed items better than men [50], and that
women are better than men at remembering the locations of specific objects
[51]. In contrast, men generally outperform women at spatial tasks involving the
manipulation of objects in space [45, 52-57]. Furthermore, studies have shown
that men are better than women at 'mental rotation' spatial abilities [48, 58],
reportedly as an evolutionary artifact of the ability to track an animal through
unfamiliar terrain and then expeditiously navigate their way home.

3 Approach

We report three experiments in which subjects perform visual, spatial tasks
using 2D and 3D 'virtual worlds.' The first experiment is an object matching
experiment and the second and third experiments require subjects to reposition
and to resize objects viewed in space against some predefined standard. The three
experiments were designed to manipulate similar conditions under different task
circumstances such that comprehensive conclusions could be drawn regarding
the ecacy of particular depth cues in promoting spatial task performances.

3.1 Experiment #1: Object Matching

Method. The object matching experiment [8] utilized a variant of the mental
rotation paradigm [59]. Subjects were presented with pairs of object images at
different angles and orientations and the task was to determine whether the two
objects were identical or different. Figures 1 through 4 show examples of the
four types of solid and wire frame, cubical and spherical object images. Figure 1
also depicts the experimental user interface with “start,” “same” and “different”
buttons embedded. One half of the presented image pairs were identical and the
other half were different. The left object of each pair was always stationary
and the right object was always in motion. In one half of the trials, subjects
controlled the motion of the right object by rotating it around the center point
in any direction. In the remaining trials, the right object rotated automatically
in a fixed direction and speed.

Design. The experiment used a within-subjects design, manipulating the in-
dependent variables: viewing mode (stereo, mono); type of motion (controlled,
uncontrolled); object surface characteristic (wire frame, solid); and object shape
characteristic (cube, sphere). Stereo viewing was achieved using CrystalEyes
stereoscopic glasses. The measured dependent variables included error rate, the