Methods

There were 12 adult participants (9 male, 3 female) all but 1 naive to the experimental hypothesis. Six reported more than 10 minutes prior experience with virtual environments. Due to the availability of funds, and to compensate participation near the end of an academic term, the last five participants (28, 29, 30, 31 and 32) were paid $10/session. General data about participants are given in Table 4.6.

  

Table 4.6: Participant Overview for Experiment AIE2

Id	Gn	Age	Prev	EFT
21	M	36	1	24
22	M	32	0	15
23	F	28	1	37
24	M	33	0	21
25	M	55	1	15
26	M	23	1	11
27	M	31	0	30
28	M	44	1	29
29	F	28	1	7
30	F	44	0	38
31	M	21	0	26
32	M	24	0	10

Id is the participant number. Gn gives the gender, Age the age in years, and Prev is ``1'' if the participant had more than 10 minutes of prior experience in virtual environments, ``0'' otherwise. EFT gives Embedded Figures Test scores.

For general methods, including the image used, see Section 4.2. As with Experiment AIE1, participants were given a one-minute pre-exposure to each condition, in random order, during which they were asked to examine the scene and gather their impressions. Per-exposure presence ratings were then taken for each condition in an independent random order. Subsequently, visual-inertial cross-over amplitudes were found according to the procedure in Section 4.2. Participants were asked to attend to the visual scene while signaling the perceived inertial endpoints of their motion.

A 48$^{\circ}$ FOV was used (the widest the HMD allowed). In the ``random'' condition, the location of each pixel in the image was randomized. The ``meaningful'' condition was the image as originally taken.

The experiment was run in two sessions, each comparing the meaningful to the random condition with both nulling and reported presence dependent measures. The two sessions were procedurally identical, except that an Embedded Figures Test was administered following one of these sessions and the introduction was not repeated. Each session began by obtaining one per-exposure reported presence rating for each condition according to the procedure described in Section 4.2.2.

Human Interface Technology Lab