Week 10 Summmaries

Variations in Physiological Responses of Participants

During Different Stages of an Immersive Virtual

Environment Experiment

 

The paper discusses about a study conducted to measure the stress levels of participants in a virtual urban environment during different stages such as baseline recording, training, first half and second half. The experiment involved a virtual street with people walking around. The experimental results showed that the there was an increase in stress level of participants from baseline to training segment. This was attributed to the novelty of the environment where the participants tried to understand the environment as well as their potential to carry out the experiment. Later, there was a decrease in stress from training to first half of the experiment. This probably was because the participant got familiar and thus was more confident in carrying out the experiment. In the third part when the participant moves to the second half of the experiment, there was an increase in the participant’s stress level.  One possible reason for this may be that once familiar, the participant started seeing the technical and spatial limitations of the virtual environment. For the future work the authors suggest that participants be allowed to continue training till they are completely comfortable with the environment.

In my personal opinion, the study  does not provide any novel findings. The effect of increase and decrease in stress levels holds true for most of the devices that we use daily (computing as well as non-computing). The stress decreases as we get familiar with any device and again increases as we get to know it’s limitations.

 

The Uncanny Valley: Effect of Realism on the Impression of

Artificial Human Faces

 

The paper discusses about a series of experiments conducted to determine the presence of ‘uncanny valley’ (where too high realism might evoke unpleasant impression in the viewer). The authors tried to see if Mori’s graph that maps pleasantness across degree of realism holds true, particularly when it comes to dealing with robots. The experiments involved morphing of human face from unreal to real. The variations of experiment was based on uniform morphing, morphing of eyes (or head) first, manipulations of eye size (to 150%) and variations in morphing to avoid confounding.  As the experiments were conducted it was observed that uncanny valley effect actually existed. However the effect emerged only when the face images had abnormal features. Further discussion suggests that unpleasant impression might also be caused by the participants previous experience with real and animated facial features. Also the experiments only test the impression based upon the facial features and similar effect might be produced based upon the movement of robots too. The authors conclude that in the particular study it was clear that human perceptual system processes realism and abnormality as separate perceptual dimensions.

 

 

Physiological Measures of Presence in Stressful Virtual Environments

                The paper discusses about the hypothesis that the degree of reality simulated in an Virtual Environment will evoke physiological responses as the real environment would. The experiment conducted was a pit room where the users walk in a room and suddenly come across a 20ft deep virtual pit. The reactions of the users were noted which ranged from vertigo effect to boldly walking across the pit. Some of the measures noted were reliability, validity, sensitivity and objectivity of the experiment. The results of the study showed that the physiological measures are useful in measuring presence in a simulated stressful environment. Two important findings of the experiment were that

1.            Although there was significant decrease in presence measure based on physiological and reported data, it did not touch zero of became significantly small.

2.            Adding passive haptics that augmented user’s presence such as a adding a 1.5 inch ledge while simulating drop significantly increased presence.

For the future work the authors plan to measure the minimum system characteristics to achieve sense of presence. Also a need to remove cables for monitoring, tracking and rendering was noted.

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