Investigating the Impact of Perturbed Visual and Proprioceptive information in Near-Field Immersive Virtual Environment

We report the results of an empirical evaluation to examine the carryover effects of calibrations to one of three perturbations of visual and proprioceptive feedback: i) Minus condition (-20% gain) in which a visual stylus appeared at 80% of the distance of a physical stylus, ii) Neutral condition (0% gain) in which a visual stylus was co-located with a physical stylus, and iii) Plus condition (+20% gain) in which the visual stylus appeared at 120% of the distance of the physical stylus. Feedback was shown to calibrate distance judgments quickly within an IVE, with estimates being farthest after calibrating to visual information appearing nearer (Minus condition), and nearest after calibrating to visual information appearing further (Plus condition)

Learning Cultural Conversational Protocols with Immersive Interactive Virtual Humans

International audienceThis paper reports on a study conducted to investi-gate the effects of using immersive virtual humans in natural multi-modal interaction to teach users cultural conversational verbal and non-verbal protocols in south Indian culture. The study was conducted using a between-subjects experimental de-sign. We compared instruction and interactive feedback from immersive virtual humans against instruction based on a written study guide with illustrations of the cultural protocols. Partici-pants were then tested on how well they learned the cultural conversational protocols by exercising the cultural conventions in front of videos of real people. Subjective evaluations of partici-pants’ performance was conducted by three south Indian re-viewers who were blind to the condition the participants were assigned. Objective evaluations of participants’ performance were conducted on the motion tracking log data recorded during the testing session. We also measured the participants’ pre and post positive and negative affect of training in both conditions, as well as the effect of co-presence with the life-size virtual south Indians. The results of our subjective evaluation suggest that participants who trained with the virtual humans performed significantly better than the participants who studied from literature. The results also revealed that there were no significant differences in positive or negative affect between conditions. However, overall for all participants in both conditions, positive affect increased and negative affect decreased from before to after instruction

A virtual experimenter to increase standardization for the investigation of placebo effects

Abstract Background Placebo effects are mediated by expectancy, which is highly influenced by psychosocial factors of a treatment context. These factors are difficult to standardize. Furthermore, dedicated placebo research often necessitates single-blind deceptive designs where biases are easily introduced. We propose a study protocol employing a virtual experimenter – a computer program designed to deliver treatment and instructions – for the purpose of standardization and reduction of biases when investigating placebo effects. Methods To evaluate the virtual experimenter’s efficacy in inducing placebo effects via expectancy manipulation, we suggest a partially blinded, deceptive design with a baseline/retest pain protocol (hand immersions in hot water bath). Between immersions, participants will receive an (actually inert) medication. Instructions pertaining to the medication will be delivered by one of three metaphors: The virtual experimenter, a human experimenter, and an audio/text presentation (predictor “Metaphor”). The second predictor includes falsely informing participants that the medication is an effective pain killer, or correctly informing them that it is, in fact, inert (predictor “Instruction”). Analysis will be performed with hierarchical linear modelling, with a sample size of N = 50. Results from two pilot studies are presented that indicate the viability of the pain protocol (N = 33), and of the virtual experimenter software and placebo manipulation (N = 48). Discussion It will be challenging to establish full comparability between all metaphors used for instruction delivery, and to account for participant differences in acceptance of their virtual interaction partner. Once established, the presence of placebo effects would suggest that the virtual experimenter exhibits sufficient cues to be perceived as a social agent. He could consequently provide a convenient platform to investigate effects of experimenter behavior, or other experimenter characteristics, e.g., sex, age, race/ethnicity or professional status. More general applications are possible, for example in psychological research such as bias research, or virtual reality research. Potential applications also exist for standardizing clinical research by documenting and communicating instructions used in clinical trials