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Biomedical subjects

Mel Slater

Publications and source records attributed to Mel Slater.

9 recordsLinked to original sources
PubMed2006

A virtual reprise of the Stanley Milgram obedience experiments.

BACKGROUND: Stanley Milgram's 1960s experimental findings that people would administer apparently lethal electric shocks to a stranger at the behest of an authority figure remain critical for understanding obedience. Yet, due to the ethical controversy that his experiments ignited, it is nowadays impossible to carry out direct experimental studies in this area. In the study reported in this paper, we have used a similar paradigm to the one used by Milgram within an immersive virtual environment. Our objective has not been the study of obedience in itself, but of the extent to which participants would respond to such an extreme social situation as if it were real in spite of their knowledge that no real events were taking place. METHODOLOGY: Following the style of the original experiments, the participants were invited to administer a series of word association memory tests to the (female) virtual human representing the stranger. When she gave an incorrect answer, the participants were instructed to administer an 'electric shock' to her, increasing the voltage each time. She responded with increasing discomfort and protests, eventually demanding termination of the experiment. Of the 34 participants, 23 saw and heard the virtual human, and 11 communicated with her only through a text interface. CONCLUSIONS: Our results show that in spite of the fact that all participants knew for sure that neither the stranger nor the shocks were real, the participants who saw and heard her tended to respond to the situation at the subjective, behavioural and physiological levels as if it were real. This result reopens the door to direct empirical studies of obedience and related extreme social situations, an area of research that is otherwise not open to experimental study for ethical reasons, through the employment of virtual environments.

Adult↗
PubMed2006

Walking from thought.

Online analysis and classification of single electroencephalogram (EEG) trials during motor imagery were used for navigation in the virtual environment (VE). The EEG was recorded bipolarly with electrode placement over the hand and foot representation areas. The aim of the study was to demonstrate for the first time that it is possible to move through a virtual street without muscular activity when the participant only imagines feet movements. This is achieved by exploiting a brain-computer interface (BCI) which transforms thought-modulated EEG signals into an output signal that controls events within the VE. The experiments were carried out in an immersive projection environment, commonly referred to as a "Cave" (Cruz-Neira, C., Sandin, D.J., DeFanti, T.A., Surround-screen projection-based virtual reality: the design and implementation of the CAVE. Proceedings of the 20th annual conference on Computer graphics and interactive techniques, ACM Press, 1993, pp. 135-142) where participants were able to move through a virtual street by foot imagery only. Prior to the final experiments in the Cave, the participants underwent an extensive BCI training.

Adult↗
PubMed2006

An experimental study on fear of public speaking using a virtual environment.

This paper examines a necessary condition for successful exploitation of a virtual environment (VE) in therapeutic intervention for fear of public speaking. The condition is that clients experience a degree of anxiety in the VE that is similar to what they would have been expected to experience in a similar real world setting. We refer to this as a "presence" response. The experimental study involved 20 people who were confident public speakers and 16 who were phobic, assessed on a standard psychological scale. Half of each group spoke within a VE depicting an empty seminar room, and the other half within the same room but populated by a neutrally behaving virtual audience of five people. Three responses were measured--a questionnaire-based measure of anxiety, a measure of self-focused attention on somatic responses, and actual heart rate. On all responses, the people with phobia showed a significant increase in signs of anxiety when speaking to the virtual audience compared to the empty room, whereas the confident people did not. The result was strong in spite of the relatively low representational and behavioral fidelity of the virtual characters.

Adult↗
PubMed2005

From presence to consciousness through virtual reality.

Immersive virtual environments can break the deep, everyday connection between where our senses tell us we are and where we are actually located and whom we are with. The concept of 'presence' refers to the phenomenon of behaving and feeling as if we are in the virtual world created by computer displays. In this article, we argue that presence is worthy of study by neuroscientists, and that it might aid the study of perception and consciousness.

Computer Simulation↗
PubMed2005

The psychology of persecutory ideation II: a virtual reality experimental study.

A cognitive model of persecutory delusions is used to predict the occurrence of nonclinical paranoid thoughts in a virtual reality environment. Scorers across the range of paranoia entered a virtual reality scene populated by five computer characters programmed to behave neutrally (N = 30). Many appraisals of the computer characters were positive or neutral. However, there were also persecutory thoughts about the characters. Providing evidence of the validity of the experimental method, persecutory ideation was predicted by higher trait paranoia and a greater sense of presence in the environment. The psychological variables from the cognitive model that predicted persecutory ideation were anxiety, timidity, and hallucinatory predisposition. Further, hallucinatory predisposition distinguished the prediction of paranoid thoughts from social anxiety in virtual reality. It is concluded that nonclinical paranoid thoughts are most closely associated with emotional disturbances and anomalous experiences. Extreme reasoning bias may particularly contribute to the development of clinical phenomena.

Adult↗
PubMed2005

The psychology of persecutory ideation I: a questionnaire survey.

Paranoia is a complex phenomenon that is likely to arise from a number of factors. In a recent cognitive model of persecutory delusions, three key factors are highlighted: anomalous experiences, emotion, and reasoning. In the first of two linked studies, we report a questionnaire survey of nonclinical paranoia designed to assess the theoretical model. A nonclinical population (N = 327) completed measures of paranoia, anomalous experiences (hallucinatory predisposition, perceptual anomalies), emotion (depression, anxiety, self-focus, stress, interpersonal sensitivity), and reasoning (need for closure). Paranoia was best explained by separation anxiety, depression, fragile inner self, hallucinatory experiences, discomfort with ambiguity, stress, self-focus, perceptual anomalies, and anxiety. The findings are consistent with the central predictions within the model of paranoia.

Adult↗
PubMed2003

Social anxiety in virtual environments: results of a pilot study.

This paper reports on a pilot study of the extent to which social anxiety can be generated within a virtual environment. Ten subjects were exposed to a virtual reality experience depicting a London underground train and also a wine bar. The first provided a social setting with virtual characters (avatars) that had relatively neutral behaviors towards the subject, and the second was more socially demanding--with subjects required to interact with relatively disinterested avatars. The purpose was to assess whether social anxiety would be greater for the wine bar experience than the train journey experience, taking into account prior tendencies to social anxiety, and the order of presentation. The results suggest that social anxiety was higher for the wine bar experience, but lower for the second exposure.

Humans↗
PubMed2003

Can virtual reality be used to investigate persecutory ideation?

The use of virtual reality permits individuals' reactions to standard controlled environments to be studied. It may therefore provide a means for understanding the interpretations of experience relevant to clinical disorders. The use of this technology for understanding persecutory ideation has not been investigated. A pilot study was undertaken to examine whether individuals have persecutory thoughts about virtual reality characters under controlled conditions and if there are factors that predict the occurrence of such thoughts.Twenty-four nonclinical participants entered a neutral virtual environment that contained computer-generated people. The participants completed dimensional assessments of items related to psychiatric symptoms and their thoughts about the virtual characters. Positive views about the virtual characters were common. However, a number of participants had ideas of reference and ideas of persecution about the virtual characters. Individuals who had persecutory thoughts about the virtual characters had significantly higher levels of interpersonal sensitivity and anxiety. The study provides direct evidence that individuals attribute mental states to virtual reality characters. Important for the study of clinical phenomena, some individuals have thoughts of a persecutory nature about virtual characters. Additionally, the findings indicate that feelings of interpersonal vulnerability and anxiety may directly contribute to the development of persecutory ideation in response to essentially neutral contexts. Virtual reality may prove to be a valuable methodology for developing an understanding of persecutory ideation.

Adult↗