Virtual Reality in Experimental Psychology

Virtual Reality inExperimental

Psychology

Richard SouthernNational Centre for Computer Animation

Bournemouth University

R. Southern (NCCA) VR in Exp. Psych. January 9, 2013 1 / 48

What is Virtual Reality?


Virtual Reality in a nutshell

Secrets of useful Virtual RealityIllusion of place: ”I feel like I am in a different location”

Illusion of plausibility: ”This location and the events that aretaking place therein are real”

Build your own!Head mounted displays

Stereo projectors + shutter glasses

Head trackers / motion capture

A flexible game engine


Experimental Social Psychology

Evaluate social phenomena throughexperimentation

Helps to understand societal factors,e.g. public order

Example: Why do people justifysmoking with irrational statements?cognitive dissonance


This Talk

1 When and why does reality fail?

2 Why does virtual reality succeed?

3 The Bystander Effect

4 Experimental Design

5 Experimental Results

6 Factors Affecting Outcomes


Section 1

When and why does reality fail?


Experimental Psychology

Milgram experiment

Why is it that people can be persuaded to carry outatrocious acts at the behest of authority, acts that areagainst their own moral principles? (Stanley Milgram)



Ethical problemsDistressing - participants are exposed to distressing or violentsituations. This is ok if these are naturally occuringcircumstances.

“Inflicted insight” — participants find something out aboutthemselves that may be hurtful.

Deception — participants must be not be aware of the actualexperiment goals otherwise results will change.


Getting Realistic Responses

Realistic responses are difficult to assessIn violent situations, there is no percieved danger.

Everyone says they will stop the fight in this experiment.



Other problemsReproducability: when employing actors, the experiment isalways slightly different

Measurements: difficult to get physiological measurements inuncontrolled environments


Section 2

Why does virtual reality succeed?


Pit Experiment

One of the earliest experiments in VR. Often repeated.

Participants feel anxiety when they have to navigate around avirtual pit.

Anxiety greatly increase when you add virtual feet and castshadows.


Fear of Public Speaking

Participants present to a virtual audience in three conditions:neutral, attentive, disruptive.Results were very conclusive. Responses were realistic.


Treatment

Virtual Reality (graded) Exposure Therapy (VRET) — gradualexposure to stressful circumstances (public spaces, heights etc.)Patients benefit from an unobtrusive and unthreateningrehabilitation environment.In recent research, games more effective than anti–depressantsfor post-traumatic stress disorder (but both are worse thanexercise).


Virtual Milgram Experiment

UCL group created a Virtual Reality reproduction of famousexperiment.

Participant responses correspond to original experiment.

But were aware that it is not realR. Southern (NCCA) VR in Exp. Psych. January 9, 2013 15 / 48

Experimental evidence

Participants respond realistically, while knowing itis not real


Section 3

The Bystander Effect


Origins

Brutal rape and murder of Kitty Genovese.

For more than half an hour thirty-eight respectable,law-abiding citizens in Queens watched a killer stalk andstab a woman in three separate attacks in KewGardens. (New York Times, 27 March 1964)

Kitty Genovese Winston MoseleyR. Southern (NCCA) VR in Exp. Psych. January 9, 2013 18 / 48

Bystander Effect

The number of witnesses is inversely proportionalto the likelihood of intervention

Early bystander experiments (telephone, smoke)

Some affectors:I Type of incidentI Group membershipI Age of witnesses


Bystander Effect

Possible CausesLoss of individuality — Mob mentality: easier to do whatothers do than think for yourself.

Diffusion of responsibility — Responsibility distributedamongst the bystanders.

Larger likelihood of authority figure — The larger thecrowd, the higher likelihood that there is someone betterqualified to intervene.

Pluralistic ignorance — You look to what others do beforedeciding your strategy.

Not noticing

Possible StrategyIsolate an individual — Refer to them by name.


Social Grouping

Good samaritan experimentParticipants are all Manchester United fans.

Priming used to associate them with ManU or England footballspirit.

Participants told to hurry to neighbouring building.

On the way, a football supporter trips over in front of them.

Shirt is either Manchester United, Liverpool or Plain.


Social Grouping

Actor shirt Participants who helpedManU Fan Identity Football Identity

ManU 92% 80%Liverpool 30% 70%

Plain 33% 22%


Social Grouping

Intervention experimentParticipants watch CCTV of neighbouring room containing twofootball fans from rival clubs.

A fight breaks out in other room. Do participants intervene?

Identity of participants and size of group manipulated.

Experiment repeated with gender factors.


Social Grouping

Effects of “Groupiness”Group identity enhanced by priming

Bystander effect may be inversed when group identity is shared.

Intervention increases when bystander shares a social group witheither the victim or the perpetrator.


Who wants to know?


Section 4

Experimental Design


Research Questions

Evaluating the following factors on intervention:social identity — all participants are Arsenal football fans.

eye contact — victim occasionally looks at participant.

(group size)

(model / animation fidelity)


Basic Experiment

Participant Victim Aggressor

P enters an empty bar virtual environment.

V walks into a bar.

V starts conversation with P. Dialog establishes social identityof V.

A enters bar during conversation.

A starts confrontation with V.

MeasurementsWhen and how does P intervene? (Video Analysis)

Questionnaire


Experiment Platform

EquipmentVR system at University College London

3m3 space

4 stereo projected walls

Stereo shutter glasses

Head tracker


Experiment Preparation

Model PreparationTurntable images captured of BU staff and students.

Converted to virtual form by animator.



Animation captureStandard motion capture system

Retargeted to characters



Software EngineBehavior model forvirtual characters

Interface to controldialog and events

No AI, motionsynthesis


Section 5

Experimental Results


Running Experiment


Experimental Findings



About 48 participants

Participants significantly more likely to intervene in the in–groupcondition.

Victim looking at participant increased interventions only inin–group condition.

In–group more likely to have confrontation intervention.

Out–group more likely to try diffuse situation with verbalintervention.


Example Comments

I felt like I would like to stop it (the confrontation)myself, basically back up the person that I was speaking toArsenal about, protect him.

I knew it was VR, and I’m quite surprise how so angrymade me feel, the other guy, ... I got to the point that Iwanted touch him physically or pushing away I felt a bitfrustrated I couldn’t.

Very similar feelings as in real life: flustered, panic,helpless and wanting to resolve the situation and notknowing how.


Experimental Feedback


Other concerns

Participants frustrated by lack of interactivity.

Some felt scenario was not realistic:I too aggressive / not aggressive enoughI unlikely event in a London pubI no other peopleI quality of rendering


Take Home Message

The key to tackling the so called “walk–on–by” societylies in using the power of group identification to promotesocial solidarity — and to persuade and empower bystandersto intervene, in situations where this is considered by theauthorities to be appropriate. (Mel Slater)


Section 6

Factors Affecting Outcomes


Uncanny Valley: Model Fidelity

Recent experiment compared responses to rendering styles

Users liked high quality and cartoon styles


Uncanny Valley: Animation Fidelity

State of the artRockstar games LA Noire

48 camera rig captures high quality facial animation

Too expensive for us to use!


Experimental Equipment

Measurement DevicesSkin conductance and ECG areunreliable and difficult to analyse

Video analysis is time consuming andexpensive

fMRI limits range of movement

Cheap brain scans? e.g. Emotiv


Reinforcement Learning

Traditional experiments are validating an existing model(hypothesis) through experimentation.

Can you design the experiment so the model is learned frommany participants?


Questions?


Virtual Reality in Experimental Psychology

Science

Transcript of Virtual Reality in Experimental Psychology