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So, can you explain with more detail of what Place illusion is,
maybe with some examples so I can really understand the concept.
Yes. So, Place illusion is
the illusion of being in a place even though you know you're not there.
So this is a very critical aspect of it.
The second part, in real life, in everyday life,
as you walk around you're of course always
in a place and you don't go around saying to myself,
wow, I'm in a place,
you just there, that's it.
The only time you ever might make that comment is when you're in
a place that is exciting to you for some reason,
like you've gone to the Taj Mahal ,
you'll say, wow, I can't believe I'm here.
That they are talking about more that you're lucky that
you're witnessing such an interesting thing.
But you are not marveling at the fact that you're
in a place because you're always in a place.
But in virtual reality where the marvel is,
is I'm here for example, in this room,
I put on a head mounted display,
and now I'm in the Taj Mahal.
This is the wow factor.
The factor that gives me the illusion that
I'm in a place which is different from where I really am.
So, Place illusion is the strong illusion
of being in the virtual place even though you know you're not there,
and so some examples which are used have been used a lot in many different applications.
Let's take some from our own work.
So, why is this important to be able to have this?
So one of the things we're interested in is
applications of virtual reality in the area of social psychology.
One of the interesting things about social psychology,
a very interesting topic,
is called the bystander problem.
The bystander problem is that you're somewhere and
suddenly two other people start fighting,
one of them is a victim and one of them is a perpetrator,
and the perpetrator is attacking the victim.
What do you do? Do you try to intervene even though that might be dangerous to yourself?
Do you try to get help?
Do you run away? What do you do?
This is a longstanding issue in social psychology,
and I have a theory which says that,
the more other people are there,
the less likely is that any individual will do anything to help.
This actually started from a real murder that happened in the 1960's,
where there was a woman murdered and
apparently there were 38 witnesses and they did nothing.
This whole bystander theory came about from studying that event.
Now, how can we study that event experimentally?
Well, when you come in physical real life,
you cannot make a violent event and have other people there to witness it.
We wouldn't get ethics approval.
It's not practical if you did it with actors.
Every time they did it they would do something different and so on.
But in virtual reality we can create a situation
where that violent event or some event like that happens,
and because of Place illusion,
people do have the illusion that this is there,
that they are there, that this is,
they are in that reality,
and therefore it sparks in them all the kinds of similar emotions
and feelings that they would have if this was happening in real life.
I mentioned earlier the whole area of clinical psychology.
There's many different examples of that.
Another one that we've done ourselves is fear of public speaking.
Someone has fear of public speaking. What do you do?
Gradually they have to be exposed to
more and more situations where they face their fear and learn to control their anxiety.
But this is expensive, is difficult.
So if a clinical psychologist wants to help someone to be exposed to audiences,
they have to get audiences together and this is complicated.
Again if you use actors,
they won't do the same every time and they're expensive,
you have pay them and so on.
Now suppose we do fear of public speaking with
an entirely virtual audience with virtual characters.
So, I put on the head mounted display, and suddenly wow,
I'm in this auditorium and there's all these virtual people there,
my heart starts pounding and so on,
now the therapist can work with me because I've generated some anxiety.
So even though I know is not true,
I know that nothing is happening,
I know I'm just seeing pixels on the screen.
As I said before, some parts of the brain doesn't know about virtual reality,
and you just respond as if it's real.
So I've seen situations
where experienced speakers are
speaking in front of the virtual audience which is ignoring them,
and those experienced speakers can't speak
because the virtual characters are all shuffling around,
and they're looking in other directions,
and they're talking amongst themselves.
So even though they speak on you, nothing is happening.
They couldn't speak to those characters.
So these are some examples of where Place illusion is one part of
the equation of what makes virtual reality work in this situation.
I remember actually experiencing the public speaking one,
and it just really disturbing.
These people are like actively ignoring me and no matter how
much I tried to focus on my script,
I just can't get my brain to actually function properly.
And I've also been to the bystander experiment you mentioned in a cave.
I remember there were these two guys just started fighting in front of me,
and because they were so real,
and they were actually like big guys,
much taller than me,
I really felt threatened and I really felt I need to get somebody
else to intervene because I am way too small to do anything.
So it does kind of make me actually think about what I would do in a situation like that.
That's right. Yeah.
Yeah, and I think that's also probably very important because I can actually expose
myself to situations without having to risk,
to actually have this reflection.
Yes.
Yeah. Okay, very interesting.
Dr Sylvia Xueni PanLecturer, Department of Computing
Dr Marco GilliesSenior Lecturer
