Our brain uses a combination of senses to
provide information about where our body parts are. This awareness is known as proprioception. Although this mostly comes from internal body
information, it can be tricked or confused by external
senses such as sight and touch. In this activity your kids will work through
a number of illusions that are designed to trick and confuse your
brains ability to sense your body. So first of all we’re going to do a little
experiment: I’d like you all to touch your nose. Wow you’re so clever, you can all touch your
nose! As well as having senses like sight and touch
you also have a sense of where your body is. This can be introduced with this simple demonstration. Now what I’d like to you do, slightly more
challenging, is take your finger from your nose, put it
behind your back, close your eyes… now touch your nose. Wow, took a little bit longer but you all
managed to find your nose, Give yourselves a quick round of applause! So the sense that is at work that makes you
know where your own nose is, even when your eyes are closed, is called proprioception. Can everyone say that? “Proprioception”. Proprioception! And today, we’re going to do lots of experiments
to find out how proprioception works, So we’re gonna have some illusions that will
blow your mind! Are you ready? Yeah! There are 8 illusions which you can work through
in this activity. Each of them are designed to trick or confuse
your senses in a different way. Don’t worry if some illusions work better
than others, everybody responds differently. Many of these illusions work best when you
don’t know what to expect, so try them out on your children before telling
them what will happen, this way they should get the full effect. The ‘working in a mirror’ challenge shows
just how disorienting it is when what you see doesn’t
line up with what you feel. Sit at a table in front of a mirror, with
something blocking your direct view of your hand. Looking only in the mirror, try to write your name and if you want a real challenge try completing
the maze which you can find on our website. The ‘rubber hand illusion’ is a classic
experiment to show how our sense of self can be tricked. Sit your child at a table, with a screen slightly
to one side, blocking the view of one of their hands. In front of them, create a fake hand with
a stuffed rubber glove and a towel to hide the space where the rubber
glove’s arm would be. Now using a paintbrush, stroke both the rubber
hand and the hidden real hand for about a minute The participant should start to feel that
the rubber hand is actually theirs. If you want to see how well it’s really worked,
try surprising them by slamming the fake hand. Try this to give someone the sensation of
having six fingers! Set up the participant in front of a mirror
like this and ask them to look at their reflection in
the mirror. The other hand should be hidden by the mirror On both hands stroke each finger, from knuckle
to fingernail at the same time, counting each finger as you go. Repeat it again, but this time, on the hidden
hand stroke the inside of the little fingeron ‘5’, and then add a sixth stroke, on the outside
of the little finger. On the visible hand you should pretend to
stroke an invisible sixth finger next to thelittle finger. They should feel like they have a sixth digit! This simple illusion demonstrates how your
brain can get confused when different body parts feel different things. Cross your fingers like this, and stroke them
across your nose. Because the outside edge of your fingers are
touching the nose, it might feel like you have two noses! Get your child to stick their arms out, with
their thumbs facing down. They should then cross their hands over and
interlock their fingers. They should then twist their hands downwards
and then pull them back up towards their body Ask your child to wiggle a single finger on
their left hand, it’s likely that this tangled orientation
confuses their brain and makes getting correcthand a little tricky! Try the ‘cutanous rabbit’ to investigate
how precisely our body can locate sensations. Ask your child to close their eyes and stick
their arm out. Next, tap them 4 times at the wrist, 3 times
just above the elbow, and then twice on the upper arm. Try to make sure that the taps are at a constant
rhythm. It should feel like that taps were spaced
across the arm, rather than in the individual areas. This illusion should give the impression that
your arms are sinking through the floor. Get your child to lie down on the floor with
their arms straight out and eyes closed. Carefully hold their arms up by the wrists
and hold them for about a minute, then very slowly lower them back to the floor. As the arms are slowly lowered, the child
should feel that their arms are falling through the floor. Finally, the ‘heavy boxes’ test demonstrates
how expectations based on the appearance of an object can conflict with how heavy we perceive an
object to be. In this demonstration, place two equal weights
inside boxes of different sizes, cans of baked beans or soup work well for
this. Get your child to lift each box and then ask
them which they think is heavier. People tend to assume that the smaller box
is heavier, even though they actually weigh the same. You can turn this activity into a scientific
investigation by recording your observations in a table. For each illusion you should note which senses
are being confused and then rate the level of confusion out of
10. It felt like my elbow was going through already
and my hand was still trying to get through! I think it was tricking my touch, and that
would be a 9. Looking over the table, they should start
to realise that removing just one of their sense, especially sight, is enough to disrupt their
brain’s understanding of what is going on. I felt like that was my real hand because
I couldn’t see the real hand, and when she stopped stroking this hand I
thought she was stroking this one! Which of the experiments did you find the
most puzzling, and why? OK, Naimah… Throughout the activities don’t forget to
ask your kids loads of questions about what they think is going on and how their brains and their body’s are
being confused. The kids have had an absolutely brilliant
time today. If you’ve enjoyed this video and want to try
the activities for yourself, don’t forget to visit the Royal Institution
website, and don’t forget to like and subscribe to
this channel.