Chapter
Three
The grand illusion
a lack of attention in the right place might be able
to account for many change-blindness results, pay-
ing attention to the right thing certainly does not
guarantee that we will notice when it changes.
You might think that you are good at spotting the
little mistakes made by TV producers and film direc-
tors, but these results suggest that very few people
notice such inconsistencies – only those who hap-
pen to be attending to the detail in question, and
sometimes not even then.
These effects are not confined to films and labora-
tory conditions. Simons and Levin (1998) arranged
for an experimenter to approach a pedestrian on
the campus of Cornell University and ask for direc-
tions. While they talked, two men rudely carried a
door right between them. The first experimenter
grabbed the back of the door and the person who
had been carrying it let go and took over the con-
versation. Only half of the pedestrians noticed the
substitution. Again, when people are asked whether
they think they would detect such a change they are
convinced that they would – but they are quite likely
to be wrong. Change blindness and inattentional
blindness are a great resource for magicians wishing
to fool people.
More serious implications of inattentional blindness
include, as with change blindness, effects on drivers
and pilots. Talking on a mobile phone while driving is
known to slow responses and increase errors but might
also cause inattentional blindness. In experiments in
which participants concentrated on tracking moving
items in a dynamic display, a salient object suddenly
appeared and was visible for 5 seconds (Scholl et al.,
2003). Normally about 30% of people failed to see
the unexpected event, but when they were simulta-
neously having a phone conversation, although their
task performance did not suffer, 90% failed to detect it.
Later research showed that drivers’ attention is
impaired less when having a conversation with a
passenger than when speaking to someone on the
phone, presumably because the passenger is aware
of the driving situation too. In a driving simulator
involving a crowded motorway scenario, drivers
talked either to a passenger or to someone using
a handsfree phone, or used a handsfree phone
enhanced by a video link showing their face and
the driving scene. The last condition, which gave
mAGIC
If things that happen right in front of our
eyes can be invisible, then magicians should
be able to exploit this fact, and indeed, they
have long done so. now some, including
James Randi and John teller, are taking part
in psychological research, too (Kuhn et al.,
2008; macknik et al., 2008). strong magical
experiences involve the illusion of impossibil-
ity and to create this, magicians must exploit
our erroneous assumptions about the laws of
nature or the huge gaps between what we
see and what we believe we can see (Beth &
ekroll, 2015).
In a typical trick, the ‘effect’ is what the
audience see (or think they see), and the
‘method’ is how the magician achieves
the effect. For example, the audience may
‘see’ a coin passed from one hand to the
other, when in fact it remained in one hand.
In physical misdirection, magicians use movement,
high contrast, or surprise to direct interest and then
carry out the method elsewhere. they can manipulate
levels of attention with body language or joke and
carry out the method as the audience relaxes. In psy-
chological misdirection, they control expectation and
surprise, give false clues to an impossible solution, or
repeat the same effect using different methods. Above
all, they manipulate the observer’s gaze by knowing it
will follow their own.
In a simple trick, the audience ‘see’ a ball fly into the
air though it never left the magician’s moving hand.
over a century ago, psychologist and magician nor-
man triplett (1900) found that children ‘saw’ the ball
disappear somewhere between the magician and the
ceiling. In more recent research, 68% of observers
claimed to see an imaginary ball when the magician’s
gaze followed it, compared with 32% when he watched
his hand (Kuhn et al., 2008). timing is critical, too:
the illusion of a coin moving from one hand to another
is weaker when the time interval between the false
transfer and the opening of the second fist increasesC
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