Invitation to Psychology

Chapter 6 Sensation and Perception 193

but we do not see. When people are shown a video
of a ball-passing game and are asked to count
up the passes, they may even miss something as
seemingly obvious as a woman in a gorilla suit
walking slowly among the players, thumping her
chest (Most et al., 2001; Simons & Chabris, 1999;
Chabris & Simons, 2009). (Most accounts of this
research have reported that it was a “man” or
“guy” in the gorilla suit. Clearly, many who saw
the study were blind to the sentence in the origi-
nal report saying that it was a woman!)
Inattentional blindness occurs in many cir-
cumstances. When radiologists looking for signs
of lung cancer examined slides that contained a
superimposed image of an arm-waving gorilla,
most of them missed the gorilla (Drew, Võ, &
Wolfe, 2013). One research team wondered which
situation would be most likely to “blind” people to
the sight of a colorful clown riding on a unicycle:
walking along while talking on a cell phone, walk-
ing while listening to music, walking alone, or
strolling with one other person. Can you guess?
The walkers who were least likely to notice the
clown were those who were talking on their cell
phones (Hyman et al., 2010).
Selective attention, then, is a mixed blessing.
It protects us from overload and allows us to focus

Hard though it is to believe, even a person in a

gorilla suit may go unnoticed if people’s attention

is elsewhere.

Recite & Review

Recite: Say out loud everything you can recall about sensation, perception, sense receptors, the

doctrine of specific nerve energies, synesthesia, anatomical and functional codes, absolute and

difference thresholds, signal detection theory, sensory adaptation, sensory deprivation, selective

attention, and inattentional blindness.

Review: Next, it’s time to go back and read this section again, concentrating on what you

couldn’t remember.

Now take this Quick Quiz:

1. Even on the clearest night, some stars cannot be seen by the naked eye because they are
   below the viewer’s __ threshold.


2. When you jump into a cold lake but moments later the water no longer seems so cold, sensory
   __ has occurred.


3. If you are immobilized in a hospital bed, with no roommate, TV, or cell phone, and you start
   feeling edgy and disoriented, you may be suffering the effects of __.


4. During a break from your job in a restaurant, you are so caught up in a book that you fail to
   notice the clattering of dishes or orders being called out to the cook. This is an example of
   __.


5. In real-life detection tasks, is it better to be a “naysayer” or a “yea-sayer”?
   Answers:

Study and Review at MyPsychLab

Neither; it depends on the consequences of a “miss” 5. selective attention4. sensory deprivation3. adaptation2. absolute1.

or a “false alarm.” Suppose that you are in the shower and you’re not sure whether your phone is ringing in the other room. You

might want to be a yea-sayer if you are expecting a call about a job interview, but a naysayer if you are not expecting any calls

and don’t want to get out dripping wet for nothing.

on what’s important, but it also deprives us of sen-

sory information that we may need. That could be

disastrous if you are so focused on texting a friend

that you walk right into a pothole or a street full

of traffic.