Something to Consider • 263running; areas activated by tools respond well to the kinds of motion associated with
tools, such as banging with a hammer or sawing a piece of wood.
These fi ndings confi rm our description at the beginning of this section of the dis-
tributed nature of categories in the brain. Our knowledge about categories is distrib-
uted in many areas of the brain, including areas that respond to what an object looks
like and also areas that respond to other properties associated with the object, such as
what it is used for and how it moves. To emphasize this point, let’s consider another
class of objects—food. When Kyle Simmons and coworkers (2005) showed observers
pictures of food, such as cookies and hamburgers, these pictures activated both areas
in the visual cortex associated with the food’s shape and also other areas associated
with taste. Another study showed that pictures of food also activate the amygdala, an
area associated with experiencing emotion (see Chapter 8, page 208), and the prefron-
tal cortex, which may be responding to how appealing a particular food it (Kilgore
et al., 2003). Food, just like objects in other categories, is represented in the brain by
responding in an array of neurons, distributed throughout the brain, which
all together represent our knowledge about the object.Something to Consider
Categorization in Infants
All of the research we have described in this chapter involves language.
Questions such as “What do you call that?” “Is that a word or a nonword?”
and “What are the characteristics of bicycles?” all involve understanding
language and being able to use it. Does this mean that categorization is
based on language and, therefore, that infants don’t start placing things into
categories until they can speak? The answer to this question is a resound-
ing “no.” Research has shown that even newborn infants are capable of
primitive categorization (they have one category for “mother” and another
for “other women”) and that more sophisticated categorization begins
appearing at about 2 months of age. The major method used to study cat-
egorization in very young infants is the familiarization/novelty preference
procedure.METHOD Familiarization/Novelty Preference Procedure
The familiarization/novelty preference procedure makes use of the fact that
when given a choice between a familiar object and a novel one, infants generally
will look longer at the novel object. The fi rst step in a categorization experiment
is familiarization, in which infants are exposed to a number of diff erent examples
within one category. For example, infants might see a number of diff erent kinds
of cats, as shown in ● Figure 9.28a, in which a number of pairs of cats are pre-
sented to the infant. (In another set of experiments it is determined that the
infants can tell the diff erence between the cats, so during familiarization they
are seeing stimuli that look diff erent to them but share the characteristics that
make them “cats.”)
The second part of the experiment is the preference test, in which an exam-
ple the infants have never seen before from the familiarized category (cats, in our
example) is presented along with an example from another category, such as dogs
(Figure 9.28b). If the infant looks longer at the dog, it is inferred that the infant has
grouped the novel cat with all of the other cats (so it belongs to the category “cats”),
but has not included the dog in that category (the dog is in another category).● FIGURE 9.28 Procedure for determining
whether an infant has formed the category “cat.”
(a) The infant is shown pictures of 5 pairs of cats
for 15 seconds per pair during familiarization.
Two pairs are shown here. (b) The infant is then
shown another cat paired with a dog during
the preference test. Greater looking time for
the dog provides evidence that the infant has
placed the dog in a diff erent category than
“c at .” (Source: Based on Quinn et al., 1993. Photos © Cathy
Britcliff e/iStockphoto.com; Silberkorn/iStockphoto.com;
GlobalP/iStockphoto.com; Olga Utlyakova, 2010/used
under license from Shutterstock.com; A. Krotov, 2010/used
under license from Shutterstock.com; Eric Isselée, 2010/
used under license from Shutterstock.com.)
(a) Familiarization
(b) Preference test
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