252 • CHAPTER 9 Knowledge
DEMONSTRATION: Lexical Decision Task
In the lexical decision task, participants read stimuli, some of which are words and some of which are
not words. Their task is to indicate as quickly as possible whether each entry is a word or a nonword.
For example, the correct responses for bloog would be “no” and for bloat would be “yes.”Myer and Schvaneveldt used a variation of the lexical decision task by present-
ing participants with two strings of letters, one above the other, as in ● Figure 9.16.
The participants’ task was to press, as quickly as possible, the “yes” key when both
strings were words or the “no” key when one or both were not words. Thus, the two
nonwords shown in Figure 9.16a or the word and nonword in Figure 9.16b would
require a “no” response, but the two stimuli in Figure 9.16c and d would require a
“yes” response.
The key variable in this experiment was the association between the pairs of real
words. In some trials the words were closely associated (like bread and wheat), and
in some trials they were weakly associated (chair and money). The result, shown in
● Figure 9.17, was that reaction time was faster when the two words were associated.
Meyer and Schvaneveldt proposed that this might have occurred because retrieving one
word from memory triggered a spread of activation to other nearby locations in a net-
work. Because more activation would spread to words that were related, the response
to the related words was faster than the response to unrelated words.● FIGURE 9.15 How activation
can spread through a network as
a person searches from “robin” to
“bird” (blue arrow). The dashed lines
indicate activation that is spreading
from the activated bird node. Circled
concepts, which have become
primed, are easier to retrieve from
memory because of the spreading
activation.AnimalCanary OstrichRobinSpreading activation primes
canary, ostrich, and animalBird Spreading activation
Primed● FIGURE 9.17
Results of Meyer
and Schvaneveldt’s
(1971) experiment.
Participants
responded faster
for words that
were more closely
associated (left
bar).Words
associated950850Reaction time (ms) 750Words not
associatedLexical Ambiguity
Decision
● FIGURE 9.16 Stimuli and correct responses for Meyer
and Schvaneveldt’s (1971) priming experiment.(a) (b) (c) (d)StimuliCorrect
response “No”Fundt
Glurb“Yes”Chair
Money“Yes”Bread
Wheat“No”Bleem
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