Download Word Relationship 1 Running head: EFFECTS OF WORD

Word Relationship
Running head: EFFECTS OF WORD RELATIONSHIP
Effects of Word Relationship on the Lexical Decision Task
Anonymous
Texas A&M University
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Abstract
The hypothesis of the experiment was testing the spreading activation model of semantic
memory – whether word relationship had an effect on speed of reaction time in a lexical decision
task. Subjects were 112 college students that participated for class credit. A DOS-based
computer program was used that presented three different types of word pairs to the subject –
word and related word pairs, word and non-related word pairs, and word and nonword pairs. The
data were recorded by reaction time in milliseconds if the response was correct. The results
supported the hypothesis – the related word pairs had the shortest response time, followed by the
non-related words, and finally the word-nonword pairs. The conclusion of the study was that the
results support the spreading activation model – that the more that words are related, the faster
the resulting reaction time will be in a lexical decision task.
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Effects of Word Relationship on the Lexical Decision Task
When a person who is able to read is presented with a set of letters, one of the first things
he will determine will most likely be whether the set of letters is a readable word of his language.
This job of deciding whether a string of letters is a word is known as the lexical decision task. It
is done by searching through the database of words in the person’s brain, or his mental lexicon.
When the word is preceded by a related word, the reaction time for the lexical decision task of
the second word is much shorter. This phenomenon has only recently been discovered, which has
led to avid research in the field in the past 30 years. The topic of this research is to examine the
relationship between word relatedness and reaction time in the lexical decision task.
Many researchers have studied the concept of word relatedness in different ways. Word
relatedness is usually determined by a word being related by associations or semantics. Two
words are said to be related associatively when many people provide the target as the first word
that comes to mind when presented with the prime (Perea & Rosa, 2002). They are not
necessarily related in meaning, but rather they are commonly used together, (e.g. highchair –
BABY). A lexical decision is deciding whether a set of letters is a word; a semantic decision is
deciding what word category a word fits into. Semantically related words typically have similar
meanings or are of the same semantic category, (e.g. spaghetti – PASTA). This experiment used
words that are related both semantically and by association, although the two are often separated
as distinct independent variables. For example, Buchanan, Brown, Cabeza, and Maitson (1999)
and Zeelenberg and Pecher (2002) have shown that associatively related words tend to create
more false memories in the participant than semantically related words. That is, participants
allege that they have seen words in a prior study set that they really didn’t see because the words
were associatively related to words that they actually saw.
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There are several diverse models of semantic memory that have been proposed. Meyer
and Schvaneveldt (1971) suggest that perhaps both words and nonwords have places reserved in
the long-term memory. Becker (1980) proposed what is known as the verification model. This
model says that the word verification process generates a description for each of the words
presented and then compares this to the one in a non-lexical, visual storage, in a process that
determines one word at a time (Besner & Swan, 1982). Borowsky and Besner (1993), on the
other hand, propose a multistage activation model, which depends upon context, word frequency
and stimulus quality to influence the speed of word processing.
In this study, we are testing what is known as the spreading activation model. This model
proposes that there are connections inside the mental lexicon that connect words together. The
related words are closer together in the lexicon, while the non-related words are farther apart in
the lexicon. Then when a prime is presented, the mental activation spreads to the closely related
words quicker than the non-related words, which results in the reaction time being shorter. In
testing this spreading activation model, our hypothesis is that reaction time will be shorter for
related words than for non-related words, and the slowest reaction time will be for the nonwords.
We are testing reaction time in milliseconds. The word lists used are related both semantically
and by association.
Method
Participants
Participants included 112 college students form a large southwestern university.
Participation was a class requirement for their research methods lab.
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Materials
The program used in this experiment was a DOS-based program called PsycLab. This
program was written to administer multiple trials of the lexical decision task to the participant
and record the data.
Procedure
The design of the experiment was a participant x condition type, condition type being the
relationship between the target and the prime. The relationships tested in the study were related
word pairs, non-related word pairs, and word-nonword pairs. This design allowed the
experimenter to control for the effects of variation of the individual participants on the resulting
reaction time. The subjects were told to read the instructions carefully prior to starting the study.
These instructions told the participants exactly how the study was to be performed, what types of
prompts would appear on the screen, and which computer keys to use. The participants were
randomly assigned to conditions 1 or 2, which were different only in the word lists they used.
The participants were presented with a plus sign to focus them in the right place for 1000 ms,
followed by a prime for 700 ms, and finally a target 50 ms later. Upon seeing the target the
participant had between 100 and 900 ms to respond whether the target was a word or a nonword.
The data were recorded by response time if the response given was correct. The program ran
several trials of the lexical decision task. The first was a 48-trail practice, followed by two 60trial blocks in which the data were recorded.
Results
The hypothesis stated that the reaction times would be fastest for the related word pairs
condition, followed by the non-related word pairs condition, and then lastly, the word-nonword
condition. The reaction times for the related word pairs condition (M = 509.40, SD=3.02) are the
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shortest of the three conditions in the study. The non-related word pairs condition (M = 542.95,
SD = 3.02) are next shortest in reaction times, and the word-nonword pairs condition (M =
585.50, SD = 2.14) reaction times are the longest. Comparisons of the means though ANOVA
tests [F (2, 51 = 233.36, p < .001] indicate that there was at least two significant differences
among the means. This shows that a pair of measures was different among the three but is unable
to indicate which ones. According to the post-hoc tests that were then conducted, all three means
are significantly different from one another. This information leads to the conclusion that the
hypothesis was supported by this experiment.
Discussion
The hypothesis of this experiment stated that the more semantically related the target was
to the prime word, the less time it would take the test-taker to decide whether the target is a word
or a nonword. The results of the statistical tests show that the hypothesis is supported by the
experiment – semantic word-relatedness does seem to be a factor that causes the reaction time in
a lexical decision task to decrease.
The results of this experiment are consistent with those of previously conducted
experiments. Many studies have shown the effects of word relatedness on reaction time (Perea &
Rosa, 2002; Meyer & Schvaneveldt, 1971; Borowsky & Besner, 1993). Many of their
experiments were considerably more complex than ours; for example, Perea and Rosa (2002)
used different word lists that are semantically and associatively related as separate independent
variables; Borowsky and Besner (1993) use a more complex activation model than the one
proposed in this experiment. However, regardless of the complexity of the various experiments,
the results report similar findings – word relatedness does indeed have an effect on reaction time
in a lexical decision task.
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Implications
The results of this experiment have implications that apply to real life. They suggest that
when children are learning language and first encounter a word, their mental lexicon makes a
new place for the word – then the more words they know related to that word, the faster the
reaction time will be to recognize it as a word when they encounter it again. They also suggest
that regardless of whether one knows the definition of a word, if one has seen it before then he
will recognize it as a word of his language. This is because there has been a spot in the mental
lexicon for that word ever since the person first encountered it.
Limitations and Future Research
There were several limitations to our study. The sample consisted of mainly 18-22 year
old college students, which reduces the external validity because it isn’t as facile to generalize to
the rest of the population. There was also a great lack of experimental control in this experiment
– the participants completed the experiment in the comfort of their own homes instead of in a
laboratory. Some could have taken their time and responded very slowly or some could have just
sped through to get in done. This could happen because there was no experimenter supervision to
make sure the participants were complying with the instructions of the experiment. The
experimenters could have removed the outliers of the experiment – if the reaction time was
simply too fast for them to have completed the lexical decision task, for example. In the study
done by Zeelenberg and Pecher (2002), response times faster than 300 milliseconds were
removed so as not to skew the descriptive statistics of the experiment. Also participants could
have done the experiment several times in order to get everything right if they were ultraconscientious. This would obscure the results of the study.
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Future research could focus on the effects of common usage of words on reaction time –
people would most likely recognize words that they use often faster than longer, more difficult
words that don’t often occur in daily speech. It would also be interesting to conduct a study
concerning not how people recognize words of their language, as in this study, but how they
learn definitions of words to the extent that they are able to use them. If researchers were able to
see how to learn words faster, that would have amazing implications on academic life. Society
could bring the used vocabulary back up to where it was in old times and people would be able
to speak intelligently again. SAT verbal scores would soar instead of showing how dismal the
vocabularies of our students are. People would be able to read faster and assimilate information
faster because they wouldn’t constantly be using a dictionary.
There are still many things that scientists have to learn about the mental lexicon, how
people learn new words, and lexical decision tasks. One single model has not yet been accepted
and agreed upon by the experts in the field. Much ongoing research is still being conducted to
better understand this phenomenon of the lexical decision task.
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References
Becker, C. A. (1980). Semantic context effects in visual word recognition: An analysis of
semantic strategies. Memory and Cognition, 8, 493-512.
Besner, D., & Swan, M. (1982). Models of lexical access in visual word recognition. Quarterly
Journal of Experimental Psychology, 34A, 313-325.
Borowsky, R. & Besner, D. (1993) Visual word recognition: A multistage activation model.
Journal of Experimental Psychology: Learning, Memory, and Cognition, 19, 813-840.
Buchanan, L., Brown, N., Cabeza, R., & Maitson, C. (1999). False memories and the semantic
lexicon arrangement. Brain and Language, 68, 172-177.
Meyer, D., & Schvaneveldt, R. (1971). Facilitation in recognizing pairs of words: Evidence of a
dependence between retrieval operations. Journal of Experimental Psychology, 90(2),
227-234.
Perea, M., & Rosa, E. (2002). The effects of associative and semantic priming in the lexical
decision task. Psychological Research, in press.
Zeelenberg, R., & Pecher, D. (2002). False memories and lexical decision: Even twelve primes
do not cause long-term semantic priming. Acta Psychologica, 109, 269-284.
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