Lexical Decision Task


Introduction

Lexical Decision is an experimental task where participants classify visual stimuli as words or non-words as quickly and accurately as possible. The lexical decision task was first introduced in Meyer and Schvaneveldt (1971) and since then the paradigm has been manipulated in thousands of experiments providing researchers with insight about visual word recognition. In the experiment in which you are about to participate, the goal is to demonstrate differences in the speed of classifying “words” and “nonwords.” Let’s begin!


Once you have finished the experiment, press the space bar to first see your results and press again to see typical results.


Summary

In lexical decision experiments, participants usually respond faster to words than nonwords. This finding is usually interpreted as evidence that we have mental representations for words in a mental “lexicon” that we access during word recognition. We are slower at recognizing nonwords for a number of reasons, one of which is that we sometimes have to search the whole mental lexicon before we can indicate that a word is a nonword, which takes longer than searching the lexicon and finding a word. You will see this paradigm used again in the “Semantic Priming” and “Word Frequency Effect” Discovery Labs.


Review Question

Question: Suppose you conducted a lexical decision experiment where the nonwords were com-prised of consonants (e.g., GFTYS, JPRSV, etc.). How do you think response times would compare to when the nonwords had vowels in them (e.g., GETYS, JORSV, etc.) and why?


Answer: In paradigms where nonwords are made up of only consonants, participants respond to the nonwords more quickly than when there are vowels in the nonwords. This is because in the “all consonant” condition participants may quickly determine that the letter string CANNOT be a word without searching the lexicon, whereas when a vowel is present some searching must be completed.