The Lexical Decision Task (LDT) is a procedure used in many psychology and psycholinguistics experiments, and involves measuring how quickly people classify stimuli as words or non-words.
Although versions of the task had been used by researchers for a number of years, the term lexical decision task was coined by David E. Meyer and Roger W. Schvaneveldt, who brought the task to prominence in a series of studies on semantic memory and word recognition in the early 1970s. Since then, the task has been used in thousands of studies, investigating semantic memory and lexical access in general.
Subjects are presented with a mixture of words and non-words and their task is to indicate, usually by key-press, whether the presented stimulus is a word or not. The analysis is based on the reaction times and error rates for the various conditions for which the words or non-words differ.
A very common effect is that of frequency: words that are more frequent are recognized faster. In a cleverly designed experiment, one can draw theoretical inferences from differences like this. For instance, one might conclude that common words have a stronger mental representation than uncommon words.
Lexical decision tasks are often combined with other experimental techniques, such as priming, in which the subject is 'primed' with a certain stimulus before the actual lexical decision task has to be performed. In this way, it has been shown that subjects are faster to respond to words when they are first shown a semantically related prime: participants are faster to confirm "nurse" as a word when it is preceded by "doctor" than when it is preceded by "butter". This is one example of the phenomenon of priming.
Below is a demonstration of the Lexical Decision Task (LDT) experiment (with priming) created by Cognilab:
- Click HERE to download the template for the LDT
- Follow these instructions to import templates to your Cognilab account
- For more templates, tutorials and guides, visit our Resource Centre
- 1,000 ms Inter-Stimulus Interval
- 1,000 ms Fixation Point
- 1,000 ms Primer
- Therefore, deduct 3,000 ms from total reaction time per trial
Meyer, D. E., & Schvaneveldt, R. W. (1971). Facilitation in recognizing pairs of words: Evidence of a dependence between retrieval operations. Journal of Experimental Psychology, 90, 227-234.
Balota, D. A., Yap, M. J., Cortese, M. J., Hutchison, K. A., Kessler, B., Loftis, B., et al. (2007). The english lexicon project. Behavior Research Methods, 39 (3), 445-459.