The HED Task Catalog is under development. IDs are not stable until formal release. Comments are welcome at github.com/hed-standard/hed-task/issues.

Lexical Decision Task

HED task ID: hedtsk_lexical_decision

Family: Language comprehension and production tasks

Also known as: LDT, Lexical Decision

Speeded word/nonword judgment; RT and accuracy index lexical access and are sensitive to frequency, priming, and context.

Description

Participants view letter strings and must rapidly determine whether each string is a valid word or a nonword by pressing designated response buttons. Stimuli include high- and low-frequency words and pronounceable nonwords. RT and accuracy to words versus nonwords indexes lexical access efficiency. The task is often combined with priming manipulations to examine semantic, phonological, or morphological processing. It is one of the most fundamental paradigms in psycholinguistics.

Inclusion test

An experiment is an instance of this task when its procedure matches, it manipulates at least one of the listed variables, and it records at least one of the listed measures.

Procedure

Letter strings are presented one at a time; participants classify each as a real word or a nonword as quickly and accurately as possible.

Manipulation

Word frequency; word length; orthographic neighborhood; nonword type (pseudoword vs. random); priming (semantic, associative, morphological).

Measurement

RT and accuracy; frequency effect; priming effect (primed − unprimed RT); d-prime.

Variations

Named versions that change what the participant experiences or does. The identifier of a variation is hedvar_<task>__<variation>.

Variation

Description

Justification

Standard Visual LDT

hedvar_lexical_decision__standard_visual_ldt

Classify letter strings as word/nonword via button press.

Canonical: word/nonword judgment to visually presented strings

Auditory LDT

hedvar_lexical_decision__auditory_ldt

Spoken stimuli; word/nonword judgment.

Auditory presentation; different sensory modality

Masked Priming LDT

hedvar_lexical_decision__masked_priming_ldt

Briefly flashed masked prime before target; tests automatic lexical access.

Brief masked prime before target; changes prime awareness

Cross-Modal LDT

hedvar_lexical_decision__cross_modal_ldt

Auditory prime → visual target or vice versa.

Prime in one modality, target in another; cross-modal priming structure

LDT with Different Nonword Types

hedvar_lexical_decision__ldt_with_different_nonword_types

Pseudohomophones, transposed-letter nonwords, consonant-string nonwords.

Pseudowords, random letter strings, pseudohomophones; nonword type changes task difficulty

Bilingual LDT

hedvar_lexical_decision__bilingual_ldt

Mixed-language presentations; tests cross-linguistic activation.

Targets in two languages; different language switching demand

LDT Megastudies

hedvar_lexical_decision__ldt_megastudies

Thousands of items per participant (English Lexicon Project, British Lexicon Project).

Large-scale normed stimulus sets enabling item-level analyses; different methodological scope

Go/No-Go LDT

hedvar_lexical_decision__go_no_go_ldt

Respond only to words (or only to nonwords); reduces response competition.

Respond to one word class, withhold to another; different response structure

Cognitive processes

This task is designed to engage the following processes:

Key references

  • 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(2), 227-234. (DOI, PubMed)

  • Neely, J. H. (1977). Semantic priming and retrieval from lexical memory: Roles of inhibitionless spreading activation and limited-capacity attention. Journal of Experimental Psychology: General, 106(3), 226-254. (DOI)

  • Fiebach, C. J., Friederici, A. D., Muller, K., & von Cramon, D. Y. (2002). fMRI evidence for dual routes to the mental lexicon in visual word recognition. Journal of Cognitive Neuroscience, 14(1), 11-23. (DOI, PubMed)

Further references

  • Keuleers, E., & Brysbaert, M. (2010). Wuggy: A multilingual pseudoword generator. Behavior Research Methods, 42(3), 627–633. [Updated: Keuleers, E., Lacey, P., Rastle, K., & Brysbaert, M. (2012). The British Lexicon Project. Quarterly Journal of Experimental Psychology, 65(8), 1441–1469.] (DOI, PubMed)

  • Taylor, J. S. H., Rastle, K., & Davis, M. H. (2013). Can cognitive models explain brain activation during word and pseudoword reading? A meta-analysis of 36 neuroimaging studies. Psychological Bulletin, 139(4), 766–791. (DOI, PubMed)

  • Balota, D. A., Yap, M. J., Hutchison, K. A., et al. (2007). The English Lexicon Project. Behavior Research Methods, 39(3), 445–459. [Megastudy approach] (DOI, PubMed)

  • Ratcliff, R., Gomez, P., & McKoon, G. (2004). A diffusion model account of the lexical decision task. Psychological Review, 111(1), 159–182. (DOI, PubMed)

  • Ball, L. V., Brusini, P., & Bannard, C. (2025). Revisiting novel word semantic priming: The role of strategic priming mechanisms. Quarterly Journal of Experimental Psychology, 78. doi:10.1177/17470218241306747