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A reproducibly simulated psycholinguistic lexical-decision experiment, in which participants judge whether letter strings are real words. The design is fully crossed and counterbalanced: 24 participants each respond to all 40 items once (960 trials). condition (related/unrelated priming) and modality (visual/auditory) are both within-participant and within-item, assigned by a Latin-square list rotation so that, across participants, every item appears equally often in each condition and in each modality. Neither factor is therefore collinear with the item random intercept, which makes this a clean fit for crossed-random-effects models such as lmer(RT ~ condition + modality + word_frequency + (1 | participant) + (1 | item)), and hence for optimizer_fixef_plot(), coefficient_plot() and the distribution plots.

Usage

lexical_decision

Format

A data frame with 960 rows and 7 variables:

participant

Participant identifier (factor, 24 levels).

item

Item identifier (factor, 40 levels).

condition

Priming condition (factor): related or unrelated.

modality

Presentation modality (factor): visual or auditory.

word_frequency

Item-level word frequency on the Zipf scale.

RT

Reaction time, in milliseconds.

accuracy

Response accuracy: 1 correct, 0 incorrect.

Source

Simulated; see data-raw/generate_datasets.R.

Details

RT is generated log-normally from participant and item random intercepts plus the fixed effects (unrelated priming about 35 ms slower; auditory a touch slower; more frequent words faster), with a 250 ms floor; RT analyses should use correct trials (accuracy == 1). accuracy is generated from the exogenous predictors (word_frequency, condition, modality) and random effects only - it is not derived from RT - so classification demos built on it are not circular.

The data are synthetic, generated by data-raw/generate_datasets.R with a fixed seed; they do not describe any real individuals.