Lexical Decision Task
— Free to Take
A short browser-based reaction-time test. A word flashes, then a letter string appears; you decide as fast as you can whether it is a real word or a made-up non-word. When the first word is related in meaning, recognition speeds up — that speed-up is the priming effect. Free with a free account.
The two blocks
Block 1 — Associative priming. Each related pair is shown with a fixed short prime interval. Half the pairs are forward associates (the prime strongly calls the target to mind) and half are backward associates (the target calls the prime to mind, but not the reverse). Comparing the two tells you whether your priming is driven by fast automatic spreading activation or by a slower expectancy.
Block 2 — Prime interval (SOA). The same kind of related and unrelated pairs are shown at two prime-to-target intervals: a short 200 ms interval and a long 1200 ms interval. The short interval isolates automatic priming; the long interval allows controlled, strategic processing. The difference between the two estimates how much of your priming is automatic versus strategic. This block is the full research-length administration: 640 scored trials (80 word targets per condition cell plus length-matched non-words, all drawn from the Semantic Priming Project stimulus set), with a self-paced rest break every 80 trials. It takes about 45 minutes; the trial count is what makes the millisecond figures — and the ± margins reported with them — meaningful for a single person.
From your trials we report, for each block:
- Your mean reaction time to related vs. unrelated targets
- Your priming effect — how many milliseconds faster you are on related targets
- For Block 1, the forward-vs-backward comparison; for Block 2, the short-vs-long-interval comparison
- Your accuracy on word vs. non-word decisions
These are within-subject reaction-time differences in milliseconds. On Block 2 — the research-length administration — each priming effect is reported with a ± 95% margin computed from your own trial-to-trial variability, and your speed, accuracy, and priming figures are each placed as a percentile within the Semantic Priming Project per-subject sample — the same laboratory dataset the stimuli come from. Block 1 shows your priming alongside the published item-level reference magnitudes for context. There is no T-score or IQ-style composite: latencies also depend on your display, keyboard, and browser timing, so the percentile is honest context, not a norm-referenced ability score.
Want to see what a finished report looks like first? Preview a real sample for either block — no signup required.
Common questions
What is a priming effect?
When a word is preceded by a related word (NURSE before doctor), people recognize it faster than when it is preceded by an unrelated word (BREAD before doctor). That difference in reaction time is the semantic priming effect, and it is one of the most reliable findings in the study of how meaning is organized in memory.
What is the difference between forward and backward associates?
Forward associates run prime→target (the prime brings the target to mind). Backward associates run target→prime (the target brings the prime to mind, but not strongly the reverse). Forward priming can arise automatically; substantial backward priming usually points to a slower, more strategic process.
What is SOA, and why use two intervals?
SOA is the stimulus-onset asynchrony — the time between the prime appearing and the target appearing. A short SOA (200 ms) leaves no time for deliberate strategy, so it isolates automatic priming. A long SOA (1200 ms) gives time for controlled, expectancy-based processing. Comparing them separates the two contributions.
What do the percentiles mean — is this an IQ-style score?
No. On Block 2, each percentile is simply where your figure falls among the individual participants of the Semantic Priming Project laboratory sample — real empirical context, not a norm-referenced ability score. Reaction times also depend on your specific display, keyboard, and browser timing, so we report your honest within-subject priming in milliseconds, with a ± margin from your own data, and the percentile as context. Block 1 reports milliseconds against the published item-level magnitudes only.
Is it really free?
Yes. Both blocks are free to take with a free account — no credit card. Create one in under a minute and your priming profile is shown immediately at the end. Clinician and researcher reporting is arranged separately and does not affect whether you can run the task.