CONDITION

Description

CONDITION is a plain JavaScript object — not a function — exposing the active values of your experiment's variables for the current trial. Keys are variable names you declared in the Configure experiment automation › Variables tab; values are the matching strings (or arrays, for compound types). Use it to make state-listening behavior depend on within-subjects or between-subjects design.

Parameters

Not a function. Indexed as CONDITION["yourVariableName"].

Side effects

• Reads only — no writes, no signals, no $.groupState mutations. Reading CONDITION doesn't disturb experiment state.
• Backed internally by $.groupState.currentCondition, refreshed by the state machine at the start of each trial.
• Lifecycle: within-subjects values swap at the boundary between Trial - Rest and the next Trial - Start. Between-subjects values are set once per session and don't change for its duration.
• Outside trial states (e.g., during End or before the first Trial - Start), CONDITION may be empty or stale. If you need post-trial values, read them from $.groupState.currentCondition directly, or capture them into COLLECTED_DATA before the trial ends.
• A misspelled key returns undefined — there's no compile-time check. All values are strings unless your variable definition uses an array type.

Example

In Tutorial 3 (Stroop), the Stimulus × Trial - Start cell reads several within-subjects keys in a single Customized Action to drive both the visible text and its position:

// On State Start of Trial - Start
const fontColor = CONDITION["fontColor"];     // "red" or "blue"
const textMeaning = CONDITION["textMeaning"]; // "RED" or "BLUE"
const depth = CONDITION["depth"];             // "near" or "far"

SetText(textMeaning);
SetChildPosition("Stimulus", 0, depth === "near" ? 1.5 : 3.0, 0);
ShowItem();

The same value is also passed alongside collected data so each row of the eventual CSV carries the condition it came from:

SendDataToCollector("fontColor", CONDITION["fontColor"]);
SendDataToCollector("textMeaning", CONDITION["textMeaning"]);

Related

• PARTICIPANTS — the other built-in global; together they answer "what condition is this trial?" and "who is playing?".
• Reference → Variables → CONDITION — the deeper write-up with caveats and lifecycle.
• Concepts → Within vs. between subjects — where these values come from in the variable definitions.
• Tutorial 3 — Stroop Effect (Other sample) — uses CONDITION in essentially every trial-state listener.

Source

Assets/Doc/LUIDA-StateListeningItemScriptDoc.md

- Only available if **LUIDA experiment progress automation feature is enabled and during the trial states** (e.g., `Trial - Start`, `Trial - Rest`).
- Contains values from your configured experimental variables for the current trial.
- Use `CONDITION["your_variable_name"]` to retrieve a specific condition value within the current trial.