Other Visual Content in Trials

Experiments

Alongside stimuli and response widgets, Testable supports additional visual elements that appear within a trial: fixation points, overlay text, trial counters, background colors, and cursor customisation.

Fixation cross: fixation

Display a + symbol on screen at a specific moment using the fixation column:

Value	When the fixation cross is shown
ISI	During the inter-stimulus interval
ITI	During the inter-trial interval
withStim	At the same time as the stimulus
allTrial	Throughout the entire trial
allStim	During all stimulus display periods

Combine period keywords, and control the size, with semicolon-separated tokens (no spaces around the semicolons; keywords are case-sensitive):

fixation = ISI;32
fixation = withStim;150%

A plain integer token sets the cross’s font size in pixels. A percentage token maps 100% to a 2em cross (so 150% gives 3em); with no size token at all, the cross simply inherits the page font size.

Trial text: trialText

Show arbitrary text at a specific moment using the trialText column:

trialText = Remember to respond as fast as possible!

Use {} to define multiple text items on the same trial:

trialText = {First item}{Second item}

When the text appears: trialTextOptions

Value	Timing
ITI	During the inter-trial interval
ISI	During the inter-stimulus interval
firstStim	With the first stimulus
lastStim	With the last stimulus
afterStim	After stimuli are removed
allTrial	Throughout the trial
allStim	During all stimulus periods
withStim	Alongside the stimulus
withResponse	While the response widget is active

Text position: trialTextPos

Value	Position
above	Above the stimulus
below	Below the stimulus
center	Centred on screen
Npx	N pixels from the top of the stimulus area

Trial counters

counterTrial

Set counterTrial = 1 to show a “Trial x of y” counter to participants during that trial. Only rows with this column set display the counter.

Tip

Only trials that have counterTrial toggled count towards the total y in “Trial x of y”.

counterPart

Put any non-empty value (for example 1) in the counterPart column on an instructions row to show a “Part i of n” progress label on that screen. Every marked instructions row counts as one part; n is the total number of marked rows, and parts are numbered in the order the participant actually encounters them, after randomisation. Values on non-instructions rows are ignored.

Use it to label the instructions screen that opens each block of a multi-block experiment (“Part 1 of 3”, “Part 2 of 3”, …).

Note

You may see a counterBlock column mentioned in older materials or offered by the editor; it has no runtime behaviour. counterPart is the working block-progress counter.

Countdown timer: timer

Display a countdown timer in the top-right corner of the screen:

timer = 10000

This shows a timer counting down from 10 seconds. The value is in milliseconds.

Note

By default the timer display is visual only. It is independent from responseWindow and presTime, but typically corresponds to one of these. A timer configured with the skip option does act when it expires, ending the timed block; see Timers and Stopwatches.

Background and colors

All color columns accept HEX codes (e.g. #293D7A) or CSS color names (e.g. red, blue).

Column	Effect
bgColor	Override the default background color from Setup for this trial
background	Same as bgColor, but also accepts an image filename (e.g. background.jpg) to set a background image
textColor	Override the default text color from Setup for this trial
color	Color applied to fixation cross, feedback text, trial text, and word stimuli

Selective element coloring with color

The color column applies to fixation, feedback, trial text, and word stimuli by default. You can selectively target individual elements:

color = red
color = fixation: red
color = fixation: stim1: blue

• color = red: changes color of all supported elements
• color = fixation: red: only changes the fixation cross to red
• color = fixation: stim1: blue: changes the fixation cross and the word stimulus in stim1 to blue

Corner text: topLeft, topRight

Display persistent text in the top-left or top-right corners of the screen:

topLeft  = Condition A
topRight = Block 1

These stay visible regardless of what else is happening on screen.

Cursor control: cursor

Value	Cursor behaviour
(blank)	Default cursor
hide	Hide cursor for the entire trial
hideStart	Hide cursor from trial start until first interaction
crosshair	Show crosshair cursor
pointer	Show pointer cursor

Next steps

• Define and Position Stimuli: arrange stimuli themselves
• Timing Parameters: control when different elements appear
• Feedback: show response-specific text after a trial