Illustration of the Canvas Frame in Labvanced, showing freely positioned objects on a blank canvas

Canvas Frame

A Canvas Frame gives free control over layout: objects can be positioned anywhere on the frame, at exact coordinates, and rescaled or moved with drag and drop. Use this frame type when the precise position of your stimuli matters, for example in visual perception tasks, reaction time tasks, or any study where fine-grained control over where things appear on screen is needed. This positioning also stays under event control after the frame is built, for example an object's x, y, width, and height can be set or changed by events, which is not the case for objects placed on a Page Frame.

Note

For studies that need to collect behavioral data on a real external or custom website instead of Labvanced-built stimuli, a Website Frame is used instead of either Canvas or Page Frame.

The canvas can also be zoomed in and out with the mouse scroll wheel, or a two-finger scroll gesture on a trackpad, useful when working with precisely positioned small elements. If you are on a MacOS, you may need to review your system settings under Settings -> Appearance -> Show scrollbards.

Canvas Frame properties

Set in the Frame Settings panel:

  • Name: a label to identify the frame within your task (participants never see it)
  • Duration: an optional fixed display time in milliseconds; if left unset, the frame stays on screen until an event or action advances it
  • Color: the frame's background color (default: White)
  • Hide Mouse: hides the participant's cursor while the frame is active
  • Width and Height: the size of the frame, in Design Units (Canvas Frame only)
  • Sync Frame Start: appears only once the task is converted to a multi-user experiment (shared with Page Frame, not available on Website Frame); when enabled, the frame waits for every participant in the group to be ready before starting, instead of each participant starting it independently. See Multi-User Experiment Design for how this fits into a joint study.

When to use Canvas over Page

Choose a Canvas Frame when stimulus position or timing precision matters to the design, reaction time tasks, visual search, spatial cueing, anything where "where on screen" is part of what's being measured. For form-like, top-to-bottom content such as questionnaires or instructions, a Page Frame is usually the better fit.

Why a Trial Can Look Generic: the Trial System

Opening a study from the Library, the objects on a Canvas Frame can sometimes look generic: placeholder shapes, plain colors, or default text rather than the study's real stimuli. This happens when the study sets its actual stimuli per condition rather than directly on the frame; what's showing is the Default Trial, a default template for the trial, before any condition-specific content has been applied.

Condition-specific content comes from the Trial System: factors and levels are crossed to generate conditions, and an object on a Canvas Frame, its position, uploaded image, color, or text, can be set to a different value in each condition. The frame itself still shows its default objects until a condition is selected; clicking a specific row in the condition table swaps those objects to that condition's actual values.

Canvas Frame showing a trial's default, generic objects before a condition is selected
A Canvas Frame in its default trial state, also known as the Default Trial, before a condition is selected.

Canvas Frame showing condition-specific stimuli after selecting a condition in the Trial System
The same Canvas Frame after selecting a specific condition, showing that condition's actual stimuli.

The Balloon Analog Risk Task (BART) is a live example of this: the balloon's color and pop risk are condition-specific values driven by the Trial System, not properties set once on the default trial.

Balloon Analog Risk Task (BART)

This study measures risk-taking behavior using the BART. Participants pump a virtual balloon to accumulate earnings, balancing potential reward against the risk of the balloon popping and losing all gains for that trial. Pump count, trial outcome, and earnings are recorded as performance indicators.



Further Reading

Illustration of the three frame types in Labvanced: Canvas, Page, and Website Frame

Frames

The hub for all frame types and the properties every frame shares.

Illustration of the Page Frame in Labvanced, showing objects stacked automatically top to bottom

Page Frame

The automatic top-to-bottom layout frame type, for questionnaires and form-like content.

Illustration of the Website Frame in Labvanced, showing a real external website embedded in a study

Website Frame

Embeds a real external website in the study, for behavioral data collection on an external or custom site.

Illustration of the Labvanced event system, showing triggers and actions

The Event System

Triggers and actions that control stimulus presentation, record variables, and advance frames.

Trial Timeline

How frames are sequenced and repeated within a trial, and the Trial System's per-condition editing.

The Trial System

How factors and levels cross to create conditions, and how the Default Trial relates to condition-specific content.