Test name

• name: A name to identify the test.

Test settings

• • frameRate: The desired frame rate of the screen. On some devices the refresh rate of the screen is always 60 Hz, in other devices it can be 60 or 120 Hz.

• • luminance: You can control the luminance of the screen with this parameter.
    The perceived brightness is approximately proportional to the logarithm of the luminance that you set with this parameter.
    The new luminance will only be effective once the test begins.
    There are a few preferences on iOS and iPadOS that can automatically change the brightness and color temperature settings of the device:
    Auto-Brightness can be found in your device Settings, Accessibility, Display & Text Size.
    TrueTone and Night Shift options can be found in your device Settings, Display & Brightness.
    Remember to disable these options to avoid unwanted changes of brightness when running a test.
    Even with the Auto-Brightness adjustment disabled, the brightness of the device can be slightly increased automatically if you are under a bright light (outside).

• • gamma: Establish how the luminance raises with the input value.
    
    • • linear: The gamma is transformed to make the luminance linear, assuming the screen has a gamma value of 2.2, which is the gamma used in iOS and iPadOs devices.
        The correction is simply to raise the luminance to the power of 1/2.2
      • normal: No transformation is made. The values are not in linear space. This option is a good choice if you are drawing images.
      • calibrated: If you are using stimuliApp on a computer or with an external monitor, you may want to calibrate it with a photometer and manually enter the correction value for gamma. The correction is simply to raise the luminance to the power of 1/gamma.

• • XButton: The position on the screen of the button that is used to cancel a test in progress.

• • randomness: How random numbers are generated.
    
    • • automatically generated: The random numbers are generated automatically each time you run the test.
      • generated with seeds: Each time you run the test, you are asked for numeric seeds to generate the random numbers.

• • expectedViewingDistance: The viewing distance represents the expected distance between the participant and the screen — that is, the position at which the user is intended to be positioned. This value is used to compute the actual pixel size of any property measured in visual degrees. For each test performed, the expected viewing distance is stored.
    
    • • constant: The distance from the participant to the screen is a constant value. 
      • set each time: Each time you run the test, you are asked to enter the distance from the participant to the screen.

• • measureViewingDistance: Only for devices that support ARKit. Using ARKit capabilities, the system can measure and record the participant’s distance from the device. Moreover, specific scenes can be configured so that if the distance falls outside a predefined range, a warning message is displayed and the trial is skipped.
    
    • • off: The distance from the participant to the screen is a constant value. 
      • using ARKit: Each time you run the test, you are asked to enter the distance from the participant to the screen.

• • neonEyeTrackerSync: If your device and a Pupil Labs Neon eye tracker are connected to the same local network, automatic synchronization messages can be exchanged between them. This ensures that all events are logged on your device using the same clock as the Neon eye tracker. An estimated clock error, expressed in milliseconds, is also provided. This synchronization error typically remains very low, provided that the local network has sufficient bandwidth and stability.
    
    • • IP: The IP address assigned to the Neon eye tracker within the local network.

• • referenceMarkers: Enables the display of reference markers (one at each corner of the screen) during the test. These markers allow an eye tracker — such as the Neon eye tracker — to accurately detect the screen boundaries and map gaze positions onto the display.
    
    • • size: Size of each reference marker (in pixels).
      • horizontalMargin: Horizontal distance from each marker to the screen edges (in pixels).
      • verticalMargin: Vertical distance from each marker to the screen edges (in pixels).

• • longAudios: It is possible to make an audio play for its entire duration, meaning, it does not stop every time we change scenes but continues to play through different scenes and trials. This can be useful for playing an audio or background music throughout the duration of a test. For example, an audio can be generated containing a whole sequence of sounds and used to measure mismatch negativity while a test is being conducted.

 

First section

• firstSection: The first section of the test.