TrajTracker Paradigms: Main features
Paradigms supported

Number-to-position

On each trial, one or more stimuli (text/pictures) are presented, and the participants drag their finger from a "start" point to the corresponding position on a number line. The number line is constantly displayed on screen and marked only with min/max values at its ends.

A trial is initiated by touching the "start" point in mid-bottom of screen. The target onset can be triggered either by the software (in which case the finger is expected to start moving at that time) or by voluntary finger movement.

Main features:

  • Finger starts moving from the mid-bottom of the screen. The number line is on top of the screen.

  • Can present several stimuli per trial, with flexible onset & offset times

  • A CSV file sets configures, per trial, the stimuli (text or pictures), and can also configure their appearance (e.g., font, size, position) and the onset/offset times.

  • Flexible number line length

  • Record the full finger trajectories.

  • Trial initiation: either determined by software or triggered by voluntary finger movement.

  • An arrow shows the finger's landing position on the number line. The correct response can also be presented.

  • Apply restrictions on movement (all optional): min/max speed, move only upwards, prevent "zigzag" movement.

  • Minimal speed limit can be visualized as an upward-moving horizontal line.

  • Can ask for subjective confidence rating after each trial.

Discrete choice

This is a dual-choice task: on each trial, one or more stimuli (text/pictures) are presented, and the participants drag their finger from the starting point to one of two response buttons.

A trial is initiated by touching the "start" point in mid-bottom of screen. The target onset can be triggered either by the software (in which case the finger is expected to start moving at that time) or by voluntary finger movement.

Main features:

  • Finger starts moving from the mid-bottom of the screen. On the top of the screen, there are two response buttons - one in each corner - and the subject needs to drag the finger to one of them from a "start" point.

  • Can present several stimuli per trial, with flexible onset & offset times

  • A CSV file sets configures, per trial, the stimuli (text or pictures), and can also configure their appearance (e.g., font, size, position) and the onset/offset times.

  • Record the full finger trajectories.

  • Trial initiation: either determined by software or triggered by voluntary finger movement.

  • Response buttons can be configured (change their position, size, and color; add text; etc.)

  • Visual and auditory feedback once a response was made. The visual feedback can be configured in various ways (e.g., highlight one of the buttons, highlight a fixed area in different colors depending on accuracy, show a picture).

  • Apply restrictions on movement (all optional): min/max speed, move only upwards, prevent "zigzag" movement.

  • Minimal speed limit can be visualized as an upward-moving horizontal line.

  • Can ask for subjective confidence rating after each trial.

Creating an experiment

To learn how to create your own experiment, check out the samples scripts provided in this website, read the TrajTracker Paradigms API reference.

Analyzing the results

The experiment will save detailed information about each trial and the finger trajectory in that trial. See details here.

This result format is supported by TrajTracker Analyze.

On top of that, Expyriment saves two files per session - one in the data sub-directory and one in the events sub-directory. TrajTracker uses the events file to save log messages, which you can use for debugging.