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Tutorial: Adjusting the timing of trials

In the first and second tutorials on how to adjust the timing of elements in your study, we covered how to control the timing of stimuli and responses within a trial. This post will show you how to control the timing of the trials within your study.

Adjust the time between trials (inter-trial intervals)

If you want to introduce a delay between the end of one trial and the beginning of the next, modify the delay property of the relevant trial_template with the desired number of seconds. In the example below, the trial template delayed_trials will produce 4 trials, each with 1 stimulus (drawn from the list of s1, s2, s3, and s4 stimuli) and 1 response. By setting the delay to 2, each trial will start with 2 seconds of a blank screen:

"delayed_trials": {
      "type": "basic",
      "stimuli": ["s1", "s2", "s3", "s4"],
      "responses": ["r1"],
      "delay": 2

Create trials that proceed automatically

By default, FindingFive waits for a participant response before proceeding to the next trial, either by collecting a response as defined in a trial_template‘s responses, or by waiting for the participant to click a “Continue” button. In order to create trials that proceed automatically, you can set the duration property of your trial_template. This is the number of seconds (fractions supported) to wait before automatically proceeding to the next trial. If you set the duration property in trials that collect participant responses, the trial will end after the participant gives their response or the duration is reached, whichever happens first. Just make sure that the delay property of your response is set properly so that participants will have a chance to respond before the specified trial duration is up!

"timed_trial": {
      "type": "basic",
      "stimuli": ["s1", "s2"],
      "responses": ["r1"],
      "duration": 3, // trial will end after 3 seconds or at the participant's response, whichever happens first
      "delay": 1, // intertrial interval is 1 second
      "countdown_visible": false // change this to true to display a countdown for participants

To display a countdown for the participants, set the countdown_visible property to true in your trial_template definition.

Example: Speed-accuracy tradeoff paradigm

In our first timing tutorial, we went through how you could set up an auditory speed-accuracy tradeoff paradigm using the barrier property of auditory stimuli. In that example, participants are told to respond as quickly as possible once they detect a pure tone in an auditory noise stimulus. But many speed-accuracy tradeoff paradigms enforce a time limit on the participant’s decision, further encouraging a speeded response. This can be implemented by simply adding a duration to the trial_template.

"tt_sound_detection": {
  "type": "basic",
  "stimuli": ["sound_barrier_off"],
  "responses": ["sound_detection_choice"],
  "duration": 3

Now the trial will end when the participant provides a response or after 3 seconds, whichever happens first.

For more technical details about adjusting the timing of your study’s trials, check out the Trial Templates section of the FindingFive API.

If you have any questions about this post or how to adjusting the timing of trials in FindingFive, please don’t hesitate to contact us at!