logtrial in practice Demo Experiment Run Experiment

logtrial in practice

Jaap Murre

Demo how to use the logtrial() function in a typical reaction time experiment.

The logtrial() function works well with the datadashboard (speedometer icon). In addition to logging just a value and a variable name, as you do with log(), you can also log the conditions.

In this example, there is one condition: Yes and No, where one has to click anywhere on text(‘Yes’) and do nothing with text(‘No’), which will lead to a timeout. In the example, we log this with:


where stimuli is either ‘Yes’ or ‘No’ (assigned by you) and e.type is either ‘click’ (an event) or ‘timeout’ (subject did not click).  

In the datadashboard, you will see the data neatly sorted according to the two conditions. These are called Con1 and Con2 (these labels cannot be changed), as follows:


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var stimuli = ["yes","no","no","yes","no","yes"];

var i,e;

instruction("Click only if you see 'Yes'");

for (i = 0; i < stimuli.length; i++) {
    e = await("click",2000);
//    logtrial(1,"Accuracy",stimuli[i],e.type);

text("Thank you!");

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