A broad introduction to task switching can be read in the other task switching library entry. Click here to go there.

There are two types of task-switching paradigms:

Paradigm type Description

Alternate runs paradigm

Participant needs to know when to switch. For example, the switching rule can be to switch every two trials . The other lesson has a demo of this.

Cued taskswitching paradigm

A cue stimulus tells the participant which task to do on every trial. Used in this library experiment.

There are also some paradigms which are a bit inbetween. A good example is the one in which the cue is implicit, as you can see in the multitasking paradigm on this website. Click here to the multitasking experiment.

A good example of a paper about cued task switching is Meiran’s 1996 study (see references).

About this implementation

In this paradigm, we have a shape and a color task. The cue for the color task is the word "color" and the cue for the shape task is the word shape. In the shape task, you need to respond to circles and shapes while ignoring the color; in the color task you need to respond to the color while ignoring the shape.

You can change the duration of the cue presentation, the delay between cue and imperative stimulus, the between trial interval. All these variables will influence the task switch costs. At the end of the trial, you will get feedback about your performance, task-switch cost, etc.

We can calculate a task switch and a task interference or task congruence cost.

Run the demo

In this experiment, you respond with the keys b and n to circles and squares (in the shape task) and the color purple and yellow (in the color task). The instructions are all on screen and require some concentrated reading.

Data output file

In PsyToolkit, the data output file is simply a textfile. The save line of the PsyToolkit experiment script determines what is being saved in the data output file. Typically, for each experimental trial, you would have exactly one line in your text file, and each number/word on that line gives you the information you need for your data analysis, such as the condition, response speed, and whether an error was made.

Meaning of the columns in the output datafile. You need this information for your data analysis.

Colum Meaning






Congruent or incongruent (as word)


Congruent or incongruent (as number 1 or 2)


Required button press (left = b-key, right = n-key)


Response time in milleseconds


Status (1=correct, 2=wrong, 3=timeout)


Taskswitching (1=repeat, 2=switch)


If you have a PsyToolkit account, you can upload the zipfile directly to your PsyToolkit account. Watch a video on how to do that. If you want to upload the zipfile into your PsyToolkit account, make sure the file is not automatically uncompressed (some browsers, especially Mac Safari, by default uncompress zip files). Read here how to easily deal with this.

Further reading

  • Meiran, N. (1996). Reconfiguration of Processing Mode Prior to Task Performance. Journal of Experimental Psychology. Learning, Memory, and Cognition, 22, 1423-1442.