Part 1: Questionnaires

You will be presented with a series of questions online, which should take between 10 and 20 minutes to complete. These questions will ask you about your perceptual experiences and your use of cannabis and other substances.

Some of those Questions might be:

Have you ever seen objects, people or animals that other people can't see?

Have you ever felt as if there is a conspiracy against you?

Have you ever heard voices when you were alone?

Have you ever used cannabis? How often do you use cannabis?

What type of cannabis do you use?

Part 2: Tasks

After completion of the questionnaires, you will be asked to complete two online tasks, each of which will take approximately 15-20 minutes. Your chance to win the prize will thereby increase the more points you receive during the tasks. Please be aware that you must not take part more than once in those tasks. You may use your phone or your computer to complete the tasks, depending on which device you feel more comfortable with. Please decide before the start of the study, which one you would like to use as it is not possible to change in between.


Space Task

In this task you have to move a rover around a virtual planet to collect space junk.


Prediction Task

In this task, you will have to predict the outcome of a colour draw (blue or green) taking different advices into account that you will receive during the task.

Part 3 (optional): Follow-up Study

After completion of the online-study you may be invited to take part in a reimbursed follow-up study if you provide us with your contact details. This is not mandatory for taking part in the online-study.

The follow-up study consists of interviews and cognitive testing that will take part either online or in-person in the facilities of the Institute of Psychiatry, Psychology and Neuroscience, King's College London.

After completion of the online-study you may be invited to take part in a follow-up stu