Balloon Analogue Risk Task (BART)

The Balloon Analogue Risk Task (BART) helps psychologists study how people take risks. In the task, you see a virtual balloon on the screen. With each button press, you can inflate the balloon to earn more points. But if you pump it too far, it might explode, and you lose the points for that round. The trick is deciding when to stop and collect your winnings before the balloon bursts.

The task was first developed by Lejuez and colleagues (2002) as a simple and engaging way to measure risk-taking in a controlled environment. What makes the BART so useful is that it mimics real-life situations where we have to balance potential rewards against the risk of loss—like deciding how fast to drive, how much money to invest, or when to speak up in a group. Because of this, researchers use BART to understand decision-making in both healthy individuals and those with psychological or behavioural conditions.

The score on the BART task correlates well with Barratt’s impulsivity scale (available here on PsyToolkit) and some other scores. Here is a short quote from the 2002 paper: "Correlations among Adj BART and the risk-related constructs are shown in Table 2. With the exception of Eysenck Venturesome subscale score, Adj BART score was significantly correlated with each of the relevant measures of risk-related constructs, including Barratt Impulsiveness total score, Eysenck Impulsivity subscale score, MPQ Behavioral Constraint superfactor score, and Sensa- tion Seeking total score." (page 79 of Lejuez et al., 2002).

Participants need to collect money. In total there are 90 trials.

There are 3 types of baloons (30 blue, 30 yellow, and 30 orange ones):

Obviously, orange balloons cannot be pumped much, while blue ones can be pumped up a long time.

On each trial, they are shown a ballon and they can inflate it with clicking a "pump" button or "collect $$$" button to collect the money.

With each additional pump, the trial counter adds up 5 cents. There are two counters on the screen, one for the current trial and one for the total earned.

Here we follow the original 2002 paper except for the following:

First, we added three training trials. The added training trials do not interfere with the training as the training balloons are green and all explode only if people would have pressed the pump up button 10 times. You can remove this from the task easily. You simply remove the line task bart 3 and you remove the block feedback1.

Second, we provide after the training block and at the end of the experiment a feedback report about how much money was earned and more. The idea here is that this is of interest. If you do not like this, you can take this out of the experiment by removing blocks feedback1 and feedback2.

The block order is as in the paper except for the first training block which PsyToolkit added.

The BART score is calculated as in the 2002 study. It is the average number of pumps for trials in which the balloon did not explode. In the paper they call this the adjusted score.

Each participant gets exactly the same explosion points offered, so you can compare participants really well. We did not have the exact explosion points of the original paper, but we followed the same logic of a mean of 64 for blue balloons, 16 for yellow balloons, and 4 for orange balloons. Further we ensured these numbers held over blocks of 10 trials to ensure a good distribution.

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

The PsyToolkit code

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.