Balloon Analogue Risk Task - BART

Technical Manual

Last Modified: November 21, 2025 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © Millisecond Software, LLC

Background

This script implements the BART (Lejuez et al, 2002), a measure of impulsivity and risk aversion.

References

Lejuez, C. W., Read, J. P., Kahler, C. W., Richards, J.B., Ramsey, S. E., Stuart, G. L., et al. (2002). Evaluation of a behavioral measure of risk-taking: The Balloon Analogue Risk Task (BART). Journal of Experimental Psychology: Applied, 8, 75–84.

Duration

7 minutes

Description

Participants are given 30 (default) balloons. For each balloon they get the choice to pump up the balloon or collect their winnings. For each successful pump, they can earn money. However, if a balloon pops before participants collect their potential winnings, they lose all their potential winnings for the current balloon. The average number of pumps for unexploded balloons is the main Dependent Variable in this paradigm. High numbers indicate increased risk seeking behavior.

Procedure

• 30 ballons to pump up
• each (successful) pump increases the possible winnings gained from this balloon
Determination of Explosionpoints: random for each balloon
script samples randomly without replacement from a list of numbers 1-128: once the 1 gets sampled, the current balloon pops.
The probability that the 1 gets sampled increases after each successful pump.

• participant can decide whether to "collect" the winnings or keep pumping to increase the
reward further. Participants are told that each balloon will explode at some point and that in the
case of an exploding balloon no money will be won from the popped balloon. Further, participants are alerted to
the fact that some balloons may explode after only 1 pump while others may fill up the entire screen before they explode.
•after 30 balloons have been pumped, the experiment is over, and participants can collect their total winnings

Instructions

Instructions can be easily edited in bart_instructions_inc.iqjs (or language specific script)

Summary Data

File Name: bart_summary*.iqdat

Data Fields

NameDescription
inquisit.version Inquisit version number
computer.platform Device platform: win | mac |ios | android
computer.touch 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities
computer.hasKeyboard 0 = no external keyboard detected; 1 = external keyboard detected
startdate Date script was run
starttime Time script was started
subjectid Assigned subject id number
groupid Assigned group id number
sessionid Assigned session id number
elapsedtime Time it took to run script (in ms); measured from onset to offset of script
completed 0 = Test was not completed
1 = Test was completed
totalEarnings Sums up the earnings across balloons
balloonCount Running total of number of balloons
balloonCount1 Separate measures for number of balloons for the first third (trials 1-10)
balloonCount2 Separate measures for number of balloons for the second third (trials 11-20)
balloonCount3 Separate measures for number of balloons for the last third (trials 21-30)
totalExplosions The number of exploded balloons
totalExplosions1 Separate measures for the number of totalExplosions for the first third (trials 1-10)
totalExplosions2 Separate measures for the number of totalExplosions for the second third (trials 11-20)
totalExplosions3 Separate measures for the number of totalExplosions for the last third (trials 21-30)
nonExplodedBalloons The number of balloons out of (default) 30 that did NOT explode
nonExplodedBalloons1 Separate measures for the number of nonExplodedBalloons for the first third (trials 1-10)
nonExplodedBalloons2 Separate measures for the number of nonExplodedBalloons for the second third (trials 11-20)
nonExplodedBalloons3 Separate measures for the number of nonExplodedBalloons for the last third (trials 21-30)
totalPumpCount Total number of times the participant presses the pump button across all balloons (includes exploded balloons)
totalPumpCount1 Separate measures for the first third (trials 1-10)
totalPumpCount2 Separate measures for the second third (trials 11-20)
totalPumpCount3 Separate measures for tthe last third (trials 21-30)
averagePumpCount The mean average pump count (includes exploded balloons)
averagePumpCount1 Separate measures for the mean average pump count for the first third (trials 1-10)
averagePumpCount2 Separate measures for the mean average pump count for the second third (trials 11-20)
averagePumpCount3 Separate measures for the mean average pump count for the last third (trials 21-30)
adjustedTotalPumpCount Sums up the pumps of balloons that did not explode
adjustedTotalPumpCount1 Separate measures for the pumps of balloons that did not explode for the first third (trials 1-10)
adjustedTotalPumpCount2 Separate measures for the pumps of balloons that did not explode for the second third (trials 11-20)
adjustedTotalPumpCount3 Separate measures for the pumps of balloons that did not explode for the last third (trials 21-30)
adjustedAveragePumpCount Mean number of pumps only of balloons that did not explode (=Main Dependent Variable)
the lower the number the more risk averse the participant
adjustedAveragePumpCount1 Separate measures for pumps only of balloons that did not explode for the first third (trials 1-10)
adjustedAveragePumpCount2 Separate measures for pumps only of balloons that did not explode for the second third (trials 11-20)
adjustedAveragePumpCount3 Separate measures for pumps only of balloons that did not explode for the last third (trials 21-30)
postExplosionAdjustmentScore Measures sensitivity to punishment/loss
Difference in the mean number of pumps after successful collection - mean number of pumps after explosions
=> positive: trials after explosions had on average lower pump counts (sensitive to punishment)
=> negative: trials after explosions had on average higher pump counts (sensitive to losses)
postExplosionAdjustmentScore1 Separate measures for the first third (trials 1-10)
postExplosionAdjustmentScore2 Separate measures for the second third (trials 11-20)
postExplosionAdjustmentScore3 Separate measures for the last third (trials 21-30)

Raw Data

File Name: bart_raw*.iqdat

Data Fields

NameDescription
build Inquisit version number
computer.platform Device platform: win | mac |ios | android
computer.touch 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities
computer.hasKeyboard 0 = no external keyboard detected; 1 = external keyboard detected
date Date the session was run
time Time the session was run
subject Participant ID
group Group number
session Session number
blockcode The name the current block (built-in Inquisit variable)
blocknum The number of the current block (built-in Inquisit variable)
trialcode The name of the currently recorded trial (built-in Inquisit variable)
trialnum The number of the currently recorded trial (built-in Inquisit variable)
trialnum is a built-in Inquisit variable; it counts all trials run
even those that do not store data to the data file.
balloonCount Running total of number of balloons
response The participant's response
latency The response latency (in ms)
pumpCount Number of times the participant presses the pump button for each balloon (resets for each balloon)
pumpResult The selected digit from list.pumpResult (1 = balloon explodes)
totalEarnings Currently earned reward up to this point
timeBefore1stPump Time (in ms) before 1.pump
timeBeforeCollectWithoutPump Time (in ms) before collecting without pumping first
timeBtwLastPumpAndCollect Time (in ms) btw. last pump and collect
timeBtwPumps Time (in ms) between pumps (excluding time before first pump)
meanTimeBtwPumps Mean time between pumps for each balloon

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
totalBalloons Number of balloons: Default is 30
this script includes summary variables that distinguish between the first third (here balloons: 1-10), the second third (here balloons: 11-20), and the third (here balloons: 21-30).
30
pumpValue Payoff per pump: Default is $.050.05
balloonSizeIncrement Ballon size increment in scale proportion to the original image0.01
showPumpCount Show current pump count
true: pump count is shown to participant (default)
false: pump count is not shown to participant
true
showBalloonCount Show current balloon count
true: ballon count is shown to participant (default)
false: ballon count is not shown to participant
true
showPotentialEarnings Show potential earnings for the current balloon (default)
true: potential earnings for the current balloon is shown to participant (default)
false: potential earnings for the current balloon is not shown to participant
true