Balloon Analogue Risk Task (BART)

Field	Value
Name	Balloon Analogue Risk Task (BART)
Version	main (1.1)
URL / Repository	https://github.com/TaskBeacon/T000002-bart
Short Description	A risk-taking task based on BART with color-specific burst profiles.
Created By	Zhipeng Cao (zhipeng30@foxmail.com)
Date Updated	2026/03/02
PsyFlow Version	0.1.0
PsychoPy Version	2025.1.1
Modality	Behavior/EEG
Language	Chinese
Voice Name	zh-CN-YunyangNeural

1. Task Overview

BART measures risk-taking by requiring repeated choices between pumping a balloon for higher temporary reward and cashing out to bank reward safely. If a balloon explodes, that trial's temporary reward is lost.

This implementation uses deterministic explosion sampling with config-defined mode (without_replacement_cycle by default), three color conditions (blue, yellow, orange), and config-first participant-facing stimuli for localization portability.

2. Task Flow

Controller Logic

• main.py runs one unified mode-aware flow (human, qa, sim).
• BlockUnit.generate_conditions() handles condition sequencing.
• src/run_trial.py handles trial states (pre_pump_fixation, pump_decision, outcome, feedback).
• Explosion points are sampled by a deterministic condition/block sampler, not global RNG.

Block-Level Flow

Step	Description
Load Config	Load mode-specific config from config/.
Collect Subject Info	Human uses SubInfo; QA/SIM use synthetic IDs.
Setup Trigger Runtime	Hardware in human mode, mock in QA/SIM.
Initialize Window/Input	Build PsychoPy window + keyboard.
Load Stimuli	Load from StimBank (config-defined).
Show Instructions	Show config-defined instruction text.
Loop Blocks	Run trial blocks and break screen.
Show Goodbye	Show final score and terminate.
Save Data	Save trial rows to CSV.

Trial-Level Flow

Step	Description
Fixation	fixation stimulus before each trial.
Pump Decision	Balloon + dynamic score text (score_bank_text) and pump/cash response.
Outcome	Pop / cash / timeout outcome branch.
Feedback	Numeric trial score display.

Runtime Context Phases

Phase Label	Meaning
pre_pump_fixation	Pre-decision fixation stage.
pump_decision	Repeated pump-or-cash decision stage.

3. Configuration Summary

a. Subject Info

• Defined in subinfo_fields / subinfo_mapping.
• Includes subject_id, subname, age, gender.
• Participant-facing labels are config-defined for localization.

b. Window Settings

Parameter	Value
size	[1920, 1080]
units	deg
screen	1
bg_color	gray
fullscreen	True
monitor_width_cm	60
monitor_distance_cm	72

c. Stimuli

Name	Type	Notes
fixation	text	Pre-trial fixation cross
[color]_balloon	image	Balloon stimulus by condition
score_bank_text	text template	Dynamic +{score_bank} display
[color]_pop	image	Explosion outcome image
cash_screen, timeout_screen	text	Outcome text screens
win_feedback, lose_feedback	text template	Trial feedback with {fb_score}
instruction_text, block_break, good_bye	textbox/text	Participant-facing instructions and summaries

d. Timing

Parameter	Value
fixation_duration	0.8s
response_feedback_duration	1.0s
balloon_duration	2.0s (used when decision_timeout_enabled=true)
feedback_duration	1.0s

e. Task Settings

Parameter	Human	QA/SIM
total_blocks	3	1
trial_per_block	10	9
total_trials	30	9
conditions	[blue, yellow, orange]	[blue, yellow, orange]
pump_key	space	space
cash_key	right	right
explosion_sampling_mode	without_replacement_cycle	without_replacement_cycle
decision_timeout_enabled	false	true

4. Methods (for academic publication)

Participants completed a Balloon Analogue Risk Task with color-coded balloon conditions (blue, yellow, orange) that differed in burst limits and reward increments. In each trial, participants could repeatedly pump (space) to increase temporary reward or cash out (right) to bank accumulated reward before explosion. If explosion occurred, that trial's temporary reward was lost.

The human protocol uses 30 trials (3 blocks x 10 trials), while QA/SIM profiles are reduced for validation runtime. Explosion points are generated with a deterministic condition/block sampler configured by explosion_sampling_mode, and participant-facing text/stimuli are config-defined to support localization.

5. References

• Lejuez, C. W., Read, J. P., Kahler, C. W., Richards, J. B., Ramsey, S. E., Stuart, G. L., Strong, D. R., & Brown, R. A. (2002). Evaluation of a behavioral measure of risk taking: The Balloon Analogue Risk Task (BART). Journal of Experimental Psychology: Applied, 8(2), 75-84. https://doi.org/10.1037/1076-898X.8.2.75
• See references/ for structured evidence artifacts and mapping tables.