Difference between revisions of "BART"

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==Task Background Info==
 
==Task Background Info==
  
Sample Text
+
'''Sample Text'''
  
 
In the BART (Lejuez et al., 2002), participants were allowed to pump a series of green (experimental) and white (control) balloons (Figure 1B). On each trial, participants chose to pump the balloon or cash out and collect their accumulated earnings for that round. For experimental balloons, after a trial in which the participant successfully pumped the balloon (meaning it did not result in an explosion), an image of a larger balloon was presented, the participant earned 5 points, and was able to pump again or cash-out. After a trial in which the participant chose to cash out, the participant’s accumulated earnings for that round were displayed and the task moved onto the next round. On an explosion trial (necessarily following a Risky choice trial), an exploded balloon was presented, the participant received no points for that round, and the task moved onto the next round. In this version of the BART, balloons exploded randomly on a number drawn from a uniform distribution over numbers of pumps, with 12 maximum pumps possible before an explosion or end of a round. Thus, participants experienced the probability as non-stationary, as the likelihood of a loss event increased with each trial in a round and as no information was provided to subjects about the probability of explosion. Participants also responded to control balloons, which increased in size on successive trials, but which neither resulted in points nor exploded. For both balloons (green and white), the balloon would disappear from the screen once the participant responded, and each balloon trial was separated by a jittered delay. An outcome trial (following a Cash-out choice or a Loss event) was displayed for a fixed duration of 2 s. Each trial was separated by a blank screen that was presented for a variable duration (1-2 s, average 1.5 s); each round was separated by a blank screen that was presented for variable duration (1-12 s, average 4 s).  
 
In the BART (Lejuez et al., 2002), participants were allowed to pump a series of green (experimental) and white (control) balloons (Figure 1B). On each trial, participants chose to pump the balloon or cash out and collect their accumulated earnings for that round. For experimental balloons, after a trial in which the participant successfully pumped the balloon (meaning it did not result in an explosion), an image of a larger balloon was presented, the participant earned 5 points, and was able to pump again or cash-out. After a trial in which the participant chose to cash out, the participant’s accumulated earnings for that round were displayed and the task moved onto the next round. On an explosion trial (necessarily following a Risky choice trial), an exploded balloon was presented, the participant received no points for that round, and the task moved onto the next round. In this version of the BART, balloons exploded randomly on a number drawn from a uniform distribution over numbers of pumps, with 12 maximum pumps possible before an explosion or end of a round. Thus, participants experienced the probability as non-stationary, as the likelihood of a loss event increased with each trial in a round and as no information was provided to subjects about the probability of explosion. Participants also responded to control balloons, which increased in size on successive trials, but which neither resulted in points nor exploded. For both balloons (green and white), the balloon would disappear from the screen once the participant responded, and each balloon trial was separated by a jittered delay. An outcome trial (following a Cash-out choice or a Loss event) was displayed for a fixed duration of 2 s. Each trial was separated by a blank screen that was presented for a variable duration (1-2 s, average 1.5 s); each round was separated by a blank screen that was presented for variable duration (1-12 s, average 4 s).  
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For the practice run, participants had one minute to complete 5 balloon rounds.
 
For the practice run, participants had one minute to complete 5 balloon rounds.
 +
 +
==Task Instructions==
 +
'''Demo Instructions'''
 +
We’re going to do a couple trials of the balloon task. In the following game, your goal is to earn as many points as possible. You will see a balloon appear on the screen.  Every time you press the key you will pump up the balloon and earn more points. Sometimes the balloon will explode and you will not receive the points earned on that balloon. 
 +
 +
You will see either green or white balloons. For green balloons, you can get 5 points for each pump! However, when the balloon explodes, you get no points.  You can save your points by choosing to stop pumping before the balloon explodes. For white balloons, you won’t earn points, so just pump up the white balloons until they go away.
 +
 +
There are a set number of trials in this experiment, so maximize your points on each trial. To pump up the balloon, press the first button. To stop inflating the balloon before it explodes, press the second button.
 +
 +
 +
'''Scan Instructions'''
 +
This task is the one where you score points by inflating balloons.  You push the first button to inflate the balloon, and the second button to stop inflating and move on to the next one.  The more you inflate the balloon the more points you’ll get, but if you inflate it too much the balloon will pop and you won’t get any points.  There are two different colors of balloons, green and white.  Green balloons give points, but white balloons don’t, so when you see a white balloon you can just inflate it until it goes away to move on to the next one.  You only get a limited number of balloons, so try to get as many points as you can on each. Any questions?
 +
 +
 +
'''Participants saw on the screen'''
 +
Press the FIRST button to inflate the balloon.
 +
Press the SECOND button to stop inflating and move onto the next balloon.
 +
If the balloon explodes, you will get no points.
 +
Green balloons give points, but white do not.
 +
When you see a white balloon, inflate it until it goes away to move o.
 +
 +
Try to get as many points as you can!
 +
 +
==Scoring Behavioral Data==
 +
/space/raid2/data/poldrack/CNP/scripts/behav_analyze/BART<br/>
 +
 +
1. All scripts can either be run so that you do all subjects of a given group at once, or do one subject at a time.
 +
There are comments in the code that instruct you to indicate first with group (e.g., CONTROLS) you will be doing. By default, it will run all subjects in the selected group unless you choose to comment in a couple lines and enter in a particular subject's ID (e.g., CNP_10150). This applies to both scripts. <br/>
 +
 +
2. in matlab, run 'BART_behav_output_function.m' <br/>
 +
This will either create behavioral output (in SUBJ/behav/BART) for each subject in your group or just the subject you specified. This script creates 3 files: <br/>
 +
a. It adds to the 'GROUP_BART_group_output.txt' file, by adding a line for each subject with their summary scores. <br/>
 +
b. It creates a 'SUBJ_BART_behav_output.txt' file in the subject's behav/BART directory. <br/>
 +
c. It creates a 'SUBJ_BART_trial_by_trial_output.txt' file in the subject's behav/BART directory. <br/>
 +
 +
The file created under 2a will be used for analysis of behavioral data collected during the BART scan. In most cases, this data will be provided after query. <br/>
 +
 +
 +
==Creating Onset files (EVs)==
 +
/space/raid2/data/poldrack/CNP/scripts/behav_analyze/BART<br/>
 +
 +
1. All scripts can either be run so that you do all subjects of a given group at once, or do one subject at a time.
 +
There are comments in the code that instruct you to indicate first with group (e.g., CONTROLS) you will be doing. By default, it will run all subjects in the selected group unless you choose to comment in a couple lines and enter in a particular subject's ID (e.g., CNP_10150). This applies to both scripts. <br/>
 +
 +
2. In matlab, run 'BART_mk_onsets_function.m' <br/>
 +
This will either create onset files (in SUBJ/behav/BART) for each subject in your group or just the subject you specified.
 +
 +
3. running this script will create 19 onset files in each subject's behav/BART directory (a subset of which are used for the current models): <br/>
 +
'SUBJ_accept_fixed_ons.txt' <br/>
 +
'SUBJ_accept_ons.txt' <br/>
 +
'SUBJ_accept_total_dem_fixed_ons.txt' <br/>
 +
'SUBJ_accept_total_dem_ons.txt' <br/>
 +
'SUBJ_accept_total_ons.txt' <br/>
 +
'SUBJ_balloons.txt' <br/>
 +
'SUBJ_control_fixed_ons.txt' <br/>
 +
'SUBJ_control_ons.txt' <br/>
 +
'SUBJ_explode_fixed_ons.txt' <br/>
 +
'SUBJ_explode_meandur_ons.txt' <br/>
 +
'SUBJ_explode_total_dem_fixed_ons.txt' <br/>
 +
'SUBJ_explode_total_dem_meandur_ons.txt' <br/>
 +
'SUBJ_explode_total_dem_ons.txt' <br/>
 +
'SUBJ_explode_total_ons.txt' <br/>
 +
'SUBJ_reject_fixed_ons.txt' <br/>
 +
'SUBJ_reject_ons.txt' <br/>
 +
'SUBJ_reject_total_dem_fixed_ons.txt' <br/>
 +
'SUBJ_reject_total_dem_ons.txt' <br/>
 +
'SUBJ_reject_total_ons.txt' <br/>
 +
 +
4. The onset files will have three columns, but the format will vary between them. <br/>
 +
 +
==Running First Level Analyses==
 +
/space/raid2/data/poldrack/CNP/scripts/run_level1_scripts/BART<br/>
 +
 +
1. So far, we have 2 BART models, so we have 2 BART first-level scripts for each group. For CONTROLS, these scripts are: <br/>
 +
'run_level1_BART_CONTROLS_model1.sh' <br/>
 +
'run_level1_BART_CONTROLS_model2.sh' <br/>
 +
 +
Each of these scripts creates an individualized .fsf file for each subject (which is then stored in /space/raid2/data/poldrack/CNP/scripts/designs/BART), then runs it, and the output is stored in the subject's analysis/BART directory. <br/>
 +
 +
2. To run each script, open it in emacs. <br/>
 +
a. As is commented into the script, you need to comment in certain sections depending on whether the subject was scanned at BMC vs. CCN. This is in two places, at the top and bottom of the script. <br/>
 +
b. Enter in the subject(s) ID(s) on a new line of code (e.g., 'for id in 11131, do'). <br/>
 +
c. Save and submit to grid to run. <br/>
 +
 +
==Data Checking==
 +
 +
There are quite a few subjects that are Flagged under BART because of the nature of the task and set-up of the model.
 +
If a subject has few Explosion trials or few Cash-out trials, then their model is rank deficient (too few trials for that EV, or too few trials with the same weighting) which makes the data unusable.
 +
 +
Other users may set-up a different model or analyze the data differently, which completely ignores these trial types, and therefore may recover more subjects.
 +
 +
For subjects with rank-deficient models, they have this recorded under the BART task (ImgA_FLAG_BART_S). These subjects are not marked for exclusion and will be distributed, but their data should likely not be included in group analyses which focus on these trial types. Remove these subjects and re-rerun group analyses of Explosion and/or Cash-out trials.
 +
 +
==List of Models==
 +
level1_BART_model1 <br/>
 +
level1_BART_model2 (this is the preferred model to use now) <br/>
 +
 +
==Model description and contrasts==
 +
[[BART model1 detail]] <br/>
 +
[[BART model2 detail]]
 +
 +
==Behavioral variables==
 +
[[BART behavioral variables]]
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
----
 +
Link back to [[LA5C]] page. <br/>
 +
Link back to [[HTAC]] page.

Latest revision as of 15:13, 13 June 2012

BART

Task Background Info

Sample Text

In the BART (Lejuez et al., 2002), participants were allowed to pump a series of green (experimental) and white (control) balloons (Figure 1B). On each trial, participants chose to pump the balloon or cash out and collect their accumulated earnings for that round. For experimental balloons, after a trial in which the participant successfully pumped the balloon (meaning it did not result in an explosion), an image of a larger balloon was presented, the participant earned 5 points, and was able to pump again or cash-out. After a trial in which the participant chose to cash out, the participant’s accumulated earnings for that round were displayed and the task moved onto the next round. On an explosion trial (necessarily following a Risky choice trial), an exploded balloon was presented, the participant received no points for that round, and the task moved onto the next round. In this version of the BART, balloons exploded randomly on a number drawn from a uniform distribution over numbers of pumps, with 12 maximum pumps possible before an explosion or end of a round. Thus, participants experienced the probability as non-stationary, as the likelihood of a loss event increased with each trial in a round and as no information was provided to subjects about the probability of explosion. Participants also responded to control balloons, which increased in size on successive trials, but which neither resulted in points nor exploded. For both balloons (green and white), the balloon would disappear from the screen once the participant responded, and each balloon trial was separated by a jittered delay. An outcome trial (following a Cash-out choice or a Loss event) was displayed for a fixed duration of 2 s. Each trial was separated by a blank screen that was presented for a variable duration (1-2 s, average 1.5 s); each round was separated by a blank screen that was presented for variable duration (1-12 s, average 4 s).

The task performed in the scanner was self-paced, but the task was programmed such that participants saw approximately 30 virtual balloons, with an approximate run time of 9 minutes. Each successful pump was worth 5 points, but participants did not collect their earnings at the end of the scan.

For the practice run, participants had one minute to complete 5 balloon rounds.

Task Instructions

Demo Instructions We’re going to do a couple trials of the balloon task. In the following game, your goal is to earn as many points as possible. You will see a balloon appear on the screen. Every time you press the key you will pump up the balloon and earn more points. Sometimes the balloon will explode and you will not receive the points earned on that balloon.

You will see either green or white balloons. For green balloons, you can get 5 points for each pump! However, when the balloon explodes, you get no points. You can save your points by choosing to stop pumping before the balloon explodes. For white balloons, you won’t earn points, so just pump up the white balloons until they go away.

There are a set number of trials in this experiment, so maximize your points on each trial. To pump up the balloon, press the first button. To stop inflating the balloon before it explodes, press the second button.


Scan Instructions This task is the one where you score points by inflating balloons. You push the first button to inflate the balloon, and the second button to stop inflating and move on to the next one. The more you inflate the balloon the more points you’ll get, but if you inflate it too much the balloon will pop and you won’t get any points. There are two different colors of balloons, green and white. Green balloons give points, but white balloons don’t, so when you see a white balloon you can just inflate it until it goes away to move on to the next one. You only get a limited number of balloons, so try to get as many points as you can on each. Any questions?


Participants saw on the screen Press the FIRST button to inflate the balloon. Press the SECOND button to stop inflating and move onto the next balloon. If the balloon explodes, you will get no points. Green balloons give points, but white do not. When you see a white balloon, inflate it until it goes away to move o.

Try to get as many points as you can!

Scoring Behavioral Data

/space/raid2/data/poldrack/CNP/scripts/behav_analyze/BART

1. All scripts can either be run so that you do all subjects of a given group at once, or do one subject at a time. There are comments in the code that instruct you to indicate first with group (e.g., CONTROLS) you will be doing. By default, it will run all subjects in the selected group unless you choose to comment in a couple lines and enter in a particular subject's ID (e.g., CNP_10150). This applies to both scripts.

2. in matlab, run 'BART_behav_output_function.m'
This will either create behavioral output (in SUBJ/behav/BART) for each subject in your group or just the subject you specified. This script creates 3 files:
a. It adds to the 'GROUP_BART_group_output.txt' file, by adding a line for each subject with their summary scores.
b. It creates a 'SUBJ_BART_behav_output.txt' file in the subject's behav/BART directory.
c. It creates a 'SUBJ_BART_trial_by_trial_output.txt' file in the subject's behav/BART directory.

The file created under 2a will be used for analysis of behavioral data collected during the BART scan. In most cases, this data will be provided after query.


Creating Onset files (EVs)

/space/raid2/data/poldrack/CNP/scripts/behav_analyze/BART

1. All scripts can either be run so that you do all subjects of a given group at once, or do one subject at a time. There are comments in the code that instruct you to indicate first with group (e.g., CONTROLS) you will be doing. By default, it will run all subjects in the selected group unless you choose to comment in a couple lines and enter in a particular subject's ID (e.g., CNP_10150). This applies to both scripts.

2. In matlab, run 'BART_mk_onsets_function.m'
This will either create onset files (in SUBJ/behav/BART) for each subject in your group or just the subject you specified.

3. running this script will create 19 onset files in each subject's behav/BART directory (a subset of which are used for the current models):
'SUBJ_accept_fixed_ons.txt'
'SUBJ_accept_ons.txt'
'SUBJ_accept_total_dem_fixed_ons.txt'
'SUBJ_accept_total_dem_ons.txt'
'SUBJ_accept_total_ons.txt'
'SUBJ_balloons.txt'
'SUBJ_control_fixed_ons.txt'
'SUBJ_control_ons.txt'
'SUBJ_explode_fixed_ons.txt'
'SUBJ_explode_meandur_ons.txt'
'SUBJ_explode_total_dem_fixed_ons.txt'
'SUBJ_explode_total_dem_meandur_ons.txt'
'SUBJ_explode_total_dem_ons.txt'
'SUBJ_explode_total_ons.txt'
'SUBJ_reject_fixed_ons.txt'
'SUBJ_reject_ons.txt'
'SUBJ_reject_total_dem_fixed_ons.txt'
'SUBJ_reject_total_dem_ons.txt'
'SUBJ_reject_total_ons.txt'

4. The onset files will have three columns, but the format will vary between them.

Running First Level Analyses

/space/raid2/data/poldrack/CNP/scripts/run_level1_scripts/BART

1. So far, we have 2 BART models, so we have 2 BART first-level scripts for each group. For CONTROLS, these scripts are:
'run_level1_BART_CONTROLS_model1.sh'
'run_level1_BART_CONTROLS_model2.sh'

Each of these scripts creates an individualized .fsf file for each subject (which is then stored in /space/raid2/data/poldrack/CNP/scripts/designs/BART), then runs it, and the output is stored in the subject's analysis/BART directory.

2. To run each script, open it in emacs.
a. As is commented into the script, you need to comment in certain sections depending on whether the subject was scanned at BMC vs. CCN. This is in two places, at the top and bottom of the script.
b. Enter in the subject(s) ID(s) on a new line of code (e.g., 'for id in 11131, do').
c. Save and submit to grid to run.

Data Checking

There are quite a few subjects that are Flagged under BART because of the nature of the task and set-up of the model. If a subject has few Explosion trials or few Cash-out trials, then their model is rank deficient (too few trials for that EV, or too few trials with the same weighting) which makes the data unusable.

Other users may set-up a different model or analyze the data differently, which completely ignores these trial types, and therefore may recover more subjects.

For subjects with rank-deficient models, they have this recorded under the BART task (ImgA_FLAG_BART_S). These subjects are not marked for exclusion and will be distributed, but their data should likely not be included in group analyses which focus on these trial types. Remove these subjects and re-rerun group analyses of Explosion and/or Cash-out trials.

List of Models

level1_BART_model1
level1_BART_model2 (this is the preferred model to use now)

Model description and contrasts

BART model1 detail
BART model2 detail

Behavioral variables

BART behavioral variables






Link back to LA5C page.
Link back to HTAC page.