Food Progressive Ratio Button Press Task

Technical Manual

Script Author: Sean Draine (seandr@millisecond.com), Millisecond

Created: January 14, 2023

Last Modified: January 10, 2025 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a 'Progressive Ratio Button Press Task' to determine the "breakpoint" at which the reward (food) is no longer worth the effort of clicking a mouse button. The implemented template is based on the procedure described by Miras et (2012).

References

Miras AD, Jackson RN, Jackson SN, Goldstone AP, Olbers T, Hackenberg T, Spector AC, le Roux CW. Gastric bypass surgery for obesity decreases the reward value of a sweet-fat stimulus as assessed in a progressive ratio task. Am J Clin Nutr. 2012 Sep;96(3):467-73. doi: 10.3945/ajcn.112.036921. Epub 2012 Jul 25. PMID: 22836034.

Duration

The duration of the script varies depending on the participant's perserverance.

Description

Participants are instructed to repeatedly click the left mouse button for rewards. When they no longer wish to click the mouse button, they can press a spacebard to end the task. The number of clicks required to receive a reward is increased by a multiple (2 by default) with each round.

The task continues until the participant opts out by pressing the space bar. The number of clicks in the last completed round is considered the "breakpoint" after which the reward is no longer worth the effort.

Procedure

- A practice round is run at the beginning with parameters.startingRatio as the required number of clicks.
- The practice round is followed by test rounds until the participant presses SHIFT+SPACE to quit.
- As participants complete each test round, they are shown a screen indicating they will receive a reward. The
number of clicks required to complete the next round is multiplied by parameters.geometricIncrement.
- The task continues with progressively longer rounds until the participant opts out by pressing the SHIFT+SPACE

Stimuli

The task presents instructions but does not otherwise present any stimuli.

Instructions

provided by Millisecond - can be edited under section Editable Instructions

Summary Data

File Name: progressiveratio_miras_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 the session was run
startTime Time the session was run
subjectId Participant ID
groupId Group number
sessionId Session number
elapsedTime Session duration in ms
completed 0 = Test was not completed
1 = Test was completed
startingRatio The total clicks for the first round
geometricIncrement The factor by which the number of clicks per round is multiplied
breakPoint The total clicks for the last completed round
roundsCount The total number of completed rounds excluding practice rounds
clickCount The total number of clicks excluding practice rounds

Raw Data

File Name: progressiveratio_miras_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.
response The response given
latency Response time in milliseconds.
roundCount Total number of rounds excluding the practice round
clickCount Total number of mouse clicks excluding the practice round
currentRatio Number of clicks required to complete the current round

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
startingRatio The required total clicks for the first round10
geometricIncrement The factor by which the number of clicks per round is multiplied2