Cognitive Effort Discounting Task with Speech Task - COGED

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond

Credits:
Millisecond thanks Jenny Crawford and the Braver lab at Washington University in St. Louis
for help fine-tuning this Cognitive Effort Discounting Task procedure!

for help fine-tuning this Cognitive Effort Discounting Task procedure!

Last Modified: January 03, 2025 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a variant of the Cognitive Effort Discounting Procedure to establish indifference points (minimum price points) at which people start to discount ("devalue") monetary rewards paid for higher effort tasks in favor of less paid lower effort tasks.

The implemented procedure in this script mirrors the n-back Cognitive Effort Discounting Procedure (see Inquisit script cognitiveeffortdiscountingtask.iqjs) but uses a speech task as the cognitive task (McLaughlin et al, 2020).

References

McLaughlin, D.J, Todd S. Braver,T.S., Peelle, J.E. (2020). Measuring the Subjective Cost of Listening Effort Using a Discounting Task.

Westbrook A, Kester D, Braver TS (2013). What Is the Subjective Cost of Cognitive Effort? Load, Trait, and Aging Effects Revealed by Economic Preference. Pessiglione M, ed. PLoS One 981 8:e68210.

Duration

20 minutes

Description

Participants are repeatedly asked to choose between a more difficult cognitive task with a higher earning potential or an easier cognitive task with less earning potential. Through a series of questions the participants' cognitive effort indifference point for the pair of tasks is determined (aka the price point at which participants start to devalue the potential higher pay for a challenging cognitive task in favor of less pay for a less challenging one).

In this script, the cognitive task chosen is a 'Speech' task (McLaughlin et al, 2020). For the Speech task participants are given sentences distorted by different signal to noise ratios (SNR) and have to repeat the sentences. This script uses 4 levels of difficulty for the Speech task (SNR0, SNR-4, SNR-8, SNR-12)

The procedure is divided into 3 phases:

1. Participants get familiar with the Speech task procedure and work through each level (from the easiest to the hardest). Each level presents 15 sentences.

2. Participants work through the indifference point estimation procedure (without actually performing speech tasks) for the 3 higher levels of N (1 vs.2; 1 vs. 3; 1 vs. 4) => 3 indifference points are estimated for each level of N tested

3. One of the participant's choices is randomly selected, the participant works through 20 more trials of the Speech task at the selected level for the promised reward. The reward will be multiplied by parameters.phase3Run (default: 5) to be comparable to the speech version of the test.

Procedure

3 phases:

(1) Phase 1: Speech Task Practice

Speech task: participants are given sentences distorted by progressively increasing signal to noise ratios (SNR)
and have to repeat the sentence by entering the sentence they heard into a textbox.

- by default, this script runs through four levels of the speech task in order of difficulty (= increased noise levels)
- each level presents 15 sentences
N = 1 (level1) => Black task (SNR0)
N = 2 (level2) => Red task (SNR-4)
N = 3 (level3) => Blue task (SNR-8)
N = 4 (level4) => purple task (SNR-12)

- at the end of each block, participants receive feedback

- Accuracy Determination (see expression.responseCleaning for how the entered response is cleaned up for comparison):
The script uses the 'correct responses' declared in sentencelist_1.iqjs to sentencelist_repeat.iqjs.
Each correct response should contain the important key words in singular form and in lower case letters.
The script cleans up the entered response by
- turning all letters to lowercase
- removing 'the' , 'a', and 'an'
- removing ",", ".", ":", ";" and newlines
- removing '-' and joining hypenated words into one (e.g. boy-friend)
- removing trailing 's' from individual words
- corrected spellings for a couple of individual words
(e.g. 'familie' is corrected to 'family', 'grey' is corrected to 'gray', 'men' is corrected to 'man')
- comparing the 'cleaned-up' input to the correct response


after each level participants are asked to self-report on the 6 rating scales of the NASA TASK LOAD INDEX- Survey:
/mentalDemand
/physicalDemand
/temporalDemand
/performance
/effort
/frustration

(2) Phase 2: Indifference Point Estimations
- 3 Indifference Points for level of N tested (e.g. 3 different standard amounts are offered for each level of N)
- by default this script runs 54 trials = 3 levels of N (2, 3, 4) x 3 IPs per N level x 6 trials
- the trials are presented in random order in a mixed design
- level of speech tasks are referred to only by color
- the position (right/left) of the standard amount is randomly determined:
for half the trials the standard amount appears on the right
- participants have 9s to make a choice (after 9s the black task is automatically assigned as the default choice)

Indifference Point Algorithm:
- the harder level N always offers a higher (fixed) reward (see section Editable Parameters),
- the possible reward for the easier black speech task starts at 1 but gets adjusted according to the choices made:
- if the harder choice was previously selected; the reward goes up (by half the previous adjustment)
- if the easier choice was previously selected; the reward goes down (by half the previous adjustment)
- Indifference Points: the adjusted reward for level 1 after the last choice (aka: the reward offered for level 1 on the
7th round)

(3) Phase 3: Actual Money Earning Phase (can be skipped; see parameters.phase3Runs for more info)
- one of the 3 (level of N: 2-4) * 6 (trials per level of N) * 3 indifference points per N level = 54 choice trials
from Phase 2 is randomly selected by the computer
- the chosen difficulty level N (= chosen color task) during that trial as well as the promised reward is used
for one more block of 20 speech trials. Participants are told that they may have to work through 5 more blocks of these
but the reward is multiplied by 5 after this single block.

This script does not provide any behavioral measure of actual 'effort' during phase 3

Stimuli

• soundfiles provided by McLaughlin et al (2020): https://osf.io/8jpnx/files/.

Instructions

provided by Millisecond as *.htm files.
To change instructions, edit the htm files directly (e.g. in TextEdit for Macs or Notepad for Windows).
Instructions have been generously shared by Jenny Crawford and her lab

Summary Data

File Name: cognitiveeffortdiscountingtask_speechtask_summary*.iqdat

Data Fields

Raw Data

File Name: cognitiveeffortdiscountingtask_speechtask_raw.iqdat

Data Fields

Parameters

The procedure can be adjusted by setting the following parameters.