Belief Updating Task

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

Credits:
Millisecond Software thanks C. Hobbs for sharing the script with the library1

Created: January 15, 2021

Last Modified: January 01, 2025 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a custom Belief Updating Procedure (Hobbs et al, 2022) used to study people's tendency to update their current beliefs based on provided information .

References

Hobbs, C., Vozarova, P., Sabharwal, A., Shah, P., & Button, K. (2022). Is depression associated with reduced optimistic belief updating? Royal Society Open Science, 9(2), 190814–190814. https://doi.org/10.1098/rsos.190814

Duration

60 minutes

Description

Participants are given positive and negative life events and are asked to provide probability estimate that these events might be happening (not happening) to them throughout their lives. In-between an initial estimate and a re-estimate of the probebility, they are given the actual probability of the event happening (not happening) to someone like them. Later, their memory for these actual probabilities. The script further collects ratings for each life event on 7 scales ("vividness", "familiarity", "prior experience", "emotional arousal", "negativity", "positivity", "controllability").

Procedure

(I) 8 counterbalanced groups (every combination of values.valenceOrder/values.listOrder/values.happeningOrder):

Group1: Neg Before Pos, N Before Nh, List1 Before List2

Group2: Neg Before Pos, Nh Before H, List2 Before List1

Group3: Neg Before Pos, H Before Nh, List2 Before List1

Group4: Neg Before Pos, Nh Before H, List1 Before List2

Group5: Pos Before Neg, N Before Nh, List1 Before List2

Group6: Pos Before Neg, Nh Before H, List2 Before List1

Group7: Pos Before Neg, H Before Nh, List2 Before List1

Group8: Pos Before Neg, Nh Before H, List1 Before List2

Stimuli

provided by Katie Hobbs, see section Editable Stimuli

Task stimuli for the test consist of short descriptions of 40 negative and 40 positive life events and the
average probability of someone in the same environment as the participant experiencing these events in
their lifetime.

In keeping with previous research very common (greater than 70%) and very rare (less than 10%) events
will not be included. This will allow for change between initial and re-estimates.
To allow for variability in ratings for high and low probability life events,
participants are told that event probabilities fell within 3% and 77%.

Of the 72 negative life events used by Korn et al, 42 (2 for practice, 40 for test) of the
same negative life events are used, although new estimates were estimated to account for
possible changes in available statistics for probabilities following the publication of Korn et al (2014).

In addition, estimates for 42 positive life events (2 for practice, 40 for test).
Estimates were derived from reputable resources including peer reviewed academic journal articles,
governmental resources (e.g. the Office for National Statistics),
non-governmental organisation resources, and marketing and consumer data companies.

the default stimuli might be cultural-specific

Instructions

provided by Katie Hobbs

Summary Data

File Name: beliefupdating_summary*.iqdat

Data Fields

Raw Data

File Name: beliefupdating_raw*.iqdat

Data Fields

Parameters

The procedure can be adjusted by setting the following parameters.