Emotion Dot Probe Task

Technical Manual

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

Created: January 27, 2017

Last Modified: January 09, 2023 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements an emotion dotprobe procedure to measure attentional bias towards emotion words from different categories.

The implemented procedure is based on:

Tina M. Sutton & Jeanette Altarriba (2011). The automatic activation and perception of emotion in word processing: Evidence from a modified dot probe paradigm. Journal of Cognitive Psychology, 23:6, 736-747, DOI: 10.1080/20445911.2011.554392

Duration

2 minutes

Description

Participants are presented word pairs consisting of one emotion word and one control word flashed onto the screen to the left (top) or right (bottom) of a center fixation cross for a short duration. The word pairs are immediately followed by the letter 'R' or 'P'(= the probe). The probe is presented either in the location of the emotion word or in the location of the control word. Participants are asked to press one key (R) when the probe is an R and another key (P) if the probe is a P.

Procedure

2 emotions x 2 probe congruences are tested in a mixed design (emotions are blocked)
The order of the 'positive' and 'negative' blocks is counterbalanced by groupnumber.
Odd groupnumbers run order "Negative -> Positive"
Even groupnumbers run order "Positive -> Negative"

Practice Block:
• Each test block is preceded by a practice block that presents 6 practice trials to adjust to the task.
• In this script practice trials will turn into test trials without further interruption.
• word pairs are fixed but presented in random order
• locations of words is selected randomly with replacement
• location of probe is selected randomly with replacement
• 50% of the probes during practice trials are randomly selected to be probe1 (R)

Test Block:
• 14 trials
• word pairs are fixed but presented in random order
• 50% of the probes in each test block are randomly selected to be probe1 (R)
• 50% of the test trials in each block present congruent probes (sit in place of emotion words)

across both test blocks (see Sutton & Altarriba, 2011, p.741):
• the emotion word (EW) is located on the left(above) half the time (and half of the left EW are followed by a probe)
this script balances congruence x EWlocation across the two test blocks (due to the number of trials it's not
possible to achieve balance within one test block). If the number of trials per block is changed to 16 (for example),
complete balancing across 1 block would be possible.

Trial Sequence:
Fixation (default: 500ms) -> Word Pair (default: 180ms) -> Mask (optional, default: 0ms)-> Probe (until response)->errorfeedback for 500ms (if incorrect response))
if no response occurrs within 2000ms, a response reminder is flashed onto the screen.

Stimuli

emotion and control words for the test blocks are taken from Sutton & Altarriba (2011).
Negative words were paired with words from category "sports equipment" in a pseudo-random way,
while trying to match the wordlength of each pair.
Positive words were paired with words from category "animals" in a pseudo-random way,
while trying to match the wordlength of each pair.
Practice words were added by Millisecond
(negative words paired with fruits, positive words paired with furniture).
All words can be changed under section Editable Stimuli.

Words are presented white on a black background with font Arial.
To change sizing in screen locations, check section Editable Parameters.

Instructions

provided by Millisecond - can be edited under section Editable Instructions

Summary Data

File Name: emotiondotprobe_summary*.iqdat

Data Fields

NameDescription
inquisit.version Inquisit version number
computer.platform Device platform: win | mac |ios | android
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
Task Parameters
horizontalPresentation True (1) = the words will be presented left and right next to the fixation cross (default)
false (0) = the words will be presented on top and bottom of the fixation cross => vertical presentation
conditionOrder The order in which the emotion blocks are run
"negative -> positive" (odd groupnumbers); "positive -> negative" (odd groupnumbers)
Summary Variables
propCorrectNegEWCongruent Proportion correct responses for negative words when the probe was presented in Position
propCorrectNegEWIncongruent Proportion correct responses for negative words when the probe was presented in CTRL Position
propCorrectPosEWCongruent Proportion correct responses for positive words when the probe was presented in Position
propCorrectPosEWIncongruent Proportion correct responses for positive words when the probe was presented in CTRL Position
meanRTNegEWCongruent Mean latency (in ms) of correct responses for negative words when the probe was presented in Position
meanRTNegEWIncongruent Mean latency (in ms) of correct responses for negative words when the probe was presented in CTRL Position
abNegative AB = Attentional Bias Measure
positive value = (Attentional) Focus towards Negative Words
negative value = Avoidance of Negative Words
meanRTPosEWCongruent Mean latency (in ms) of correct responses for positive words when the probe was presented in Position
meanRTPosEWIncongruent Mean latency (in ms) of correct responses for positive words when the probe was presented in CTRL Position
abPositive AB = Attentional Bias Measure
positive value = Focus (Attentional Bias) towards Positive Words
negative value = Avoidance of Positive Words

Raw Data

File Name: emotiondotprobe_raw*.iqdat

Data Fields

NameDescription
build Inquisit version number
computer.platform Device platform: win | mac |ios | android
date Date the session was run
time Time the session was run
subject Participant ID
group Group number
session Session number
blockCode Name of the current block
blockNum Number of the current block
trialCode Name of the current trial
trialNum Number of the current trial
Parameter Values
horizontalPresentation True (1) = the words will be presented left and right next to the fixation cross (default)
false (0) = the words will be presented on top and bottom of the fixation cross => vertical presentation
conditionOrder The order in which the emotion blocks are run
"negative -> positive" (odd groupnumbers); "positive -> negative" (odd groupnumbers)
Performance Metrics
valence "negative" vs. "positive"
ctrl Stores the current control word (CTRL)
ctrlX The assigned x-coordinate for control words
ctrlY The assigned y-coordinate for control words
ew Stores the current emotion word (EW)
ewLocation 1 = left (top); 2 = right (bottom)
ewX The assigned x-coordinate for EW words
ewY The assigned y-coordinate for EW words
probe Stores the current probe letter
probeLocation 1 = left (top); 2 = right (bottom)
probeX The assigned x-coordinate for the probe letter
probeY The assigned y-coordinate for the probe letter
congruence 1 = probe sits in EW position; 0 = probe sits in CTRL position
response The participant's response (scancode of response button)
19 = R
25 = P
correct Accuracy of response: 1 = correct response; 0 = otherwise
latency The response latency (in ms); measured from: onset of probe

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
runMask True (1) = the script will mask ("XXXXX") the emotion and control words
false (0) = the script will not mask the emotion and control words (default)
horizontalPresentation True (1) = the words will be presented left and right next to the fixation cross (default)
false (0) = the words will be presented on top and bottom of the fixation cross => vertical presentation
fixationDuration The duration (in ms) of the fixation cross at the start of trial 500ms
wordPresentationDuration The duration (in ms) of the word presentations 180ms
maskDuration The duration (in ms) of the mask (if runMask = true)
Sutton & Altarriba (2011, Experiment1): word presentation for 30ms and mask for 150ms
0
iti The intertrial interval (in ms) 0ms
readyDuration Duration (in ms) of the 'get ready' trial 5000ms
reminderOnset Onset (in ms) of reminder after probe has appeared on screen 2000ms after onset of probe
probe1ResponseKey The response key for probe 1 "R", left response key
probe1 Probe 1 R
probe2ResponseKey The response key for probe 2 "P", right response key
probe2 Probe 2
interface
Sutton & Altarriba (2011, p. 741)
"The more central edge of each word appeared at 1.5degree and the distal edge at a maximum of 5degree of visual angle from
fixation."
Due to different monitor sizing, final positioning of the words is left open and can be easily changed by
changing the coordinate values below.
P
fixationSize The proportional size of the fixation cross to canvas height 8%
wordSize The proportional size of the words to canvas height 8%
leftX The left coordinate of the words (if horizontal presentation) 25%
rightX The right coordinate of the words (if horizontal presentation) 75%
topY The top coordinate of the words (if vertical presentation) 25%
bottomY The bottom coordinate of the words (if vertical presentation)
Note
- for horizontal presentations, the y-coordinate is automatically set to 50%.
- for vertical presentations, the x-coordinate is automatically set to 50%.
25%