Affective Priming Procedure with Pictures

Technical Manual

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

Created: January 09, 2015

Last Modified: January 18, 2025 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a simple Affective Priming procedure with supraliminal picture primes and word targets. In general, priming procedures are simple response-timed binary categorization tasks of items from two target categories (e.g. positive vs. negative adjectives). Priming Procedures are based on the assumption that people respond faster if the target category was already 'mentally activated' by briefly presenting items (called 'primes') that are closely connected in one's mind. Thus, a person should be faster to quickly categorize the target word 'good' as 'positive' after the brief presentation of the prime word/image of 'ice-cream' (assuming good and ice-cream are associated in one's mind) than after the brief presentation of the prime word/image 'war' (assuming good and war are not closely associated in one's mind). If the primes are presented with a temporal duration that can be consciously processed, the primes are called 'supraliminal'.

References

The implemented procedure is not based on any particular published paradigm.

Duration

7 minutes

Description

Participants are asked to categorize affective target words into pleasant and unpleasant categories. For baseline measures, a baseline supraliminal prime '***' precedes the target words. For test measures, supraliminal picture primes precede the target words.

Procedure

2 affective primes (pleasant vs unpleasant: here flowers vs. insect pics) x 2 affective targets (pleasant vs unpleasant), tested within subjects

1. baseline ("practice"): 48 trials (all 48 targets) are tested with a baseline prime (***); targets are selected at random
2. test: 48 trials (all 48 targets); targets are selected at random
- all 48 words occur once as prime and once as target

Trialsequence:
Prime (200ms, editable) -> prime-target ISI (100ms, editable)
-> Targets (until response; latency measured from onset of target)->ITI (2500ms)

Stimuli

Words are taken from:
Draine, S.C, & Greenwald, A.G. (1998). Replicable Unconscious Semantic Priming. Journal of Experimental Psychology:
General, 127, 286-303.
pictures collected from the internet as well as the Inquisit AMP.iqjs- they are used as placeholders
Insects - > unpleasant primes
Flowers -> pleasant primes
edit under section Editable Stimuli

Instructions

generic instructions; can be edited under section Editable Instructions

Summary Data

File Name: affectivepriming_pictures_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 script was run
starttime Time script was started
subjectid Assigned subject id number
groupid Assigned group id number
sessionid Assigned session id number
elapsedtime Time it took to run script (in ms); measured from onset to offset of script
completed 0 = Test was not completed
1 = Test was completed
propCorrect Overall proportion correct (across baseline and test)
meanRT Overall mean correct response time in ms (across baseline and test)
propCorrectBase Proportion correct baseline trials
meanRTBase Mean latency (ms) of correct baseline trials
propCorrectUBase Proportion correct Unpleasant baseline trials
meanRTUBase Mean latency (ms) of correct Unpleasant baseline trials
propCorrectPBase Proportion correct Pleasant baseline trials
meanRTPBase Mean latency (ms) of correct Pleasant baseline trials
propCorrectTest Proportion correct test trials
meanRTTest Mean latency (ms) of correct test trials
propCorrectUUTest Proportion correct test trials that pair Unpleasant primes with Unpleasant targets
meanRTUUTest Mean latency (in ms) of correct test trials that pair Unpleasant primes with Unpleasant targets
propCorrectUPTest Proportion correct test trials that pair Unpleasant primes with Pleasant targets
meanRTUPTest Mean latency (in ms) of correct test trials that pair Unpleasant primes with Pleasant targets
propCorrectPUTest Proportion correct test trials that pair Pleasant primes with Unpleasant targets
meanRTPUTest Mean latency (in ms) of correct test trials that pair Pleasant primes with Unpleasant targets
propCorrectPPTest Proportion correct test trials that pair Pleasant primes with Pleasant targets
meanRTPPTest Mean latency (in ms) of correct test trials that pair Pleasant primes with Pleasant targets

Raw Data

File Name: affectivepriming_pictures_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.
primeCategory Unpleasant vs Pleasant
targetCategory Unpleasant vs Pleasant
primeItemNumber Stores the itemnumber of the currently presented prime (0-based => first item in a list has index 0)
prime Stores the presented prime
targetItemNumber Stores the itemnumber of the currently presented target (0-based => first item in a list has index 0)
target Stores the presented target
response Scancode of the pressed response button (Example:)
18 = E = left
23 = I = right
57 = spacebar
responseCategory The interpretation of the key-response: "pleasant" or "unpleasant"
correct Accuracy of response: 1 = correct response; 0 = otherwise
latency The response latency (in ms); measured from: onset of target

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
baselinePrime The symbols used for the baseline "prime""***"
baselinePrimeHeight The height of the baseline prime in % of canvas height 5%
primeSize The size of the prime pictures in % of canvas height 30%
targetHeight The size of the targets in % of canvas height 5%
primeDuration The duration of the primes in ms 200
ptISI The duration of the prime-target interstimulus interval 100
iti The intertrial interval 2500
responseKeyLeft The left response key in this script the left response key is used as the unpleasant key"E"
responseKeyRight The right response key in this script the right response key is used as the pleasant key"I"