Subliminal Priming Task - Bona Fide Pipeline

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

Created: January 25, 2013

Last Modified: January 19, 2023 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a Subliminal Priming Procedure.

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. For example, a person should be faster to quickly categorize the target word 'good' as 'positive' after the brief presentation of the prime word 'ice-cream' than after the brief presentation of the prime word 'famine'. Priming Procedure can thus be used to study implicit attitudes. Faster reaction times to targets after primes from a specific category are interpreted as indicative of an existing relationship/association between the categories in the person's mind.

If the primes are presented with a temporal duration that can be consciously processed, the primes are called 'supraliminal'. If the duration of the primes is so short that they are outside one's conscious awareness the primes are called 'subliminal'. This script uses subliminal primes.

In this script, the primes that are used have been previously be conditioned to be a positive or a negative condition stimulus (CS). Without the conditioning the default primes used in this script have likely no affect on target categorization.

References

Michael A. Olson, M.A. & Fazio, R.H. (2002). Implicit acquisition and manifestation of classically conditioned attitudes. Social Cognition, 20, 89-103.

Duration

3 minutes

Description

After seeing an alphanumeric mask (that is very briefly "interrupted" by a subliminal prime), participants are asked to categorize adjectives as positive or negative. Two primes are used that have been conditioned to be a positive and a negative CS in a prior study (for more info on the conditioning part of the study see Olson & Fazio, 2002).

Procedure

• 2 primes (Shelder vs. Metapod) x 2 adjective valence (positive vs. negative)
=> 4 experimental trial conditions
• 16 positive and 16 negative adjectives

Blocks:
1) Practice Block: runs 16 trials (8 with positive and 8 with negative adjectives) with a pseudo "prime"
to achieve a similar "look" as the experimental trials (Olson and Fazio (2002) may not have used a pseudo "prime")
2) 2 Experimental Blocks of 32 trials:
- across all 64 experimental trials, each prime is paired once with each of the 32 adjectives.
- all 32 adjectives are sampled ONCE during each block (no repeats); see LISTS for more details

Trials: stimulus durations taken from Olson & Fazio (2002)
- pre-mask consisting of a string of alphanumeric characters for 56ms
- followed by a prime for 28ms
- post-mask (same alphanumeric string) for 42ms
- 98ms later: adjective
=> timeline: 0ms: premask; 56ms: prime; 84ms: postmask; 126ms: postmask eraser; 224ms: adjective

Stimuli

most of the stimuli used in this script are not the originals;
they can be edited under section Editable Stimuli

Instructions

the instructions used in this script are not originals;
they can be edited under section Editable Instructions

Summary Data

File Name: subliminalpriming_summary*.iqdat

Data Fields

Raw Data

File Name: subliminalpriming_raw*.iqdat

Data Fields

Parameters

The procedure can be adjusted by setting the following parameters.