Purchase this article with an account.
Sascha Meyen, Iris Zerweck, Catarina Amado, Ulrike von Luxburg, Volker Franz; Re-analyzing unconscious priming: Is there really an indirect task advantage?. Journal of Vision 2019;19(10):275b. doi: https://doi.org/10.1167/19.10.275b.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Many studies in the field of priming claim that masked stimuli are processed without participants’ conscious awareness of these ‘prime’-stimuli. Evidence is often based on two tasks: In the ‘direct’ task, participants try to discriminate or identify the primes and perform close to chance level. This is seen as evidence that participants have no conscious awareness of the primes. Nevertheless, the same prime-stimuli produce clear effects on behavioral or neuro-physiological measures (e.g., reaction times/RTs, skin conductance, EEG, fMRI) in an ‘indirect’ task where participants respond to another ‘target’-stimulus. For example, when prime and target belong to the same category, then there are clear congruency effects (e.g., faster RTs) even though participants only respond to the target but not to the prime. This is seen as evidence that participants discriminated the primes better in the indirect task (unconsciously) than in the direct task (consciously). Such an indirect task advantage (ITA) – that is better discrimination of the prime in the indirect than direct task – would be surprising because the primes are not even task-relevant in the indirect task. Independent of inferences about conscious/unconscious processing we demonstrate that the typical reasoning to conclude an ITA is flawed for statistical reasons. We present a method to re-analyze existing studies based on the typically published results (e.g., t-test or ANOVA). With minimal assumptions, this method allows to test directly whether the indirect task indicates superior processing compared to the direct task. We reanalyzed 13 highly influential studies (overall more than 2800 citations in WebOfScience) and show that – contrary to the original claims of these studies – there is little evidence for better discrimination of the prime in the indirect than direct task. This suggests that some caution is needed with respect to the literature on (unconscious) priming effects.
This PDF is available to Subscribers Only