Reversed Priming Effects May Be Driven by Misperception Rather than Subliminal Processing

Abstract

A new paradigm for investigating whether a cognitive process is independent of perception was recently suggested. In the paradigm, primes are shown at an intermediate signal strength that leads to trial-to-trial and inter-individual variability in prime perception. Here, I used this paradigm and an objective measure of perception to assess the influence of prime identification responses on Stroop priming. I found that sensory states producing correct and incorrect prime identification responses were also associated with qualitatively different priming effects. Incorrect prime identification responses were associated with reversed priming effects but in contrast to previous studies, I interpret this to result from the (mis-)perception of primes rather than from a subliminal process. Furthermore, the intermediate signal strength also produced inter-individual variability in prime perception that strongly influenced priming effects: only participants who on average perceived the primes were Stroop primed. I discuss how this new paradigm, with a wide range of d′ values, is more appropriate when regression analysis on inter-individual identification performance is used to investigate perception-dependent processing. The results of this study, in line with previous results, suggest that drawing conclusions about subliminal processes based on data averaged over individuals may be unwarranted.

When Perception Trumps Reality

“…If so, perceptual failures of both kinds (i.e., misperception and no perception) may be possible in such conditions. If perceived meaning causes Stroop priming, then in cases of misperception (e.g., "RED" misperceived as "BLUE"), reversed Stroop priming would be expected, because response time to a red object would be slower, not faster, after "RED" was misperceived as "BLUE," although prime and target are objectively congruent (Sand, 2016). Therefore, weak or absent subliminal-priming effects may in fact hide two substantial effects: Stroop priming and reversed Stroop priming.…”

Subliminal or not? Comparing null-hypothesis and Bayesian methods for testing subliminal priming

“…The main difficulty in supporting a claim that priming is subliminal is that observers differ in their absolute thresholds (e.g., Albrecht & Mattler, 2012;Dagenbach et al, 1989;Greenwald et al, 1995;Haase & Fisk, 2015;Sand, 2016). This means that a certain prime stimulus intensity will likely be subliminal for some observers and supraliminal for others.…”

“…This occurs because experimenters try to use a prime stimulus setting that is subliminal for all observers. For another approach that use a range of d 0 d for which regression analysis is more robust, see Sand (2016) or Haase and Fisk (2015).…”

“…Observers, however, differ in their thresholds (e.g., Albrecht & Mattler, 2012;Dagenbach, Carr, & Wilhelmsen, 1989;Greenwald, Klinger, & Schuh, 1995;Haase & Fisk, 2015;Sand, 2016). To take individual differences in thresholds (and thus perception, given a specific prime stimulus intensity) into account, another conventional analysis is regression analysis (e.g., Jusyte & Schönenberg, 2014;Ocampo, 2015;Schoeberl et al, 2015;Xiao & Yamauchi, 2014).…”

“…We wanted to specify H 1 for the effect ''observers (at a mean level) were marginally able to perceive the prime stimulus but lower sensitivities are more likely than higher sensitivities". Based on previous experimental conditions using very difficult to perceive but not subliminal stimuli (e.g., Atas, Vermeiren, & Cleeremans, 2013;Haase & Fisk, 2015;Sand, 2016;Schoeberl et al, 2015), we chose to represent this using a normal distribution with a mean of 0 and a standard deviation of 0.2 but with the probability of values below 0 set to 0 (i.e., a half-normal distribution). That is, H 1 was ''true mean d 0 slightly above zero, with larger d 0 having smaller probabilities and d 0 > 0.4 being improbable"; i.e., using the notation from Dienes (2015) we used a B H(0,0.2) to specify H1.…”