Disentangling Genuine Semantic Stroop Effects in Reading from Contingency Effects: On the Need for Two Neutral Baselines

Abstract

The automaticity of reading is often explored through the Stroop effect, whereby color-naming is affected by color words. Color associates (e.g., “sky”) also produce a Stroop effect, suggesting that automatic reading occurs through to the level of semantics, even when reading sub-lexically (e.g., the pseudohomophone “skigh”). However, several previous experiments have confounded congruency with contingency learning, whereby faster responding occurs for more frequent stimuli. Contingency effects reflect a higher frequency-pairing of the word with a font color in the congruent condition than in the incongruent condition due to the limited set of congruent pairings. To determine the extent to which the Stroop effect can be attributed to contingency learning of font colors paired with lexical (word-level) and sub-lexical (phonetically decoded) letter strings, as well as assess facilitation and interference relative to contingency effects, we developed two neutral baselines: each one matched on pair-frequency for congruent and incongruent color words. In Experiments 1 and 3, color words (e.g., “blue”) and their pseudohomophones (e.g., “bloo”) produced significant facilitation and interference relative to neutral baselines, regardless of whether the onset (i.e., first phoneme) was matched to the color words. Color associates (e.g., “ocean”) and their pseudohomophones (e.g., “oshin”), however, showed no significant facilitation or interference relative to onset matched neutral baselines (Experiment 2). When onsets were unmatched, color associate words produced consistent facilitation on RT (e.g., “ocean” vs. “dozen”), but pseudohomophones (e.g., “oshin” vs. “duhzen”) failed to produce facilitation or interference. Our findings suggest that the Stroop effects for color and associated stimuli are sensitive to the type of neutral baseline used, as well as stimulus type (word vs. pseudohomophone). In general, contingency learning plays a large role when repeating congruent items more than incongruent items, but appropriate pair-frequency matched neutral baselines allow for the assessment of genuine facilitation and interference. Using such baselines, we found reading processes proceed to a semantic level for familiar words, but not pseudohomophones (i.e., phonetic decoding). Such assessment is critical for separating the effects of genuine congruency from contingency during automatic word reading in the Stroop task, and when used with color associates, isolates the semantic contribution.

Disentangling semantic and response learning effects in color-word contingency learning

“…Crucially, we had to make sure in this experiment that no further learning of the correct pair took place within the Stroop task. In fact, there is reliable evidence that the congruency effect in the manual Stroop task is partially due to word-response associations learned during the experiment itself ([15, 16] with color naming). This is because, in the typical four-color Stroop experiment with 50% congruent and 50% incongruent trials, each color word appears three times as often in its congruent print color as in either of the three incongruent print colors [17, 18].…”

Evidence against conflict monitoring and adaptation: An updated review

“…It may, of course, still be fair to say that the conflict-monitoring account must predict a much stronger interaction between congruency and PC, as the (large) interference effect for incongruent trials should be more inflated than the (small) facilitation effect for congruent trials (for a review, seeMacLeod, 1991; also related,Lorentz et al, 2016), so a (roughly) additive pattern is more problematic for this view.3 A just-significant one-tailed test was reported, but one-tailed tests are generally inappropriate(Lombardi & Hurlbert, 2009;Ruxton & Neuhauser, 2010), especially in cognition research.Psychon Bull Rev (2019) 26:753-771…”

Lexical processing of Chinese sub-character components: Semantic activation of phonetic radicals as revealed by the Stroop effect

“…Note that this automatic semantic activation is more in depth than mere lexical activation from recognizing the orthography of the radicals; in Lorentz et al . 18 , they also found Stroop effects in color associative words, suggesting that the Stroop effect is not just a product of lexical activation. This is also confirmed in our Experiment 4 where Associative-Radical condition also gave rise to the Stroop effect.…”

“…In practice, however, if the activation of the phonetic radical’s semantic information has become unavoidable, it may simply be obligatory despite the unwanted interference. The Stroop paradigm we used in this study has an advantage over other paradigms in tackling this issue: a Stroop effect indicates automatic semantic activation 17 , 18 , 62 , since the task at hand (i.e., report the font color) is irrelevant to the semantics of the characters/radicals. Therefore, the Stroop effect caused by an invalid phonetic radical, in the sense that neither its pronunciation nor its meaning provides cues to the character, reveals the indispensable nature of its semantic activation.…”

“…Also commonly observed is a facilitation effect in which naming the color of a congruent word (e.g., blue written in blue) is faster than naming the color of the neutral control, though this effect is usually not as robust or consistent as the interference effect 16 . The interference and facilitation effects have been taken as evidence for unavoidable word processing up to semantic level 17 , 18 and can thus be exploited to investigate the question of whether phonetic radicals are also semantically processed in a compound character.…”