The involvement of reading processes and synesthetic color experiences during the classical and synesthesia Stroop task

Both synesthetes and non-synesthetes commonly report orthography-based letter-color associations (e.g., B is blue). This study examined whether reading processes can confound results on the synesthesia Stroop by comparing 18 synesthetes and 18 non-synesthetes using full color words and their initial letters. Critically, congruent stimuli were based on orthography (e.g., R in red) while clashing with synesthetes’ color experiences (e.g., R perceived as yellow). Both groups showed congruency effects in the color-naming task for full color words and their initial letters. Notably, synesthetes showed reduced interference for full color words compared to initial letters over time, suggesting a strategy to avoid reading-based interference for full color words. These findings highlight the need to control for orthographic cueing in synesthesia Stroop paradigms, as such associations can mimic true synesthetic effects. The study deepens our understanding of how reading processes interact with synesthetic experiences during the Stroop task and its synesthesia variation.