The within-language Stroop superiority effect extends to newly learned pseudowords.

Limited previous research has investigated how the size of the Stroop interference effect varies depending on level of proficiency in newly learned colour pseudowords. The experiments presented here add to the literature by investigating how the size of Stroop interference varies for two sets of newly learned colour pseudowords, one set is orthographically similar to a set of English colour words (e.g. Red-Rop) and the other is orthographically dissimilar (Red – Janko). In Experiment One, the Similar and Dissimilar pseudoword sets were assessed using a between-language Stroop paradigm whereas in Experiment Two the pseudoword sets were assessed using a within-language paradigm. Results show that following a very short training period (20 trials) a Stroop interference effect was observed in both experiments, with the size of the interference greater for the within-language paradigm (Experiment Two) compared to the between-language paradigm. The relative differences in interference between Experiment One and Two indicate that orthographic overlap between target and distractor stimuli in the Stroop task modulates the size of Stroop interference even when the two languages use the same script and following a short period of training/low level of familiarity with the pseudoword sets.