Flanking letter effects: a replication and extension with non-letter flankers

In a flanking letters lexical decision experiment, we replicated the seminal findings of (Dare, N., & Shillcock, R. (2013). Serial and parallel processing in reading: Investigating the effects of parafoveal orthographic information on non-isolated word recognition. Quarterly Journal of Experimental Psychology, 66(3), 487–504. https://doi.org/10.1080/17470218.2012.703212) that have recently been called into question. In this task, central targets are flanked by letters that could be related to the target or not. Participants performed a lexical decision task on central targets. The findings in question are the fact that switched flankers (e.g. CK ROCK RO) facilitate processing of the central target word (ROCK) to the same extent as repeated (intact) flankers (e.g. RO ROCK CK). In this study we provide a further replication of the findings of Dare and Shillcock, and we introduce a non-letter flanker condition. This condition revealed that unrelated letter flankers (i.e. flankers composed of letters that are not present in the target) interfere with target processing compared with non-letter flankers. Therefore, orthographically related flankers alleviate this overall interference driven by the mere presence of flanking letters.