The role of orthographic neighbourhood effects in lateralized lexical decision: A replication study and meta-analysis.

Abstract

Orthographic neighbourhood size (N) effects differ under lateralized presentation. Evidence suggests a facilitatory effect of N in the right hemisphere. However, the effect of N in the left hemisphere remains controversial: it may have a weaker facilitative role or it may even be inhibitory. In a pre-registered online experiment, we aimed to replicate the interaction between N and visual field and provide support for an inhibitory effect of N in the left hemisphere. We subsequently conducted a pre-registered systematic review and meta-analysis to synthesise the available evidence and determine the direction of N effects across hemispheres. Based on the evidence, it would seem the effect is inhibitory in the left hemisphere. Furthermore, the size of the N effect is considerably smaller in the left hemisphere. Both studies revealed vast heterogeneity between participants and studies, and we consider the implications of this for future work.

Lexical processing across the visual field

“…Information presented in the left visual field (LVF) that is projected to the right hemisphere may be initially processed less efficiently (e.g., by serial orthographic analysis; Brand et al, 1983;Ellis et al, 1988;Eng & Hellige, 1984), and must be transferred to the left hemisphere via the corpus callosum, resulting in slower processing and/or some loss in fidelity. Consistent with this account, evidence that orthographic neighborhood (N) effects are larger and facilitatory in the LVF and weaker and inhibitory in the RVF (see Parker et al, 2021, for a review) may reflect stronger top-down activation from the word level within an interactive system for letter strings in the LVF. Words in the LVF would then suffer from slower and more error-prone bottom-up processing due to interhemispheric transfer.…”

“…First, the experiments were conducted entirely online, limiting experimental control over participants' viewing conditions, hardware, operating system, or browser, which all can potentially affect timing performance. However, recent studies have demonstrated comparable performance in online and laboratory studies of lateralized word processing (Mills et al, 2022;Parker et al, 2021;Veldre et al, 2022) and masked priming (Angele et al, 2022), suggesting that online data collection is suitable for paradigms requiring precise timing.…”