Spatial location does not consistently constrain perceptual learning in speech

Abstract

Recent research showed selectivity of perceptual learning in speech to linguistic variables and non-linguistic variables. With regard to the latter Keetels et al. (2016) reported that perceptual learning for one spatial location does not fully generalize to another. This spatial selectivity has been suggested to indicate that learning may target non-linguistic representations. We test whether spatial selectivity is a general property of perceptual learning or whether it is related to specific design choices, such as using a single nonword throughout the study. Therefore, we aimed to replicate spatial selectivity with a paradigm that makes use of a larger set of word and nonword stimuli. However, in three experiments, one in-person and two web-based, no effect of spatial selectivity was observed. A Bayesian analysis suggests that the null hypothesis is better supported by the data than the alternative hypothesis based on the previously reported effect size. Repercussions for the debate about pre-lexical representations in speech processing are discussed.