SingleMALD: Investigating practice effects in auditory lexical decision

We present SingleMALD, a large-scale auditory lexical decision study in English with a fully crossed design. SingleMALD is freely available and includes over 2 million trials in which 40 native speakers of English responded to over 26,000 different words and over 9000 different pseudowords, each in 67 balanced sessions. SingleMALD features a large number of responses per stimulus, but a smaller number of participants, thus complementing the Massive Auditory Lexical Decision (MALD) dataset which features many listeners but fewer responses per stimulus. In the present report, we also use SingleMALD data to explore how extensive testing affects performance in the auditory lexical decision task. SingleMALD participants show signs of favoring speed over accuracy as the sessions unfold. Additionally, we find that the relationship between participant performance and two lexical predictors - word frequency and phonological neighborhood density - changes as sessions unfold, especially for certain lexical predictor values. We note that none of the changes are drastic, indicating that data collected from participants that have been extensively tested is usable, although we recommend accounting for participant experience with the task when performing statistical analyses of the data.