From Real-Time Measures to Real World Differences New [and Old] Statistical Approaches to Individual Differences in Real-Time Language Processing
Bob McMurray, Jacob Oleson, Ethan Kutlu · 2024
In the last 30 years, the Visual World Paradigm has rapidly become a dominant experimental paradigm for understanding real-time language processing. Part of this derives from the rich visualizations of the millisecond-by-millisecond timecourse of language processing that it offers. While the field has converged on strong statistical approaches for this in experimental paradigms, a great deal of recent work has sought to apply the Visual World Paradigm in individual differences paradigms to examine factors such as development and aging, multi-lingualism and various types of communicative and cognitive disorders. However, sophisticated individual differences work must confront issues of collinearity and co-morbidity among predictor variable, and often seek to examine more than just a simple correlation with some portion of the timecourse of processing. We argue that existing statistical and methodological approaches are unsuited to this. Instead, we argue that analysis should start by developing a quantitative “profile” of processing that can be captured in a small number of variables. These can then be used in more sophisticated regressions like hierarchical regression, commonality analysis and mediation analysis which can unpack shared and unique variance, and test multiple causal pathways. We illustrate this with tutorials based on our own work on hearing loss, development and language disorders that illustrate how these approaches can provide greater insight into individual differences.