The acronym superiority effect

Abstract

The visual world is replete with noisy, continuous, perceptually variant linguistic information, which fluent readers rapidly translate from percept to meaning. What are the properties the language comprehension system uses as cues to initiate lexical/semantic access in response to some, but not all, orthographic strings? In the behavioral, electromagnetic, and neuropsychological literatures, orthographic regularity and familiarity have been identified as critical factors. Here, we present a study in the Reicher-Wheeler tradition that manipulates these two properties independently through the use of four stimulus categories: familiar and orthographically regular words, unfamiliar but regular pseudowords, unfamiliar illegal strings, and familiar but orthographically illegal acronyms. We find that, like letters in words and pseudowords, letters in acronyms enjoy an identification benefit relative to similarly illegal, but unfamiliar strings. This supports theories of visual word recognition in which familiarity, rather than orthographic regularity, plays a critical role in gating processing.

Figure 1

Data from Laszlo and Federmeier (2007). As can be seen in panel A, N400 repetition effect size for words, pseudowords, and familiar acronyms is similar (does not differ statistically, though the effect for acronyms is numerically larger than that for words or pseudowords), whereas ERP amplitude in the N400 window does not change with repetition of unfamiliar illegal strings. Repetition effect sizes are plotted negative up, on the y-axis. As can be seen in panel B, single-presentation N400 amplitude for words and pseudowords, which are regular, differs from single-presentation N400 amplitude for familiar acronyms and illegal strings, which are not. Error bars represent the standard error of the means.

Figure 2

Mean percentage letter identification accuracy collapsed across Experiments 1–3 for words, pseudowords, acronyms, and illegal strings, as well as breakdown of illegal string performance by experiment. Performance is statistically best for words, then pseudowords, and then acronyms, with performance being worst for illegal strings. Performance is identical on all three categories of illegal strings. Error bars represent the standard error of the means.