Validity of an eyetracking method for capturing auditory-visual cross-format semantic priming.

INTRODUCTION: Semantic priming paradigms are important for understanding lexical-semantic processing and the nature of linguistic deficits accompanying language performance in neurologically impaired individuals such as people with aphasia. Reaction-time-(RT)-based traditional semantic priming tasks entail potential confounds, especially problematic when applied to people with aphasia, who may have concomitant neurocognitive challenges that limit task performance. Some of these confounds include requirements of following complex instructions, making metalinguistic judgments, and using speech or limb-based motor actions to indicate overt responses. Eyetracking methods have great potential for avoiding some of these confounds. We tested the validity of an eyetracking method in capturing semantic priming in an auditory-visual cross-format priming paradigm (auditory word prime-visual image target).

METHOD: A total of 72 neurologically unimpaired adults participated in two phases: a stimulus development phase using traditional priming (n = 32) and an experimental eyetracking phase (n = 40). Each phase included two conditions, representing distinct levels of prime-target semantic relatedness: unrelated and related. Mean RT data from the traditional priming (stimuli development) phase guided image selection for the eyetracking experiment. Eyetracking indices of fixation duration and latency of fixation were recorded to capture semantic priming in the eyetracking experiment.

RESULTS: Eye fixation data indicated that images related to auditory primes were attended to earlier and attracted significantly greater visual attention than unrelated images. These results mirrored RT data from the traditional priming method, which showed faster RT latencies and more accurate naming performance for related images than for unrelated images.

CONCLUSIONS: Results support the validity of eyetracking indices of semantic priming and offer a robust testing protocol for future studies in this line of research. Current clinical relevance for people with aphasia is highlighted. Further empirical testing of the psychometric properties of the eyetracking measures in various semantic priming contexts is recommended.