The Effect of Automatic and Controlled Processing Metaphorical Sentences on the N400: An Event Related Potentials Study

Faculty Mentor(s)

Dr. Gwenda Schmidt-Snoek

Document Type


Event Date



We compared automatic and controlled processing of metaphors using literal and metaphorical sentences, a varied inter-stimulus interval (ISI) and related and unrelated word pairs. To assess the difference between automatic and controlled processing, we manipulated the ISI, which was either 100 ms (short) or 1400 ms (long). Previous research has shown that an ISI of 100 ms elicits automatic processing while an ISI of 1400 ms elicits controlled processing. Stimuli were literal sentences (The penetrating needle was painful) or metaphorical sentences (The principal’s eyes were knives) paired with a related word (pierce) or unrelated word (rosy). Literal sentences paired with related words were the control sentences. We examined the differences using event-related potentials (ERP) derived from an electroencephalogram (EEG), which measures electrical activity at the scalp. The dependent measure was the amplitude of the N400, a negative waveform that occurs approximately 400 ms after the presentation of the stimulus. A larger N400 amplitude indicates greater difficulty in understanding the semantic context of the target word stimulus. We hypothesized that metaphorical sentences with an ISI of 1400 ms will have a larger N400 than literal sentences with an ISI of 100 ms because both controlled processing and processing of metaphors require greater cognitive effort. These findings will help us understand the differences in automatic versus controlled processing of figurative language in college controls. We plan to extend this study to participants with autism in order to better understand the literal bias of autism spectrum disorder.


This research was supported in part by Howard Hughes Medical Institute Research Scholars Award to Lauren Janness, Howard Hughes Medical Institute Faculty Development Research Award to Dr. Schmidt-Snoek, and Psychology Department funds.

This document is currently not available here.