The N400 as a snapshot of interactive processing: Evidence from regression analyses of orthographic neighbor and lexical associate effects


  • Sarah Laszlo,

    1. Department of Psychology, Carnegie Mellon University, Pittsburgh, Pennsylvania
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  • Kara D. Federmeier

    1. Department of Psychology, University of Illinois at Urbana Champaign, Urbana, Illinois
    2. Program in Neuroscience, University of Illinois at Urbana Champaign, Urbana, Illinois
    3. Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana Champaign, Urbana, Illinois
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  • The authors wish to acknowledge B. Armstrong, B. Gonsalves, C. Lee, K. Mathewson, G. Miller, D. Plaut, and E. Wlotko for insightful discussion of the single item data set, as well numerous research assistants for their efforts in data collection and processing—especially P. Anaya, H. Buller, and C. Laguna. This research was supported by National Institute of Mental Health Training grant T32 MH019983 to Carnegie Mellon University, which supported SL, and NIA grant AG26308 to KDF.

Address correspondence to: Sarah Laszlo, Carnegie Mellon University, 5000 Forbes Ave, Baker Hall 254T, Pittsburgh, PA 15213. E-mail:


Linking print with meaning tends to be divided into subprocesses, such as recognition of an input's lexical entry and subsequent access of semantics. However, recent results suggest that the set of semantic features activated by an input is broader than implied by a view wherein access serially follows recognition. EEG was collected from participants who viewed items varying in number and frequency of both orthographic neighbors and lexical associates. Regression analysis of single item ERPs replicated past findings, showing that N400 amplitudes are greater for items with more neighbors, and further revealed that N400 amplitudes increase for items with more lexical associates and with higher frequency neighbors or associates. Together, the data suggest that in the N400 time window semantic features of items broadly related to inputs are active, consistent with models in which semantic access takes place in parallel with stimulus recognition.