Phonotactic constraint violations in German grammar are detected automatically in auditory speech processing: A human event-related potentials study JOHANNA STEINBERG, a,c HUBERT TRUCKENBRODT, b and THOMAS JACOBSEN c a Institute of Psychology, University of Leipzig, Leipzig, Germany b Centre for General Linguistics (ZAS), Berlin, Germany c Experimental Psychology Unit, Helmut Schmidt University/University of the Federal Armed Forces, Hamburg, Germany Abstract In this human ERP study, effects of language-specific phonotactic restrictions on automatic auditory speech processing were investigated by means of the dorsal fricative assimilation (DFA) that is obligatory in German grammar. Using a multiple passive oddball paradigm, we studied the deviance-related processing of phonotactically ill-formed strings violating DFA. Eight VC-syllables were created by exhaustively combining the vowels [ʏ œ ʊ ɔ] and the dorsal fricatives [ç x], resulting in four well-formed and four ill-formed stimuli that were contrasted in oddball blocks with changing probabilities of occurrence. Only the ill-formed deviants elicited a negative ERP deflection maximal at about 100 msec after the onset of the fricative. This negativity is considered to reflect a phonotactic evaluation process requiring the activation of implicit phonotactic knowledge from long-term memory and resulting in the automatic detection of a DFA violation. Descriptors: Event-related potential (ERP), Mismatch negativity (MMN), Speech perception, Phonotactic constraints In recent years, phonological knowledge has become a frequently studied research topic in cognitive neuroscience. Electrophysio- logical measures such as the Mismatch Negativity (MMN) event- related potential (ERP) component have been successfully ap- plied to investigate the mental organization of phonological knowledge and its involvement in different speech processing stages (for reviews, see Na¨ a¨ ta¨ nen, 2001; Na¨ a¨ ta¨ nen, Paavilainen, Rinne, & Alho, 2007; Shtyrov & Pulvermu¨ ller, 2007). This study aims at adding to this knowledge by investigating the impact of an abstract phonotactic restriction in German grammar on early automatic speech processing. MMN reflects a preattentive memory-based mechanism de- tecting any violation of an expectancy created by the regularity of the preceding acoustic stimulation (Na¨a¨ ta¨nen, 1992; Na¨ a¨ ta¨nen, Gaillard, & Ma¨ntysalo,1978; Na¨a¨ta¨nen & Winkler, 1999; Win- kler, 2007). Usually, MMN is elicited by infrequently occurring auditory events (deviants) whose representation mismatches the representation of the regularities extracted from frequently re- peated standard stimuli. Since MMN is sensitive to contents of the long-term memory and because the underlying mechanism operates nonvolitionally, the MMN can be used to investigate what phonological information is accessed when sounds are not in the focus of attention. Phonological knowledge of a native speaker includes lan- guage-specific sounds (phonemes) and abstract principles regu- lating the co-occurrence of phonemes in sound sequences. The latter, commonly referred as phonotactic restrictions, are as- sumed to be represented independently of the phoneme inventory and to not be included in the entries of the mental lexicon (de Lacy, 2007; Kenstowicz, 1994). Phonotactic restrictions function as well-formedness conditions in speech comprehension. By hy- pothesis, they enable us to distinguish categorically between meaningless but possible sound sequences (pseudowords) and impossible, i.e., ungrammatical structures (nonwords) in a cer- tain language (Chomsky, 1988; Chomsky & Halle, 1991). Here, we used MMN to investigate the preattentive process- ing of categorical knowledge about phonotactic restrictions by presenting irreparably ill-formed speech material. As such, our approach differs from studies that investigate the impact of fac- ultative phonological variation. Such research has been done, for example, by Mitterer and Blomert (2003) and more recently by Tavabi, Elling, Dobel, Pantev, and Zwitzerlood (2009) who in- vestigated the effects of contextual appropriateness of optional nasal place assimilations on automatic speech processing. Both studies inter alia found that stimulus contrasts bearing The authors are grateful to Mariam Hartinger, Mira Mu¨ ller, Anja Roye, Annekathrin Weise, Jo¨ rg Dreyer, and Andreas Widmann for help in various matters, and to an anonymous reviewer for helpful comments on an earlier version of this article. This work was supported by the German Research Foundation (Priority Programme 1234 grant JA1009/ 10-1 to T.J. and H.T.). Address correspondence to: Johanna Steinberg, Institute of Psychol- ogy, University of Leipzig, Seeburgstrasse 14–20, D-04103 Leipzig, Ger- many. E-mail: j.steinberg@uni-leipzig.de Psychophysiology, 48 (2011), 1208–1216. Wiley Periodicals, Inc. Printed in the USA. Copyright r 2011 Society for Psychophysiological Research DOI: 10.1111/j.1469-8986.2011.01200.x 1208