• Event-related potential (ERP);
  • Mismatch negativity (MMN);
  • Speech perception;
  • Phonotactic constraints


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 inline image and the dorsal fricatives inline image, 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.