Arild Hestvik

Mismatch negativity arises from the construction of a memory trace encoding regularities extracted from auditory stimuli in an oddball paradigm. A previous study argued that when phonetic standards are varied within the limits of a phoneme category (i.e., the mental representation of speech sounds), the auditory cortex retrieves a discrete phoneme representation from long‐term memory and uses it as the memory trace for deviance detection. This claim has motivated a body of work using varying‐standards paradigms to probe phonological underspecification. A strong version of this claim predicts that varying standards should eliminate mismatch negativity when both standards and deviants belong to the same phoneme category, because the memory trace is purely phonemic and lacks acoustic detail. We tested this prediction in three electroencephalography experiments using English /t/ varying in voice onset time. In Experiment 1, a within‐category deviant with a long voice onset time elicited a robust mismatch negativity even when standards varied across shorter values, contrary to the prediction of an exclusively symbolic phoneme‐based memory trace. Experiments 2 and 3 further examined whether the within‐category mismatch response reflects long‐term memory representations of phonetic realizations associated with the evoked phoneme category or listeners' ad hoc representation of the stimulus distribution. The weight of the evidence suggests that the within‐category mismatch negativity in the varying‐standards paradigm reflects sensitivity to the statistical structure of the stimulus physical properties, rather than exclusive access to abstract phonological categories. Findings invite reinterpretation of studies using varying‐standards paradigm in light of encoding of stimulus statistics.

A critical part of the Mismatch Negativity (MMN) mechanism is the construction of a memory trace encoding regularities extracted from the stimuli in an oddball paradigm. In an influential study, Phillips et al. (2000) argued that varying phonetic standards within the limits of a phoneme category prompts the auditory cortex to access representations of the “discrete phonological categories” (p. 1050), resulting in a mismatch response by comparing the deviant stimulus to an abstract, evoked category representation. The present study tested the strongest interpretation of this claim–namely, that the phoneme itself is retrieved from long-term memory and serves as the memory trace for the stimulus sequence. This interpretation has been the implicit, if not explicit, basis for a body of research employing the varying-standards paradigm to probe phonological underspecification. However, while previous research has focused on contrasts between distinct phonemes, we examined a previously untested prediction of this interpretation: that varying the standards should eliminate the MMN when the contrast is within a single phoneme category. Contrary to this prediction, we observed a mismatch negativity to a within-category deviant even when standards were varied. In two additional experiments we further examined whether the within-category MMN is from long-term memory representations of phonetic realizations of the phoneme, or from listeners constructing ad hoc statistical representations of the stimulus distribution. The weight of the evidence suggests that the within-category MMN observed with varying standards reflects sensitivity to the statistical structure of the stimuli, rather than activation of abstract phonological categories.

Previous ERP studies showed that false affirmative sentences elicited a larger N400 than their true versions, but they found the reverse pattern when the sentences were of negative form as if N400 was blind to negation. This negation-blind N400 pattern arguably constituted evidence for two-step accounts of negation processing: When processing negative sentences, a comprehender first computes an internal proposition and then considers the negation. However, the prior studies were confounded by a lexical priming relation between subject and object. Therefore, it was an open question whether or not the observed ERP pattern really reflected the two-step process. To tackle this question, we conducted an ERP experiment, using size-comparison statements where subjects and objects are semantically unrelated. This design allowed us to remove the priming confound. We predicted that if the previous negation-blind N400 pattern is unrelated to lexical priming, it would be replicated; if not, it would disappear. The result was consistent with the second prediction. This suggests that the previously observed negation-blind N400 pattern does not necessarily constitute evidence for two-step accounts of negation processing.

Editorial: Phonological Representations and Mismatch Negativity Asymmetries

Corrigendum: Developmental Language Disorder as Syntactic Prediction Impairment

This paper investigates how late L2 learners resolve filler-gap dependencies (FGD) in real-time and how proficiency and working memory (WM) modulate their brain responses in an event-related potential (ERP) experiment. A group of intermediate to highly proficient Mandarin Chinese learners of English listened to sentences such as “The zebra that the hippo kissed *the camel on the nose ran far away,” in which the extra noun phrase “the camel” created a ‘filled-gap’ effect. The results show that although L2 behavioral responses are comparable to native speakers and are positively correlated with proficiency and WM span, the brain responses to the filled gap are qualitatively different. Importantly, L2 processing patterns did not become more nativelike with higher proficiency levels or greater WM capacity. Specifically, while the native speakers exhibited a P600 typically observed for syntactic violations and repair, the L2 group produced a prefrontal-central positivity. Similar ERPs have previously been reported to reflect domain-general attentional and non-structural-based processes, suggesting that the L2 group has a reduced sensitivity to structural requirements for gap positing in the online resolution of FGDs. Our findings are discussed in light of various proposals accounting for L1-L2 processing differences, including the Shallow Structure Hypothesis.

This study examined how discriminability and prototypicality of nonnative phones modulate the amplitude of the Mismatch Negativity (MMN) event-related brain potential. We hypothesized that if a frequently occurring (standard) stimulus is not prototypical to a listener, a weaker predictive memory trace will be formed and a smaller MMN will be generated for a phonetic deviant, regardless of the discriminability between the standard and deviant stimuli. The MMN amplitudes of Japanese speakers hearing the English vowels /æ/ and /ɑ/ as standard stimuli and /ʌ/ as a deviant stimulus in an oddball paradigm were measured. Although the English /æ/-/ʌ/ contrast was more discriminable than the English /ɑ/-/ʌ/ contrast for Japanese speakers, when Japanese speakers heard the /æ/ standard stimulus (i.e., less prototypical as Japanese /a/) and the /ʌ/ deviant stimulus, their MMN amplitude was smaller than the one elicited when they heard /ɑ/ as a standard stimulus (i.e., more prototypical as Japanese /a/) and /ʌ/ as a deviant stimulus. The prototypicality of the standard stimuli in listeners’ phonological representations modulates the MMN amplitude more robustly than does the discriminability between standard and deviant stimuli.

An emerging body of studies has claimed that exposure to phonetically varying speech sounds results in strictly phonological representations of speech sounds by the brain’s auditory prediction system (Cornell et al., 2011 Cornell, S. A. , Lahiri, A. , & Eulitz, C. (2011). “What you encode is not necessarily what you store”: Evidence for sparse feature representations from mismatch negativity. Brain Research, 1394, 79–89. https://doi.org/10.1016/j.brainres.2011.04.001 [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] ; Eulitz & Lahiri, 2004 Eulitz, C. , & Lahiri, A. (2004). Neurobiological evidence for abstract phonological representations in the mental lexicon during speech recognition. Journal of Cognitive Neuroscience, 16(4), 577–583. https://doi.org/10.1162/089892904323057308 [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] ; Hestvik et al., 2020 Hestvik, A. , Shinohara, Y. , Durvasula, K. , Verdonschot, R. G. , & Sakai, H. (2020). Abstractness of human speech sound representations. Brain Research, 1732(January), 146664. https://doi.org/10.1016/j.brainres.2020.146664 [Crossref], [PubMed] , [Google Scholar] ; Hestvik & Durvasula, 2016 Hestvik, A. , & Durvasula, K. (2016). Neurobiological evidence for voicing underspecification in English. Brain and Language, 152, 28–43. https://doi.org/10.1016/j.bandl.2015.10.007 [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] ; Phillips et al., 2000 Phillips, C. , Pellathy, T. , Marantz, A. , Yellin, E. , Wexler, K. , Poeppel, D. , McGinnis, M. , & Roberts, T. (2000). Auditory cortex accesses phonological categories: An MEG mismatch study. Journal of Cognitive Neuroscience, 12(6), 1038–1055. https://doi.org/10.1162/08989290051137567 [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] ). We test this claim by measuring mismatch negativity (MMN) to a subcategorical contrast with two sets of phonetically varying standards. When controlling for non-prediction related contributors to the MMN, we find a mismatch in a late time window. However, the mismatch effect is only significant for participants who perceived the contrast as an across-category contrast (/t/ vs /d/). Additionally, we find no modulation of mismatch amplitude predicated on phonetic distance between standards and deviant. Taken together, this indicates that the prediction generated by the auditory system in response to phonetically varying speech sounds is indeed phonological and lacks any fine-grained phonetic content.

We provide evidence that children with Developmental Language Disorder (DLD) are impaired in predictive syntactic processing. In the current study, children listened passively to auditorily-presented sentences, where the critical condition included an unexpected “filled gap” in the direct object position of the relative clause verb. A filled gap is illustrated by the underlined phrase in “The zebra that the hippo kissed the camel on the nose…”, rather than the expected “the zebra that the hippo kissed [e] on the nose”, where [e] denotes the gap. Brain responses to the filled gap were compared to a control condition using adverb-relative clauses with identical substrings: “The weekend that the hippo kissed the camel on the nose [e]…”. Here, the same noun phrase is not unexpected because the adverb gap occurs later in the structure. We hypothesized that a filled gap would elicit a prediction error brain signal in the form of an early anterior negativity, as we have previously observed in adults. We found an early (bilateral) anterior negativity to the filled gap in a control group of children with Typical Development (TD), but the children with DLD exhibited no brain response to the filled gap during the same early time window. This suggests that children with DLD fail to predict that a relativized object should correspond to an empty position after the relative clause verb, suggesting an impairment in predictive processing. We discuss how this lack of a prediction error signal can interact with language acquisition and result in DLD.