Publications

Abstract

Spoken language is one of the most compact and structured ways to convey information. The linguistic ability to structure individual words into larger sentence units permits speakers to express a nearly unlimited range of meanings. This ability is rooted in speakers’ knowledge of syntax and in the corresponding process of syntactic encoding. Syntactic encoding is highly automatized, operates largely outside of conscious awareness, and overlaps closely in time with several other processes of language production. With the use of positron emission tomography we investigated the cortical activations during spoken language production that are related to the syntactic encoding process. In the paradigm of restrictive scene description, utterances varying in complexity of syntactic encoding were elicited. Results provided evidence that the left Rolandic operculum, caudally adjacent to Broca’s area, is involved in both sentence-level and local (phrase-level) syntactic encoding during speaking.

Abstract

Following up on an earlier positron emission tomography (PET) experiment (Indefrey et al., 2001), we used a scene description paradigm to investigate whether a posterior inferior frontal region subserving syntactic encoding for speaking is also involved in syntactic parsing during listening. In the language production part of the experiment, subjects described visually presented scenes
using either sentences, sequences of noun phrases, or sequences of syntactically unrelated words. In the language comprehension part of the experiment, subjects were auditorily presented with the same kinds of utterances and judged whether they matched the visual scenes. We were able to replicate the previous finding of a region in caudal Broca s area that is sensitive to the complexity of
syntactic encoding in language production. In language comprehension, no hemodynamic activation differences due to syntactic complexity were found. Given that correct performance in the judgment task did not require syntactic processing of the auditory stimuli, the results suggest that the degree to which listeners recruit syntactic processing resources in language comprehension may be a function of the syntactic demands of the task or the stimulus material.

Abstract

The articles in this volume are the result of an invited conference entitled "The Earliest Stages of Language Learning" held at the Max Planck Institute for Psycholinguistics in Nijmegen, The Netherlands, in October 2009.

Abstract

In language comprehension a syntactic representation is built up even when the input is semantically uninterpretable. We report data on brain activation during syntactic processing, from an experiment on the detection of grammatical errors in meaningless sentences. The experimental paradigm was such that the syntactic processing was distinguished from other cognitive and linguistic functions. The data reveal that in syntactic error detection an area of the left dorsolateral prefrontal cortex, adjacent to Broca’s area, is specifically involved in the syntactic processing aspects, whereas other prefrontal areas subserve general error detection processes.

Abstract

The Abelson helper integration site 1 (AHI1) gene locus on chromosome 6q23 is among a group of candidate loci for schizophrenia susceptibility that were initially identified by linkage followed by linkage disequilibrium mapping, and subsequent replication of the association in an independent sample. Here, we present results of a replication study of AHI1 locus markers, previously implicated in schizophrenia, in a large European sample (in total 3907 affected and 7429 controls). Furthermore, we perform a meta-analysis of the implicated markers in 4496 affected and 18,920 controls. Both the replication study of new samples and the meta-analysis show evidence for significant overrepresentation of all tested alleles in patients compared with controls (meta-analysis; P = 8.2 x 10(-5)-1.7 x 10(-3), common OR = 1.09-1.11). The region contains two genes, AHI1 and C6orf217, and both genes-as well as the neighbouring phosphodiesterase 7B (PDE7B)-may be considered candidates for involvement in the genetic aetiology of schizophrenia.

Abstract

In order to separate the cognitive processes associated with phonological encoding and the use of a visual word form lexicon in reading, it is desirable to compare the processing of words presented in a visually familiar form with words in a visually unfamiliar form. Japanese Kana orthography offers this possibility. Two phonologically equivalent but visually dissimilar syllabaries allow the writing of, for example, foreign loanwords in two ways, only one of which is visually familiar. Familiarly written words, unfamiliarly written words, and pseudowords were presented in both Kana syllabaries (yielding six conditions in total) to participants during an fMRI measurement with a silent articulation task (Experiment 1) and a phonological lexical decision task (Experiment 2) using an event-related design. Consistent over two experimental tasks, the three different stimulus types (familiar, unfamiliar, and pseudoword) were found to activate selectively different brain regions previously associated with phonological encoding and word retrieval or meaning. Compatible with the predictions of the dual-route model for reading, pseudowords and visually unfamiliar words, which have to be read using phonological assembly, caused an increase in brain activity in left inferior frontal regions (BA 44/47), as compared to visually familiar words. Visually familiar and unfamiliar words were found to activate a range of areas associated with lexico-semantic processing more strongly than pseudowords, such as the left and right temporo-parietal region (BA 39/40), a region in the left middle/inferior temporal gyrus (BA 20/21), and the posterior cingulate (BA 31).

Abstract

The results of a self-paced reading study with German second language (L2) learners of Dutch showed that noun animacy affected the learners' on-line commitments when comprehending relative clauses in their L2. Earlier research has found that German L2 learners of Dutch do not show an on-line preference for subject–object word order in temporarily ambiguous relative clauses when no disambiguating material is available prior to the auxiliary verb. We investigated whether manipulating the animacy of the ambiguous noun phrases would push the learners to make an on-line commitment to either a subject- or object-first analysis. Results showed they performed like Dutch native speakers in that their reading times reflected an interaction between topichood and animacy in the on-line assignment of grammatical roles

Abstract

Initial lexical activation in typical populations is a direct reflection of the goodness of fit between the presented stimulus and the intended target. In this study, lexical activation was investigated upon presentation of polysyllabic pseudowords (such as procodile for crocodile) for the atypical population of dyslexic adults to see to what extent mismatching phonemic information affects lexical activation in the face of overwhelming support for one specific lexical candidate. Results of an auditory lexical decision task showed that sensitivity to phonemic mismatch was less in the dyslexic population, compared to the respective control group. However, the dyslexic participants were outperformed by their controls only for word-initial mismatches. It is argued that a subtle speech decoding deficit affects lexical activation levels and makes spoken word processing less robust against distortion.

Abstract

Background: There is evidence that, unlike in typical populations, initial lexical activation upon hearing spoken words in aphasic patients is not a direct reflection of the goodness of fit between the presented stimulus and the intended target. Earlier studies have mainly used short monosyllabic target words. Short words are relatively difficult to recognise because they are not highly redundant: changing one phoneme will often result in a (similar-sounding) different word. Aims: The present study aimed to investigate sensitivity of the lexical recognition system in aphasia. The focus was on longer words that contain more redundancy, to investigate whether aphasic adults might be impaired in deactivation of strongly activated lexical candidates. This was done by studying lexical activation upon presentation of spoken polysyllabic pseudowords (such as procodile) to see to what extent mismatching phonemic information leads to deactivation in the face of overwhelming support for one specific lexical candidate. Methods & Procedures: Speeded auditory lexical decision was used to investigate response time and accuracy to pseudowords with a word-initial or word-final phonemic mismatch in 21 aphasic patients and in an age-matched control group. Outcomes & Results: Results of an auditory lexical decision task showed that aphasic participants were less sensitive to phonemic mismatch if there was strong evidence for one particular lexical candidate, compared to the control group. Classifications of patients as Broca's vs Wernicke's or as fluent vs non-fluent did not reveal differences in sensitivity to mismatch between aphasia types. There was no reliable relationship between measures of auditory verbal short-term memory and lexical decision performance. Conclusions: It is argued that the aphasic results can best be viewed as lexical “overactivation” and that a verbal short-term memory account is less appropriate.

Abstract

Natural fast speech differs from normal-rate speech with respect to its temporal pattern. Previous results showed that word intelligibility of heavily artificially time-compressed speech could not be improved by making its temporal pattern more similar to that of natural fast speech. This might have been due to the extrapolation of timing rules for natural fast speech to rates that are much faster than can be attained by human speakers. The present study investigates whether, at a speech rate that human speakers can attain, artificially time-compressed speech is easier to process if its timing pattern is similar to that of naturally produced fast speech. Our first experiment suggests, however, that word processing speed was slowed down, relative to linear compression. In a second experiment, word processing of artificially time-compressed speech was compared with processing of naturally produced fast speech. Even when naturally produced fast speech is perfectly intelligible, its less careful articulation, combined with the changed timing pattern, slows down processing, relative to linearly time-compressed speech. Furthermore, listeners preferred artificially time-compressed speech over naturally produced fast speech. These results suggest that linearly time-compressed speech has both a temporal and a segmental advantage over natural fast speech.

Abstract

This study investigated the encoding of syllable boundary information during speech production in Dutch. Based on Levelt's model of phonological encoding, we hypothesized segments and syllable boundaries to be encoded in an incremental way. In a selfmonitoring experiment, decisions about the syllable affiliation (first or second syllable) of a pre-specified consonant, which was the third phoneme in a word, were required (e.g., ka.No canoe vs. kaN.sel pulpit ; capital letters indicate pivotal consonants, dots mark syllable boundaries). First syllable responses were faster than second syllable responses, indicating the incremental nature of segmental encoding and syllabification during speech production planning. The results of the experiment are discussed in the context of Levelt 's model of phonological encoding.

Abstract

Three experiments are reported that examined whether stem complexity plays a role in inflecting polymorphemic words in language production. Experiment 1 showed that preparation effects for words with polymorphemic stems are larger when they are produced among words with constant inflectional structures compared to words with variable inflectional structures and simple stems. This replicates earlier findings for words with monomorphemic stems (Janssen et al., 2002). Experiments 2 and 3 showed that when inflectional structure is held constant, the preparation effects are equally large with simple and compound stems, and with compound and complex adjectival stems. These results indicate that inflectional encoding is blind to the complexity of the stem, which suggests that specific inflectional rather than generic morphological frames guide the generation of inflected forms in speaking words.

Abstract

As people find their way through their environment, objects at navigationally relevant locations can serve as crucial landmarks. The parahippocampal gyrus has previously been shown to be involved in object and scene recognition. In the present study, we investigated the neural representation of navigationally relevant locations. Healthy human adults viewed a route through a virtual museum with objects placed at intersections (decision points) or at simple turns (non-decision points). Event-related functional magnetic resonance imaging (fMRI) data were acquired during subsequent recognition of the objects in isolation. Neural activity in the parahippocampal gyrus reflected the navigational relevance of an object's location in the museum. Parahippocampal responses were selectively increased for objects that occurred at decision points, independent of attentional demands. This increase occurred for forgotten as well as remembered objects, showing implicit retrieval of navigational information. The automatic storage of relevant object location in the parahippocampal gyrus provides a part of the neural mechanism underlying successful navigation.

Abstract

Kun kuuntelemme puhetta tai luemme tekstiä, alamme välittömästi rakentaa koherenttia tulkintaa. Toisin kuin lukemisessa, puheen havaitsemisessa kuulija voi harvoin kontrolloida nopeutta, jolla hänelle puhutaan. Huolimatta hyvin nopeasta syötteestä - noin 4-7 tavua sekunnissa - ihmiset kykenevät tulkitsemaan puhetta hyvin vaivattomasti. Lauseen ymmärtämisen tutkimuksessa selvitetäänkin, miten tällainen nopea ja useimmiten vaivaton tulkintaprosessi tapahtuu, mitkä kognitiiviset prosessit osallistuvat reaaliaikaiseen tulkintaan ja millaista informaatiota missäkin vaiheessa prosessointia ihminen käyttää hyväkseen johdonmukaisen tulkinnan muodostamiseksi. Tämä kappale on katsaus lauseen ymmärtämisen prosesseihin ja niiden tutkimukseen. Käsittelemme lyhyesti prosessointimalleja, aikuisten ja lasten kielen suhdetta, lauseen sisäisten ja välisten viittaussuhteiden tulkintaa ja sensorisen ympäristön sekä motorisen toiminnan roolia lauseiden tulkintaprosessissa.

Abstract

Discrete phonological phenomena form our conscious experience of language: continuous changes in pitch appear as distinct tones to the speakers of tone languages, whereas the speakers of quantity languages experience duration categorically. The categorical nature of our linguistic experience is directly reflected in the traditionally clear-cut linguistic classification of languages into tonal or non-tonal. However, some evidence suggests that duration and pitch are fundamentally interconnected and co-vary in signaling word meaning in non-tonal languages as well. We show that pitch information affects real-time language processing in a (non-tonal) quantity language. The results suggest that there is no unidirectional causal link from a genetically-based perceptual sensitivity towards pitch information to the appearance of a tone language. They further suggest that the contrastive categories tone and quantity may be based on simultaneously co-varying properties of the speech signal and the processing system, even though the conscious experience of the speakers may highlight only one discrete variable at a time.

Abstract

When listening to speech, we often benefit when also seeing the speaker talk. If this benefit is not domain-specific for speech, then the recognition of sung lyrics should likewise benefit from seeing the singer. Nevertheless, previous research failed to obtain a substantial improvement in that domain. Our study shows that this failure was not due to inherent differences between singing and speaking but rather to less informative visual presentations. By presenting a professional singer, we found a substantial audiovisual benefit of about 35% improvement for lyrics recognition. This benefit was further robust across participants, phrases, and repetition of the test materials. Our results provide the first evidence that lyrics recognition just like speech and music perception is a multimodal process.

Abstract

In the present study, we examined the distribution and processing of information over time in auditory and visual speech as it is used in unimodal and bimodal word recognition. English consonant—vowel—consonant words representing all possible initial consonants were presented as auditory, visual, or audiovisual speech in a gating task. The distribution of information over time varied across and within features. Visual speech information was generally fully available early during the phoneme, whereas auditory information was still accumulated. An audiovisual benefit was therefore already found early during the phoneme. The nature of the audiovisual recognition benefit changed, however, as more of the phoneme was presented. More features benefited at short gates rather than at longer ones. Visual speech information plays, therefore, a more important role early during the phoneme rather than later. The results of the study showed the complex interplay of information across modalities and time, since this is essential in determining the time course of audiovisual spoken-word recognition.

Abstract

Past research has demonstrated that infants can rapidly extract syllable distribution information from an artificial language and use this knowledge to infer likely word boundaries in speech. However, artificial languages are extremely simplified with respect to natural language. In this study, we ask whether infants’ ability to track transitional probabilities between syllables in an artificial language can scale up to the challenge of natural language. We do so by testing both 5.5- and 8-month-olds’ ability to segment an artificial language containing four words of uniform length (all CVCV) or four words of varying length (two CVCV, two CVCVCV). The transitional probability cues to word boundaries were held equal across the two languages. Both age groups segmented the language containing words of uniform length, demonstrating that even 5.5-month-olds are extremely sensitive to the conditional probabilities in their environment. However, either age group succeeded in segmenting the language containing words of varying length, despite the fact that the transitional probability cues defining word boundaries were equally strong in the two languages. We conclude that infants’ statistical learning abilities may not be as robust as earlier studies have suggested.

Abstract

Explanations in the domain of kinship can be sought on several different levels: Jones addresses online processing, as well as issues of origins and innateness. We argue that his framework can more usefully be applied at the levels of developmental and historical change, the latter especially. A phylogenetic approach to the diversity of kinship terminologies is most urgently required.

Abstract

In early Dutch learner varieties, there is no evidence of finiteness being a functional category. There is no V2nd: no correlation between inflectional morphology and movement. Initially, learners express the illocutive function of finiteness through the use of illocutive markers, with the non-use of an illocutive marker expressing the default illocutive function of assertion. Illocutive markers are functioning as adjuncts with scope over the predicate. Illocutive markers become re-analysed as functional elements.The driving force is the acquisition of the auxiliary verbs that occur with past participles. It leads to a reanalysis of illocutive markers as two separate elements: an auxiliary verb and a scope adverb. The (modal) auxiliary carries illocutive function. Lexical verb-argument structure (including the external argument) occurs within the domain of the auxiliary verb. The predicate as the focus constituent occurs within the domain of a scope adverb. This reanalysis establishes a position for the external argument within the domain of AUX. The acquisition of AUX causes the acquisition of a (hierarchical) structure with a complement as a constituent which represents an underlying verb-argument structure, a predicate as the domain of elements that are in focus, and an external (specifier) position as a landing site for elements with topic function.

Abstract

Gesture and speech are assumed to form an integrated system during language production. Based on this view, we propose the integrated‐systems hypothesis, which explains two ways in which gesture and speech are integrated—through mutual and obligatory interactions—in language comprehension. Experiment 1 presented participants with action primes (e.g., someone chopping vegetables) and bimodal speech and gesture targets. Participants related primes to targets more quickly and accurately when they contained congruent information (speech: “chop”; gesture: chop) than when they contained incongruent information (speech: “chop”; gesture: twist). Moreover, the strength of the incongruence affected processing, with fewer errors for weak incongruities (speech: “chop”; gesture: cut) than for strong incongruities (speech: “chop”; gesture: twist). Crucial for the integrated‐systems hypothesis, this influence was bidirectional. Experiment 2 demonstrated that gesture’s influence on speech was obligatory. The results confirm the integrated‐systems hypothesis and demonstrate that gesture and speech form an integrated system in language comprehension.

Abstract

When you compare the behavior of two different age groups which are trying to master the same sensori-motor or cognitive skill, you are likely to discover varying learning routes: different stages, different intervals between stages, or even different orderings of stages. Such heterogeneous learning trajectories may be caused by at least six different types of factors: (1) Initial state: the kinds and levels of skills the learners have available at the onset of the learning episode. (2) Learning mechanisms: rule-based, inductive, connectionist, parameter setting, and so on. (3) Input and feedback characteristics: learning stimuli, information about success and failure. (4) Information processing mechanisms: capacity limitations, attentional biases, response preferences. (5) Energetic variables: motivation, emotional reactions. (6) Final state: the fine-structure of kinds and levels of subskills at the end of the learning episode. This applies to language acquisition as well. First and second language learners probably differ on all six factors. Nevertheless, the debate between advocates and opponents of the Fundamental Difference Hypothesis concerning L1 and L2 acquisition have looked almost exclusively at the first two factors. Those who believe that L1 learners have access to Universal Grammar whereas L2 learners rely on language processing strategies, postulate different learning mechanisms (UG parameter setting in L1, more general inductive strategies in L2 learning). Pienemann opposes this view and, based on his Processability Theory, argues that L1 and L2 learners start out from different initial states: they come to the grammar learning task with different structural hypotheses (SOV versus SVO as basic word order of German).

Abstract

We outline an algorithm capable of generating varied but natural sounding sequences of argument NPs in subordinate clauses of German, a semi-free word order language. In order to attain the right level of output flexibility, the algorithm considers (1) the relevant lexical properties of the head verb (not only transitivity type but also reflexivity, thematic relations expressed by the NPs, etc.), and (2) the animacy and definiteness values of the arguments, and their length. The relevant statistical data were extracted from the NEGRA–II treebank and from hand-coded features for animacy and definiteness. The algorithm maps the relevant properties onto “primary” versus “secondary” placement options in the generator. The algorithm is restricted in that it does not take into account linear order determinants related to the sentence’s information structure and its discourse context (e.g. contrastiveness). These factors may modulate the above preferences or license “tertiary” linear orders beyond the primary and secondary options considered here.

Abstract

Two experimental results often reported in support of perceptual interpretations concerning the influence of set on perception are critically examined: (a) the relation between word frequency and recognition threshold, and (b) the so-called compromise reactions between set and stimulus, Alter elimination of certain methodological artifacts (e.g., introduction of a temporal forced-choice method instead of the ascending-limits method), both phenomena disappear; the influence of set on perception appears to be wholly a matter of response bias.

Abstract

Listeners cannot recognize highly reduced word forms in isolation, but they can do so when these forms are presented in context (Ernestus, Baayen, & Schreuder, 2002). This suggests that not all possible surface forms of words have equal status in the mental lexicon. The present study shows that the reduced forms are linked to the canonical representations in the mental lexicon, and that these latter representations induce reconstruction processes. Listeners restore suffixes that are partly or completely missing in reduced word forms. A series of phoneme-monitoring experiments reveals the nature of this restoration: the basis for suffix restoration is mainly phonological in nature, but orthography has an influence as well.

Abstract

Drozd's critique of Crain & Thornton's (C&T) (1998) book Investigations in Universal Grammar (IUG) raises many issues concerning theory and experimental design within generative approaches to language acquisition. I focus here on one of the strongest theoretical claims of the Modularity Matching Model (MMM): continuity of processing. For reasons different to Drozd, I argue that the assumption is tenuous. Furthermore, I argue that the focus of the MMM and the methodological prescriptions contained in IUG are too narrow to capture language acquisition.

Abstract

Usage-based approaches to language acquisition argue that children acquire the grammar of their target language using general-cognitive learning principles. The current paper reports on an experiment that tested a central assumption of the usage-based approach: argument structure patterns are connected to high frequency verbs that facilitate acquisition. Sixty children (N = 60) aged 4- and 6-years participated in a sentence recall/lexical priming experiment that manipulated the frequency with which the target verbs occurred in the finite sentential complement construction in English. The results showed that the children performed better on sentences that contained high frequency verbs. Furthermore, the children’s performance suggested that their knowledge of finite sentential complements relies most heavily on one particular verb – think, supporting arguments made by Goldberg [Goldberg, A.E., 2006. Constructions at Work: The Nature of Generalization in Language. Oxford University Press, Oxford], who argued that skewed input facilitates language learning.

Abstract

Two studies showed that adults who reported having an imaginary companion as a child differed from adults who did not on certain personality dimensions. The first yielded a higher mean on the Gough Creative Personality Scale for the group who had imaginary companions. Study 2 showed that such adults scored higher on the Achievement and Absorption subscales of Tellegen's Multidimensional Personality Questionnaire. The results suggest that some differences reported in the developmental literature may be observed in adults

Abstract

Pauses during continuous speech, particularly those that occur within clauses, are thought to reflect the planning of forthcoming verbal output. We used functional Magnetic Resonance Imaging (fMRI) to examine their neural correlates. Six volunteers were scanned while describing seven Rorschach inkblots, producing 3 min of speech per inkblot. In an event-related design, the level of blood oxygenation level dependent (BOLD) contrast during brief speech pauses (mean duration 1.3 s, SD 0.3 s) during overt speech was contrasted with that during intervening periods of articulation. We then examined activity associated with pauses that occurred within clauses and pauses that occurred between grammatical junctions. Relative to articulation during speech, pauses were associated with activation in the banks of the left superior temporal sulcus (BA 39/22), at the temporoparietal junction. Continuous speech was associated with greater activation bilaterally in the inferior frontal (BA 44/45), middle frontal (BA 8) and anterior cingulate (BA 24) gyri, the middle temporal sulcus (BA 21/22), the occipital cortex and the cerebellum. Left temporal activation was evident during pauses that occurred within clauses but not during pauses at grammatical junctions. In summary, articulation during continuous speech involved frontal, temporal and cerebellar areas, while pausing was associated with activity in the left temporal cortex, especially when this occurred within a clause. The latter finding is consistent with evidence that within-clause pauses are a correlate of speech planning and in particular lexical retrieval.

Abstract

Gesture is an integral part of face-to-face communication, and provides a rich area for cross-cultural comparison. “Locally-anchored spatial gestures” are gestures that are roughly oriented to the actual geographical direction of referents. For example, such gestures may point to a location or a thing, trace the shape of a path, or indicate the direction of a particular area. The goal of this task is to elicit locally-anchored spatial gestures across different cultures. The task follows an interview format, where one participant prompts another to talk in detail about a specific area that the main speaker knows well. The data can be used for additional purposes such as the investigation of demonstratives.

Abstract

No area in the study of human languages has a longer history and a higher practical signifi cance than lexicography. The advent of the computer has dramaticually changed this discipline in ways which go far beyond the digitisation of materials in combination with effi cient search tools, or the transfer of an existing dictionary onto the computer. They allow the stepwise elaboration of what is called here Digital Lexical Systems, i.e., computerized systems in which the underlying data - in form of an extendable corpus - and description of lexical properties on various levels can be effi ciently combined. This paper discusses the range of these possibilities and describes the present form of the German „Digital Lexical System of the Academy“, a project of the Berlin-Brandenburg Academy of Sciences (www.dwds.de).

Abstract

Verbs are traditionally assumed to have an “argument structure”, which imposes various constraints on form and meaning of the noun phrases that go with the verb, and an “event structure”, which defines certain temporal characteristics of the “event” to which the verb relates. In this paper, I argue that these two structures should be brought together. The verb assigns descriptive properties to one or more arguments at one or more temporal intervals, hence verbs have an “argument-time structure”. This argument-time structure as well as the descriptive properties connected to it can be modified by various morphological and syntactic operations. This approach allows a relatively simple analysis of familiar but not well-defined temporal notions such as tense, aspect and Aktionsart. This will be illustrated for English. It will be shown that a few simple morphosyntactic operations on the argument-time structure might account for form and meaning of the perfect, the progressive, the passive and related constructions.

Abstract

During the last 25 years, second language acquisition (SLA) research hasmade considerable progress, but is still far from proving a solid basis for foreign language teaching, or from a general theory of SLA. In addition, its status within the linguistic disciplines is still very low. I argue this has not much to do with low empirical or theoretical standards in the field—in this regard, SLA research is fully competitive—but with a particular perspective on the acquisition process: SLA researches learners' utterances as deviations from a certain target, instead of genuine manifestations of underlying language capacity; it analyses them in terms of what they are not rather than what they are. For some purposes such a "target deviation perspective" makes sense, but it will not help SLA researchers to substantially and independently contribute to a deeper understanding of the structure and function of the human language faculty. Therefore, these findings will remain of limited interest to other scientists until SLA researchers consider learner varieties a normal, in fact typical, manifestation of this unique human capacity.