Connectionist models provide a promising alternative to the traditional computational approach that has for several decades dominated cognitive science and artificial intelligence, although the nature of connectionist models and their relation to symbol processing remains controversial. Connectionist models can be characterized by three general computational features: distinct layers of interconnected units, recursive rules for updating the strengths of the connections during learning, and “simple” homogeneous computing elements. Using just these three features one can construct surprisingly elegant and powerful models of (...) memory, perception, motor control, categorization, and reasoning. What makes the connectionist approach unique is not its variety of representational possibilities or its departure from explicit rule-based models, or even its preoccupation with the brain metaphor. Rather, it is that connectionist models can be used to explore systematically the complex interaction between learning and representation, as we try to demonstrate through the analysis of several large networks. (shrink)

The target article advanced the null, unified and widely misinterpreted generative hypothesis regarding second language (L2) acquisition. Postulating that UG (Universal Grammar) constrains L2 knowledge growth does not entail identical developmental trajectories for L2 and first language (LI) acquisition; nor does it preclude a role for the L1. In embracing this hypothesis, we maintain a distinction between competence and performance. Those who conflate the two repeat fundamental and by no means unprecedented misconstruals of the generative enterprise, and more specifically, of (...) the empirical content of the null hypothesis regarding L2 linguistic knowledge growth. We hope to have identified certain common goals, the adoption of which might constitute a firm foundation for continued productive interdisciplinary development of contemporary theoretical and experimental L2 acquisition research. (shrink)

The role of metalinguistic ability in L2 development is seriously underestimated. It may be seen both (1) as a means of initiating or boosting the flow of primary linguistic data and (2) as a generator of substitute knowledge (derived, but epistemologically distinct from domain-specific knowledge) that may compete with or compensate for perceived gaps in the learners current underlying competence. It cannot serve as a simple means of distinguishing the rival theoretical positions.

The most compelling evidence for Epstein et al.'s central thesis that adult second language acquisition is constrained by the innate cognitive structures that constrain native language acquisition would be evidence of poverty of the stimulus. Although there are studies that point to such evidence, Epstein et al.'s primary form of argumentation, targetlike performance by second-language acquiring adults, is much less convincing.

L2 learners may access UG principles because these are realized in all natural languages. Since this is not the case for the parametrized aspects of language, parameter setting may be progressively replaced by restructuring mechanisms which are specifically related to the process of representational redescription because L2 learners are not sensitive to the [±] features which define parameters.

Children in a given linguistic environment all uniformly acquire their target language, but adult learners of L2 do not. UG accounts for children's uniform linguistic behavior, but it cannot serve a similar role in accounting for adult learners' linguistic behavior. I argue that Epstein etal.'s study does not answer the question of why L2 learners end up with nonuniform and imperfect linguistic competence in learning a second language.

Epstein et al. attribute second language learning to the forces of transfer and language universals. They show that transfer is minimally involved in certain types of learning and therefore conclude that universals are involved. However, they forget to consider the important role of learning in second language acquisition.

Curiously, two central areas are unaddressed by Epstein et al.: (i) L1A–L2A differences; (ii) L2 development. Here, findings relevant to (i) and (ii) – as well as their significance – are discussed. Together these form the basis for contesting Epstein et al.'s “Full Access” approach, but nonetheless analyses of the L2 data argue for UG-constrained L2A. Also discussed is the inadequacy of accounts (like Epstein et al.'s) without an explicit and prominent role for the L1.

The contribution to L2-acquisition which comes from UG is conceptually distinct from that which comes from L1 (or from L1 and L2 jointly), but it is difficult to tease the two apart. The workings of deep, core principles (e.g., locality and subjacency) are so massively evident in L1 and L2 as to be of questionable use in the search for the contribution which is purely of UG.

We argue that the model developed in Epstein et al.'s target article does not explain differences between child first language (LI) acquisition and adult second language (L2) acquisition. We therefore sketch an alternative view, originally developed in Clahsen and Muysken (1989), in the light of new empirical findings and theoretical developments.

The current conception of the relation between UG and the grammar of a language rules out the no-access hypothesis, but does not distinguish between the full-access and partial-access hypotheses. The former raises the issue of why language acquisition in child and adult should be so different. The evidence presented in Epstein et al.'s target article seems inconclusive regarding a choice between hypotheses.

The evidence that L2 learners have full access to UG is not convincing. The following will be shown: (1) The argument that L2 learners “expect” L2 to have particular properties rests on the conceptual confusion ofhaving the concept of language(in the sense of knowing the meaning of “language”) withhaving accessto UG. (2) The claim that L2 acquisition takes place under the constraints imposed by universal principles lacks empirical support. (3) The assumption that L2 learners assign new parameter values is based (...) on a problematic example and remains unclear. (shrink)

Epstein, Flynn, and Martohardjono trivialize the question of access to universal grammar in second language acquisition by arguing against a straw-man version of the no-access position and by begging the question of how second language (L2) knowledge is represented in the mind/brain of an adult L2 learner. They compound their errors by employing a research methodology that fails to provide any relevant evidence.

Epstein et al. fail to show that L2 learners have full access to UG because they do not explain the relationship between UG and functional categories (FCs). Nor do they provide an explanation of why learners with (supposed) full knowledge of FCs fail to use them in a native-like way.

Although theFull-accesshypothesis accounts for a range of empirical generalizations of L2A, it underrepresents the role of language transfer in the construction of the L2 grammar. We suggest the possibility that linguistic principles which constrain the L2 grammar are available both directly from UG and via the L1, a logical hypothesis which Epstein et al. do not consider.

Chomskyian claims of a genetically hard-wired and cognitively autonomous “universal grammar” are being promoted by generative linguistics as facts about language to the present day. The related doctrine of an evolutionary discontinuity in language emergence, however, is based on misconceptions about the notions of homology and preadaptation. The obvious lack of equivalence between symbolic communicative capacities in existing nonhuman primates and human language does not preclude common roots. Normal and disordered language development is strongly influenced by the genome, but there (...) is no evidence for the existence of specific genes underlying “universal grammar.” In the mature brain, stages of language processing can be distinguished and “first-pass” syntactic analyses appear to precede semantic decoding. However, this partial seriality – as well as behavioral and clinical dissociations between lexical and functional categories – can be best described, not in terms of serially activated and discrete modules, but in terms of classes of cell assemblies that differ in their distributional properties. Whereas cell assemblies involved in semantic interpretation (“content word” assemblies) are widely distributed and are generally less vulnerable to focal lesion, those involved in structural decoding (functor assemblies) are primarily distributed within the left perisylvian cortices and are selectively vulnerable to left perisylvian lesion. These distributional differences are explained in terms of the perceptuomotor components involved in the acquisition of relevant representations. The emerging “motivated” or “toposemantic” brain regional specificity can only be accommodated with “soft” and maturational versions of modularity. The failure to reproduce double dissociations in current connectionist models is due to overly simple neuroscientific assumptions, notably that of overall equipotentiality. Linguistic models should not be expected to be “implemented” in the brain, but need to be constrained by neuroscientific evidence on how biological brains function. (shrink)

Evidence is presented from a polyglot savant to suggest that double dissociations between linguistic and nonverbal abilities are more important than Müller's target article implies. It is also argued that the special nature of syntax makes its assimilation to other aspects of language or to nonhuman communication systems radically implausible.

One can disagree with Müller that it is neurobiologically questionable to suppose that human language is innate, specialized, and species-specific, yet agree that the precise brain mechanisms controlling language in any individual will be influenced by epigenesis and genetic variability, and that the interplay between inherited and acquired aspects of linguistic capacity deserves to be investigated.

Because Müiller fails to distinguish between two senses of the term “autonomy,” there is a danger that his results will be misinterpreted by both linguists and neuroscientists. Although he may very well have been successful in refuting one sense of autonomy, he may actually have helped to provide an explanation for the correctness of autonomy in its other sense.

Neurobiological models of language need a level of analysis that can account for the typical range of language phenomena. Because linguistically motivated models have been successful in explaining numerous language properties, it is premature to dismiss them as biologically irrelevant. Models attempting to unify neurobiology and linguistics need to be sensitive to both sources of evidence.

Müller's target article aims to summarize approaches to the question of how language elements (phonemes, morphemes, etc.) and rules are laid down in the brain. However, it suffers from being too vague about basic assumptions and empirical predictions of neurobiological models, and the empirical evidence available to test the models is not appropriately evaluated. (1) In a neuroscientific model of language, different cortical localizations of words can only be based on biological principles. These need to be made explicit. (2) Evidence (...) for and against word class differences could be evaluated more rigorously. (3) All (and only) humans are able to learn languages with complex syntactic structures; it is, therefore, not appropriate to deny innateness and universality of syntactic principles. The real question appears to be the following: Which neurobiological principles are the linguistic principles based on? (shrink)

We agree with Müller's epigenetic view of evolution and ontogeny and applaud his multilevel perspective. With him, we stress the importance in ontogeny of progressive specialisation rather than prewired structures. However, we argue that he slips from “speech” to “language” and that, in seeking homologies, these two levels need to be kept separate in the analysis of evolution and ontogeny.

The conclusion that language is not really innate or modular is based on several fallacies. I show that the target article confuses communicative skills with linguistic abilities, and that its discussion of brain/language relations is replete with factual errors. I also criticize its attempt to contrast biological and linguistic principles. Finally, I argue that no case is made for the “alternative” approach proposed here.

Müller provides a valuable synthesis of neurobiological evidence on the epigenetic development of neural structures involved in language acquisition. The pluripotentiality of developing neural tissue crucially constrains linguistic/cognitive theorizing about supposedly innate neural mechanisms and contributes significantly to our understanding of experience–dependent processes involved in language acquisition. Without this understanding, any proposed explanation of language acquisition is suspect.

Müller argues that double dissociations do not imply underlying modularity of the cognitive system, citing neural networks as examples of fully distributed systems that can give rise to double dissociations. We challenge this claim, noting that suchdouble dissociations typically do not “scale-up,” and that even some singledissociations can be difficult to account for in a distributed system.

I enlarge on the theme that the brain mechanisms required for languageand other aspects of the human mind evolved through selective changes in the regulatory genes governing growth. Extension of the period of postnatal growth increases the role of the environment in structuring the brain, and spatiotemporal programming (heterochrony) ofgrowth might explain hierarchical representation, hemispheric specialization, and perhaps sex differences.

The study of signed languages has inspired scientific' speculation regarding foundations of human language. Relationships between the acquisition of sign language in apes and man are discounted on logical grounds. Evidence from the differential hreakdown of sign language and manual pantomime places limits on the degree of overlap between language and nonlanguage motor systems. Evidence from functional magnetic resonance imaging reveals neural areas of convergence and divergence underlying signed and spoken languages.

Both autonomy and local specificity are compatible with observed interconnectivity at the cell level when considering two different levels: cell assemblies and brain systems. Early syntactic structuring processes in particular are likely to representan autonomous module in the language/brain system.

Müller misconstrues autonomy to mean strict locality of brain function, something quite different from the functional autonomy that linguists claim. Similarly, he misperceives the interaction of learned and innate components hypothesized in current generative models. Evidence from sign languages, Creole languages, and neurological studies of rare forms of aphasia also argues against his conclusions.

The concepts of the innateness, universality, species-specificity, and autonomy of the human language capacity have had an extreme impact on the psycholinguistic debate for over thirty years. These concepts are evaluated from several neurobiological perspectives, with an emphasis on the emergence of language and its decay due to brain lesion and progressive brain disease.Evidence of perceptuomotor homologies and preadaptations for human language in nonhuman primates suggests a gradual emergence of language during hominid evolution. Regarding ontogeny, the innate component of language (...) capacity is likely to be polygenic and shared with other developmental domains. Dissociations between verbal and nonverbal development are probably rooted in the perceptuomotor specializations of neural substrates rather than the autonomy of a grammar module. Aphasiologicaldata often assumed to suggest modular linguistic subsystems can be accounted for in terms of a neurofunctional model incorporating perceptuomotor-based regional specializationsand distributivity of representations. Thus, dissociations between grammatical functors and content words are due to different conditions of acquisition and resulting differences in neural representation. Human brains are characterized by multifactorial interindividual variability, and strict universality of functional organization is biologically unrealistic.A theoretical alternative is proposed according to which (1) linguistic specialization of brain areas is due to epigenetic and probabilistic maturational events, not to genetic ”hard-wiring,” and (2) linguistic knowledge is neurally represented in distributed cell assemblies whose topography reflects the perceptuomotor modalities involved in the acquisition and use of a given item of knowledge. (shrink)

This target article's handling of theory and data and the range of evidence surveyed for its main contention fall short of normal BBS standards. However, the contention itself is reasonable and can be supported if one rejects the metaphor for linguistic competence and accepts that are no more than the way the brain does language.

To what extent, if any, does Universal Grammar (UG) constrain second language (L2) acquisition? This is not only an empirical question, but one which is currently investigable. In this context, L2 acquisition is emerging as an important new domain of psycholinguistic research. Three logical possibilities have been articulated regarding the role of UG in L2 acquisition: The first is the hypothesis that claims that no aspect of UG is available to the L2 learner. The second is the hypothesis that claims (...) that only LI instantiated principles and LI instantiated parameter-values of UG are available to the learner. The third, called the hypothesis, asserts that UG in its entirety constrains L2 acquisition. (shrink)

Most biologists and some cognitive scientists have independently reached the conclusion that there is no such thing as learning in the traditional “instructive‘ sense. This is, admittedly, a somewhat extreme thesis, but I defend it herein the light of data and theories jointly extracted from biology, especially from evolutionary theory and immunology, and from modern generative grammar. I also point out that the general demise of learning is uncontroversial in the biological sciences, while a similar consensus has not yet been (...) reached in psychology and in linguistics at large. Since many arguments presently offered in defense of learning and in defense of “general intelligence‘ are often based on a distorted picture of human biological evolution, I devote some sections of this paper to a critique of “adaptationism,‘ providing also a sketch of a better evolutionary theory. Moreover, since certain standard arguments presented today as “knock-down‘ in psychology, in linguistics and in artificial intelligence are a perfect replica of those once voiced by biologists in favor of instruction and against selection, I capitalize on these errors of the past to draw some lessons for the present and for the future. (shrink)

Arguments from the Logical Problem of Language Acquisition suggest that since linguistic experience provides few negative data that would falsify overgeneral grammatical hypotheses, innate knowledge of the principles of Universal Grammar must constrain learners hypothesis formulation. Although this argument indicates a need for domain-specific constraints, it does not support their innateness. Learning from mostly positive data proceeds unproblematically in virtually all domains. Since not every domain can plausibly be accorded its own special faculty, the probative value of the argument in (...) the linguistic case is dubious. In ignoring the holistic and probablistic nature of theory construction, the argument underestimates the extent to which positive data can supply negative evidence and hence overestimates the intractability of language learning in the absence of a dedicated faculty. While nativism about language remains compelling, the alleged Logical Problem contributes nothing to its plausibility and the emphasis on the Problem in the recent acquisition literature has been a mistake. (shrink)

Memory is fleeting. New material rapidly obliterates previous material. How, then, can the brain deal successfully with the continual deluge of linguistic input? We argue that, to deal with this “Now-or-Never” bottleneck, the brain must compress and recode linguistic input as rapidly as possible. This observation has strong implications for the nature of language processing: (1) the language system must “eagerly” recode and compress linguistic input; (2) as the bottleneck recurs at each new representational level, the language system must build (...) a multilevel linguistic representation; and (3) the language system must deploy all available information predictively to ensure that local linguistic ambiguities are dealt with “Right-First-Time”; once the original input is lost, there is no way for the language system to recover. This is “Chunk-and-Pass” processing. Similarly, language learning must also occur in the here and now, which implies that language acquisition is learning to process, rather than inducing, a grammar. Moreover, this perspective provides a cognitive foundation for grammaticalization and other aspects of language change. Chunk-and-Pass processing also helps explain a variety of core properties of language, including its multilevel representational structure and duality of patterning. This approach promises to create a direct relationship between psycholinguistics and linguistic theory. More generally, we outline a framework within which to integrate often disconnected inquiries into language processing, language acquisition, and language change and evolution. (shrink)