Exploring Variation Between Artificial Grammar Learning Experiments: Outlining a Meta-Analysis Approach

Artificial grammar learning (AGL) has become an important tool used to understand aspects of human language learning and whether the abilities underlying learning may be unique to humans or found in other species. Successful learning is typically assumed when human or animal participants are able to distinguish stimuli generated by the grammar from those that are not at a level better than chance. However, the question remains as to what subjects actually learn in these experiments. Previous studies of AGL have frequently introduced multiple potential contributors to performance in the training and testing stimuli, but meta‐analysis techniques now enable us to consider these multiple information sources for their contribution to learning—enabling intended and unintended structures to be assessed simultaneously. We present a blueprint for meta‐analysis approaches to appraise the effect of learning in human and other animal studies for a series of artificial grammar learning experiments, focusing on studies that examine auditory and visual modalities. We identify a series of variables that differ across these studies, focusing on both structural and surface properties of the grammar, and characteristics of training and test regimes, and provide a first step in assessing the relative contribution of these design features of artificial grammars as well as species‐specific effects for learning

The myth of language universals and the myth of universal grammar

Evans & Levinson (E&L) argue that language universals are a myth. Christiansen and Chater (2008) have recently suggested that innate universal grammar is also a myth. This commentary explores the connection between these two theses, and draws wider implications for the cognitive science of language

Brains, genes, and language evolution: A new synthesis

Our target article argued that a genetically specified Universal Grammar (UG), capturing arbitrary properties of languages, is not tenable on evolutionary grounds, and that the close fit between language and language learners arises because language is shaped by the brain, rather than the reverse. Few commentaries defend a genetically specified UG. Some commentators argue that we underestimate the importance of processes of cultural transmission; some propose additional cognitive and brain mechanisms that may constrain language and perhaps differentiate humans from nonhuman primates; and others argue that we overstate or understate the case against co-evolution of language genes. In engaging with these issues, we suggest that a new synthesis concerning the relationship between brains, genes, and language may be emerging

Structured sequence learning across sensory modalities in humans and nonhuman primates

Structured sequence processing tasks inform us about statistical learning abilities that are relevant to many areas of cognition, including language. Despite the ubiquity of these abilities across different tasks and cognitive domains, recent research in humans has demonstrated that these cognitive capacities do not represent a single, domain-general system, but are subject to modality-specific and stimulus-specific constraints. Sequence processing studies in nonhuman primates have provided initial insights into the evolution of these abilities. However, few studies have examined similarities and/or differences in sequence learning across sensory modalities. We review how behavioural and neuroimaging experiments assess sequence processing abilities across sensory modalities, and how these tasks could be implemented in nonhuman primates to better understand the evolution of these cognitive systems

Confluence of CHR Revisited:Invariants and Modulo Equivalence

Abstract simulation of one transition system by another is introduced as a means to simulate a potentially infinite class of similar transition sequences within a single transition sequence. This is useful for proving confluence under invariants of a given system, as it may reduce the number of proof cases to consider from infinity to a finite number. The classical confluence results for Constraint Handling Rules (CHR) can be explained in this way, using CHR as a simulation of itself. Using an abstract simulation based on a ground representation, we extend these results to include confluence under invariant and modulo equivalence, which have not been done in a satisfactory way before.Comment: Pre-proceedings paper presented at the 28th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2018), Frankfurt am Main, Germany, 4-6 September 2018 (arXiv:1808.03326

The biological origin of linguistic diversity

In contrast with animal communication systems, diversity is characteristic of almost every aspect of human language. Languages variously employ tones, clicks, or manual signs to signal differences in meaning; some languages lack the noun-verb distinction (e.g., Straits Salish), whereas others have a proliferation of fine-grained syntactic categories (e.g., Tzeltal); and some languages do without morphology (e.g., Mandarin), while others pack a whole sentence into a single word (e.g., Cayuga). A challenge for evolutionary biology is to reconcile the diversity of languages with the high degree of biological uniformity of their speakers. Here, we model processes of language change and geographical dispersion and find a consistent pressure for flexible learning, irrespective of the language being spoken. This pressure arises because flexible learners can best cope with the observed high rates of linguistic change associated with divergent cultural evolution following human migration. Thus, rather than genetic adaptations for specific aspects of language, such as recursion, the coevolution of genes and fast-changing linguistic structure provides the biological basis for linguistic diversity. Only biological adaptations for flexible learning combined with cultural evolution can explain how each child has the potential to learn any human language

Two new species of Phalangopsis Serville, 1831 (Orthoptera: Grylloidea: Phalangopsidae) from Brazilian Amazon Forest

We describe here two new species of the genus Phalangopsis Serville, 1831 from the Brazilian Amazon Forest. The male genitalia and the female copulatory papilla were described, and a combination of diagnostic characteristics was given to separate both new species from the other described species. The principal morphological characteristics of this genus were discussed.Aqui foram descritas duas espécies novas do gênero Phalangopsis Serville, 1831 da Floresta Amazônica brasileira. A genitália masculina e a papila copulatória feminina são descritas, bem como uma combinação de características diagnósticas para separar ambas as novas espécies das outras espécies descritas. As principais características morfológicas foram discutidas

In vivo axial loading of the mouse tibia

Noninvasive methods to apply controlled, cyclic loads to the living skeleton are used as anabolic procedures to stimulate new bone formation in adults and enhance bone mass accrual in growing animals. These methods are also invaluable for understanding bone signaling pathways. Our focus here is on a particular loading model: in vivo axial compression of the mouse tibia. An advantage of loading the tibia is that changes are present in both the cancellous envelope of the proximal tibia and the cortical bone of the tibial diaphysis. To load the tibia of the mouse axially in vivo, a cyclic compressive load is applied up to five times a week to a single tibia per mouse for a duration lasting from 1 day to 6 weeks. With the contralateral limb as an internal control, the anabolic response of the skeleton to mechanical stimuli can be studied in a pairwise experimental design. Here, we describe the key parameters that must be considered before beginning an in vivo mouse tibial loading experiment, including methods for in vivo strain gauging of the tibial midshaft, and then we describe general methods for loading the mouse tibia for an experiment lasting multiple days

A Small RNA Controls Expression of the Chitinase ChiA in Listeria monocytogenes

In recent years, more than 60 small RNAs (sRNAs) have been identified in the gram-positive human pathogen Listeria monocytogenes, but their putative roles and mechanisms of action remain largely unknown. The sRNA LhrA was recently shown to be a post-transcriptional regulator of a single gene, lmo0850, which encodes a small protein of unknown function. LhrA controls the translation and degradation of the lmo0850 mRNA by an antisense mechanism, and it depends on the RNA chaperone Hfq for efficient binding to its target. In the present study, we sought to gain more insight into the functional role of LhrA in L. monocytogenes. To this end, we determined the effects of LhrA on global-wide gene expression. We observed that nearly 300 genes in L. monocytogenes are either positively or negatively affected by LhrA. Among these genes, we identified lmo0302 and chiA as direct targets of LhrA, thus establishing LhrA as a multiple target regulator. Lmo0302 encodes a hypothetical protein with no known function, whereas chiA encodes one of two chitinases present in L. monocytogenes. We show here that LhrA acts as a post-transcriptional regulator of lmo0302 and chiA by interfering with ribosome recruitment, and we provide evidence that both LhrA and Hfq act to down-regulate the expression of lmo0302 and chiA. Furthermore, in vitro binding experiments show that Hfq stimulates the base pairing of LhrA to chiA mRNA. Finally, we demonstrate that LhrA has a negative effect on the chitinolytic activity of L. monocytogenes. In marked contrast to this, we found that Hfq has a stimulating effect on the chitinolytic activity, suggesting that Hfq plays multiple roles in the complex regulatory pathways controlling the chitinases of L. monocytogenes

The Making of a Monster: Postnatal Ontogenetic Changes in Craniomandibular Shape in the Great Sabercat Smilodon

Derived sabercats had craniomandibular morphologies that in many respects were highly different from those of extant felids, and this has often been interpreted functionally as adaptations for predation at extreme gape angles with hypertrophied upper canines. It is unknown how much of this was a result of intraspecific postnatal ontogeny, since juveniles of sabercats are rare and no quantitative study has been made of craniomandibular ontogeny. Postnatal ontogenetic craniomandibular shape changes in two morphologically derived sabercats, Smilodon fatalis and S. populator, were analysed using geometric morphometrics and compared to three species of extant pantherines, the jaguar, tiger, and Sunda clouded leopard. Ontogenetic shape changes in Smilodon usually involved the same areas of the cranium and mandible as in extant pantherines, and large-scale modularization was similar, suggesting that such may have been the case for all felids, since it followed the same trends previously observed in other mammals. However, in other respects Smilodon differed from extant pantherines. Their crania underwent much greater and more localised ontogenetic shape changes than did the mandibles, whereas crania and mandibles of extant pantherines underwent smaller, fewer and less localised shape changes. Ontogenetic shape changes in the two species of Smilodon are largely similar, but differences are also present, notably those which may be tied to the presence of larger upper canines in S. populator. Several of the specialized cranial characters differentiating adult Smilodon from extant felids in a functional context, which are usually regarded as evolutionary adaptations for achieving high gape angles, are ontogenetic, and in several instances ontogeny appears to recapitulate phylogeny to some extent. No such ontogenetic evolutionary adaptive changes were found in the extant pantherines. Evolution in morphologically derived sabercats involved greater cranial ontogenetic changes than among extant felids, resulting in greatly modified adult craniomandibular morphologies