Semantic Parsing with Bayesian Tree Transducers

Many semantic parsing models use tree transformations to map between natural language and meaning representation. However, while tree transformations are central to several state-of-the-art approaches, little use has been made of the rich literature on tree automata. This paper makes the connection concrete with a tree transducer based semantic parsing model and suggests that other models can be interpreted in a similar framework, increasing the generality of their contributions. In particular, this paper further introduces a variational Bayesian inference algorithm that is applicable to a wide class of tree transducers, producing state-of-the-art semantic parsing results while remaining applicable to any domain employing probabilistic tree transducers.9 page(s

Towards a Robuster Interpretive Parsing

The input data to grammar learning algorithms often consist of overt forms that do not contain full structural descriptions. This lack of information may contribute to the failure of learning. Past work on Optimality Theory introduced Robust Interpretive Parsing (RIP) as a partial solution to this problem. We generalize RIP and suggest replacing the winner candidate with a weighted mean violation of the potential winner candidates. A Boltzmann distribution is introduced on the winner set, and the distribution’s parameter $T$ is gradually decreased. Finally, we show that GRIP, the Generalized Robust Interpretive Parsing Algorithm significantly improves the learning success rate in a model with standard constraints for metrical stress assignment

Syntax across domains: overlap in global and local structure processing

The research that has been presented in the current dissertation aims to address the recent debate concerning the extent to which structural processing across content domains (language, music, math, and action) might be supported by domain-general resources (Slevc & Okada, 2015). Following the development of novel pitch sequences and an off-line structural processing measure, we found interference during the joint structural processing of sentences and pitch sequences, which suggests that structural processing in both domains is supported by a domain-general pool of (working memory and cognitive control) resources. On the basis of this finding, we investigated to what extent such interactions between the structural processing of linguistic and non-linguistic materials could be found when studying ecologically valid materials. In an EEG study, we found that the event-related potentials (P2, P3, LAN, and P600) which were observed for dispreferred sentential disambiguations could be influenced by structural expectations on the basis of previously disambiguated pitch sequences. In two subsequent structural priming studies, we found that the completion of syntactically (Scheepers et al., 2011) and thematically (Allen et al., 2010) structured sentence beginnings (Scheepers et al., 2011) could be primed by the attachment structure of preceding linguistic, mathematical and pitch sequence materials. Furthermore, we found that similar cross-domain priming effects could be observed on the perception of implicitly structured pitch sequences. These findings thus strongly argue for broad, domain-general interactions in structural processing even when studying more naturalistic processing of ecologically valid materials. We tentatively interpret the current findings as evidence in favour of a domain-general pool of cognitive processing resources supporting structural processing across domains (Kljajevic, 2010; Slevc & Okada, 2014). With regards to our cross domain priming findings, we suggest that our results align with an ‘incremental-procedural’ account of attachment priming (see Scheepers & Sturt, 2014) according to which encountering a complexity in the structural processing of materials might (through a process of error-based implicit learning, Chang et al., 2006) influence the resource allocation during the structural processing of subsequent materials. In this way, our cross domain priming findings can be aligned with the idea of structural complexities processing being supported by domain-general cognitive resources (Slevc & Okada, 2015). At this point, it is important to remark that the results reported in the dissertation should of course be further replicated, and might be generalized to include harmonic processing and action perception as domains of structural processing. Furthermore, the interpretations of the current findings are not fully conclusive, as our studies were mainly guided by the goal of investigating whether there was evidence for interaction in structural processing across domains (showing several primary findings), rather than directly comparing alternative accounts in the interpretation of such interactions. Nevertheless, the research reported in the current dissertation clearly shows that, in relationship to the ongoing discussion on domain-generality of structural processing across domains (Slevc & Okada, 2015), interactions in structural processing across domains can be found when controlling for limitations of previous research (Perruchet & Poulin-Charronnat, 2013), and that those interactions can also be observed in situations that more closely approximate the processing of information from several domains in ‘daily life’. These primary findings suggest that domain-general cognitive processing resources support structural processing across domains, which provides several perspectives for theoretical approaches in psycholinguistics as well as other domains of cognition involving structural processing, such as math, music, and action

Geometric representations for minimalist grammars

We reformulate minimalist grammars as partial functions on term algebras for strings and trees. Using filler/role bindings and tensor product representations, we construct homomorphisms for these data structures into geometric vector spaces. We prove that the structure-building functions as well as simple processors for minimalist languages can be realized by piecewise linear operators in representation space. We also propose harmony, i.e. the distance of an intermediate processing step from the final well-formed state in representation space, as a measure of processing complexity. Finally, we illustrate our findings by means of two particular arithmetic and fractal representations.Comment: 43 pages, 4 figure

Principled Explanations in Comparative Biomusicology – Toward a Comparative Cognitive Biology of the Human Capacities for Music and Language

The current thesis tackles the question “Why is music the way it is?” within a comparative biomusicology framework by focusing on musical syntax and its relation to syntax in language. Comparative biomusicology integrates different comparative approaches, biological frameworks as well as levels of analysis in cognitive science, and puts forward principled explanations, regarding cognitive systems as different instances of the same principles, as its central research strategy. The main goal is to provide a preliminary answer to this question in form of hypotheses about neurocognitive mechanisms, i.e., cognitive and neural processes, underlying a core function of syntactic computation in language and music, i.e., mapping hierarchical structure and temporal sequence. In particular, the relationship between language and music is discussed on the basis of a top-down approach taking syntax as combinatorial principles and a bottom-up approach taking neural structures and operations as implementational principles. On the basis of the top-down approach, the thesis identifies computational problems of musical syntax, cognitive processes and neural correlates of music syntactic processing, and the relationship to language syntax and syntactic processing. The neural correlates of music syntactic processing are investigated by ALE meta-analyses. The bottom-up approach then studies the relationship between language and music on the basis of neural processes implemented in the cortico-basal ganglia-thalamocortical circuits. The main result of the current thesis suggests that the relationship between language and music syntactic processing can be explained in terms of the same neurocognitive mechanisms with different expressions on the motor-to-cognitive gradient. The current thesis, especially its bottom-up approach, opens up a possible way going toward comparative cognitive biology, i.e., a comparative approach to cognitive systems with a greater emphasis on the biology