Neural blackboard architectures of combinatorial structures in cognition

Human cognition is unique in the way in which it relies on combinatorial (or compositional) structures. Language provides ample evidence for the existence of combinatorial structures, but they can also be found in visual cognition. To understand the neural basis of human cognition, it is therefore essential to understand how combinatorial structures can be instantiated in neural terms. In his recent book on the foundations of language, Jackendoff described four fundamental problems for a neural instantiation of combinatorial structures: the massiveness of the binding problem, the problem of 2, the problem of variables and the transformation of combinatorial structures from working memory to long-term memory. This paper aims to show that these problems can be solved by means of neural ‘blackboard’ architectures. For this purpose, a neural blackboard architecture for sentence structure is presented. In this architecture, neural structures that encode for words are temporarily bound in a manner that preserves the structure of the sentence. It is shown that the architecture solves the four problems presented by Jackendoff. The ability of the architecture to instantiate sentence structures is illustrated with examples of sentence complexity observed in human language performance. Similarities exist between the architecture for sentence structure and blackboard architectures for combinatorial structures in visual cognition, derived from the structure of the visual cortex. These architectures are briefly discussed, together with an example of a combinatorial structure in which the blackboard architectures for language and vision are combined. In this way, the architecture for language is grounded in perception

Linking population dynamics and high-level cognition: Ambiguity resolution in a neural sentence processing model

Conference Abstract Neuroinformatics 201

A neural blackboard architecture of sentence structure

We present a neural architecture for sentence representation. Sentences are represented in terms of word representations as constituents. A word representation consists of a neural assembly distributed over the brain. Sentence representation does not result from associations between neural word assemblies. Instead, word assemblies are embedded in a neural architecture, in which the structural (thematic) relations between words can be represented. Arbitrary thematic relations between arguments and verbs can be represented. Arguments can consist of nouns and phrases, as in sentences with relative clauses. A number of sentences can be stored simultaneously in this architecture. We simulate how probe questions about thematic relations can be answered. We discuss how differences in sentence complexity, such as the difference between subject-extracted versus object-extracted relative clauses and the difference between right-branching versus center-embedded structures, can be related to the underlying neural dynamics of the model. Finally, we illustrate how memory capacity for sentence representation can be related to the nature of reverberating neural activity, which is used to store information temporarily in this architecture

The role of recurrent networks in neural architectures of grounded cognition: learning of control

Recurrent networks have been used as neural models of language processing, with mixed results. Here, we discuss the role of recurrent networks in a neural architecture of grounded cognition. In particular, we discuss how the control of binding in this architecture can be learned. We trained a simple recurrent network (SRN) and a feedforward network (FFN) for this task. The results show that information from the architecture is needed as input for these networks to learn control of binding. Thus, both control systems are recurrent. We found that the recurrent system consisting of the architecture and an SRN or an FFN as a "core" can learn basic (but recursive) sentence structures. Problems with control of binding arise when the system with the SRN is tested on number of new sentence structures. In contrast, control of binding for these structures succeeds with the FFN. Yet, for some structures with (unlimited) embeddings, difficulties arise due to dynamical binding conflicts in the architecture itself. In closing, we discuss potential future developments of the architecture presented here

From unified to specific theories of cognition

Abstract: This article discusses the unity of cognitive science that seemed to emerge in the 1950s, based on the computational view of cognition. This unity would entail that there is a single set of mechanisms (i.e. algorithms) for all cognitive behavior, in particular at the level of productive human cognition as exemplified in language and reasoning. In turn, this would imply that theories in psychology, and cognitive science in general, would consist of algorithms based on symbol manipulation as found in digital computing. However, a number of developments in recent decades cast doubt on this unity of cognitive science. Also, there are fundamental problems with the claim that cognitive theories are just algorithms. This article discusses some of these problems and suggests that, instead of unified theories of cognition, specific mechanisms for cognitive behavior in specific cognitive domains could be needed, with architectures that are tailor-made for specific forms of implementation. A sketch of such an architecture for language is presented, based on modifiable connection paths in small-world like network structures.Keywords: Connection Paths; Control of Activation; Small-world Networks; Symbol Manipulation; Unity of Cognition Dalle teoria unificate della cognizione a quelle specificheRiassunto: Questo articolo discute l’unità della scienza cognitiva che sembrava emergere negli Anni ’50 e che era basata su una concezione computazionale della cognizione. Questa unità prevedeva l’esistenza di un singolo insieme di meccanismi (algoritmi) per tutti i comportamenti cognitivi, in particolare al livello della cognizione umana produttiva come, per esempio, linguaggio e ragionamento. A sua volta ciò implicava che le teorie psicologiche e, più in generale della scienza cognitiva, prevedessero algoritmi basati sulla manipolazione di simboli come nella computazione digitale. E, tuttavia, diversi sviluppi degli ultimi decenni hanno messo in dubbio questa unità della scienza cognitiva. Affermare che le teorie cognitive sarebbero solo algoritmi presenta problemi di fondo. Questo articolo discute alcuni di questi problemi, suggerendo che, invece di teorie della cognizione unificata, si potrebbe aver bisogno di meccanismi specifici per il comportamento cognitivo in specifici domini cognitivi, con architetture ritagliate per specifiche forme di implementazione. Questo articolo presenta uno schizzo di una simile architettura per il linguaggio, basata su vie di connessione modificabili in piccoli mondi come le strutture di reti.Parole chiave: Vie di connessione; Controllo dell’attivazione; Reti di piccoli mondi; Manipolazione di simboli; Unità della cognizion

Evaluating creative ideas:Insights from erps and changes in the upper alpha bank

Thus far, electrophysiological research on creativity has employed production tasks and measured changes in the alpha band in time windows lasting several seconds, while participants produced creative ideas. These studies had, however, limited temporal resolution, which made it difficult to identify specific cognitive processes underlying creative thinking. In the current study, we employed a modified version of the alternate uses task, in which participants evaluated word pairs representing the common, creative, and impossible uses of objects according to how (im)possible and (un)common they seemed. In the even-related potential (ERP) analysis, a graded effect was found, with impossible uses evoking the largest, common the lowest, and creative intermediate N400 amplitudes. Moreover, greater power in the upper alpha band was observed in the creative than common condition in the time window between 400–1000ms. Interestingly, this effect was absent in the lower alpha band, which differs from previous reports in which an increase in both the upper and lower alpha bands was found. The graded N400 effect can be interpreted as reflecting increased activity in semantic memory needed to evaluate the creative word pairs. The difference in the upper alpha band might index increased semantic processing demands and larger inhibition of task-irrelevant information on creative than common trials. Since task demands remain comparable on all trials, these findings seem directly related to cognitive processes involved in evaluating creative ideas

Editorial: Neural plasticity for rich and uncertain robotic information streams

Editorial: Neural plasticity for rich and uncertain robotic information stream

A Semantic Map for Evaluating Creativity

We present a semantic map of words related with creativity. The aim is to empirically derive terms which can be used to rate processes or products of computational creativity. The words in the map are based on association studies performed by human subjects and augmented with words derived from the literature (based on human raters). The words are used in a card sorting study to investigate the way they are categorized by human subjects. The results are arranged in a heat map of word relations based on a hierarchical cluster analysis. The cluster analysis and a principal component analysis provide a set of five to six clusters of items related to each other, and as clusters related to creativity. These clusters could form a basis for scales used to rate aspects of computational creativity

Extra-pair mating opportunities mediate parenting and mating effort trade-offs in a songbird

In socially monogamous species with bi-parental care, males may face a trade-off between providing parental care and pursuing extra-pair matings. The "parenting-mating trade-off" hypothesis predicts that high-quality males-who have greater potential to gain extra-pair matings, for example, larger males usually win the competition for extra-pair mating-should reduce parental care and spend more time looking for extra-pair matings. However, the trade-off between parenting and mating efforts may be complicated by variation in the availability of extra-pair mating opportunities. By using field data of hair-crested drongos (Dicrurus hottentottus), a species exhibiting bi-parental incubation behavior, collected in central China from 2010 to 2017, we tested whether the potential negative relationship between male quality and paternal care was dependent on the number of nearby fertile females. We found that male drongos mainly seek extra-pair matings during the incubation period and high-quality individuals (males with longer tarsi) are more likely to sire extra-pair offspring. In agreement with the "parenting-mating trade-off" hypothesis, high-quality males incubated less by recessing longer between incubation bouts. However, this was only the case when sufficient fertile females nearby for extra-pair mating opportunities. Females compensated for reduced male care, but this was independent of male quality. This suggests that the reduction in care by high-quality males might be a direct response to extra-pair mating opportunities rather than facilitated by differential allocation of females. Our results indicate that individual quality and available mating opportunities may shape the optimal trade-off between parental care and seeking additional matings for males. Lay Summary: How do individual quality and the number of potential extra-pair mates influence the optimal trade-off between parental care and engaging extra-pair courtship in animals? In hair-crested drongos, high-quality males, who are more successful in obtaining extra-pair fertilizations, reduced their share in incubation, but only when they had sufficient extra-pair mating opportunities. Females partially compensate for the reduced incubation of their partners, but the compensation was not affected by male quality