This paper is a commentary on the target article by Lokendra Shastri & Venkat Ajjanagadde [S&A]: “From simple associations to systematic reasoning: A connectionist representation of rules, variables and dynamic bindings using temporal synchrony” in same issue of the journal, pp.417–451. -/- It puts S&A's temporal-synchrony binding method in a broader context, comments on notions of pointing and other ways of associating information - in both computers and connectionist systems - and mentions types of reasoning that are a challenge to (...) S&A's system (amongst many other connectionist systems, recognizing that S&A's is much more capable as regards reasoning than most other contemporary systems). (shrink)

Human agents draw a variety of inferences effortlessly, spontaneously, and with remarkable efficiency – as though these inferences were a reflexive response of their cognitive apparatus. Furthermore, these inferences are drawn with reference to a large body of background knowledge. This remarkable human ability seems paradoxical given the complexity of reasoning reported by researchers in artificial intelligence. It also poses a challenge for cognitive science and computational neuroscience: How can a system of simple and slow neuronlike elements represent a large (...) body of systemic knowledge and perform a range of inferences with such speed? We describe a computational model that takes a step toward addressing the cognitive science challenge and resolving the artificial intelligence paradox. We show how a connectionist network can encode millions of facts and rules involving n-ary predicates and variables and perform a class of inferences in a few hundred milliseconds. Efficient reasoning requires the rapid representation and propagation of dynamic bindings. Our model (which we refer to as SHRUTI) achieves this by representing (1) dynamic bindings as the synchronous firing of appropriate nodes, (2) rules as interconnection patterns that direct the propagation of rhythmic activity, and (3) long-term facts as temporal pattern-matching subnetworks. The model is consistent with recent neurophysiological evidence that synchronous activity occurs in the brain and may play a representational role in neural information processing. The model also makes specific psychologically significant predictions about the nature of reflexive reasoning. It identifies constraints on the form of rules that may participate in such reasoning and relates the capacity of the working memory underlying reflexive reasoning to biological parameters such as the lowest frequency at which nodes can sustain synchronous oscillations and the coarseness of synchronization. (shrink)

This paper is devoted to discuss a general tendency in contextualism which is known as "radical contextualism". In the first part I state the well known paradox of semantic holism, as discussed in philosophy of language: if meaning is holistic there is no possibility to share any meaning. In the second part I present the different answers to this paradox, from atomism to different forms of holism. In the third part I give a criticism of the traditional interpretation of Wittgenstein (...) as a supporter of global holism. I stress some similarities between Wittgenstein's thought and Multi Context theories in artificial inteligence. In the last part I give some argument against a rigid interpretation of "local holism": I claim the need to give restrictions to local holim and to develop a study of the connections between "default" properties and high level rules which are studied in Multi−Context theories. (shrink)

This paper tries to give some substance to local holism, a picture that seems to fit Wittgenstein’s analysis of the working of language. In the first part I state the well-known paradox of semantic holism, as discussed in philosophy of language: if meaning is holistic there is no possibility to share any meaning. In the second part I present the different answers to this paradox, from atomism to different forms of holism. In the third part I give a criticism of (...) the traditional interpretation of Wittgenstein as a supporter of global holism. As an alternative lecture I will suggest some lines of Wittgenstein's thought leading towards a definition of local holism. Eventually I will show connections with ideas developed in Multi Context theories in artificial intelligence, which help to show a possible direction of inquiry about restrictions on locality. (shrink)