Metacognitive Development and Conceptual Change in Children

There has been little investigation to date of the way metacognition is involved in conceptual change. It has been recognised that analytic metacognition is important to the way older children acquire more sophisticated scientific and mathematical concepts at school. But there has been barely any examination of the role of metacognition in earlier stages of concept acquisition, at the ages that have been the major focus of the developmental psychology of concepts. The growing evidence that even young children have a capacity for procedural metacognition raises the question of whether and how these abilities are involved in conceptual development. More specifically, are there developmental changes in metacognitive abilities that have a wholescale effect on the way children acquire new concepts and replace existing concepts? We show that there is already evidence of at least one plausible example of such a link and argue that these connections deserve to be investigated systematically

Feedback through graph motifs relates structure and function in complex networks

In physics, biology and engineering, network systems abound. How does the connectivity of a network system combine with the behavior of its individual components to determine its collective function? We approach this question for networks with linear time-invariant dynamics by relating internal network feedbacks to the statistical prevalence of connectivity motifs, a set of surprisingly simple and local statistics of connectivity. This results in a reduced order model of the network input-output dynamics in terms of motifs structures. As an example, the new formulation dramatically simplifies the classic Erdos-Renyi graph, reducing the overall network behavior to one proportional feedback wrapped around the dynamics of a single node. For general networks, higher-order motifs systematically provide further layers and types of feedback to regulate the network response. Thus, the local connectivity shapes temporal and spectral processing by the network as a whole, and we show how this enables robust, yet tunable, functionality such as extending the time constant with which networks remember past signals. The theory also extends to networks composed from heterogeneous nodes with distinct dynamics and connectivity, and patterned input to (and readout from) subsets of nodes. These statistical descriptions provide a powerful theoretical framework to understand the functionality of real-world network systems, as we illustrate with examples including the mouse brain connectome.Comment: 31 pages, 20 figure

Free serum haemoglobin is associated with brain atrophy in secondary progressive multiple sclerosis.

Background A major cause of disability in secondary progressive multiple sclerosis (SPMS) is progressive brain atrophy, whose pathogenesis is not fully understood. The objective of this study was to identify protein biomarkers of brain atrophy in SPMS. Methods We used surface-enhanced laser desorption-ionization time-of-flight mass spectrometry to carry out an unbiased search for serum proteins whose concentration correlated with the rate of brain atrophy, measured by serial MRI scans over a 2-year period in a well-characterized cohort of 140 patients with SPMS. Protein species were identified by liquid chromatography-electrospray ionization tandem mass spectrometry. Results There was a significant (p<0.004) correlation between the rate of brain atrophy and a rise in the concentration of proteins at 15.1 kDa and 15.9 kDa in the serum. Tandem mass spectrometry identified these proteins as alpha-haemoglobin and beta-haemoglobin, respectively.  The abnormal concentration of free serum haemoglobin was confirmed by ELISA (p<0.001). The serum lactate dehydrogenase activity was also highly significantly raised (p<10-12) in patients with secondary progressive multiple sclerosis. Conclusions An underlying low-grade chronic intravascular haemolysis is a potential source of the iron whose deposition along blood vessels in multiple sclerosis plaques contributes to the neurodegeneration and consequent brain atrophy seen in progressive disease. Chelators of free serum iron will be ineffective in preventing this neurodegeneration, because the iron (Fe2+) is chelated by haemoglobin

Empirical Lessons for Philosophical Theories of Mental Content

This thesis concerns the content of mental representations. It draws lessons for philosophical theories of content from some empirical findings about brains and behaviour drawn from experimental psychology (cognitive, developmental, comparative), cognitive neuroscience and cognitive science (computational modelling). Chapter 1 motivates a naturalist and realist approach to mental representation. Chapter 2 sets out and defends a theory of content for static feedforward connectionist networks, and explains how the theory can be extended to other supervised networks. The theory takes forward Churchland’s state space semantics by making a new and clearer proposal about the syntax of connectionist networks − one which nicely accounts for representational development. Chapter 3 argues that the same theoretical approach can be extended to unsupervised connectionist networks, and to some of the representational systems found in real brains. The approach can also show why connectionist systems sometimes show typicality effects, explaining them without relying upon prototype structure. That is discussed in chapter 4, which also argues that prototype structure, where it does exist, does not determine content. The thesis goes on to defend some unorthodox features of the foregoing theory: that a role is assigned to external samples in specifying syntax, that both inputs to and outputs from the system have a role in determining content, and that the content of a representation is partly determined by the circumstances in which it developed. Each, it is argued, may also be a fruitful way of thinking about mental content more generally. Reliance on developmental factors prompts a swampman-type objection. This is rebutted by reference to three possible reasons why content is attributed at all. Two of these motivations support the idea that content is partly determined by historical factors, and the third is consistent with it. The result: some empirical lessons for philosophical theories of mental content.Philosophy of Min

Representation in Cognitive Science - Replies

In their constructive reviews, Frances Egan, Randy Gallistel and Steven Gross have raised some important problems for the account of content advanced by Nicholas Shea in Representation in Cognitive Science (2018, OUP). Here the author addresses their main challenges as follows. Egan argues that the account includes an unrecognised pragmatic element; and that it makes contents explanatorily otiose. Gallistel raises questions about homomorphism and correlational information. Gross puts the account to work to resolve the dispute about probabilistic contents in perception, but argues that a question remains about whether probabilities are found in the content or instead in the manner of representation

Organized representations forming a computationally useful processing structure

Peter Godfrey-Smith recently introduced the idea of representational ‘organization’. When a collection of representations form an organized family, similar representational vehicles carry similar contents. For example, where neural firing rate represents numerosity (an analogue magnitude representation), similar firing rates represent similar numbers of items. Organization has been elided with structural representation, but the two are in fact distinct. An under-appreciated merit of representational organization is the way it facilitates computational processing. Representations from different organized families can interact, for example to perform addition. Their being organized allows them to implement a useful computation. Many of the cases where organization has seemed significant, but which fall short of structural representation, are cases where representational organization underpins a computationally useful processing structure

Distinguishing Top-Down From Bottom-Up Effects

Is there a space of the sensory modalities? Such a space would be one in which all the actual, and at least some of the possible, sensory modalities could be represented. The position of the senses in this space would indicate how similar and how different the senses are from each other. The chapter argues that such a space can be constructed in a non-arbitrary manner. The space is one with a high number of dimensions. Principal component analysis (PCA) can be used to reduce the number of dimensions, and doing so might (a) reveal factors important for individuating the senses not previously considered, (b) help to define what a sense is, and (c) provide grounds for deciding what is one token sense rather than multiple token senses. Philosophers should consider whether PCA might be useful in taxonomizing other entities

Representation in Cognitive Science

How can we think about things in the outside world? There is still no widely accepted theory of how mental representations get their meaning. In light of pioneering research, Nicholas Shea develops a naturalistic account of the nature of mental representation with a firm focus on the subpersonal representations that pervade the cognitive sciences

Exploited isomorphism and structural representation

An interesting feature of some sets of representations is that their structure mirrors the structure of the items they represent. Founding an account of representational content on isomorphism, homomorphism or structural resemblance has proven elusive, however, largely because these relations are too liberal when the candidate structure over representational vehicles is unconstrained. Furthermore, in many cases where there is a clear isomorphism, it is not relied on in the way the representations are used. That points to a potential resolution: that an isomorphism must be used, hence usable, if it is to be an ingredient in a theory of content. This paper argues that the class of exploitable isomorphisms can indeed play a content-constituting role