Constraints on Constraints: Surveying the Epigenetic Landscape

It is now relatively commonplace to advocate the need for some sorts of constraints on learning and knowledge acquisition. The critical issues to cognitive science concern the sorts of constraints that are able to best model various phenomena of learning and development. Four types of constraints on learning are proposed to be used as an interpretative framework within which to: 1. Better understand the nature of current research: 2. Allow the exploration of alternative models of learning related phenomena, and 3. See more clearly needs for further research. Superficially similar learning phenomena can be modeled by very different configurations of underlying constraints with strong implications for the sorts of representational states that are involved. Each of the five papers in this issue (Brown, Gelman, Markman, Newport, and Spelke) is considered in terms of the configuration of constraints after which each author intends to model their phenomena and in terms of alternate configurations. The papers are construed as illustrating a diverse set of models of how constraints might guide learning, and while the evidence generally favors the configurations suggested by the authors, in each case alternative models are possible and motivate quite specific future research questions. More broadly, it is suggested that asking detailed questions about the sorts of Constraints types that could potentially model complex cases of natural knowledge acquisition helps motivate fundamental questions about learning and the nature of knowledge and that the five papers in this issue are superb examples of how adopting this kind of perspective has been fruitful research orientation.     

Constraints on Analogical Inference

The ability to reason by analogy is particularly important because it permits the extension of knowledge of a target domain by virtue of its similarity to a base domain via a process of analogical inference. The general procedure for analogical inference involves copying structure from the base to the target in which missing information is generated, and substitutions are made for items for which analogical correspondences have already been found. A pure copying with substitution and generation process is too profligate to be useful, and so constraints must be placed on what information is to be carried over. In this paper, the importance of systematicity as a constraint on inference is explored in four studies in which subjects find correspondences between domains and also make inferences. This work suggests that people prefer to make inferences of information connected to systematic correspondences between domains. A second important theme of this paper is that violations of one-to-one mapping can lead to inconsistent object substitutions in inference. The data reveal no such inconsistent substitutions in people's inferences, suggesting that they do respect one-to-one mapping in analogical inference. These findings are discussed relative to four prominent computational models of analogical mapping and inference.     

Syntactical Constraints on Definitions

This essay considers arguments for and against syntactical constraints on the proper formalization of definitions, originally owing to Alfred Tarski. It discusses and refutes an application of the constraints generalized to include a prohibition against not only object‐place but also predicate‐place variables in higher‐order logic in a criticism of a recent effort to define the concept of heterologicality in a strengthened derivation of Grelling's paradox within type theory requirements. If the objections were correct, they would offer a more general moral for the proper formal definition of terms in philosophical logic. The criticism nevertheless seems mistaken both in the substance and specific application with respect to legitimate synctactical constraints on definitions of key concepts in the case of Grelling's paradox. As such, the critique provides no justification for overturning previous conclusions concerning the possibility of resurrecting a type‐observant version of Grelling's heterologicality paradox.     

Constraints on sentence comprehension

The process of comprehending sentences involves the integration of a variety of different information sources, constrained by the available computational resources. This paper surveys the evidence for four types of constraints on sentence comprehension: (1) lexical constraints, (2) contextual constraints, (3) locality-based computational resource constraints, and (4) phrase-level contingent frequency constraints. These four constraints, in combination with grammatical phrase-formation information and prosody, are sufficient to explain how interpretations are constructed for sentences as they are encountered, including complexity effects in unambiguous sentences and interpretation preferences in ambiguous sentences.     

Constraints on Colour Category Formation

This article addresses two questions related to colour categorization, to wit, the question what a colour category is, and the question how we identify colour categories. We reject both the relativist and universalist answers to these questions. Instead, we suggest that colour categories can be identified with the help of the criterion of psychological saliency, which can be operationalized by means of consistency and consensus measures. We further argue that colour categories can be defined as well-structured entities that optimally partition colour space. We provide some empirical support for this claim by presenting experimental results, which indicate that internal structure is a better predictor of colour categories than perceptual saliency.     

Maturational Constraints on Language Learning

This paper suggests that there are constraints on learning required to explain the acquisition of language, in particular, maturational constraints. First, empirical evidence for this claim is reviewed. The evidence from several studies of both first and second language acquisition suggests that normal language learning occurs only when exposure to the language begins early in life. With exposure beginning later in life, asymptotic performance in the language declines: the effects over age of first exposure are approximately linear through childhood, with a flattening of the function in adulthood. These outcomes argue that some type of constraints ensuring successful language learning exist early in life, and weaken with increasing maturation. Second, two hypotheses are considered as to the nature of these maturational changes. One hypothesis is that constraints on learning particular to language acquisition undergo maturational decay. A second hypothesis, which is considered in more detail, suggests that language learning abilities decline because of the expansion of nonlinguistic cognitive abilities.     

信息侵权的伦理规约

信息权利已经成为当代公民最基本的权利之一,但其实现状况却不尽如人意。信息侵权行为大量涌现,究其原因,信息伦理观念的紊乱、信息道德评价的困难、信息伦理规范的失效与信息伦理教育弱化等因素,都加剧了公民信息权利的危机。为此,从伦理层面上,应该通过营造健康的舆论导向、对把关人角色进行重塑、培育公民的责任感、采取他律与自律相结合、加强对公民的信息伦理教育等伦理规约手段,有效遏制信息侵权行为的泛滥。     

Logical Constraints on Judgement Aggregation

Logical puzzles like the doctrinal paradox raise the problem of how to aggregate individual judgements into a collective judgement, or alternatively, how to merge collectively inconsistent knowledge bases. In this paper, we view judgement aggregation as a function on propositional logic valuations, and we investigate how logic constrains judgement aggregation. In particular, we show that there is no non-dictatorial decision method for aggregating sets of judgements in a logically consistent way if the decision method is local, i.e., only depends on the individual judgements on the proposition under consideration.     

Constraints on theories of cognitive aging

There is currently little consensus regarding what must be explained by theories of cognitive aging. In the present article, four empirical generalizations that seem to imply certain constraints in theorizing are identified. These generalizations, and their possible implications or constraints, are that (1) age-related differences are found in a wide range of cognitive variables, implying that either a large number of specific factors or a small number of general factors must be contributing to the age-related differences; (2) the age-related influences on different cognitive variables are not independent, and unique age-related influences appear to be few in number and small in magnitude, implying that some fairly general factors need to be postulated to account for the shared age-related influences; (3) only a small proportion of distinct age-related variance occurs late in practice and at long presentation durations, implying that adequate explanations must include factors operating when the individuals are just beginning to perform the task and when the stimuli can first be registered; and (4) measures of how quickly very simple cognitive tasks can be performed share considerable age-related variance with many cognitive variables, implying that factors related to simple processing efficiency need to be incorporated into the explanations.     

Possible-Word Constraints in Cantonese Speech Segmentation

A Cantonese syllable-spotting experiment was conducted to examine whether the Possible-Word Constraint (PWC), proposed by Norris, McQueen, Cutler, and Butterfield (1997), can apply in Cantonese speech segmentation. In the experiment, listeners were asked to spot out the target Cantonese syllable from a series of nonsense sound strings. Results suggested that listeners found it more difficult to spot out the target syllable [kDm1] in the nonsense sound strings that attached with a single consonant [tkDm1] than in the nonsense sound strings that attached either with a vowel [a:kDm1] or a pseudo-syllable [khow1kDm1]. Finally, the current set of results further supported that the PWC appears to be a language-universal mechanism in segmenting continuous speech.     

Constraints on children's color term acquisition

Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) address an age-old question: Why do children find it difficult to learn color terms? Here these articles are reflected on, providing a focused examination of the issues central to this question. First, the criteria by which children are said to find color naming difficult are considered. Although the age of color term acquisition is decreasing, and color naming might not be more difficult than other abstract attributes, several stages of difficulty are identified. Second, it is argued that there are potentially multiple constraints (e.g., conceptual, attentional, and linguistic) for these multiple stages of difficulty with color term acquisition. Third, it is argued that the validity and reliability of techniques for identifying constraints need to be considered and that converging evidence for the constraints should be provided. Finally, a series of new questions that need to be asked to provide a well-rounded explanation of the difficulties children face when learning color terms is outlined.