A reexamination of mental arithmetic models and data: A reply to Ashcraft

In a review of the chronometric literature, M. Ashcraft (1982, Developmental Review, 2, 213–236) concludes that adults store each basic arithmetic fact in a table-like retrieval network. In my commentary (1983, Developmental Review, 3, 225–230), I argued that procedural knowledge (stored rules, principles, or heuristics) might be a cognitively more economical basis for generating many number combinations. In this paper, I draw an analogy between this alternative model of number fact representation and how computers efficiently reconstruct arithmetic combinations, note that the research findings do not clearly support any one model of mental arithmetic, and attempt to address Ashcraft's (1983, Developmental Review, 3, 231–235) criticisms of my model.     

Learning to form relationships in infancy: Parallel attainments with parents and peers

Freud's assertion notwithstanding, the attachment relationship is not “without parallel” in social life. Children's attainments in forming attachments to parents parallel the steps they take in relating to their peers. During the first 3 years of life, in both domains, infants come to recognize prospective social partners, communicate with them, engage them in patterned interaction, including both cooperation and conflict, learn from their presence and actions, and interact in idiosyncratic ways with particular companions. Toward the end of this period, children show signs of acquiring generalized concepts of the social relationships in which they engage. It is proposed that biological constraints on learning promote human infants' interest in and rudimentary abilities to interact with other members of their species. Subsequent incidental and intentional learning processes shape both the child's attachments and less intense relationships with other persons.     

Eye-fixation patterns during reading confirm theories of language comprehension

Eye-movement patterns during reading are consistent with proposition-by-proposition models of speech comprehension. (1) Fixation times are least affected by word length at ends of clauses: this confirms the theory based on the study of speech comprehension that, at such points, attention is directed inward to text integration. (2) Fixation time for words at the end of clauses is longer for canonical sequences which conform to the pattern, “N-V-N = actor-action-object”; this confirms the view that complete semantic integration of such sequences is routinely delayed until their completion. A two-variable model based on principles of exhaustive visual search and speech comprehension accounts for 80% of the fixation durations in a sample paragraph from Just and Carpenter (1980) and Thibodeou, Just ond Carpenter (1982). This comprehension-based model compares favorably with their models constructed within a production-system framework. This result clarifies the relationship between reading and listening.     

Computing with connections in visual recognition of origami objects

This paper summarizes our initial foray in tackling Artificial Intelligence problems using a connectionist approach. The particular task chosen was the visual recognition of objects in the Origami world as defined by. The two major questions answered were how to construct a connectionist network to represent and recognize projected line drawings of Origami objects and what advantages such an approach would have. The structure of the resulting connectionist network can be described as a hierarchy of parameter or feature spaces with each node in each of the feature spaces representing a hypothesis about the possible existence of a specific geometric feature of an Origami object. The dynamic behavior of the network is a form of iterative refinement or relaxation whose major characteristic is to prefer more globally interesting interpretations of the input over locally pleasing ones. Examples from the implementation illustrate the system's ability to deal with forms of noise, occlusion and missing information. Other benefits are an inherently parallel approach to vision, limitation of explicit ordering of the search involved in matching model to instance and the elimination of backtracking due to the sharing of partial results as the search progresses. Extensions and problems are also discussed.     

Ear asymmetry in recognition of unfamiliar voices

Female right-handed subjects were presented with a memory set consisting of five unfamiliar female voices. They were then tested with a recognition procedure in which samples of voice, memory set or novel, 2 or 4 sec in duration, were heard in one ear and a competing noise stimulus was heard in the other ear. There was an overall left-ear advantage in accuracy of recognition. This advantage held particularly for identifications of memory-set voices in the second half of trials. Internal analyses indicated that the left-ear advantage could not be attributed to greater retroactive interference during right-ear presentation. Congruent with studies of recognition of unfamiliar faces, the findings suggested right-hemisphere superiority in the recognition of unfamiliar voices.     

Social-cognitive development: Domain distinctions and coordinations

Recent research on social-cognitive development has identified three conceptual domains which form the basis of the child's structuring of the social world: the moral, societal, and psychological domains. Research on distinct conceptual domains has thus far focused on events and actions that are clear examples of content for the domains. The issue of domain coordinations has not been addressed. This paper examines coordinations between conceptual domains in children's social judgments through a discussion of the experiential origins of the domains and judgments about mixed, second-order, and ambiguously multifaceted events. The utility of the conceptual domain model for understanding social judgments and social development is discussed.     

Positive feedback in hierarchical connectionist models: Applications to language production

Recent connectionist models of the perception and production of words make use of positive feedback from later to earlier levels of processing. This paper focuses on production and identifies several specific effects of phoneme-tomorpheme feedback. In addition, I argue that there is support for the use of this kind of feedback in production from experimental and naturalistic studies of slips of the tongue.