Simulating a skilled typist: a study of skilled cognitive-motor performance

We review the major phenomena of skilled typing and propose a model for the control of the hands and fingers during typing. The model is based upon an Activation-Trigger-Schema system in which a hierarchical structure of schemata directs the selection of the letters to be typed and, then, controls the hand and finger movements by a cooperative, relaxation algorithm. The interactions of the patterns of activation and inhibition among the schemata determine the temporal ordering for launching the keystrokes. To account for the phenomena of doubling errors, the model has only “type” schemata—no “token” schemata—with only a weak binding between the special schema that signals a doubling, and its argument. The model exists as a working computer simulation and produces an output display of the hands and fingers moving over the keyboard. It reproduces some of the major phenomena of typing, including the interkeystroke interval times, the pattern of transposition errors found in skilled typists, and doubling errors. Although the model is clearly inadequate or wrong in some of its features and assumptions, it serves as a useful first approximation for the understanding of skilled typing.     

Risk- and protective factors for memory plasticity in aging

ABSTRACT

Risk and protective factors for cognitive function in aging may affect how much individuals benefit from their environment or life experiences by preserving or improving cognitive abilities. We investigated the relations between such factors and outcome from episodic-memory training in 136 healthy young and older adults. Tested risk factors included carrying the ?4 variant of the apolipoprotein E allele (APOE), age, body mass index, blood pressure, and cholesterol. Protective factors included higher levels of education, intelligence quotient (IQ), physical activity, fatty acids, and vitamin D. Average increases in memory performance were seen after training, with ample variation between individuals. Being young, female, and having higher IQ were positive predictors of memory improvement. No other relationships were observed. Similar benefit was observed across APOE allelic variation. This indicates that beyond IQ, age, and sex, known risk -and protective factors of cognitive function in aging were not significantly related to memory plasticity.     

CONSUETUDO CARNALIS IN AUGUSTINE'S CONFESSIONS: Confessing Identity/Belonging to Difference

The political theorist William E. Connolly reads Augustine's Confessions as an exhortation to deny the paradox of identity/difference. The paradox for Connolly is this: if one confesses a true identity, one must be false to difference, but if one is true to difference, one must sacrifice the promise of true identity. I revisit Augustine's Confessions here in order to offer a reading of their paradoxical character that contrasts with Connolly's. I will argue that Augustine's confession does not deny the paradox of identity/difference but exemplifies what it means to struggle within it. I turn to James Wetzel's work on Augustine's idea of free will and Catherine Keller's work on the doctrine of creatio ex nihilo to suggest that treating Augustine's confession as confession reveals this struggle.     

Beyond androgyny: The emergence of sex-role transcendence as a theoretical construct

Recent trends in sex-role research are reviewed with the purpose of showing a paradigm shift in the kinds of issues and questions thought to be important for an understanding of sex-role development. Two recent advances, conceptualizations of androgyny and sex-role transcendence are described with particular emphasis on the emergence of sex-role transcendence as a new theoretical construct. It is argued that while personality, social-learning, and structural-developmental theories account for sex-role identity and androgyny, only structural-developmental theory provides an adequate conceptual framework for the construct of sex-role transcendence. Questions are raised concerning the empirical demonstration of the concept.     

Conceptual combination with prototype concepts

This paper deals with how people combine simple, prototype concepts into complex ones; e.g., how people combine the prototypes for brown and apple so they can determine the typicality of objects in the conjunction brown apple. We first consider a proposal from fuzzy-set theory (Zadeh, 1965), namely, that the typicality of an object in a conjunction is equal to the minimum of that object's typicality in the constituents (e.g., an object's typicality as a brown apple cannot exceed its typicality as a brown or as an apple). We evaluated this “min rule” against the typicality ratings of naive subjects in two experiments. For each of numerous pictured objects, one group of subjects rated its typicality with respect to an adjective concept, a second group rated its typicality vis-à-vis a noun concept, and a third group rated its typicality with respect to the adjective-noun conjunction. In both studies, most objects were rated as more typical of the conjunction than of the noun. These findings violate not only the min rule but also other simple rules for relating typicality in a conjunction to typicalities in the constituents. As an alternative to seeking such rules, we argue for an approach to conceptual combination that starts with the prototype representations themselves. We illustrate one version of this approach in some detail, and show how it accounts for the major findings of the present experiments.     

Behavior modification in education: Contributions and limitations

Behavior modification has been applied widely in educational settings encompassing a wide range of student populations, ages, and areas of focus. Major contributions of behavior modification include development and evaluation of a large number of techniques with extensive classroom research. As a direct consequence of technique development, behavior modification has provided teachers with a selection of classroom practices and information regarding their use. Despite the widespread application of behavioral principles in education, several limitations can be identified including the responses that are altered, the emphasis on response consequences, the focus on child performance rather than behaviors of teachers and others, and the lack of maintenance of improvements evident in many programs. Although limitations can be identified within the field, remarkable advances have been made in identifying educational practices that can improve student and teacher behavior. A major limitation in applying behavior modification to education pertains to dissemination and extension of existing techniques to a large number of settings likely to profit their use. The present paper considers various contributions and limitations of contemporary behavior modification and suggests areas for expansion to augment the progress that has been made.