A classical IQ model of the stages of cognitive development

Based on the construct of classical IQ (mental age/chronological age), a model of the proportions of the population at various stages of cognitive development as a function of age is proposed. The model, which accounts well for empirical data for the age range 13 through 17 years, is shown to compare favorably with other theoretical models. The success of the model provides further evidence of the salience of the construct of general cognitive capacity in differential psychology.     

RESPONSE TO CRITIQUES OF ETHICS IN AN AGE OF TECHNOLOGY

Abstract. Both Roger Shinn and Robert Stivers ask whether technology has a momentum of its own that is difficult if not impossible to control (“autonomous technology” or “technological inevitability”). I reply that the difficulty in controlling technology is a product of economic and political institutions (such as corporate lobbying and campaign contributions) rather than of any inherent characteristics of technology. Against Stivers's assertion that the ecosystem should be the center of value in environmental ethics, I defend the process view that all beings are valuable, but they are not equally valuable in their richness of experience or their contribution to the experience of others. I also consider his caveats about ambiguities in the concept of sustainability. Two questions raised by Mary Gerhart are taken up: the difficulties of interdisciplinary writing and the role of theological ethics in discussions of public policy. In dialogue with Frederick Ferre I explore the role of alternative visions of the good life as a source of social change. In the face of diminished concern about social justice and environmental sustainability among citizens and in Congress since the book was written, I express long-range hope, but not optimism about the short-term prospects for change.     

An optical encoder and XY oscilloscope interface for the IBM PC

This paper outlines a prototype dual-purpose interface card for the IBM PC for use in research on motor learning and control. The card enables automatic interfacing for up to four angular optical encoders and presents high-speed visual data on an XY oscilloscope. In addition, it uses two single-chip microcontrollers with minimal external hardware, providing a more powerful instrument than is available in discrete hardware. Two microcontrollers operate independently of the experimental computer (IBM PC), using a common interface allowing the exchange of data. This interface card frees the experimental computer from the workload associated with optical encoders and high-speed XY displays, resulting in less complex experimental setups and data collection programs.     

Role of optical flow field asymmetry in the perception of heading during linear motion

During linear translation through a stationary environment, the pattern of optical flow generated on each retina is symmetrical when the head is aligned with the heading, but during lateral gaze the optical flow is asymmetric. We assessed whether human subjects could use the magnitude of this asymmetry to determine the direction of heading during passive translation through a 3-D environment. When allowed to move their heads in order to look in the direction of self-motion, subjects indicated their heading precisely and accurately. When the head was locked in alignment with the misaligned body, and gaze adjustments were not allowed, responses were quite precise, but showed a large bias which increased with increasing heading angle.     

Objects and attributes in divided attention: Surface and boundary systems

A series of experiments investigated concurrent discriminations of surface and nonsurface attributes, including color, brightness, texture, length, location, and motion. In all cases but one, results matched those previously reported: Interference occurred when two discriminations concerned different objects, but not when they concerned the same one. In the two-object case, interference was the same whether discriminations were similar (e.g., two surface discriminations) or different (e.g., one surface, one boundary). Such results support a model of visual attention in which separate visual subsystems are coordinated, converging to work on surface and boundary properties of the same selected object. A partial exception is color: For reasons that are unclear, color escapes twoobject interference except from other, concurrent surface discriminations     

The kinematics,movement phasing and timing of a skilled action in response to varying conditions of uncertainty

This study was designed to provide a detailed analysis of the parameters which interact to produce a field hockey drive. The drive was performed by an elite performer under two conditions of uncertainty (Blocked and Random). The subject was asked to drive a field hockey ball toward a specified target. In the Blocked condition the speed of the approaching ball remained constant (20, 30 and 40 m.p.h.) while in the Random condition these speeds were randomly assigned to each trial. Cine analysis of the subject's successful responses under the two experimental conditions led to an investigation of the kinematics, phasing, and timing of the stroke. The subject placed emphasis upon varying the initial phases of the stroke (i.e., backswing and preparatory phases) in order to produce a temporally consistent ballistic downswing to ball contact. It seemed likely that the subject appraised the ball speed that was being delivered and then incorporated additional stick movement to ‘mark time’ before initiating temporally consistent movement phases, as spatial uncertainty increased, the subject delayed her response initiation, but then tended to respond in intervals of one reaction time for each stroke phase. Consistency was evident for displacement and initiation point values, but to a lesser extent than existed for the other variables. However, as a result of this adjustment in spatial location and displacement of the stick end during the preliminary phases of the response, the subject was able to produce a consistent and accurate ballistic downswing.     

Similarity and contrast in memory for relations

The paper reports four experiments concerned with memory for sets of categorically related or unrelated nouns, as a function of the extent to which initial processing focused on categorical or distinctive features of the nouns. The general finding is that distinctive features are valuable for later intracategory discrimination in recall and recognition, but categorical features are not, as judged by cued recall, recognition, measures of association between items, and categorical intrusion errors. A theoretical framework, based on the diagnostic value of features for various classifications, is offered as an account of the results.