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.     

The “good manager”: Sex-typed,androgynous, or likable?

Recent studies have indicated that people describe a “good manager” in masculine terms. It was hypothesized that this could simply reflect cultural stereotypes, rather than people's perceptions of what combination of traits is desirable in a leader. In Experiments 1 and 2, subjects were presented managerial profiles ascribing all masculine, all feminine, or a combination of masculine and feminine traits (i.e., “androgynous” profiles) to hypothetical managers. Feminine-trait combinations were rated as significantly less desirable than either masculine or androgynous combinations, which were rated as equally desirable. Thus, while femininity per se was not seen as desirable in a leader, it was not viewed as a liability when combined with masculinity, a corroboration of much behavioral research on androgyny. Experiment 3 varied trait likableness and sex-role orientation. Experiments 1 and 2 were replicated for unlikable traits. Surprisingly, the opposite pattern was obtained for likable traits: the feminine combinations were rated as the most desirable, and the masculine combinations were rated as the least desirable. The results are discussed in the context of early research on impression formation and recent work on social cognition.     

A cognitive mediation theory of task goals and human performance

A theory is proposed to explain the linkages between individual task goals and performance. Two cognitive constructs are postulated to mediate between task goals and performance:performance expectancy and performance valence. It is asserted that an individual's task goal has a positive influence on performance expectancy and a negative influence on performance valence. Performance expectancy is proposed to have a positive influence on performance while performance valence is proposed to have a negative influence on performance. Task ability is hypothesized to influence performance both directly and indirectly through its influence on performance expectancy. A laboratory experiment was designed to test the causal model proposed by the theory. A path analysis on the data from this experiment provides strong support for the model, with performance expectancy, performance valence, and task ability predicting 63% of the variance in performance on the laboratory task.     

Who we are: The political origins of the medical humanities

The medical humanities were organized, beginning in the late 1960s, by a small group of people who shared a critique of medical education and a commitment to vigorous action to change it. They proposed to create several demonstration programs in humanities education at American schools. Although the group began with a religious orientation, it soon acquired a broader, more secular mission. As a result of shrewd political organizing, the group attracted members from within medicine, and was awarded a grant to promote the medical humanities. This paper describes these events and sets them in the context of the social and medical history of the 1960s and early 1970s.     

Mid-career change in academia: The decision to become an administrator

This study explored the reasons why professors would leave their teaching/ research occupations to begin new careers as administrators. Valence-Instrumentality-Expectancy theory of occupational preference and choice was used as a framework to examine mid-career change among professors and department chairmen at a major university. Data showed that professors' intentions to change careers and become administrators could be explained by the theory. Analyses of job characteristics demonstrated that professors who want a mid-career change are primarily attracted by the power and formal authority vested in the administrative position, while professors who prefer to remain in their career paths do so because of the autonomy it offers.     

Tables of d′ for variable-standard discrimination paradigms

Signal detection theory (SDT) allows a bias-free measure of sensitivity, d′, to be simply estimated from discrimination data when certain conditions are met. The computation is not straightforward, however, in several popular discrimination designs, such as two- and four-interval same-different designs and the ABX design. The present tables, derived from the SDT models of Macmillan, Kaplan, and Creelman (1977), make possible the estimation of d’ from these complex discrimination designs.     

A deglitching circuit for the AA50 D/A converter

Switching transients or “glitches” are frequently encountered in signal processing applications involving digital-to-analog (D/A) conversion. A low-cost “deglitching” circuit is described and implemented for the Digital Equipment Corporation AA50 D/A converter option on the PDP-8/e minicomputer. Switching transients were eliminated using a noninverting, unity-gain sample-and-hold circuit (employing Datei System’s SHM-IC-1). Switching transients were reduced to below-noise levels across a wide range of output levels and sampling rates.