Use of a virtual reality car-driving stressor in cardiovascular reactivity research

Eighteen subjects (11 males, 7 females) completed a virtual reality car-driving stressor on two occasions several weeks apart. Immediately before and throughout task performance, blood pressure, cardiac output, and total peripheral resistance were assessed. Reactivity scores were calculated for each parameter for each subject as the arithmetic difference between task level and baseline level. The task elicited considerable hemodynamic activation on each occasion of testing, as well as high levels of self-reported task realism, engagement, excitement, and nervousness. Correlation analyses of both absolute and reactivity scores revealed evidence of test-retest reliability. Males were found to exhibit greater absolute levels of and greater increases in systolic blood pressure. The development of tasks suitable for inclusion in a battery of behavioral stressors, responses to which may help identify those at risk for later disease, is of considerable interest in cardiovascular behavioral medicine. The present findings suggest that the virtual reality car-driving task may be useful in this context.     

Soft commitment: self-control achieved by response persistence.

With reinforcement contingent on a single peck on either of two available keys (concurrent continuous reinforcement schedules) 4 pigeons, at 80% of free-feeding weights, preferred a smaller-sooner reinforcer (2.5 s of mixed grain preceded by a 0.5-s delay) to a larger-later reinforcer (4.5 s of mixed grain preceded by a 3.5-s delay). However, when the smaller-sooner and larger-later reinforcers were contingent on a concurrent fixed-ratio 31 schedule (the first 30 pecks distributed in any way on the two keys), all pigeons obtained the larger-later reinforcer much more often than they did when only a single peck was required. This "self-control" was achieved by beginning to peck the key leading to the larger-later reinforcer and persisting on that key until reinforcement occurred. We call this persistence "soft commitment" to distinguish it from strict commitment, in which self-control is achieved by preventing changeovers. Soft commitment also effectively achieved self-control when a brief (1-s) signal was inserted between the 30th and 31st response of the ratio and with concurrent fixed-interval 30-s schedules (rather than ratio schedules) of reinforcement. In a second experiment with the same subjects, the fixed ratio was interrupted by darkening both keys and lighting a third (center) key on which pecking was required for various fractions of the fixed-ratio count. The interruption significantly reduced self-control. When interruption was complete (30 responses on the center key followed by a single choice response), pigeons chose the smaller-sooner reinforcer as frequently as they did when only a single choice response was required.     

Like a bee on a windowpane: Heyting's reflections on solipsism

This paper presents the content of the unpublished notes that the Dutch mathematician Arend Heyting wrote in different periods of his life on solipsism and that are preserved in Heyting's archive at the University of Amsterdam. Most of the notes are quoted here and translated into English. Their study shows the originality of Heyting's reflections on a subject that was typical of his master, L. E. J. Brouwer, the father of intuitionism.     

Content validity: A neglected strategy for developing managerial selection tests?

There is a lack of quick, valid, and cost effective methods for selection of low-and mid-level managerial personnel. Using content-valid methods to develop managerial selection instruments may reap substantial benefits for applicants as well as for the organizations using such tools. To this end, based upon extensive job analysis, a content-valid managerial selection test was developed. Criterion-based validity collected on the new instrument suggested that an instrument developed using content-valid procedures can also show acceptable levels of criterion validity.     

Tolerance of ambiguity: A review of the concept, its measurement and applications

This paper reviews the scattered and diffuse literature on the tolerance of ambiguity construct (AT). The work by Frenkel-Brunswik (1948) is considered in some detail to help explain the origin of the concept as well as its diffusion to many areas of psychology. Second, thirty years of correlational research, which looks at the studies correlating AT measures with a variety of psychological variables, are reviewed. Third, evidence for the differential distribution of AT among particular groups is reviewed. Fourth, the psychometric properties of the various self-report AT measures are considered in some detail. The two final sections look at organizational and cultural correlates of AT (the areas currently most interested in the AT concept). The conclusion attempts to explain varying patterns of interest in the AT construct and its current status.     

Change in affective state assessed by impaired color-naming of threat-related words

This study investigated the effects of mood induction on Stroop color-naming times for threat-related words. The subjects’ task was to color-name sets of threat-related words and affectively neutral matched control words both before and after mood-induction. Subjects were shown a short film about the medical effects of nuclear war (negative affect manipulation), a humorous cartoon, or no film. A significant and highly reliable color-naming decrement of the threat-related words was observed only after the negative affect manipulation. This indicates that the attentional bias towards the processing of threat-related material observed in clinically anxious or high Trait-Anxious subjects can be induced in initially nonanxious subjects. An incidental recall task included in the procedure provided no evidence of mood state dependent recall.     

An inexpensive 1-millisecond experiment control interface for IBM PCs and its user-friendly control language

An inexpensive, professionally manufactured, digital I/O experiment control interface for any PC-compatible computer is described. It plugs into a standard printer port and provides 1-msec accuracy for up to 4 inputs and 22 outputs. It also allows experiment control procedures to be written in an easy-to-learn, easy-to-use Experiment Control language (ECBASIC). In addition to many instructions specifically designed to simplify behavioral research, ECBASIC provides for transparent collection and storage of event logs.     

Creating a hypertext markup language document for an information server

This paper briefly overviews the World-Wide Web. It then provides a short tutorial on the use of the hypertext markup language to publish information on the web. Hypertext markup language is a special page-layout language that was developed to help make creating and retrieving information on the web consistent and efficient. Hyperlinks within hypertext markup language make the language especially powerful because they enable the browser to transparently retrieve images, movies, or audio files from virtually any computer on earth simply by clicking on an item displayed on the monitor.     

Gender, object, and humor

Male and female respondents rated jokes with either a female initiator/male target of joke or vice versa. For male respondents, the gender of the joke target made no difference. For female respondents, however, jokes with males as the target received significantly higher ratings than jokes with females as the target.     

Habituating effects of nonhydrational oral stimulation on ingestive behaviors

The role of oral stimulation in the control of ingestive behavior was investigated using an airlicking procedure. It was hypothesized that the oral experience of airlicking would inhibit subsequent ingestive activity (water intake), possibly via an habituation process as suggested by recent research (Swithers, 1996). Rats were implanted with gastric cannulas and trained to lick at a stream of air. Experimental conditions con-sisted of combinations of airlicking and intragastric hydration followed by oral intake of water. In support of the main hypothesis, airlicking did reduce subsequent ingestive activity. While the role of habituation was not tested directly, the results lend support to the proposal that oral stimulation does control ingestion, and this control could act through an habituation process.