Reaction time and diazepam plasma concentration in subjects with normal gastric pH

The present study investigated the relationship of reaction time with the plasma concentration of four different formulations of diazepam (liquid, original, new, and generic). On four separate days, over a 4-month period, subjects with normal gastric pH (N=7) were administered each of the diazepam formulations. Blood samples were obtained prior to each dose and at subsequent intervals. Likewise, reaction times were evaluated prior to dosing and then at ten different intervals post-dosing. As hypothesized, reaction time performance was associated with plasma diazepam concentration, regardless of formulation type. This suggests that reaction time is a sensitive measure of cerebral functioning for individuals who are treated with diazepam. In addition to providing a measure of drug effects on cognitive functioning, the results of this study have implications concerning possible hazards of operating machinery or driving motor vehicles for individuals being treated with diazepam.     

Dimensions of sexual behaviour in homosexual men: replicability across time and country

Data on sexual practices in the past two months were obtained from 176 Australian and 159 New Zealand homosexually active men. Factor analysis yielded three major underlying dimensions of homosexual behaviour in each sample, accounting for 53.4 and 54.0% of total variance at baseline and 55.1 and 62.1% at follow-up, respectively. These three dimensions represented unsafe sex involving predominantly anal activity, safe (oral and mutual masturbatory) sex without condoms, and safe anal sex with condoms and withdrawal. Comparison of the four matrices (two countries by two times), using Cattell's S index, indicated high stability of the factor structure across countries and times. These three dimensions of homosexual behaviour appear to represent consistent behavioural clusters across samples and times. They suggest that use of these dimensions in further research on homosexually active men is warranted and that homosexual activities cluster into a number of limited dimensions on which sexual behaviours are interrelated.     

Evaluations of pairs of experiences: A preference for happy endings

Experiences often consist of a number of temporally separated events or outcomes, events which might be positive or negative. Building on previous research, the present paper proposes that the chronological order of the component events influences overall evaluations of these experiences. In particular, a preference for happy endings is hypothesized such that an experience consisting of a positive and a negative event is evaluated as more satisfactory if the positive event occurs last. This preference is examined in three studies in a variety of contexts. A preference for happy endings is shown to influence people's preferences, even to the extent of influencing preferences for segregated versus integrated events (Thaler, 1985). The implications of a preference for happy endings for decision researchers are also explored.     

A text-stimuli presentation manager for the IBM PC with ipsatization correction for response sets and reaction times

IPSAPRO, an ipsative scoring program written for the IBM PC, aids in the detection and transformation of response sets that often contaminate rating scale and reaction time experiments. Response sets such as the tendency to use only extreme points of a rating scale or to work for speed over accuracy in reaction time experiments are removed in IPSAPRO by standardizing each subject’s ratings or times against their own means and standard deviations. Ipsatization can be applied to existing data sets or take place automatically at the data collection stage in a text-stimuli presentation manager that is provided with the program.     

Charpentier (1891) on the size-weight illusion

This paper offers background for an English translation of an article originally published in 1891 by Augustin Charpentier (1852-1916), as well as a summary of it. The article is frequently described as providing the first experimental evidence for the size-weight illusion. A comparison of experiments on the judged heaviness of lifted weights carried out by Weber (1834) and by Charpentier (1891) supports the view that Charpentier's work deserves priority; review of other experimental studies on the size-weight illusion in the 1890s suggests that the idea that the illusion depended on "disappointed expectations," especially with respect to speed of lift, became dominant almost immediately following the publication of Charpentier's paper. The fate of this and other ideas, including "motor energy," in 20th-century research on the illusion is briefly described.     

UNDEFEATED NATURALISM

Philosophical Studies -     

Sex differences in the object representations in the dreams of adolescents

The present study explored sex and age differences in the level of object representations and human movement in the dreams of adolescents. In order to test empirically the contention that early object relations are significantly linked to the formation of children’s gender identity, 389 dreams recorded by 115 adolescents, ages 15–18, were scored for object representations and levels of human movement. As predicted, there were significant differences in the quality of object representations in male and female adolescent’s dream content. In addition, female’s dreams contained significantly higher amounts of human movement than males’ dreams although these differences may well be attributable to longer dream narratives in the female sample. Further, these sex differences were most pronounced at the highest end of the sample age range. Results are discussed in terms of object relations adolescent development. The authors wish to thank Patricia Heenan, M.A., for her invaluable assistance with data management, Alice Pope, Ph.D., for her helpful suggestions, and Dave Cowen, Ph.D., for making his data available to us. Portions of this paper were presented at the Association for the Study of Dreams, June 1996, Berkeley, CA.     

EXPERIENCE AND THE WATER-LEVEL TASK REVISITED:

Abstract— A recently published study (Hecht & Proffitt, 1995) reported that adults in Munich, Germany, whose occupations involved considerable experience with liquids in containers, were less accurate on Piaget's water-level task than were comparable adults in other occupations. The present study attempted to replicate that experiment with a North American sample, but using lighter controls. The resulting data and conclusions contrast with those of the original study and indicate instead, that individuals in occupations that provide much experience with liquids in containers (bartenders, waiters and waitresses) are, in fact, more accurate on two versions of the water level task than individuals of equivalent gender, age, and education in control occupations (salespeople, clerical worker). The data are discussed in terms of both the impact and the limit s of experience on spatial-task performance.