On sensitive rank tests for comparing the effects of two treatments on a single group

The rank testR _n of Cronholm and Revusky [1965] in effect doubles the number of comparisons carried out in the Mann-Whitney test between Treated and Control subjects chosen from a single group ofn and triples the asymptotic Pitman efficiency against shift alternatives by using a series ofn — 1 subexperiments. However, the full series can be too costly or time-consuming. It is shown thatj appropriately chosen subexperiments will permit one to make at leastj/(j+1) of the number of comparisons possible underR _n, with large sample efficiency ofj/(j+2) relative toR _n against shift alternatives and small sample efficiency greater than that,j=2, 3, ...,n — 2. The resulting test criterion is a sum ofj independent Mann-Whitney test statistics. Its null distribution is tabulated forn10 and small sample efficiency comparisons are carried out forn=10.     

Visual and proprioceptive adaptation to altered oculomotor adjustments

Adaptation to spectacles that alter in equivalent amounts the accommodation and the convergence with which objects are viewed was produced under two conditions. In one, S alternately pushed away or pulled toward him a screen that exhibited only a single vertical contour while wearing glaaaes that caused decreases in accommodation and convergence equivalent to 1.5 lens diopters. Here kinesthesis for these arm movements provided the only veridical distance cues, A small, but highly significant, adaptation effect was obtained with a teat in which S, before and after the adaptation period, pointed to the location of a test line in the distance dimension. Corresponding tests consisting in size and in depth estimates did not show an adaptation effect. In the other condition of adaptation, S moved objects by hand toward and away from himself while wearing spectacles that increased accommodation and convergence by the equivalent of 1.5 lens diopters. In addition to the altered oculomotor cues, some veridical visual cues for distance such as are caused by perspective were present. This condition yielded changes in size and depth estimates indicative of an adaptation in visual distance perception and a larger effect of adaptation measured by the pointing test. We concluded that the excess of the adaptation effect measured by pointing over that measured by size estimation represents an adaptation in proprioception, as did the pointing effect produced by our first adaptation condition.     

Primate learning tasks reveal strong impairments in patients with presenile or senile dementia of the Alzheimer type

Eight subjects with the likely diagnosis of presenile or senile dementia of the Alzheimer type were tested on two frequently used primate learning tasks: a concurrent object discrimination task and a delayed non-match-to-sample task. In addition, various tests for cognitive, mnemonic, perceptual, and language functions were applied. The results suggest a severe decline of the Alzheimer subjects in all measures when compared with 10 control subjects matched for age, gender, and education. The two animal learning tasks revealed strong impairments, thus demonstrating a high sensitivity for the detection and assessment of human amnesic disorders. Implications of these findings for human neuropsychological, and especially comparative neuropsychological, research are discussed.     

Slope of regard as a distance cue

It is proposed that some distance cues are learned when a perceptual parameter that varies with observation distance is regularly associated with objects whose distances are perceived because another distance cue operates. If that is the way distance cues can come into existence, it may be possible to identify a parameter that varies with distance but is not a known distance cue and to show that it functions as one. The slope of regard with which an object on the ground is viewed is such a potential distance cue. Its angle varies approximately with the reciprocal of distance. An experiment was done that showed that this slope angle functions as a distance cue. Subjects who looked through a device that altered slope angles gave estimates of the dimensions of an object on the ground. Perceived sizes, which vary inversely with distance, were found to be altered in accordance with the altered slope angle.     

A theory of behavior interaction in dyads: A structuralist account

A theory from the behavioral and social sciences is presented from the structuralist point of view. A more comprehensive theory-net is outlined, some basic terms and core assumptions are formulated, and an expansion of the theory towards two intended applications is given. Finally, some results of a first empirical test of the theory are reported. The aim of the paper is to show that the structuralist account of scientific theories is not confined to mathematical theories from the natural sciences, but can also be applied to relatively informal constructions of the behavioral and social sciences.     

National differences in personality; Brazil and England

The Eysenck Personality Questionnaire (E.P.Q.) was used to compare the structure of personality in Brazilian and English men and women, and to compare the mean scores of these population on the test. Six hundred and thirty six male and 760 female Brazilian adults were compared with 500 English males and 500 English females. It was found that identical factors appeared in the Brazilian as had been discovered in the English populations, and that intercorrelations of scales, reliabilities, etc. were similar for the two populations. Some items from the original study were found inapplicable in Brazil, and new items were substituted. A comparison of the mean scores of the two populations on a reduced scale, embodying only those items which were valid for both populations, showed that there were very few differences between the populations.     

Adaptation in stereoscopic depth constancy

Stereovision is a complex process because perceived depth intervals depend not only on retinal disparity, but also on cues for distance. Because disparity decreases in proportion to the square of the object distance, a compensation process called constancy of stereoscopic depth makes the necessary correction in the perception of depth by taking object distance into account. This compensation process was altered by adaptation. Subjects were exposed to artificial conditions where disparity decreased in proportion to distance instead of distance squared. Alterations in depth perception amounting to 20% were obtained.