Theangular function of arod-and-frame illusion

It was predicted that vertical settings of a rod surrounded by a square frame would be in error in the direction of the frame axis closest to true vertical as the frame varied in tilt. Results were in accord with this hypothesis. The implications of the results are discussed.     

When is a weight not illusory?

Weight illusions occur whenever some aspect of an object--such as its size, material or colour--arouses the expectation that its weight will be heavier or lighter than it actually is. The direction of the illusion normally contrasts with the expected weight. When objects are hidden from sight and lifted by strings they can provide no misleading cues, and a correct weight-expectation should be achieved after one or two trials. When a visible object has the same physical and apparent weight as a hidden object, it can be defined as non-illusory. Weighted tins and polystyrene blocks of various sizes were compared with hidden weights. Tins were found to be non-illusory when their density was about 1.7, and polystyrene blocks when their density was about 0.14.

Weight illusions may be due to a central scaling process which enables a wide range of weights to be estimated, different ranges being selected according to the expected value of the weight. If the selected range is inappropriate an illusion occurs. Changes in expected value could also allow for the operation of “weight-constancy” during changes in proprioceptive stimulation.     

Stability and Change in the Career Plans of Ninth Grade Girls

Changes in career plans occurring between the ninth grade and one year after high school were examined in a sample of 7,061 girls from the Project talent Data Bank. Longitudinal changes for five career groups (Natural Sciences, Professions, Teaching, Office Work, and Housewife) were examined as a function of selected aptitude and interest measures. Girls who change differ from girls who maintain the same plans over time in each career group on most of the measures employed. There is a tendency for the brighter girls to change from initial careers in Office Work and Housewife more frequently than the less able girls, whereas those who shift out of the career-oriented groups, Sciences, Professions, and Teaching, are scholastically less capable than those who maintain these same plans over time.     

Is the weber fraction a function of physical or perceived input?

It is well known that a given physical input (e.g. intensity of light or sound, length or weight of an object) does not always give rise to the same sensation. For example, arrow heads affect the perceived length of lines (Muller-Lyer illusion) and size affects the apparent weight of an object (size-weight illusion). It is generally assumed that the differential threshold is a simple function of the physical intensity of the stimulus. We may however ask whether the differential threshold is affected by illusions.

To try to answer this question we estimate differential thresholds under a pair of conditions in which the relevant input is the same but appears different. Using the size-weight illusion, we have found that the differential threshold for weight is greater for a set of small weights than for a set of larger and apparently lighter weights.     

Factors Associated with the Participation of Women Doctorates in the Labor Force

Participation in the labor force by 1,547 women doctorates of 1957 and 1958 and the factors associated with their career development and commitment were examined. 91 per cent of the women doctorates of 1957 and 1958 are in the labor force at present, and of those, 81 per cent work full time. When a woman doctorate's family responsibilities are greatest, i.e., during the rearing of her pre-school children, she is not as likely to participate fully in the labor force. However, if the married woman doctorate has demonstrated an early career commitment, she persists likewise later on.     

The size-constancy of underwater swimmers

The size-constancy of divers was measured by requiring them to adjust the distance between two disks of unequal size so that they appeared phenomenally equal. In clear water divers showed greater constancy-ratios than on land. In murky water, where visibility was reduced by suspended particles, constancy-ratios were the same as, or less than, on land. It is suggested that these effects may be due to changes in apparent distance: in clear water objects appear nearer through refraction, but in murky water they appear further away because of the distance cues provided by the visibility gradient.

The orientation of the display, or of the diver's body, did not affect constancy under water, though it does on land. It is argued that the effect on land is due to visual and proprioceptive cues which are absent in the water.     

Some Effects of Reduction of Extra-Classroom Crowding in a School Environment

The effects of reduced enrollment were studied by examining two architecturally identical schools. One school experienced a 43% reduction in enrollment while the other's enrollment remained constant. Reduction in enrollment had a number of positive benefits, including improved attitudes about the school environment and reduced faculty absenteeism. Findings regarding academic performance were less clear.     

Dynamic changes in work/rest duty cycles in a study of sleep deprivation

The effects of moderate workload and 72 h of sleep deprivation were studied using a modified continuous-performance paradigm. Ten subjects were tested hourly on a number of perceptual and cognitive tasks designed to require approximately 30 min to complete, with the remainder of each hour free. As sleep deprivation continued, the average time on task increased at an accelerating rate. The rate of increase differed among tasks, with longer tasks showing greater absolute and relative increases than shorter ones. Such increases confound sleep deprivation and workload effects. In this paper, we compare the advantages and disadvantages of several experimental paradigms; describe details of the present design; and discuss methodological problems associated with separating the interactions of sleep deprivation, workload, and circadian variation with performance.