Binocular depth discrimination depends on orientation

Using both the method of adjustment and forced-choice techniques, it was found that binocular depth thresholds depend on the orientation of the test targets, which in these experiments consisted of long, thin rods. Stereoacuity is greatest with vertical rods and decreases progressively as the angle of orientation approaches horizontal. The relationship between stereoacuity and orientation is governed by the orientation of the images of the targets on the retina, and is predicted fairly well by the sine of the angle of orientation, suggesting an equivalence between angular rotation and reductions in rod length.     

Auditory contralateral induction: An early stage in binaural processing

Binaural interaction was studied using headphones presenting signals (tones or filtered speech) to one ear and noises of various spectral compositions to the other. Every half-second, the sides receiving the signal and noise were reversed. The noise was always perceived to alternate from side to side, but the signal appeared to be stationary and diffusely localized about the midsaggital plane when the noise contained the spectral components of the signal at appropriate intensity levels. This delateralization of a monaural signal results from a process called “contralateral induction” (CI). Additional observations indicate that CI corresponds to an early stage in binaural interaction which generally escapes notice because of further perceptual processing.     

Distance perception under binocular and monocular viewing conditions

First, third, and fifth graders and college adults made judgments of absolute distance in a binocular (full-information) condition and in one of three monocular conditions: redundant texture gradient, compression gradient, and control (no texture). No age-related differences in accuracy of judgment were observed in any of the conditions. Substantial differences in the effectiveness of different kinds of information were found, however. The results indicate that the ability to register information for distance is well developed by first grade, but that substantial limitations exist on the visual system’s ability to process various forms of redundant information.     

Lump detection in simulated human breasts

Sixteen observers palpated silicone models of human breasts containing lumps 1.6-12.1 mm in diameter. Detectability depended on the size of the lump, producing a systematic psychometric function. In eight observers who participated in three or more sessions, performance improved with practice, with most improvement occurring within one or two 26-trial sessions. Three-week retention measures disclosed no appreciable decrease in performance, but a significant correlation was found between the number of lumps detected and duration of trial (p < .01). There was no difference in performance between four observers who used their preferred hands and four observers who used their nonpreferred hands. These data establish that examination of breast models for the detection of lumps simulating cancer is a task amenable to experimental analysis.     

Alcohol-induced changes in contrast sensitivity following high-intensity light exposure

Relatively low doses of alcohol produced large, significant, dose-related increases in the time required to recover foveal contrast sensitivity following bright light exposure. Nine subjects participated in a double-blind experiment involving three dose levels of alcohol (including placebo). The luminance parameters of the test were comparable to those encountered in practical situations such as driving. The alcohol-induced delay in glare recovery is probably retinal and lasts for several hours after drinking.     

Rules, risk and self-disclosure

The notions of rules and risk are inextricably involved with self-disclosure in counselling and in personal relationships. A hundred single British male under-graduates were asked to rate 120 self-referent items in terms of whether, if that item were true of them, they would like or dislike that aspect of themselves; and then to assess the degree of risk that might be entailed in disclosing it to a close male friend, a close female friend, a male acquaintance, and a female acquaintance. The characteristics most positively valued included happiness, health, heterosexuality, agood' job, and getting on well with others (including parents). In general, subjects anticipated greater risk in disclosing negative than positive characteristics, though there were some exceptions. The degree of friendship with the recipient of the disclosure appeared to lessen the anticipated risk of disclosure, while the sex of the disclosee generally made only a marginal difference. The findings are discussed in terms both of students' self-esteem and also of their relevance to counselling. Additionally, the social exchange implications of positive and negative self-disclosure are considered.     

Fear of failure and fear of success

Verbal leads were used to elicit TAT responses from 160 male and female high school seniors, under neutral and aroused conditions. These protocols were scored for fear of success (FOS) according to the 1973 revised scoring system developed by Horner, Tresemer, Berens, and Watson (Note 1) and also scored for fear of failure (FOF) according to the Hostile Press Scoring System developed by Birney, Burdick, and Teevan (1969). Significant positive correlations between the two motive scores were obtained under both neutral and aroused conditions. The lack of independence between the FOS and FOF scores reflects theoretical similarities in the definitions of the motives, as well as considerable overlap in the scoring systems. It was hypothesized that for those people (especially women) whose affiliative and achievement needs are interrelated, FOF and FOS may be nearly equivalent, since fear of social rejection thus becomes tantamount to fear of failure.     

Digital computer estimation of eye fixations

A method is presented for estimating eye fixations to the degree of accuracy desired. In the process, the quantity of data is greatly reduced so that analysis can be accomplished at the end of each experimental run. The algorithm is particularly suitable for “slow” computers because the analog-to-digital conversion rate can be low and because the data reduction process decreases the number of calculations required to obtain the analytical results.