Monocular stereopsis with and without head movement

Random dots moving with various velocity gradients were presented to observers; the motion was yoked to head movement in one condition and to no head movement in another. In Experiment 1, 12 observers were shown motion gradients with sine, triangle, sawtooth, and square waveforms with amplitudes (equivalent disparities) of 12' and 1 degrees 53'. In Experiment 2, 48 observers were shown only the sinewave or square-wave gradient of 1 degrees 53' disparity either with or without head movement so that the observers' expectation to see depth in one condition did not transfer to another. The main findings were: (1) with 12' disparity, the head-movement condition produced perceived depth but almost no perceived motion, whereas the no-head-movement condition produced both perceived depth and perceived motion; (2) with 1 degrees 53' disparity, both conditions produced perceived depth and perceived motion; and (3) when the expectation to see depth was removed, the no-head-movement condition with the square-wave gradient produced no perceived depth, only motion. We suggest that monocular stereopsis with head movement can be achieved without perception of motion but monocular stereopsis without head movement requires perception of motion.     

Perceived parental inconsistency as a factor in the emotional development of behaviour-disordered children

55 English-speaking institutionalized adolescents (37 boys and 18 girls between ages of 14 and 19 yr.) were given questionnaires measuring perceived parental inconsistency and different components of emotional development. Canonical correlation analysis indicated that a significant proportion (51%) of the variation in emotional adjustment was accounted for by parental inconsistency. It is suggested that the efficiency of using parents as agents of change for their behaviour-disordered children can be enhanced by including theory on parenteral inconsistency in program content.     

How far can attraction-caused misalignment account for the Morinaga misalignment effect?

Summary When a line (the pointer) is collinear with a dot, the addition of a second line (the induction line) contiguous with the dot or near it may cause the pointer to appear to be collinear with a point further along or nearer to the induction line. The geometrical relations upon which this effect, which we call attraction-caused misalignment, depends have been studied with the Obonai and Wundt-Loeb (Hotopf, 1981; Hotopf & Brown, 1988) figures. Drawing upon the studies of misalignment in the Morinaga figure carried out by Restle (1976), Day, Bellamy, and Norman (1983), and Day and Kasperczyk (1985), as well as upon two new experiments, we show that misalignment in the Morinaga figure is also attraction-caused misalignment, as previously defined. We conclude with a discussion of a number of theories that aim at accounting for attraction misalignment.     

Murder in the family: An analysis of two Poe short stories

Learning to be possessed has been described elsewhere by the writer as a form of pathogenic relating begun when children are taught by adults that they will receive a lesser penalty for misbehavior if they can show they were not responsible, such as if it were caused by an evil agent or the Devil. It was suggested that learning to be possessed can be an underlying cause of psychopathology, the delusion of persecution in particular. Two short stories by the distinguished American writer Edgar Allan Poe are examined to develop the formulation of learning to be possessed, especially when it has passed to a delusion of persecution. Two propositions are offered: (1) Where it appears that a family member is murdered by a delusional assailant by accident, it is not an accident; and (2) the delusion of persecution entails a memory loss so that the murderer not only can claim lack of personal responsibility for the act, but also spares himself the guilt of having broken a fundamental taboo. Further comparison is made between learning to be possessed as a cause of delusion, and the psychoanalytic theory in which the defense mechanism of projection is central. In the latter theory, interpretation of the delusion is critical; whereas in the former, interpretation is counterproductive because it merely reinforces the delusion.Probably a note of appreciation is due the writer's daughter Cary, who at age 14 is an expert at badgering her father for help with homework assignments. For several weeks the writer was alternatively pestered and cajoled to help Cary with her Poe Project for high school English which required an essay analyzing the work of a great American writer denigrated by the author as weird by his recollection formed decades earlier. Cary's persistence required the author to consider Poe anew, to recognize his unwarranted earlier prejudice, and to recognize that Poe offered him a gift of understanding regarding a topic about which the author had been thinking for several years, namely that form of pathogenic relating named learning to be possessed.     

Continuous and discrete latent structure models for item response data

Relations are examined between latent trait and latent class models for item response data. Conditions are given for the two-latent class and two-parameter normal ogive models to agree, and relations between their item parameters are presented. Generalizationss are then made to continuous models with more than one latent trait and discrete models with more than two latent classes, and methods are presented for relating latent class models to factor models for dichotomized variables. Results are illustrated using data from the Law School Admission Test, previously analyzed by several authors.     

Effects of alcohol and extended practice on divided-attention performance

The effects of alcohol and extended practice on divided attention were investigated using a visual tracking task and an auditory detection task. Subjects performed the tasks with and without alcohol, under single-task (S) and dual-task (D) conditions, both before and after they had received extended practice under single-task conditions without alcohol. Tracking accuracy improved with practice and was impaired under divided-attention conditions but was not affected by alcohol. Speed of detection was impaired by alcohol, improved by practice, and impaired by divided attention. Extended practice did not reduce the influence of alcohol. The effects of both alcohol and practice on speed of detection were significantly greater under dual-task conditions than under single-task conditions. Analysis of detection-task reaction times in terms of relative divided-attention costs, (D-S)/S, showed no effect of alcohol, but a highly significant reduction in costs with extended practice. It is concluded that (1) alcohol and practice can have quantitatively, but not qualitatively, similar effects on speeded performance, and (2) the effect of alcohol is not influenced by the attentional requirements of the task.     

The role of compliance in hypnotic and nonhypnotic analgesia

We modified the standard procedure for administering finger pressure pain in order to assess the extent to which subjects biased their reports of pain reduction when exposed to compliance-inducing instructions. Experiment 1 used only highly hypnotizable subjects and found that compliance-induced reductions in reported pain were about half as large as the reported reductions produced by hypnotic analgesia suggestions. Experiment 2 used low as well as high hypnotizables and administered hypnotic or nonhypnotic analgesia instructions and compliance instructions to the same subjects on separate pain trials. Reported pain reductions produced by hypnotic and nonhypnotic analgesia suggestions and those produced by compliance instructions were substantially and significantly correlated. Furthermore, hypnotizability correlated with compliance-induced reported pain reductions as highly as it correlated with the reported reductions produced by hypnotic analgesia suggestions. Among high hypnotizables (but not low hypnotizables) compliant responding was predicted by social desirability. The findings of both studies indicate that compliance strongly influences the reports of hypnotic and nonhypnotic analgesia proffered by high hypnotizables. The role of compliance in the pain reductions reported by low hypnotizables is less clear-cut.