An application of the optic sphere theory in discrimination of slant with minimal information

In Johansson and Börjesson (1989), a new theory of visual space perception—the optic sphere theory—was presented in which the hemispheric shape of the retina is utilized for determination of slant of plane surfaces in wide-angle perception. The process of the optic sphere mechanism can be described as the projection of a translating distal line on the optic sphere, and an extrapolation of this projection to a great circle. The determination of the 3-D slant of the distal line is made by identification of points of no change on the great circle during its rotation. The main objective of the present study was to investigate this process as applied to central stimulation of the retina with reduced and minimal information of slant or horizontal orientation. Each stimulus pattern consisted of either two continuous lines or two pairs of dots in motion presented on a computer screen. The pairwise lines and the pairs of dots defined simulated 3-D slants (or horizontal orientations) of different magnitude within each pair, and the subjects' task was to discriminate between these simulated slants. It was shown that the simulations evoke percepts of 3-D slants, and of horizontal orientations, and that it is possible to discriminate between them even from minimal information (pairs of dots). Further, the empirical findings of Börjesson (1994) indicated that longer extrapolations of the projected arc to a point of no change yield less accurate discriminations of slant. We failed to replicate this in Experiment 4, in which case stimulus variables that covaried with extrapolation length were eliminated or minimized. It is suggested that this raises some doubt about discrimination accuracy as dependent on extrapolation length per se. The overall conclusion, however, is that the optic sphere theory represents a possible explanation of, or analogy to, the process utilized by the visual system for determination of the simulated 3-D slants and horizontal orientations in the present study.     

THE INTRINSIC VALUE OF NON-BASIC STATES OF AFFAIRS

Philosophical Studies -     

The effect of polar projection on the perception of euclidean structure from motion

The aim of the present study was to examine whether euclidean structure could be recovered from apparent motion sequences under polar projection. In Experiment 1, length judgments of two sides of a simulated triangle rotating in depth did not reveal effects of type of projection, polar or parallel, on the perception of euclidean structure. However, there was a significant correlation between simulated and produced slants. The results also indicated that absolute depth judgments could not be accounted for by a random mechanism suggested by Todd and Bressan (1990). Experiments 2 and 3, in which a continuous dot surface was substituted for the triangle, showed that polar projection information from a relatively large visual angle, 17.40°, as compared with a small visual angle, 4.35°, facilitated discrimination of depth. Produced height:width ratios were consistently related to simulated shape, although the depth dimension was underestimated. Finally, Experiment 4 showed significant correlations between simulated and produced height:width ratios that could be accounted for only by an analysis in whichX andY velocities were treated independently. As in previous experiments, the variation in the depth dimension was underestimated. It was concluded that the visual system utilizes the additional information that is available in polar projection when recovering structure from motion, but that for different reasons the perceived structure does not become euclidean. These reasons are discussed briefly.     

SOME ETHICAL CONSIDERATIONS OF SHORT-TERM WORKSHOPS IN THE PRINCIPLES AND METHODS OF BEHAVIOR MODIFICATION1

Workshops and seminars to expose different sectors of the professional community to the principles and applications of behavior modification are briefly discussed. The possible misapplication of procedures by conference participants, whose only exposure to behavioral methods has been at these workshops is viewed as a potentially serious ethical issue. It is suggested that the goals of such seminars and workshops must be clarified, and methods of evaluation of the participants' skills devised, lest we contribute to the misapplication of procedures and to the criticism that behavioral methods are unethical approaches to treatment.     

Formal systems of dialogue rules

Section 1 contains a survey of options in constructing a formal system of dialogue rules. The distinction between material and formal systems is discussed (section 1.1). It is stressed that the material systems are, in several senses, formal as well. In section 1.2 variants as to language form (choices of logical constants and logical rules) are pointed out. Section 1.3 is concerned with options as to initial positions and the permissibility of attacks on elementary statements. The problem of ending a dialogue, and of infinite dialogues, is treated in section 1.4. Other options, e.g., as to the number of attacks allowed with respect to each statement, are listed in section 1.5. Section 1.6 explains the concept of a chain of arguments.From section 2 onward four types of dialectic systems are picked out for closer study: D, E, Di and Ei. After a preliminary section on dialogue sequents and winning strategies, the equivalence of derivability in intuitionistic logic and the existence of a winning strategy (for the Proponent) on the strength of Ei is shown by simple inductive proofs.Section 3 contains a — relatively quick — proof of the equivalence of the four systems. It follows that each of them yields intuitionistic logic.     

Irony in psychoanalysis

Irony is a more important element of analysis than we generally recognize. First, verbal irony characterizes the discourse of certain patients who employ it as a defense, both adaptively and as a resistance, especially against the expression of intense affect associated with the transference. The frequent employment of irony reflects a significant character trait, an habitual mode of dealing with conflict. It is also a frequent manifestation of a particularly active self-critical faculty. Ironic employment of a "double audience" is also relevant to analytic technique. Second, situational irony is inherent in many aspects of psychoanalysis, as a process and a point of view. It implies the acceptance of the inevitability of conflict, ambiguity and paradox, never quite capable of perfect resolution. It emphasizes critical examination of mixtures of motives of both analysand and analyst, and it requires perpetual questioning of what might otherwise be taken as accepted doctrine, including the principles of psychoanalysis per se. An ironic stance requires some degree of detachment in conjunction with deep commitment, itself an ironic circumstance. Third, the capacity to understand and employ irony can be traced to childhood, relatively early in the course of development of speech and sphincter control; some of its early determinants are to be found in the anal phase of psychosexual development; it reflects as well the capacity to use certain early defenses and mechanisms originally described as characteristic of the dream work. Its later fate as a prominent feature of character is very much a matter of ego and superego development, including such components as intelligence, verbal skills, the capacity for joking and for play, i.e., controlled regression. Sources of identification in the family and the culture are of obvious importance. Finally, an understanding of irony has an important place in the theory of technique, especially with regard to transference and resistance. An ironic stance and understanding on the part of the analyst are valuable, even essential; but irony may become a questionable defense for him as well as for his patient.     

The changing nature of diagnosis in an inpatient service over 20 years

This study examined factors related to mental illness in children and adolescents. A survey of all 362 files of child and adolescent patients discharged from a single residential treatment facility in 1961-1962, 1971-1972, and 1978 revealed several major diagnostic trends. The proportion of cases diagnosed as schizophrenic decreased by one-third, those diagnosed as neurotic increased over ten-fold, and significant increases occurred in the proportion of children diagnosed as autistic, personality disorder, and behavior disorder of childhood and adolescence. There was a decrease in cases between 6 and 12 years of age and a significant increase in 13- to 18-year-olds. The relative importance of symptoms appeared to be interpreted differently at various times. Significant changes were also found In treatment length, in medications used, and in a number of factors related to the characteristics of the family.     

Recognition hypermnesia: The growth of recognition memory (d') over time with repeated testing

This study sought to determine whether recognition hypermnesia (unforgetting) might be obtained over time with repeated testing of recognition memory. Four types of stimuli were investigated: pictures or words (captions) from configured (funny) or non-configured (non-funny) cartoons. Three recognition tests, each comprising the same stimulus and distractor items, were successively administered after the presentation of a large set of captioned cartoons. Silent think intervals of 5 min were interpolated between recognition tests. Recognition hypermnesia, measured by increasing d' estimates of accessible recognition memory, was obtained with the pictures from configured (funny) cartoons but not with any of the other groups.     

The measurement of loudness using direct comparisons of sensory intervals

Subjects were required in each trial to directly compare two pairs of tones and indicate which pair of tones had the greater loudness difference. Ten 1200 Hz tones differing only in intensity were employed. Subjects made binary comparisons among the 45 tone pairs which can be formed from the set of ten tones. The subjects' binary comparisons of the tone pairs were found to satisfy the transitivity and monotonicity requirements of a positive difference structure. These comparisons of loudness intervals were used to construct a rank order of loudness difference. A loudness scale was constructed from a nonmetric analysis of the rank order of loudness difference for the 45 tone pairs and indicated that loudness was a power function of sound pressure with an exponent of 0.26.