The role of spatial-frequency channels in the perception of local and global structure

Adaptation and reaction-time techniques were used to examine the role of different spatial-frequency channels in the perception of local and global structure. Subjects were shown figures consisting of a large C composed of smaller Cs and asked to identify the orientation of either the global C or its local elements. Prior to performing the task subjects were adapted to different spatial frequencies and the effect on subsequent performance was assessed. Two main results were found. First, the adapting frequency that most affected the global task was often lower than that most affecting the local task, suggesting that high and low frequencies independently code the structure of an image. Second, reaction time to global figures was often faster than to local figures at all levels of detectability, again suggesting a role of low-frequency channels in global processing.     

Visual object recognition in patients with right-hemisphere lesions: axes or features?

An investigation is reported of the ability of normal subjects and patients with right-hemisphere lesions to identify 3-D shadow images of common objects from different viewpoints. Object recognition thresholds were measured in terms of angle of rotation (through the horizontal or vertical axis) required for correct identification. Effects of axial rotation were very variable and no evidence was found of a typical recognition threshold function relating angle of view to object identification. Although the right-hemisphere-lesion group was consistently and significantly worse than the control group, no qualitative differences between the groups were observed. The findings are discussed in relation to Marr's theory that the geometry of a 3-D shape is derived from axial information, and it is argued that the data reported are more consistent with a distinctive-features model of object recognition.     

The integration of visual and functional classifications in concept formation

Summary Simple motor responses of different similarity were assigned to geometric figures of different similarity. Subsequently, subjects had to learn hierarchical classifications of visually similar or dissimilar figures which were associated with either similar or dissimilar responses. In this way, the visual and the functional similarity of the conceptually united figures were orthogonally varied. It was found that visually similar figures are conceptually classified fastest regardless of their functional similarity. In contrast, functional similarity has a considerable impact on the hierarchical classification of visually dissimilar figures. Functionally similar figures are conceptually faster classified than dissimilar ones. From the results we conclude that concepts are autonomously formed as mediating representations in stimulus-response coordinations. The hierarchical organization of concepts is thereby based on the sequential organization of both the visual input and the behavioral output. Further consequences of this approach are discussed.Portions of this research were presented at the International Symposium on Structure and Function of Human Memory, in Memoriam Hermann Ebbinghaus, Berlin, July 1985     

San Diego suicide study: comparison of gay to straight males

Previous large studies of completed suicides have not considered sexual orientation in their data analyses. In this study, data from the known homosexual subpopulation (13 males, aged 21-42) in a series of 283 suicides were examined. They were compared with all other aged male suicides 21-42 (n = 106). Both groups showed considerable substance abuse plus a variety of other psychiatric diagnoses. Both also had a high frequency of relationship difficulties near the time of death. Gays who committed suicide did not have a history of more police trouble and were no more likely to be living alone than the comparison group. They did not have more prior suicide attempts or previous psychiatric treatment. We conclude that, among the factors examined here, there appears to be little difference between gay and heterosexual male suicides.     

On the relation between genuine and simulated amnesia

When claims of amnesia are made in legal cases, it is necessary to determine whether they are genuine or simulated. This article assesses current knowledge of the relation between genuine and simulated amnesia and discusses issues that are critical to understanding of the problem. It is argued that there are few well established facts regarding the nature of simulated amnesia, and no evidence that experts can distinguish accurately between genuine and simulated amnesia. Suggestions are made for future research that draw upon recent advances in cognitive psychology, social psychology, and neuropsychology.     

Cognitive and social functioning across adulthood: age or student status differences?

Younger adult students between 19 and 24 years of age (M = 21.3 years), older adult students between 61 and 76 years of age (M = 67.9 years), and older adult nonstudents between 62 and 76 years of age (M = 68.5 years) were assessed for health (self-ratings of physical and mental health), social functioning (self-ratings of physical and mental activity, perceived role activity level, perceived roles, locus of control, and age-norm expectations), and cognitive functioning (Wechsler Adult Intelligence Scale-Revised vocabulary and block design, and paired associate memory). Age differences were observed in self-ratings of health, social roles, intellectual performance, and memory. No student status differences were observed. The results are discussed in terms of plasticity of intellectual function and characteristics of student status in later adulthood.     

Personality characteristics of Divorce-Prone individuals: A preliminary clinical study

This study focuses on Divorce-Prone individuals and the question of why some persons fail in one marriage after another. The authors studied 12 individuals who had each been divorced two or more times. They found that the cases fell into one of three broad and overlapping groups. The groups have been called the Self-Involved Narcissists, the Compliant Depressed, and the Casualties of Life's Vicissitudes. The individuals and the groups demonstrate a different etiology, different treatment problems, and a very different prognosis.     

Book reviews

Current Psychology -