The effect of repetition on the perception of single letters

Single letters were presented for from one to five flashes, with S required to report what he saw after each flash. The clarity of the letter increased sharply with repetition. Since the letters were no larger than one-third of a degree in size, clarity could not have been increased by S making different fixations from flash to flash and combining them into a total percept. Nor was S guessing, since this could be ruled out by other indicators. Thus, it was concluded that repetition of the stimulus can have a direct effect on the clarity of a S’s percept of that stimulus.     

Sexual addiction: Understanding and treating the phenomenon

The authors describe their multi-faceted treatment of sex addicts and co-dependents, make observations about the needs and issues involved in such therapy, and discuss some of the desired outcomes from the combination of professional help and self-help in the treatment regimen.Ralph H. Earle, PhD, and Gregory M. Crow, PhD, are family therapists and psychologists in private practice in Scottsdale, Arizona     

Psychological effects of sustained shipboard operations on U.S. Navy personnel

This study investigated the psychological and physical health status of 265 crew members on two U.S. Navy ships (a guided missile cruiser and a frigate on convoy escort duty for tankers under U.S. flag) during the Persian Gulf conflict at four time periods during combat-ready operations on a single day. Findings suggest that adaptation occurs to extreme stressors associated with sustained operations. Suggestions are made relative to measures that may minimize psychological and physical conditions that adversely affect performance under conditions of heavy stress. Report No. 89-18, supported by the Naval Medical Research and Development Command, Bethesda MD, Department of the Navy, under research Work Unit No. 63206N.M0096. The opinions expressed in this paper are those of the author and do not reflect the official policy or position of the Department of the Navy, Department of Defense, nor the U.S. Government.     

Properties of spatial representations: Data from sighted and blind subjects

Five questions concerning the properties of spatial representations are explored. (1) How accurately does a spatial representation correspond to the true scene? (2) If inaccurate, how does it differ? (3) Are representations of a familiar scene more accurate than those of an unfamiliar one? (4) Do representations of a scene currently in view differ from those retained in memory? (5) Do the representations of the blind have properties comparable to those-of the sighted? Seven sighted and 7 highly mobile blind subjects, all familiar with a room, and 6 sighted subjects unfamiliar with it, were asked to estimate the absolute distances between 10 salient objects in the room. The 14 familiar subjects made their estimates twice: while they were in the room, and while they were remote from it. Regression analyses showed that the estimates of all subjects had strong metric properties, being linearly related to true distance, with a true zero point; and multidimensional scaling showed that all subjects produced distance estimates that could be scaled in two dimensions to closely match the actual locations of the objects. Familiarity had no effect. The effect of location of testing was the same for both the sighted and the blind: all subjects displayed better spatial knowledge when tested in the room; and all subjects underestimated true distance substantially when tested out of the room. The results showed no qualitative differences as a function of blindness, at least for these highly skilled blind travelers.     

Infant use of relative motion as information for form: Evidence for spatiotemporal integration of complex motion displays

Previous studies of infants’ ability to integrate and to utilize relative motion as information for form in the absence of structural cues have primarily involved motions that are uniform in rate, direction, and path within the form to be constructed. In the present study, we examined infants’ ability to integrate relative motion information from motions that are nonuniform along these dimensions, and from this integrative process to construct a coherently rotating two-dimensional form. Infants’ ability to integrate nonuniform motion was measured with regard to their ability to discriminate the rotating form from a noncoherent control display containing the same absolute motions. The results showed that discrimination of the coherent and incoherent displays was not demonstrated until 7 months of age. Two additional experiments were conducted to rule out the possibility that this discrimination was based on the detection of local regions of coherence, rather than the perception of the global rotating form. In both experiments, the results did not support discrimination based exclusively on local cues alone. From the combined results of all three experiments, we conclude that infants demonstrate the capacity to integrate the information contained within nonuniform trajectories into a coherent structure by 7 months of age.     

The Use of Psychoendocrine Strategies in Post-Traumatic Stress Disorder1

An overview is presented of a pilot psychoendocrine study of PTSD inpatients in comparison with several subgroups of schizophrenic and affective disorder patients. Using a hormonal profile including Cortisol, norepinephrine, epinephrine, testosterone, and thyroxine, it was found that the mean values for the PTSD group were at or near the extreme end of the range for every hormone measured, i.e., relatively low for Cortisol and high for the remaining hormones. The possible clinical meaning of these findings is considered in the light of prior psychoendocrine research on chronic stress. The hormonal alterations in PTSD appear to be persistent and suggest the possibility of being linked largely to traits or character structure, perhaps particularly to cognitive variables related to defense and coping mechanisms, as reviewed in detail for each hormonal system. There appears to be a potential for a fruitful union between the traumatic stress and psychoendocrine fields and some future strategies for developing and strengthening such a union are suggested.     

Inferential procedures for multifaceted coefficients of generalizability

A two-facet measurement model with broad application in the behavioral sciences is identified, and its coefficient of generalizability (CG) is examined. A normalizing transformation is proposed, and an asymptotic variance expression is derived. Three other multifaceted measurement models and CGs are identified, and variance expressions are presented. Next, an empirical investigation of the procedures follows, and it is shown that, in most cases, Type I error control in inferential applications is precise, and that the estimates are relatively efficient compared with the correlation coefficient. Implications for further research and for practice are noted. In an Appendix, four additional models, CGs, and variance expressions are presented.The research reported herein formed part of a doctoral dissertation conducted by Marsha Schroeder (Schroeder, 1986), under the direction of Ralph Hakstian, at the University of British Columbia. We acknowledge with thanks the contributions to this research of Todd Rogers and James Steiger. We are also very indebted to an mous reviewer who provided some important clarifications in connection with two of the models considered. Some support for this research was provided by a grant to Ralph Hakstian from the Natural Sciences and Engineering Research Council of Canada.     

Values of Postpartum Women from the Inner City: An Exploratory Study

An exploratory study of the values of inner-city postpartum women was conducted. Subjects were largely single, with many on/or going on public assistance. Each subject was given the Rokeach Value Scale and asked to prioritize the terminal values (goals) in terms of herself and the instrumental values (means) in terms of what she would like to teach her child. Rankings were compared to corresponding rankings compiled by a national sample, considered a more traditional era, and by marital status within the postpartum mother sample itself. Economic values were ranked higher by inner-city mothers than by the national sample. The top terminal value was family security and the top instrumental value was responsible. When compared by marital status, the only significant difference was the higher ranking of mature love given by married women. Results suggests that the values of the inner-city single postpartum mother can be conceptualized as a mosaic incorporating values shared with the mainstream and values adapted to the conditions of poverty.