The distorted room illusion, equivalent configurations, and the specificity of static optic arrays

The distorted room illusion (DRI) and the attendant argument for perceptual ambiguity is critically analyzed from a Gibsonian/ecological point of view. The notions of multiple specification, conflicting information, and perceptual skill are invoked in showing how the ecological approach can accommodate illusion effects that may remain under mobile binocular viewing conditions. Static optic arrays are shown not to be ambiguous. So-called equivalent configurations are found to be analytic artifacts, appearing when the problem of information is treated in geometrical terms without regard for constraints due to physical and ecological regularities. The relative importance of motion-based and motion-independent information is discussed.     

A maturation effect in response inhibition in the rat

The finding that there are maturational differences between the ability to learn and to perform a task requiring young Wistar rats to inhibit a response was examined. Using an operant task, different from that employed in the previous studies, it was established that the finding was not task specific. The relative contribution of different periods in the early training stage to later savings in learning was also examined. It was confirmed that there is an early performance deficit by weanling rats on tasks requiring them to inhibit a previously learned response in the presence of a discriminative cue. Rats given early training on the task during this period of performance deficit nevertheless showed significant savings in later learning of the task, indicating that they had learned as much in that stage as they would have if given the same training at an age when performance is at the adult level. It was revealed that despite age-related differences in performance it was not so much the age at which early training took place as the amount of training given that affected later savings. The results are discussed in light of evidence of similar differences between the learning and performance of discrimination tasks exhibited by young children.     

Modulation of male mouse genital sniff, attack, and mount behaviors by urogenital substances from estrous females

The modulation of attacks, genital sniffs, and mounts in male SJL/J mice by ovarian-dependent urogenital substances in the urine voided by estrous females was examined. Urogenital substances were applied onto the external urogenital areas of ovariectomized mice. When compared with urine voided by estrous females, which stimulated genital sniffing, mounting, and reduced aggression, bladder urine was ineffective. Genital sniffing and mounting was stimulated by estradiol-17 beta, vaginal fluids, and preputial extract. Aggression was reduced by estradiol-17 beta, urethral catheterized urine, and vaginal fluids. Preputialectomy reduced, but did not eliminate, urinary stimulation of genital sniffing and mounting. Preputial extract stimulated aggression. Urogenital substances from ovariectomized females were ineffective in reducing attacks and stimulating genital sniffs and mounts. It was concluded that the ovarian-dependent chemosignals in the urine voided by estrous females are contributed by the urethra, vagina, and preputial gland, perhaps in part through the excretion of unconjugated estrogens.     

Developmental change in the understanding of affective meaning in music

The development of the understanding of affective meaning in music was investigated. Subjects aged 4, 5, 6, and 19 assigned verbal labels to musical segments previously determined by adults to be representative of one of four affects (happy, sad, angry, afraid). Analysis of correct interpretations and errors revealed a pattern of interactions among age, sex, and affect indicating that the ability to verbalize an understanding of affective meaning in music consistent with that of adult subjects is present during the preschool years. Age-related similarities in performance, as well as differences favoring both younger and older subjects, were observed and were discussed in relation to recent research in, and theories of, affective development and communication.The authors thank H. Julia Hannay, Edward Kemery, Shiela MacDonald, and Robert McGrath for their assistance in this research. The conceptual inspiration of Joseph Intrieri is gratefully acknowledged. We also thank Leslie Brody, Robin Hornik, and several anonymous reviewers for their comments on an earlier draft of the paper. Portions of this research were presented at the Southeastern Conference on Human Development, Baltimore, April 1982.     

Exercise as a buffer of life stress: a prospective study of adolescent health

The hypothesis that physical exercise provides benefits to individuals under periods of life stress has rarely been subject to empirical verification. This article presents the results of a longitudinal study of stress and well-being in adolescence in which the ability of exercise to buffer stress-induced deteriorations in physical health was examined. In accordance with predictions, prospective analyses revealed that the negative impact of stressful life events on health declined as exercise levels increased. These findings suggest that exercise may be a valuable resource for combating life stress. Discussion centers on possible mediating mechanisms and on the practical implications of the results.     

The relationship among genital herpes simplex virus, stress, and social support

Despite widespread popular belief in the activation of recurrent lesions in genital herpes simplex virus (HSV) by psychosocial stress, little empirical evidence supports that contention. This study retrospectively examined the role of stress in activation of HSV lesions as mediated by social support. Participants were 59 volunteers who had self-reported culture-positive genital HSV for at least 10 months. Measures of stress proneness (State-Trait Anxiety Inventory; STAI-Trait), recent stressful events (Schedule of Recent Events; SRE), and subjective appraisal of stress (global self-rating) were administered along with measures of general social support and herpes-specific social support. When retrospective reports of HSV symptoms were examined using a multiple-regression approach, duration of disease and amount of herpes-specific social support were found to be significant moderators of the relation between stress and number of HSV recurrences in the preceding 12 months. When duration of disease was short (less than 4 years), stress (SRE) and number of recurrences were positively associated; when disease duration was longer, there was no relationship. Similarly, at low levels of herpes-specific social support, a positive relation between stress (SRE) and number of recurrences was found. However, at higher levels of herpes-specific social support, no association was found. No relation was found between stress proneness (STAI-Trait) and HSV symptoms. However, subjective appraisal (global rating) of stress in the preceding 12 months was positively and significantly correlated with reported number of recurrences. Results are discussed in terms of their clinical implications.     

Typical delay determines waiting time on periodic-food schedules: Static and dynamic tests

Pigeons and other animals soon learn to wait (pause) after food delivery on periodic-food schedules before resuming the food-rewarded response. Under most conditions the steady-state duration of the average waiting time, t, is a linear function of the typical interfood interval. We describe three experiments designed to explore the limits of this process. In all experiments, t was associated with one key color and the subsequent food delay, T, with another. In the first experiment, we compared the relation between t (waiting time) and T (food delay) under two conditions: when T was held constant, and when T was an inverse function of t. The pigeons could maximize the rate of food delivery under the first condition by setting t to a consistently short value; optimal behavior under the second condition required a linear relation with unit slope between t and T. Despite this difference in optimal policy, the pigeons in both cases showed the same linear relation, with slope less than one, between t and T. This result was confirmed in a second parametric experiment that added a third condition, in which T + t was held constant. Linear waiting appears to be an obligatory rule for pigeons. In a third experiment we arranged for a multiplicative relation between t and T (positive feedback), and produced either very short or very long waiting times as predicted by a quasi-dynamic model in which waiting time is strongly determined by the just-preceding food delay.     

Discrimination learning in a foraging situation

Rats were allowed to forage in a simulated natural environment made up of eight food sources (patches) each containing a fixed number of pellets. Two of the eight contained an extra supply of peanuts. The peanut patches were signaled by an olfactory/visual cue located at the bottom of the ladder leading to the patch. In successive phases the number of sessions per day, height of the patches, and availability of peanuts were manipulated. Subjects showed evidence of discrimination learning under these conditions, although the degree of discriminatory behavior varied as a function of environmental manipulations. Assessment of behavior within foraging sessions showed that subjects systematically changed their patterns of utilization of patches across time. Sampling or exploration, as well as food reinforcement, seem implicated in these results.     

Religion,Type A behavior,and health

In a study of air traffic controllers, religious differences are found in the way Type A behavior is associated with several health status indicators. Associations between the Jenkins Activity Survey (JAS) and physical illness incidence, health-promotive behavior, diastolic and systolic blood pressure, subjective distress and impulse control problems, and alcohol consumption are examined by religious attendance, religious affiliation, and change in affiliation. Findings confirm that Type A does not vary significantly by religion. However, there are several significant findings between Type A and various health indicators. Type A is associated with illness incidence, overall and more strongly in several religion, subgroups. Type A and alcohol consumption are related positively in Protestants and converts, and negatively in churchgoing Catholics. Type A is related to impulse control problems in churchgoing Protestants and to subjective distress in churchgoing Catholics. Finally, in individuals with weak or no religious ties, Type A is associated with lower blood pressure. This last finding suggests that in some people (for example, the irreligious or unchurched), the coronary-prone behavior pattern may have cardiovascular effects which are salutary in at least one respect.The authors wish to thank Dr. Kyriakos S. Markides and Laura A. Ray for their assistance with this study. Address requests for reprints to Dr. Levin at the Institute of Gerontology, 300 North Ingalls, Ann Arbor, MI 48109.