PIGEONS ARE SENSITIVE TO THE SPATIAL ORGANIZATION OF COMPLEX VISUAL STIMULI

Abstract— Two experiments investigated the role of spatial organisation in the discrimination and generalization of complex visual stimuli by pigeons. In Experiment 1, after pigeons had been trained to discriminate line drawings of four objects, they were tested with novel pictures in which the same component parts of the objects were spatially rearranged. The spatially scrambled pictures led to a dramatic drop in recognition accuracy, hut responding remained above chance. In Experiment 2, pigeons reached a high level of discriminative performance when required to choose among four different spatial arrangements of the same object parts. These results confirm Cerella's (1980) conclusion that pigeons discriminate the component parts of complex visual stimuli, but. unless it is assumed that the scrambling deleted or created emergent features, the results disconfirm his conclusion that spatial organization plays no role in pigeons' picture perception.     

Person-centered theory and the contemporary practice of psychological testing

This paper examines the effects of person-centered theory on contemporary psychological testing. Seven basic ideas or assumptions, which are integral to and guide the testing process, are identified and briefly discussed. Each idea is considered to have been affected either directly or indirectly by person-centered philosophy. Some of the ways in which these ideas are reflected in contemporary testing practice are indicated.     

Arguing about definitions

What are the implications of taking seriously Chaïm Perelman's proposition that “definitions are rhetorical”? Efforts to find Real Definitions are dysfunctional to the extent they direct argumentation toward pseudo “is” claims and away from explicit “ought” claims about how words are to be used. Addressing definitional disputes explicitly as propositions ofought rather thanis could put on the agenda the pragmatic concerns of definitional choice that might otherwise remain tacit.     

Twenty-five basic theorems in situation and world theory

Conclusion The foregoing set of theorems forms an effective foundation for the theory of situations and worlds. All twenty-five theorems seem to be basic, reasonable principles that structure the domains of properties, relations, states of affairs, situations, and worlds in true and philosophically interesting ways. They resolve 15 of the 19 choice points defined in Barwise (1989) (see Notes 22, 27, 31, 32, 35, 36, 39, 43, and 45). Moreover, important axioms and principles stipulated by situation theorists are derived (see Notes 33, 37, and 38). This is convincing evidence that the foregoing constitutes a theory of situations. Note that worlds are just a special kind of situation, and that the basic theorems of world theory, which were derived in previous work, can still be derived in this situation-theoretic setting. So there seems to be no fundamental incompatibility between situations and worlds — they may peacably coexist in the foundations of metaphysics. The theory may therefore reconcile two research programs that appeared to be heading off in different directions. And we must remind the reader that the general metaphysical principles underlying our theory were not designed with the application to situation theory in mind. This suggests that the general theory and the underlying distinction have explanatory power, for they seem to relate and systematize apparently unrelated phenomena.This research was conducted at the Center for the Study of Language and Information (CSLI). I would like to thank John Perry for generously supporting my research both at CSLI and in the Philosophy Department at Stanford. I would also like to thank Bernard Linsky, Chris Menzel, Harry Deutsch and Tony Anderson for many worthwhile and interesting suggestions for improving the paper. An earlier version of the paper, more narrowly focused on situation theory, has appeared in Zalta (1991).     

Phantom cotherapist: Treatment of a suicidal Arab by a Jewish therapist

A case study is presented of the treatment of an Arab coed by a Jewish trainee, and a phantom cotherapist using a modified dialectical therapeutic approach. Its effect on the treatment process and outcome, and on the therapist is discussed.     

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.     

The Future of Psychology in Family Medicine

Psychology has been integral to the field of family medicine since its inception as a medical specialty in the 1960s. Psychologists and other behavioral scientists contribute to family medicine in teaching clinical skills, in defining research questions, in developing research methodology, and in creating integrated physical/mental health care delivery systems. Future developments in the field of psychology in family medicine are likely to emphasize development and evaluation of screening measures which identify mental health problems in primary care, development of early intervention for those mental health problems, and more precise measurement of process and quality of care and health outcomes. Psychologists have an important role to fulfill in educating physicians on alternatives to pharmacologic and medical interventions for common presenting problems in primary care. However, current economic forces shaping the practice of medicine may work against further enhancing the efficacy of the physician in dealing with psychosocial issues. The future role of psychology in family medicine is not yet delineated, and while the move toward parity of reimbursement for mental and physical health care delivery may enhance this collaboration, there is a need to continue to evaluate how the psychological well-being of patients is influenced in the evolution of new models of care delivery.     

Operate your own World-Wide Web server

Although many researchers wishing to use the World-Wide Web for academic purposes rely on centralized Web services, they should be aware that it is neither expensive nor difficult to operate their own server. Doing so provides research-related benefits such as complete control over their host name and documents provided, the guaranteed ability to execute common gateway interface and server-side include programs, immediate access to their collected data, and the ability to better control who participates in their experiments. This paper surveys Web-server software features likely to be of interest to psychologists and conceptually summarizes their operation and use. The basic steps required to set up a Web server on popular microcomputers are reviewed, and security issues concerning Web-server operation are discussed. An accompanying resource Web page can assist users in setting up their own servers.     

Capacity and retention capability of working memory modify the strength of the RT/IQ correlation: a short note

The limited capacity theory assumes that working memory (WM) has limited capacity to process information and, at the same time, to store other pieces of information, necessary for further processing. Quick processing of data is supposed to be the only way to solve the task without the risk of losing vital pieces of information. We predicted, then, that the correlation between mental speed, measured by reaction time (RT), and the intelligence quotient (IQ) should not appear in the case of persons who possess a relatively capacious WM store, or who show increased retention capability of their WM store. Such persons do not need to be fast, whereas, for people who show poorer indices of capacity or retention capability of WM, mental speed is the only way to tackle a complex and difficult intellectual task. As predicted, the RT/IQ correlation appeared much stronger in the group of subjects characterized by lower retention capability and capacity of WM.