Tail-measurability in monotone latent variable models

We consider latent variable models for an infinite sequence (or universe) of manifest (observable) variables that may be discrete, continuous or some combination of these. The main theorem is a general characterization by empirical conditions of when it is possible to construct latent variable models that satisfy unidimensionality, monotonicity, conditional independence, andtail-measurability. Tail-measurability means that the latent variable can be estimated consistently from the sequence of manifest variables even though an arbitrary finite subsequence has been removed. The characterizing,necessary and sufficient, conditions that the manifest variables must satisfy for these models are conditional association and vanishing conditional dependence (as one conditions upon successively more other manifest variables). Our main theorem considerably generalizes and sharpens earlier results of Ellis and van den Wollenberg (1993), Holland and Rosenbaum (1986), and Junker (1993). It is also related to the work of Stout (1990).The main theorem is preceded by many results for latent variable modelsin general—not necessarily unidimensional and monotone. They pertain to the uniqueness of latent variables and are connected with the conditional independence theorem of Suppes and Zanotti (1981). We discuss new definitions of the concepts of true-score and subpopulation, which generalize these notions from the stochastic subject, random sampling, and domain sampling formulations of latent variable models (e.g., Holland, 1990; Lord & Novick, 1968). These definitions do not require the a priori specification of a latent variable model.The authors made equivalent contributions to the results of this article. Ellis' research was supported by the Dutch Interuniversitary Graduate School of Psychometrics and Sociometrics. Junker's research was supported by ONR Grant N00014-87-K-0277, NIMH Grant MH15758, and a Carnegie Mellon University Faculty Development Grant. In addition Junker would like to acknowledge the hospitality of the Nijmegen Institute for Cognition and Information during his visit to the University of Nijmegen in August 5–10, 1993.     

The effect of punishment on free-operant choice behavior in humans

During Phase I, three female human subjects pressed a button for monetary reinforcement in five variable-interval schedules specifying different frequencies of reinforcement. On alternate days, responding was also punished (by subtracting money) according to a variable-ratio 34 schedule. In the absence of punishment, response rates conformed to Herrnstein's equation for single variable-interval schedules. Punishment suppressed responding at all frequencies of reinforcement. This was reflected in a change in the values of both constants in Herrnstein's equation: the value of the theoretical maximum response-rate parameter was reduced, and the parameter describing the reinforcement frequency corresponding to the half-maximal response rate was elevated. During Phase II, the same five schedules (A) were in operation (without punishment), but in addition, a concurrent variable-interval schedule (B) of standard reinforcement frequency was introduced. On alternate days, responding in Component B was punished according to a variable-ratio 34 schedule. In the absence of punishment, absolute response rates conformed to equations proposed by Herrnstein to describe performance in concurrent schedules; the ratios of the response rates in the two components and the ratios of the times spent in the two components conformed to the Matching Law. When responding in Component B was punished, response rates in Component B were reduced and those in Component A were elevated, these changes being reflected in distortions of the matching relationship.     

Permeability and Demarcation in the Psychoanalytic Process Functions of the Contact‐Barrier1

Introjection, identifi cation and projection are concepts that designate processes in which something is being put into or taken out of something else. These processes presuppose the overcoming of some form of separation between two entities. The permeability or impermeability of a fi ctive boundary between the representations of subject and object set the emotional tone of their coexistence. There are moments of complete diffusion, in which subject and object can no longer be differentiated, and moments of autistic enclosure in which the individual can no longer be reached at all. Permeability and demarcation result from the processing of stimuli carried out by the ‘contact‐barrier’, as an ego function. Stimuli of internal, libidinal or aggressive origin, as well as ‘im‐pressions’ of external origin, are classifi ed and processed with the aid of various kinds of factors arising from coagulated object‐relational experiences. Whereas for Freud the contact‐barrier regulates the quantity of energy and founds a topographical structure, Bion understands the contact‐barrier as a psychic function that simultaneously regulates boundary demarcation and making contact. In the psychoanalytic process, the contact‐barrier created by patient and analyst regulates the events in the transference and countertransference. An awareness of the struggle for contact and demarcation at the dynamic boundary representations that are constantly being recreated by both partners in the analytic process may be helpful in our clinical work. The author presents an examination of the ways in which patient and analyst make contact and demarcate the boundaries, which provides a better understanding of the dynamics of transference processes. He demonstrates this in relation to clinical material.     

Cardinality without Enumeration

We show that the notion of cardinality of a set is independent from that of wellordering, and that reasonable total notions of cardinality exist in every model of ZF where the axiom of choice fails. Such notions are either definable in a simple and natural way, or non-definable, produced by forcing. Analogous cardinality notions exist in nonstandard models of arithmetic admitting nontrivial automorphisms. Certain motivating phenomena from quantum mechanics are also discussed in the Appendix.     

Counselling Australian baby boomers: examining the loss and grief issues facing aging distance-separated sibling dyads

It has long been recognised that mature-aged sibling dyads provide each other with emotional support. What has yet to be determined is whether this support function is maintained within the baby boomer generational cohort of sibling dyads who through economic relocation/migration have become separated by distance. As such, this paper highlights the need for research to be conducted into the experiences of baby boomers dealing with sibling loss and grief-related issues without the support of their nuclear and extended family members.     

Plagiarism: Words and Ideas

Plagiarism is a crime against academy. It deceives readers, hurts plagiarized authors, and gets the plagiarist undeserved benefits. However, even though these arguments do show that copying other people's intellectual contribution is wrong, they do not apply to the copying of words. Copying a few sentences that contain no original idea (e.g. in the introduction) is of marginal importance compared to stealing the ideas of others. The two must be clearly distinguished, and the 'plagiarism' label should not be used for deeds which are very different in nature and importance.     

Neonatal tactile stimulation enhances spatial working memory, prefrontal long-term potentiation, and D1 receptor activation in adult rats

Environmental stimuli during neonatal periods play an important role in the development of cognitive function. In this study, we examined the long-term effects of neonatal tactile stimulation (TS) on spatial working memory (SWM) and related mechanisms. We also investigated whether TS-induced effects could be counteracted by repeated short periods of maternal separation (MS). Wistar rat pups submitted to TS were handled and marked transiently per day during postnatal days 2–9 or 10–17. TS/MS pups were stimulated in the same way as TS pups and then individually separated from their mother for 1 h/day. Their nontactile stimulated (NTS) siblings served as controls. In adulthood, TS and TS/MS rats showed better performance in two versions of the delayed alternation task and superior in vivo long-term potentiation of the hippocampo–prefrontal cortical pathway when compared with controls. Furthermore, there were more doses of A77636 (a selective dopamine D1 agonist) to significantly improve SWM performance in TS and TS/MS rats than in NTS rats, suggesting that activation of prefrontal D1 receptors in TS and TS/MS rats is more optimal for SWM function than in NTS rats. MS did not counteract TS-induced effects because no significant difference was found between TS/MS and TS animals. These data indicate that in early life, external tactile stimulation leads to long-term facilitative effects in SWM-related neural function.     

Distributive Full Lambek Calculus Has the Finite Model Property

We prove the Finite Model Property (FMP) for Distributive Full Lambek Calculus (DFL) whose algebraic semantics is the class of distributive residuated lattices (DRL). The problem was left open in [8, 5]. We use the method of nuclei and quasi–embedding in the style of [10, 1]. Presented by Daniele Mundici.     

Cognitive Error Questionnaire (CEQ): Psychometric Properties and Factor Structure of the German Translation

A central component of Beck et al.’s (1979) cognitive theory of depression is faulty information processing reflected by so-called cognitive errors. These cognitive errors are the reason why depressed individuals systematically misinterpret the significance of events in a negative way. They are usually assessed with the application of the Cognitive Error Questionnaire (CEQ). This study examines the psychometric properties and factor structure of the German version of the CEQ in a sample of 796 volunteers at a German university. Results confirmed that the German CEQ has satisfactory to very good psychometric properties, like the American original. Confirmatory factor analyses demonstrated that a hierarchical four-factor model with four subscales and 1 s order factor fits the data best. Therefore, besides using the German CEQ in studies with German-speaking samples, the similarities in psychometric properties of the American and German CEQ allow for cross-cultural studies.