Measures of spatial memory and routes of learning

Spatial memory was investigated in two experiments by direct methods. Methods included scaling of distances, estimation of bearings, and positioning of objects. Participants learned small-scale configurations under different orders of presentation. In Exp. 1, routes included a shortest path, i.e., a traveling salesman solution, a random sequence, and a path that maximized distances. In Exp. 2, spatial and temporal distances varied independently. It was analyzed whether the different methods yielded the same information. For bearing estimates a new scaling procedure was developed. Computations resulted in two-dimensional Euclidean solutions in close correspondence with the stimulus configuration. In addition, solutions showed an effect of temporal conditions of learning.     

Appletree: A multinomial processing tree modeling program for macintosh computers

Multinomial processing tree (MPT) models are statistical models that allow for the prediction of categorical frequency data by sets of unobservable (cognitive) states. In MPT models, the probability that an event belongs to a certain category is a sum of products of state probabilities. AppleTree is a computer program for Macintosh for testing user-defined MPT models. It can fit model parameters to empirical frequency data, provide confidence intervals for the parameters, generate tree graphs for the models, and perform identifiability checks. In this article, the algorithms used by AppleTree and the handling of the program are described.     

Determinants of Differential Acculturation of Developmental Timetables among Adolescent Immigrants to Germany

The acculturation of developmental timetables for autonomy was studied in a sample of 220 ethnic German immigrants from Romania, Poland, and countries of the former Soviet Union. A distinction was made between the timing of autonomy from parental supervision and autonomy in social relationships. Four waves of semi-annual asessments were conducted for two groups, newcomers (0–18 months of residence in Germany) and experienced immigrants (more than 18–36 months). From these assessments a gradual acculturation of timetables was observed, resulting, as expected, in considerably earlier ages at which the two facets of autonomy were accomplished. The rate of acculturation was predicted to be related to prior interindividual differences in parent-adolescent interaction and frequency of adolescents' activities outside the home. As expected, higher levels of conflict and permissiveness reported by parents, and lower levels of monitoring and more frequent out-of-home activities, corresponded to a more accelerated acculturation to earlier timetables concerning autonomy from parental supervision—especially among the newcomers. With regard to autonomy in social relationships, the results were less clear, presumably due to the fact that prior interpersonal experiences were less associated with this facet of autonomy. Higher levels of the family variables studied encourage “escape” from the constraints of the newcomers' provisional homes, and thus provide opportunities to make contacts and adopt the lifestyle of adolescents from the general German population. In general, prediction was not possible concerning adolescents whose residence in Germany was longer than 18 months. For this group of immigrants, such escapes no longer serve the expected purpose because they have access to other opportunities, which were not measured in this study.     

Completeness of quantum logic

This paper is based on a semantic foundation of quantum logic which makes use of dialog-games. In the first part of the paper the dialogic method is introduced and under the conditions of quantum mechanical measurements the rules of a dialog-game about quantum mechanical propositions are established. In the second part of the paper the quantum mechanical dialog-game is replaced by a calculus of quantum logic. As the main part of the paper we show that the calculus of quantum logic is complete and consistent with respect to the dialogic semantics. Since the dialog-game does not involve the excluded middle the calculus represents a calculus of effective (intuitionistic) quantum logic.In a forthcoming paper it is shown that this calculus is equivalent to a calculus of sequents and more interestingly to a calculus of propositions. With the addition of the excluded middle the latter calculus is a model for the lattice of subspaces of a Hilbert space.On leave of absence from the Institut für Theoretische Physik der Universität zu Köln, W.-Germany.     

Multicomponent models for the retention of numbers

Summary Several multicomponent models of memory (Bower, 1967) are presented and applied to the retention of three-digit numbers. Their application is based on the notion that both the digits making up a number stimulus and the position in which they appear can be interpreted as the components of a memory vector. The models are fitted to the data obtained in a Peterson-type experiment in which a single three-digit number was shown per trial. During the retention interval the subject engaged in an arithmetical task for either 13.6, 19.6, or 25.6 s. Following this, the subject attempted recall. Confidence ratings were also obtained. Twenty-four different types of correctly and incorrectly recalled responses were scored. Their frequency distributions were best predicted at each retention interval by a dual encoding model which relies on the assumption that stimuli are stored both component-wise and by means of a single unit code encoding the entire stimulus number. It is also shown that the confidence ratings may be successfully predicted from estimates of the expected number of components retained. About 80% of the rating variance is predicted by a parameter-free procedure.The original experimental study was funded by Grant Ey 4/3, Deutsche Forschungsgemeinschaft, Bad Godesberg. Further developments were made possible by Grant Sch 350/1 to R.S. from the same agency. Part of the theoretical work was done while D.V. was an NSF postdoctoral fellow at the Department of Psychology of New York University, New York. Free computer time was generously supplied by the Courant Institute of Applied Mathematics. We are grateful to Dietrich Albert, Stephanie Kelter, Micha Razel, and Paul Vitz for stimulating discussions.     

The principle of excluded middle in quantum logic

The principle of excluded middle is the logical interpretation of the law V A v in an orthocomplemented lattice and, hence, in the lattice of the subspaces of a Hilbert space which correspond to quantum mechanical propositions. We use the dialogic approach to logic in order to show that, in addition to the already established laws of effective quantum logic, the principle of excluded middle can also be founded. The dialogic approach is based on the very conditions under which propositions can be confirmed by measurements. From the fact that the principle of excluded middle can be confirmed for elementary propositions which are proved by quantum mechanical measurements, we conclude that this principle is inherited by all finite compound propositions. For this proof it is essential that, in the dialog-game about a connective, a finite confirmation strategy for the mutual commensurability of the subpropositions is used.     

Sequential modulations of interference evoked by processing task-irrelevant stimulus features

Compatibility level repetition benefits in interference paradigms have been taken to reflect enhanced processing selectivity in response to cognitive conflict elicited by a task-irrelevant stimulus feature. The authors demonstrate such sequential effects in the Simon task which (a) occur independent of previous behavioral conflict effects and (b) cannot be accounted for by selectivity enhancement. Furthermore, when presenting more than one type of irrelevant stimulus features, compatibility level repetition effects occurred in a type-specific manner. The results do not support the notion that cognitive conflict results in enhanced processing selectivity and favor a feature integration account.     

Socioemotional selectivity in cancer patients

This study analyzed the contact preferences of newly diagnosed cancer patients and healthy control group participants. In line with the theory of socioemotional selectivity, patients were more likely than control participants to prefer contact with familiar social partners, but this difference was stronger in younger and middle-aged patients than in older patients. Across a 6-month interval, patients' contact preferences changed according to the perceived success of therapy. For example, if therapy was perceived to be successful, patients showed an increasing interest in contacts with unfamiliar social partners. Results indicate that contact preferences are adapted to the perception of limited versus extended future lifetime.