The brief Reasons for Living Inventory for adolescents (BRFL-A)

This study modified and evaluated the psychometric properties of the Reasons for Living Inventory (RFL) in samples of adolescents. Internal consistency reliability, corrected item-total scale correlation, and exploratory factor analysis procedures were used with a mixed sample of 260 adolescents to identify 14 items for the brief version of the RFL (BRFL-A). Confirmatory factor analyses provided support for the five-factor oblique structure of the BRFL-A in a psychiatric inpatient sample with a range of suicidal behaviors. Reliabilities of the BRFL-A subscales were satisfactory. Four of the five subscales differentiated between suicidal and nonsuicidal adolescents. Significant correlations were found between three BRFL-A subscales and several suicide indices. Convergent-discriminant validity was examined by correlating the BRFL-A subscales with the Minnesota Multiphasic Personality Inventory—Adolescents (MMPI-A) Content Scales. Limitations of the study are discussed.This study was supported in part by a Project Grant from the Graduate College, The University of Northern Iowa.     

A parallel rule activation and rule synthesis model for generalization in category learning

This paper proposes a distinction between primary generalization (transfer from stored exemplars to perceived targets) and secondary generalization (transfer from inferred abstractions to perceived targets). This distinction is embodied in the parallel rule activation and rule synthesis (PRAS) model, a production model capable of exemplar-based and abstraction-based categorization. As an exemplar model, the PRAS model is related to the generalized context model (Nosofsky, 1984). Exemplars are stored in memory encoded as condition-action rules. Working as an exemplar-based model, rules are activated on the basis of their strength and their similarity to the current to-be-categorized instance. Similarity between a target and a stored exemplar is weighted for attention to the dimensions of the psychological space. Depending on the value of a special parameter, the PRAS model is also able to operate as an abstraction model. In the latter case, it attempts to construct generalizing productions, which are activated according to the same rules as the exemplar-specific rules. The model is described in detail. It is applied to a number of important observations described in the research literature, and an experiment is reported that tested the usefulness of the proposed secondary-generalization mechanism. Finally, the discussion elaborates on the implications of the present study for further research.     

Models for relevant modal logics

Semantics are given for modal extensions of relevant logics based on the kind of frames introduced in [7]. By means of a simple recipe we may obtain from a class FRM (L) of unreduced frames characterising a (non-modal) logic L, frame-classes FRM (L.M) characterising conjunctively regular modal extensions L.M of L. By displaying an incompleteness phenomenon, it is shown how the recipe fails when reduced frames are under consideration.     

A generalization of Takane's algorithm for dedicom

An algorithm is described for fitting the DEDICOM model for the analysis of asymmetric data matrices. This algorithm generalizes an algorithm suggested by Takane in that it uses a damping parameter in the iterative process. Takane's algorithm does not always converge monotonically. Based on the generalized algorithm, a modification of Takane's algorithm is suggested such that this modified algorithm converges monotonically. It is suggested to choose as starting configurations for the algorithm those configurations that yield closed-form solutions in some special cases. Finally, a sufficient condition is described for monotonic convergence of Takane's original algorithm.Financial Support by the Netherlands organization for scientific research (NWO) is gratefully acknowledged. The authors are obliged to Richard Harshman.     

The object-line inferiority effect in pigeons

Eight pigeons (Columba livia) were trained to discriminate between diagonal lines presented alone or embedded in a redundant L-shape right-angle form. The stimuli were white and were presented in an environment that was otherwise totally dark. Numerous experiments done with human observers have shown a strong superiority effect when the diagonal lines are embedded in redundant contexts. However, in Experiment 1 ofthe present study, the pigeons discriminated significantly better between the two diagonal lines when presented alone than when they were embedded in the right-angle context. In order to check on the possibility that these results were restricted to the semi-Ganzfeld condition of Experiment 1, a second experiment was done with black stimuli presented on a white background. Results of Experiment 2 also showed a strong distractor effect. The results of the present experiments confirmed the predictions of the Heinemann and Chase model of pattern recognition by pigeons.     

A voice-activated key for the Apple Macintosh computer

An interface circuit to connect a microphone to an Apple Macintosh computer is described. The Apple Macintosh mouse port is used as the input port, and the microphone activation simulates a mouse press.     

Sex differences and bilateral electrodermal activity

The present study was aimed at replicating the results of a previous work on sex differences and electrodermal asymmetry from our laboratory (Román,et al. 1987). Skin conductance was bilaterally recorded in a sample of 44 dextral volunteers (22 males and 22 females) during a stimulus-free period, and the performance of two tasks (verbal and spatial). Subjects were grouped into two groups of right-hand and left-hand dominance in their electrodermal responses (EDRs) in accordance with their laterality coefficient scores at rest. During the tasks subjects appeareed clearly differentiated by their lateralization in the magnitude and frequency of EDRs independently of gender: right-hand responders showed higher electrodermal activity on their right hand, while left-hand responders showed higher electrodermal activity on their left hand. Sex differences were not observed within each responsiveness pattern. The orientation of phasic electrodermal changes remained constant throughout the different conditions.     

A replication of the use of public posting in traffic speed control

In an attempt to replicate several previous studies, a reversal design was used to assess the effects of publicly posted feedback on vehicle speed reduction. The intervention phases consisted of daily posted feedback that supplied drivers with either accurate or inaccurate information regarding the percentage of vehicles exceeding the speed limit on the road. Results from the two feedback conditions indicated no speed reduction in comparison to baseline levels. These results are discussed in light of previous studies that found strong effects for such feedback. Baseline levels of driver compliance and methodological differences may limit the effectiveness of posted feedback in reducing speeding.     

Movement errors and levels of processing in sentence production

From a corpus of 3,530 slips of the tongue in Spanish, a sample of 753 cases of movement errors was analyzed, comprising those tokens that could be unambiguously assigned to the major categories of anticipations, perseverations, exchanges, and shifts. The analysis was performed according to two main criteria: (a) the degree of correspondence between the linguistic elements interacting in an error, and (b) the distance between such elements in terms of the type and number of the intervening linguistic boundaries. The results of this analysis converge with those obtained in English, supporting a model of sentence planning with different levels of representation and processing. Furthermore, Spanish provides a clear case to attest the role of syllabic structure in production processes, the constraints set by word boundaries in sublexical errors, and the contribution of inflectional suffixes to the assignment of grammatical category to the root morphemes.