Perceptual scaling of synthesized musical timbres: Common dimensions,specificities, and latent subject classes

To study the perceptual structure of musical timbre and the effects of musical training, timbral dissimilarities of synthesized instrument sounds were rated by professional musicians, amateur musicians, and nonmusicians. The data were analyzed with an extended version of the multidimensional scaling algorithm CLASCAL (Winsberg & De Soete, 1993), which estimates the number of latent classes of subjects, the coordinates of each timbre on common Euclidean dimensions, a specificity value of unique attributes for each timbre, and a separate weight for each latent class on each of the common dimensions and the set of specificities. Five latent classes were found for a three-dimensional spatial model with specificities. Common dimensions were quantified psychophysically in terms of log-rise time, spectral centroid, and degree of spectral variation. The results further suggest that musical timbres possess specific attributes not accounted for by these shared perceptual dimensions. Weight patterns indicate that perceptual salience of dimensions and specificities varied across classes. A comparison of class structure with biographical factors associated with degree of musical training and activity was not clearly related to the class structure, though musicians gave more precise and coherent judgments than did nonmusicians or amateurs. The model with latent classes and specificities gave a better fit to the data and made the acoustic correlates of the common dimensions more interpretable.     

Assessment of Supervisee Developmental Level and Supervision Environment Across Supervisor Experience

Supervisors representing different levels of experience viewed videotape vignettes of counselors demonstrating the first three developmental levels of Stoltenberg's (1981) Counselor Complexity Model. Supervisors assessed each counselor on his or her developmental level and on the supervision environment he or she would provide for the trainee. Results indicated that supervisor experience did not influence the assessment of developmental level or the ability to make accurate environmental matches. Nevertheless, supervisors had the most difficulty accurately assessing counselors representing Level 2 in Stoltenberg's model and tended to make relative judgments about counselor developmental level. Implications for training and further research are discussed.     

Distortions and fluctuations in topographic memory

Two experiments dealing with, the learning of a space by map or by navigation approached the questions of equivalency of the cognitive processes involved in spatial information and of response fluctuation. In the first experiment, 11 subjects were asked to situate, six times, 18 lo-cations on a blank map. In the second experiment, the subjects were first given 3 min to learn a map with 12 locations marked, and then asked to reproduce it. The task was repeated six times, using three different maps. This gave us several trials per subject, so that distortion could be distinguished from response fluctuation. In Experiment 1, the range of values was the same for response inaccuracy and response, fluctuation; in Experiment 2, the range was greater for response inaccuracy than for response fluctuation. The results showed that space learning by navigation and space learning by map involve different cognitive processes.     

Computing Cohen’s kappa coefficients using SPSS MATRIX

This short paper proposes a general computing strategy to compute Kappa coefficients using the SPSS MATRIX routine. The method is based on the following rationale. If the contingency table is considered as a square matrix, then the observed proportions of agreement lie in the main diagonal’s cells, and their sum equals the trace of the matrix, whereas the proportions of agreement expected by chance are the joint product of marginals. The generalization to weighted kappa, which requires an additional square matrix of disagreement weights, both matrices having the same order, becomes possible by the use of the Hadamard product-that is, the elementwise direct product of two matrices.     

Modifications of the Poggendorff effect as a function of random dot textures between the verticals

In the present research, we investigated the modification of the strength of the Poggendortf illusion as a function of different densities ofrandom dot textures failing the space between the verticals. The results ofExperiment 1 show that the illusory effect is a nonlinear function ofthe texture parameterr, the ratio of black pixels to white and black pixels, with a minimum forr=0.5, approximately, and a maximum forr=0 andr=1. The results may be interpreted by an analytical model of perceptual space dynamics, in which the effect dependson the amount of interaction between points of different light intensity. A computer simulation performed by applying the analytical model to different values ofr shows a good agreement between the predictions and the experimental data. To test the hypothesis underlying the model, a second experiment was carried out to measure the magnitude of the expansion ofthe space between the verticals as a function of the parameterr. The results are consistent with the hypothesis of the model. The overall data are discussed in terms of their implications on various theories proposed for the Poggeadorff illusion.     

Resetting the pitch-analysis system: 1. Effects of rise times of tones in noise backgrounds or of harmonics in a complex tone

The question of whether sudden increases in the amplitude of pure-tone components would perceptually isolate them from a more complex spectrum was investigated in two experiments. In Experiment 1, a 3.5-sec noise was played as a masker. During the noise, two pure-tone components of different frequencies appeared in succession. Subjects were asked to judge whether the pitch sequence went up or down. The rise time of these components had only a small and inconsistent effect on discrimination. In Experiment 2, the 3.5-sec background signal was a complex tone. The amplitudes of two of its components were incremented in succession. Again, subjects judged whether the pitch pattern went up or down. This time there was a sizable, monotonic effect of the rise time of the increments, with more rapid increments leading to better discrimination. The difference between the two results is interpreted in terms of the auditory system’s response to changing and unchanging signals and the role of its “sudden-change” responses in attracting perceptual processing to certain spectral regions.     

Forms of Authority and the Real Ad Verecundiam

This paper provides a typology of appeals to authority, identifying three distinct types: that which is based on a command; that which is based on expertise; and that which is based on dignity. Each type is distinguished with respect to the reaction that a failure to follow it ordinarily evokes. The rhetorical roots of Locke's ad verecundiam are traced to the rhetorical practices of ancient Rome.     

Gifted Achievers and Underachievers: A Comparison of Patterns Found in School Files

Underachievement in gifted students has perplexed educators and parents for decades. Researchers are continually looking for information about the nature and patterns of gifted underachievers that will enlighten those concerned. Counselors are particularly involved, because they often are asked to provide illumination and interventions. This study demonstrates how information in the cumulative school file, accessible to the school counselor, is a rich resource for understanding the patterns of achievement and underachievement among students identified as gifted and for use in planning interventions for students at risk for underachievement. Participants were gifted students (N = 153) who were determined to be either achievers or under-achievers, based on their grade point average at graduation. High and moderate achievers and moderate and extreme underachievers were compared on information found in the school file, such as attendance, tardiness, course selection, and onset and duration of underachievement. Results indicate that there are differences between achievers and underachievers on a number of variables found in the school files. Profiles of these groups are presented with suggestions for actions by counselors.