Attention switching is not a fatigable process: methodological comments on Axelrod and Guzy (1972)

Guzy and Axelrod investigated auditory attention switching by means of the click-counting paradigm and concluded that attention switching is a fatigable process. In the present comment it is shown that this conclusion is based on a faulty analysis of the data: The scores subjected to the analysis of variance were transformed such that they were no longer linear combinations of the factorial effects. Reanalyzing the data in the correct way renders perfectly linear conting functions that deviate from theoretical fatigue functions. It is concluded that the attention-switching mechanism is not fatigable.     

A generalization of Kristof's theorem on the trace of certain matrix products

Kristof has derived a theorem on the maximum and minimum of the trace of matrix products of the form \(X_1 \hat \Gamma _1 X_2 \hat \Gamma _2 \cdots X_n \hat \Gamma _n\) where the matrices \(\hat \Gamma _i\) are diagonal and fixed and theX _i vary unrestrictedly and independently over the set of orthonormal matrices. The theorem is a useful tool in deriving maxima and minima of matrix trace functions subject to orthogonality constraints. The present paper contains a generalization of Kristof's theorem to the case where theX _i are merely required to be submatrices of orthonormal matrices and to have a specified maximum rank. The generalized theorem contains the Schwarz inequality as a special case. Various examples from the psychometric literature, illustrating the practical use of the generalized theorem, are discussed.     

Effect on numerosity judgment of grouping of tones by auditory channels

Previous research suggests that numerosity judgments for sequences of tones improve when the sequence is structured such that equal and small groups of tones alternate between the ears. The present. study systematically investigates the effects of the structure of tone sequences on number judgment. Tone frequency is chosen as the grouping principle instead of spatial location. In the first experiment, sequences with equal groups of 2, 3, 4, 5, 6, or 7 tones (groups alternating between 800 and 1, 250 Hz) were compared with monotonous sequences. At a slow repetition rate of the tones (280 msec onset to onset), grouping the sequence deteriorated the numerosity judgment. At II fast repetition rate of the tones (100 msec onset to onset) grouping improved numerosity judgment, but only if the group size did not exceed 4 to 5 tones. In the second experiment, the equality of group size in the sequence as a necessary condition for the improvement was investigated. It was found that tone sequences comprised of equal groups were judged more accurately in number than sequences comprised of unequal groups. These results seem to give support for the existence of an auditory subitizing process. The results of this study are also compared with the results of studies in which sequences of tones, alternating one by om! between locations or frequencies, had to be judged in number.     

The Dental Subscale of the Children's Fear Survey Schedule: Predictive Value and Clinical Usefulness

This study reports on the predictive value and clinical usefulness of the Dutch parental version of the Dental Subscale of the Children's Fear Survey Schedule (CFSS-DS). Parents of 718 children (4–12 years) completed this CFSS-DS version before or during the child's visit. The dentist rated the child's dental fear during treatment on a 5-point Likert-type Scale from 1 (not afraid at all) to 5 (very afraid). Reliability analysis was performed, and correlation coefficients between the two measures were calculated. The reliability of the scale proved to be high (Cronbach's = .93) and significant correlation coefficients were found (r = .58 and r = .68, p < .01). The negative predictive value of the CFSS-DS was high (.96), whereas its positive predictive value was relatively low (0.41). It was concluded that the CFSS-DS might be of clinical value as a screening device of dental fear, whereas its predictive value of fearful behavior should not be overestimated.     

The Impact of the Big Five Personality Traits on Reports of Child Behavior Problems by Different Informants

The present study compared ratings of a standardized sample of child behavior problems across informants and examined the effects of informant personality traits on child behavior ratings by mothers, teachers, and group-care workers. Participants were 55 clinic-referred children, aged 6–12 years. All informants watched and rated the same 17-min videotaped behavior sample of a familiar target child. Independent trained observers rated the same videotapes to provide criterion ratings. Informants personality traits were assessed using the NEO Five Factor Personality Inventory. Results showed that mothers reported fewer behavior problems than did the professionals, that the informants who were familiar with the child reported more behavior problems than did the independent observers, and that higher levels of informant neuroticism were related to higher ratings of child behavior problems in the case of the professionals, but not in the case of the mothers. In addition, group-care workers who were less extraverted and open were likely to report more child behavior problems than group-care workers with normal levels of extraversion and openness. Finally, no relations were found between agreeableness or conscientiousness and ratings of child behavior. Findings suggest that professionals who work with children are not immune to distortions based on their own personality.     

Linear separability in superordinate natural language concepts

Two experiments are reported in which linear separability was investigated in superordinate natural language concept pairs (e.g., toiletry-sewing gear). Representations of the exemplars of semantically related concept pairs were derived in two to five dimensions using multidimensional scaling (MDS) of similarities based on possession of the concept features. Next, category membership, obtained from an exemplar generation study (in Experiment 1) and from a forced-choice classification task (in Experiment 2) was predicted from the coordinates of the MDS representation using log linear analysis. The results showed that all natural kind concept pairs were perfectly linearly separable, whereas artifact concept pairs showed several violations. Clear linear separability of natural language concept pairs is in line with independent cue models. The violations in the artifact pairs, however, yield clear evidence against the independent cue models.     

The force of symmetry revisited: symmetry-to-noise ratios regulate (a)symmetry effects

Freyd and Tversky's [Am. J. Psychol. 97 (1984) 109] data suggested that human observers tend to overestimate relatively high levels of symmetry (symmetry effect), and tend to underestimate relatively low levels of symmetry (asymmetry effect). However, on the basis of their holographic approach to visual regularity, van der Helm and Leeuwenberg [Psychol. Rev. 103(3) (1996) 429] predicted that, at any level of symmetry, both symmetry and asymmetry effects may occur as a consequence of correct estimates of symmetry-to-noise ratios. This prediction was tested in two experiments, with tasks and stimuli similar to those in Freyd and Tversky's study. First, subjects had to judge whether a noisy symmetry is more similar to a slightly more symmetrical variant or to a slightly less symmetrical variant. Second, for every pair of stimuli in such a triadic comparison, subjects had to judge which stimulus is the more symmetrical one. The results from both experiments show that the occurrence of (a)symmetry effects indeed depends on symmetry-to-noise ratios.     

Morally Relevant Features

This article summarizes the account of morality presented in Morality: Its Nature and Justification (Oxford, 1998), with emphasis on that aspect of morality that deals with justifying violations of the moral rules. Such justification requires a two-step procedure; the first is describing the situation using only morally relevant features. I list these features, noting how diverse they are, and describe their characteristics. The second step is estimating the consequences of publicly allowing a violation with the same morally relevant features, that is, allowing a violation when everyone knows that it is allowed to violate the rule in the same circumstances, and comparing this to the estimated consequences of not publicly allowing that kind of violation. I then explain why fully informed, impartial rational persons can sometimes disagree about whether a violation should be publicly allowed and note that such weakly justified violations are the controversial cases.