A semiautomatic method for adding behavioral data to videotape records in combination with the Noldus Observer system

The Observer 3.0 (Noldus, 1991) was used as the base for a time-saving fine analysis of animal behavior. A PC controlled a shuttlebox and a shuttlebox control unit. Learning behavior was recorded on videotapes by an S-VHS camcorder with vertical interval time code (VITC), which was used to generate an observational data file (ODF). The observational system was enhanced by automatically recorded status signals from the PC as event markers on the soundtrack of the videotape. These signals were used to subdivide a training session into numbered trials during generation of the ODF. They were later used for a PC-aided fine analysis of behavioral events, such as attention responses (AR) and orienting responses (OR) during shuttlebox learning. In this way, a large number of both automatically inserted PC event markers and manually inserted, key-defined behavioral events were registered and analyzed effectively in a semiautomatic fashion. The system is illustrated with an analysis of shuttlebox avoidance data from gerbils (Meriones unguiculatus).     

Duration estimation and the phonological loop: Articulatory suppression and irrelevant sounds

Clock-based theories of time estimation propose that clock pulses are accumulated in working memory. Although these theories do not constrain the form of the memory trace, evidence reported in the literature suggests that active manipulation of a verbal trace may be involved. Four experiments are reported in which participants reproduced or verbally estimated short durations (up to a few seconds) either in a single-task condition or in a condition with a phonological load. Experiments 1, 2 and 4 showed that both interval reproduction and verbal estimation were impaired under concurrent articulatory suppression in comparison to a timing only control condition. Neither irrelevant speech (Experiments 1-3) nor irrelevant tones and music (Experiment 3) impaired timing performance. These findings are taken to show that time estimation is mediated by phonological working memory and the involvement of an active articulatory rehearsal process.     

Sufficient conditions for uniqueness in Candecomp/Parafac and Indscal with random component matrices

A key feature of the analysis of three-way arrays by Candecomp/Parafac is the essential uniqueness of the trilinear decomposition. We examine the uniqueness of the Candecomp/Parafac and Indscal decompositions. In the latter, the array to be decomposed has symmetric slices. We consider the case where two component matrices are randomly sampled from a continuous distribution, and the third component matrix has full column rank. In this context, we obtain almost sure sufficient uniqueness conditions for the Candecomp/Parafac and Indscal models separately, involving only the order of the three-way array and the number of components in the decomposition. Both uniqueness conditions are closer to necessity than the classical uniqueness condition by Kruskal. Part of this research was supported by (1) the Flemish Government: (a) Research Council K.U. Leuven: GOA-MEFISTO-666, GOA-Ambiorics, (b) F.W.O. project G.0240.99, (c) F.W.O. Research Communities ICCoS and ANMMM, (d) Tournesol project T2004.13; and (2) the Belgian Federal Science Policy Office: IUAP P5/22. Lieven De Lathauwer holds a permanent research position with the French Centre National de la Recherche Scientifique (C.N.R.S.). He also holds an honorary research position with the K.U. Leuven, Leuven, Belgium.     

Self-concept in adults from Spain and Portugal

The aim of this work is to confirm the penta-factorial validity of the AF5 Self-Concept Questionnaire in Spanish and Portuguese adults. From the responses of a total of 2058 adults (1508 Spanish, 73.3%, and 550 Portuguese, 26.7%) was analyzed the reliability of the instrument, was compared the validity of the 5 oblique factor model proposed by the authors versus unifactorial and the orthogonal alternative models, and was studied the invariance of the Portuguese translation. The results of structural equation modeling supported the authors' penta-factorial model. The multi-group factorial invariance showed that Portuguese translation of the AF5 does not change neither the original factor weights, nor the variances and covariances of the factors. Finally, the reliability was good for the original Spanish version and Portuguese translation.     

The state of the psychological contract and its relation with employees' psychological health

In the present paper the role of the state of the psychological contract to predict psychological health results is studied in a sample of 385 employees of different Spanish companies. Results indicate that the state of the psychological contract significantly predicts life satisfaction, work-family conflict and well-being beyond the prediction produced by the content of the psychological contract. In addition, trust and fairness, two dimensions of the state of psychological contract, all together contribute to explain these psychological health variables adding value to the role as predictor of fulfillment of the psychological contract. The results support the approach argued by Guest and colleagues.     

Revisiting Huey: On the importance of the upper part of words during reading

Recent research has shown that that the upper part of words enjoys an advantage over the lower part of words in the recognition of isolated words. The goal of the present article was to examine how removing the upper/lower part of the words influences eye movement control during silent normal reading. The participants?? eye movements were monitored when reading intact sentences and when reading sentences in which the upper or the lower portion of the text was deleted. Results showed a greater reading cost (longer fixations) when the upper part of the text was removed than when the lower part of the text was removed (i.e., it influenced when to move the eyes). However, there was little influence on the initial landing position on a target word (i.e., on the decision as to where to move the eyes). In addition, lexical-processing difficulty (as inferred from the magnitude of the word frequency effect on a target word) was affected by text degradation. The implications of these findings for models of visual-word recognition and reading are discussed.     

Influence of generalized complexity of a musical event on subjective time estimation

This study examined the variations in the apparent duration of music events produced by differences in their generalized compositional complexity. Stimuli were the first 90 sec. of Gustav Mahler's 3rd Movement of Symphony No. 2 (low complexity) and the first 90 sec. of Luciano Bério's 3rd Movement of Symphony for Eight Voices and Orchestra (high complexity). Bério's symphony is another "reading" of Mahler's. On the compositional base of Mahler's symphony, Bério explored complexity in several musical elements--temporal (i.e., rhythm), nontemporal (i.e., pitch, orchestral and vocal timbre, texture, density), and verbal (i.e., text, words, phonemes). These two somewhat differently filled durations were reproduced by 10 women and 6 men with a stopwatch under the prospective paradigm. Analysis showed that the more generalized complexity of the musical event was followed by greater subjective estimation of the duration of this 90-sec. symphonic excerpt.     

Good medical research--the view of the CDBI/Council of Europe

Medical research aims to achieve a better scientific understanding of health and disease. It is firstly undertaken for the improvement of medical care in general, not excluding a potential direct benefit for participants undergoing such research. There is a traditional conflict between the fundamental rights and the dignity of those participating individuals and the interests of science, researchers and even the society. The Convention of Human Rights and Biomedicine of the Council of Europe is a new legally binding instrument for the solution of these conflicts. on behalf of the Comité Directeur pour la Bioéthique (CDBI)/Council of Europe An earlier version of this paper was presented at an International Conference on “Conflict of Interest and its Significance in Science and Medicine” held in Warsaw, Poland on 5–6 April, 2002. Professor Doppelfeld spoke on behalf of CDBI/Council of Europe.     

Statistical inference of minimum rank factor analysis

For any given number of factors, Minimum Rank Factor Analysis yields optimal communalities for an observed covariance matrix in the sense that the unexplained common variance with that number of factors is minimized, subject to the constraint that both the diagonal matrix of unique variances and the observed covariance matrix minus that diagonal matrix are positive semidefinite. As a result, it becomes possible to distinguish the explained common variance from the total common variance. The percentage of explained common variance is similar in meaning to the percentage of explained observed variance in Principal Component Analysis, but typically the former is much closer to 100 than the latter. So far, no statistical theory of MRFA has been developed. The present paper is a first start. It yields closed-form expressions for the asymptotic bias of the explained common variance, or, more precisely, of the unexplained common variance, under the assumption of multivariate normality. Also, the asymptotic variance of this bias is derived, and also the asymptotic covariance matrix of the unique variances that define a MRFA solution. The presented asymptotic statistical inference is based on a recently developed perturbation theory of semidefinite programming. A numerical example is also offered to demonstrate the accuracy of the expressions.This work was supported, in part, by grant DMS-0073770 from the National Science Foundation.     

Effects of spatial attention on detection and identification of oriented lines

In this paper, we study the effects of spatial attention on detection and identification of oriented lines presented at near-threshold luminance. In the first experiment, we found that the cuing effect was greater when observers had to discriminate between two close orientations than when they had to discriminate between two far-apart orientations. In the second experiment, we examined the effects of peripheral cues on summation of low-contrast oriented lines. We found that the range of orientations within which summation occurred was greater when the cues were invalid than when they were valid. Our results suggest that attention to a specific location in the visual field modulates the neural channels which code orientation in at least two different ways: (a) spatial attention increases the responsivity of these channels to stimuli presented at this location, and (b) it reduces the bandwidths or ranges of orientations to which these channels are sensitive. These results suggest that the properties of the orientation-tuned channels, including those that seem to exert their effects at early stages of orientation processing (e.g., tuning function), may not be fixed, but rather vary according to the attention being paid to the spatial region within which the target stimulus is presented.