Absence of perceptual processing during reconfiguration of task set

The authors manipulated stimulus contrast and response-stimulus interval in the alternating runs paradigm to investigate whether early processing could be carried out during a task switch. Subjects alternated between judging the magnitude and the parity of a digit. The results suggested that early processing was not carried out during the task switch (Experiment 1), even in the absence of potentially confounding auditory or visual warning signals (Experiment 2). This processing was, however, carried out in parallel with a demanding operation in a 2nd task (Experiment 3), using the display parameters of Experiments 1 and 2 in the psychological refractory period paradigm. It is concluded that, functionally, task switching may impose a hard bottleneck even for very early stimulus processing. ((c) 2003 APA, all rights reserved)     

Processing of metaphoric and non-metaphoric alternative meanings of words after right- and left-hemispheric lesion

This study examines the specificity of the contribution of the right hemisphere to the processing of metaphoric meaning of words. Ten right- and 10 left-hemisphere-damaged subjects, and 20 normal control subjects were submitted to: (1) a word-triad task where they had to associate alternative metaphoric and non-metaphoric words to a target word, and to (2) a word-dyad task where they had to decide whether or not there was a semantic relationship between two words. The two tasks aimed at differentiating between the subjects' preference for a given semantic meaning versus a genuine semantic deficit for a particular meaning. Results revealed that both right- and left-hemisphere-damaged groups presented a genuine semantic deficit for the processing of metaphoric meaning. The absence of a double dissociation between the two brain-damaged groups does not support the hypothesis of a specific contribution of the right-hemisphere to the processing of metaphoric meaning of words.     

A meta-analytic study of general mental ability validity for different occupations in the European community

A comprehensive meta-analysis of the validity of general mental ability (GMA) measures across 12 occupational categories in the European Community (EC) is presented. GMA measures showed that there is validity generalization and large operational validities for job performance and training success in 11 occupational groups. Results also showed that job complexity moderated the magnitude of the operational validity of GMA tests across three levels of job complexity: low, medium, and high. In general, results were similar to those found in the United States, although the European findings showed a slightly larger magnitude of operational validity in some cases. Theoretical and practical implications of these findings for personnel selection are discussed. ((c) 2003 APA, all rights reserved)     

A solution to the effect of sample size on outlier elimination

Results from a Monte Carlo study demonstrate how a non-recursive, a simple recursive, a modified recursive, and a hybrid outlier elimination procedure are influenced by population skew and sample size. All the procedures are based on computing a mean and a standard deviation from a sample in order to determine whether an observation is an outlier. Miller (1991) showed that the estimated mean produced by the simple non-recursive procedure can be affected by sample size and that this effect can produce a bias in certain kinds of experiments. We extended this result to the other three procedures. We also create two new procedures in which the criterion used to identify outliers is adjusted as a function of sample size so as to produce results that are unaffected by sample size.     

Discrimination of time intervals bounded by tone bursts

Trained listeners had to discriminate, in a four-level 2AFC paradigm, the duration of a time interval bounded by pairs of brief tone bursts. The time intervals ranged from 10 to 100 msec. When the tone-burst markers were similar in their intensity (86 dB SPL) and frequency (1 kHz), the just noticeable time difference was found to be monotonically related to the base interval. On the other hand, when the intensity of the first marker was severely attenuated (by 50 dB) or when a large (2-octave) difference was introduced between the frequencies of the two markers, the time discrimination functions became nonmonotonic. A similar, albeit slight, departure from monotonicity was also achieved by making the second marker much longer than the first (300 msec vs. 10 msec). The nonmonotonicity of these time discrimination functions is compared to the well-documented nonmonotonicity that may be observed for voice onset time (VOT) discrimination functions.     

Entraînement à l'analyse segmentale et apprentissage de la lecture

Dans cet article nous examinons les rapports qu'entretiennent la capacité d' analyse intentionnelle de la parole par les enfants et leur plus ou moins grande facilité à aborder le domaine de l'écrit. Ceci nous conduit à poser plusieurs questions. La première est relative au domaine d'application. Les sujets disposent de connaissances procédurales sur leur langue. Comment parviennent-ils à construire des connaissances sur ces connaissances? La seconde a trait à la nature de l'acquisition de ce type de compétence: s'agit-il de quelque chose de comparable à l'acquisition du langage, ou s'agit-il d'un apprentissage par instruction? La troisième concerne la nature de la “conscience phonique”. La variété des appellations qu'on trouve dans la littérature montre bien qu'il existe encore une grande incertitude sur le contenu de cette notion. Enfin dans la quatrième on s'interroge sur la valeur adaptative de ce type de compétence. Dans cette analyse, nous développons parallèlement les problèmes 1 et 2. Nous disons quelques mots du problème 3. Puis nous abordons le problème 4 en présentant quelques résultats empiriques.     

Predicting the shape of distance functions in curve tracing: Evidence for a zoom lens operator

Jolicoeur, Ullman, and MacKay (1986) showed that the time to confirm that two dots are on the same curve increases monotonically, but nonlinearly, as the curve distance between the two dots increases. These displays contained two curves and two dots. On same trials, the two dots were on the same curve (target curve), while the other curve served as a foil (distractor curve). The monotonically increasing effects of curve distance on response times for same trials suggested that the intervening curve segment was traced. In the present investigation of the source of the nonlinearity in these distance functions, it was hypothesized that differences in the distractor curves may have allowed a curve tracing operator with zoom lens properties to widen its receptive field while tracing parts of certain target curves. The wider receptive field may have allowed faster tracing over certain segments, owing to a reduced number of shifts required by the operator to scan the curve. The consequence of training certain segments of the curve more quickly than other segments of the curve would be a nonlinear effect of distance. A new set of stimuli was created for testing this hypothesis directly. Fairly linear distance effects were found for stimuli that contained a distractor curve that constrained the breadth of the postulated curve tracing operator, whereas stimuli that contained a distractor curve that could allow for a larger receptive field yielded nonlinear distance functions. The results are compared with the predictions of three quantitative models: pixel-by-pixel tracing; Jolicoeur, Ullman, and MacKay's (1991) bipartite operator; and a new zoom lens model, analogous to the zoom lens model of visual attention. The results were fit best by the latter model, in which tracing is accomplished by tracking the curve with a variably sized local operator.