Localizing the first position of a moving stimulus: The Fröhlich effect and an attention-shifting explanation

When subjects are asked to determine where a fast-moving stimulus enters a window, they typically do not localize the stimulus at the edge, but at some later position within that window (Fröhlich effect). We report five experiments that explored this illusion. An attentional account is tested, assuming that the entrance of the stimulus in the window initiates a focus shift toward it. While this shift is under way, the stimulus moves into the window. Because the first phenomenal (i.e., explicitly reportable) representation of the stimulus will not be available before the end of the focus shift, the stimulus is perceived at some later position. In Experiment 1, we established the Fröhlich effect and showed that its size depends on stimulus parameters such as movement speed and movement direction. In Experiments 2 and 3, we examined the influence of eye movements and tested whether the effect changed when the stimuli were presented within a structural background or when they started from different eccentricities. In Experiments 4 and 5, specific predictions from the attentional model were tested: In Experiment 4 we showed that the processing of the moving stimulus benefits from a preceding peripheral cue indicating the starting position of the subsequent movement, which induces a preliminary focus shift to the position where the moving stimulus would appear. As a consequence the Fröhlich effect was reduced. Using a detection task in Experiment 5, we showed that feature information about the moving stimulus is lost when it falls into the critical interval of the attention shift. In conclusion, the present attentional account shows that selection mechanisms are not exclusively space based; rather, they can establish a spatial representation that is also used for perceptual judgment—that is, selection mechanisms can bespace establishing as well.     

Directed attention prolongs the perceived duration of a brief stimulus

Stelmach, Herdman, and McNeil (1994) suggested recently that the perceived duration for attended stimuli is shorter than that for unattended ones. In contrast, the attenuation hypothesis (Thomas & Weaver, 1975) suggests the reverse relation between directed attention and perceived duration. We conducted six experiments to test the validity of the two contradictory hypotheses. In all the experiments, attention was directed to one of two possible stimulus sources. Experiments 1 and 2 employed stimulus durations from 70 to 270 msec. A stimulus appeared in either the visual or the auditory modality. Stimuli in the attended modality were rated as longer than stimuli in the unattended modality. Experiment 3 replicated this finding using a different psychophysical procedure. Experiments 4-6 showed that the finding applies not only to stimuli from different sensory modalities but also to stimuli appearing at different locations within the visual field. The results of all six experiments support the assumption that directed attention prolongs the perceived duration of a stimulus.     

John Dewey's impact on Turkish education

Conclusion The cultural characteristics of any country generally give shape to the educational system. However, no country can assert its own educational system to be wholly indigenous. All the systems come into being as a synthesis of various ingredients of the home country and other countries. And it is quite natural to make use of the experiences and stock of knowledge of the others. This fact is indispensable especially when education is concerned. The curicial problem is to what extent the borrowing process should be used. When the process of borrowing ideas become to take the form of imitation or copy, unexpected results and failure are unavoidable.     

Processing empty categories: A parallel approach

In many current theories of human sentence processing, the mechanisms and principles proposed to account for data related to processing (1) long-distance dependencies and (2) structural ambiguities, such as garden-path sentences, are independent, despite the fact that deciding whether or not to posit a gap is just a special case of ambiguity resolution. In this paper we demonstrate how the parallel parsing theory proposed by Gibson (1991, in press)—which was developed to account for nongap ambiguity resolution data—also explains a number of gap-positing facts, without additional strategies. In particular, we show how this theory correctly explains filled-object-gap effects and the lack of filled-subject-gap effects in English, as well as certain gap-processing effects in Dutch.     

Detection, genetic counseling and phenotype prevention of Duchenne muscular dystrophy

Literature data and the own ascertainment of Duchenne muscular dystrophy cases concentrated on the Leipzig county confirm the necessity of early diagnosis and of central registration, search for female carries and genetic counselling. A newborn screening is supported provided that its organization will be practicable. About 12% of Duchenne cases are secondary affections of brothers. It should be possible to prevent one third of all cases by means of counselling also of the female relatives of the mothers. The repeated estimation of serum creatinkinase activity, completed by electromyography, has the greatest practical importance for the identification of heterozygous carriers. For the genetic counselling of definite carriers and women at risk it is possible only to recommend intrauterine sex prediction and the selective abortion of male fetuses.     

Investigation into the effect of fluphenazine hydrochloride (lyorodin) in children with behaviour disorders by means of psychophysiological parameters

In a group of 44 children with behaviour disorders, the mode of action of the phenothiazine preparation fluphenazine hydrochloride (Lyorodin) was tested by means of psychophysiological methods of measurement (critical flicker-fuse frequency and measurement of the response time). In some of the comparative examinations before and after administration of the drug significant differences were found. A defined psychic stress resulted in changed measured values in both methods. Children with cerebral injuries showed a lower degree of reaction after the administration of the preparation than children not encephalopathically affected.     

Performance of an unpleasant task: Effects of over- vs under-payment on perception of adequacy of rewards and task attractiveness

Subjects who came to an experiment expecting to receive a moderate amount of money for performing a task were then told, either before or after performing it, that their pay would be higher than, equal to, or less than they had expected. When the actual payment was announced after the task was performed, subjects' evaluations of the task increased with the amount they were paid; however, they estimated a higher rate of pay to be appropriate if they received either more or less than they expected than if they received what they expected. When the actual payment was announced before the task was performed (and before subjects made their decision to perform it), a different pattern emerged. Subjects rated the task more attractive when they were offered either more or less than the expected amount, while their judgments of the appropriateness of the pay offered increased with the amount of the offer. Implications of the results for incentive and dissonance theories as well as self-perception and equity theories are discussed.     

Diphenylhydantoin stimulation test in Wilson's disease

Coeruloplasmin and diphenylhydantoin levels were studied both in patients who were stabilised for the first time on diphenylhyantoin (300 mg daily) up to reaching a stable serum concentration (N = 6) and during steady-state concentration (N = 25). No significant DPH-dependent influence on the coeruloplasmin level in the serum was found. In our opinion, DPH is no suitable for the stimulation of coeruloplasmin and thus for the diagnosis of Wilson's disease, particularly in the preclinical stage, because absence of coeruloplasmin increase in the serum being found also in healthy persons.     

Episodic psychoses in epileptic juveniles with reference to electroencephalographic findings]

The present paper describes three juveniles affected with epilepsy, who suffered from episodic psychoses. Such disorders are a very rare occurrence in young persons. The patients had grand mal epilepsy with "secondary temporalization". Clinical and electroencepholographic aspects are discussed by reference to these particular cases. Also, the authors deal with questions of classification and etiopathogenesis. Finally, possible causes producing such psychoses and giving rise to the psychopathological character thereof are pointed out within the framework of a multiconditional approach.     

Possibility of research specific utilization of clinical television setups]

The present study is intended to discuss use of video tape technics in psychiatric research in reference to method, engineering and clinical investigation. A self created variant of a clinical television system is debated. With the support of video tape methods will be realize improvements in quality of psychiatric investigation in view of procedure and determination of the results as well as reliability, objectiveness and exactitude in connection with a postgraduate continued professional training. Reconsiderations of psychiatric documentation systems with regard to reliability represent an other important field of employment.