Differential-psychologische Untersuchungen zum Vigilanzverhalten

Zusammenfassung Mit Hilfe von Korrelationsmethoden wurden inter-individuelle Leistungsunterschiede in einer ein- und einer mehrflächigen Vigilanzaufgabe untersucht. In beiden Aufgaben korrelieren bestimmte Vigilanzscores mit Interferenzindikatoren im Stroop-Versuch. In der mehrflächigen Anordnung zeigte sich eine negative Korrelation zwischen der Entdeckungswahrscheinlichkeit und der Rate der falschen Alarme. Hinsichtlich der zeitlichen Merkmale der Vigilanzleistung ergab sich, daß die Vpn den geringsten Abfall der Entdeckungswahrscheinlichkeit erkennen lassen, die zu Beginn der Vigilanzaufgabe die Rate der falschen Alarme am stärksten reduzieren konnten. Die Ergebnisse wurden im Rahmen des detection-Modells interpretiert.

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Experiments in individual differences of vigilance behavior

Summary This paper is concerned with individual differences of vigilance performance in a simple and a complex vigilance task. In both tasks certain aspects of vigilance behavior were correlated with interference in the Color Word Test by Stroop. In the complex vigilance task there was a negative correlation between the probabilities of signal detections and false alarms rates. With regard to the temporal characteristics of vigilance behavior it was found out that subjects with the least decrease of detection rate showed the greatest reduction of their false alarms rate to the beginning of the vigilance task. The results were discussed in the context of the detection model.

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Teil II der Dissertation, die im Januar 1969 der Philosophischen Fakultät der Freien Universität Berlin vorgelegt wurde.     

Gallbladder distention and the effects of several drugs on heart rate,respiratory movements and cortical potentials in cats with hypothalamic lesions

The effects of chronic hypothalamic lesions and various drugs on the viscero-visceral reflexes of cats have been investigated, utilizing measurement of the bioelectrical activity of the cerebral cortex. After coagulation of the posterolateral hypothalamus the heart rate decreased by 40–60 beats per minute, but eventually it regained its initial value. The viscero-visceral reflexes from the gallbladder to the heart were preserved after the operative procedure. Chlorpromazine and atropine blocked both arousal and the cardiorespiratory response to stimulation of the gallbladder. Similar effects were produced by novocaine and pantocaine.     

Arousal and paired-associate learning

Walker and Tarte (1963) postulate that at short retention intervals high arousal paired-associates are reproduced more poorly than low arousal items. Walker and colleagues believe that this hypothesis is confirmed by their paired-associate learning studies. However, results of these paired-associate learning studies are position confounded artifacts. Better recall of low arousal items at short-term retention is caused by the coincidence of the recency effect and low arousal at the end of the trial. When these position effects are controlled there is no action decrement for the high arousal paired-associates. To test this assumption, the Kleinsmith and Kaplan study (1963) was replicated and two other variations were conducted. In these three studies with 76 subjects, which were tested at two minutes or 1 week, the action decrement occurs only when the two position effects coincide.     

Perceived numerosity of spatiotemporal events

Numerosity discrimination was examined when items were varied in space-time position rather than in space only. Observers were instructed to indicate which of two adjacent streamsof visual events contained more items. The precision of numerosity discrimination of dynamic events was not remarkably different from that of static patterns. Two basic numerosity biases previously found for static dot patterns—inhibitory overestimation and satellite underestimation—were demonstrated for items distributed randomly over a spatiotemporal interval. It was also demonstrated that two streams, equated in the number and luminous energy of items, are not judged equal in their visible number if items in one of these two streams have longer duration than items in the second stream. These findings can be accounted for by the occupancy model of perceived numerosity (Allik & Tuulmets, 1991a) if it is supposed that the impact that each element has on its neighborhood is spread along both spatial and temporal coordinates. Perceived numerosity decreases with both spatial and temporal proximity between the-visual-items. Space and time have interchangeable effects on perceived numerosity: the amount of numerosity bias caused by the spatial proximity of items can also be produced by the properly chosen temporal proximity of items