Choice behavior and the accessibility of the reinforcer

In Experiment 1, matching of relative response rates to relative rates of reinforcement was obtained in concurrent variable-interval schedules when the absolute values of the two concurrent variable-interval schedules varied from 6 sec and 12 sec to 600 sec and 1200 sec. Increases in the duration of the changeover delay, however, produced decreases in the relative response rates and, consequently, some deviation from matching. In Experiment 2, matching of relative response rates to the relative duration of the reinforcer failed to occur when the equal variable-interval schedules arranging access to the two different reinforcer durations (1.5 and 6 sec) were varied in size from concurrent variable-interval 10-sec schedules to concurrent variable-interval 600-sec schedules.     

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.