On visual speed

Summary According toJ. F. Brown the dependence of visual speed on field factors is principally due to influences which such field factors exert on phenomenal time.K. Koffka has pointed out that the same dependence may be due to variations of the spatial threshold in fields of different properties. In this paper experiments have been reported which in two cases decide in favor ofKoffka's explanation. This explanation is likely to be applicable to further instances. — Some ofBrown's own experimental results appear to be incompatible with his theory.

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Zusammenfassung J. F. Brown erkl?rt die Abh?ngigkeit gesehener Geschwindigkeiten von Feldfaktoren durch entsprechende Variationen im Gebiet der ph?nomenalen Zeit.K. Koffka hat darauf aufmerksam gemacht, da? die gleichen Tatbest?nde auf Abh?ngigkeit der Raumschwelle von Feldfaktoren beruhen k?nnten. Die vorliegende Arbeit berichtet über Versuche, die in zwei F?llen zugungsten vonKoffkas Erkl?rung entscheiden. Wahrscheinlich kann diese Erkl?rung auf andere F?lle ausgedehnt werden. —Brown selbst hat Versuche angestellt, deren Ausfall mit seiner Theorie unvereinbar erscheint.

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With 1 Figure.

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This investigation was performed under the direction of ProfessorW. K?hler. The author is indebted to him for the formulation of the problem, to him and to Dr.H. Wallach for guidance in the interpretation and presentation of the results, and to ProfessorJ. F. Brown for his courtesy in placing at his disposal published and unpublished papers.