AMOUNT OF INDUCED AVOIDANCE BEHAVIOUR TO LIGHT IN THE PROTOZOA TETRAHYMENA AS A FUNCTION OF TIME AFTER TRAINING AND CELL FISSION

B ergström , S. R. Amount of induced avoidance behaviour to light in the Protozoa Tetrahymena as a function of time after training and cell fission. Scand. J. Psychol ., 1969, 10 , 16–20.—Two cultures of Tetrahymena, dividing synchronously after exposure to an alternating heat treatment, were exposed to series of light and electric shocks paired. After 20 and 30 exposures resp. to the stimulus combination, samples of these cultures were drawn every 18 min and placed in a partially lighted chamber. In samples drawn shortly after training, an essentially smaller proportion was found in the light, in comparison with control samples, which had received either shocks or light or neither of the two stimuli. In later samples, this proportion increased until it approached level of control samples. The course of the increase was not influenced by intervening synchronous cell division.