CLASSICAL CONDITIONING I N THE PLAN ARIA POLYCELIS tenuis (IJIMA), DUGESIA lugubris (SCHMIDT), RETENTION OF THE CONDITIONED RESPONSE, AND THE EFFECT OF CHEMICALS ON THE GENERAL BEHAVIOUR, REGENERATION AND THE LEARNING CAPACITY
Abstract
The flatworm (planarian) may be considered as an extremely significant organism from the standpoint of evolution. It stands at the bottom of bilateral animals, and is characterized by a marked bilateral symmetry wit h a differentiation of the anterior end as a head. True synaptic nervous transmission and definite encephalization appear for the first time in the planarian. An even more striking aspect of this animal is its remarkable powers of regenaration. These characteristics, thus, introduces the planarian as an important subject in the study of behavioural processes. Thompson and McConnell's (1955) experiments of classical conditioning wit h these flatworms generated great interest and controversial opinions about their learning capacities (Mc Connell et al, 1955, 1959, 1964; A.L. Jacobson 1964; R.L. James and E.S. Halas 1961, 1962, 1964, Mc Connell 1965, E.L. Bennett and M. Calvin 1964). It should be interesting to investigate the different behavioural characteristics of some of the species found in Turkey. For this purpose, two local species of planaria, Polycelis tenuis (Ijima) (1884) and Dugesia lugubris (Schmidt) (1861) were selected and several series of experiments were conducted in our Psychological Laboratory. The first of these was the application of classical conditioning experiments to these animals. Theability to be conditioned which were found in many subhuman species may also be challenged with the planaria since they possess a central nervous system of a rudimentary character. I n our experiments electric shock was used as the unconditioned stimulus (Su) and light as the conditioned stimulus (Sc). (Rc) or the conditioned responses are the natural responses of the planarian to the electric shock, such as, stopping, turning of the cephalic region and longitudinal contraction. After repeated presentations, these natural responses to the electric shock were also expected to be elicited to light. Thirty two planaria were studied. Fourteen were of the species Polycelis tenuis and eighteen were of the species Dugesia lugubris.
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Primary Language
English
Subjects
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Journal Section
Research Article
Publication Date
August 27, 2012
Submission Date
August 27, 2012
Acceptance Date
-
Published in Issue
Year 1966 Volume: 5 Number: 0