LEARNING AND FORGETTING

Hokitika Guardian, 4 August 1931, Page 2

LEARNING AND FORGETTING

Learning and forgetting appear to be physico-chemical processes. Dr, Hudson Hoagland, of Harvard University, finds that the rate at which ants can learn is accelerated approximately 100 per cent, by certain changes in the temperature of. their environment, and thnt the changes in the rate of forgetting ate even more striking. In an experiment reported in the “Journal of General Psychology” he placed ants in a compartment from which they could escape into another compartment through a simple mnze, To get away from the fumes of peppermint oil, especially irritating to those insects, they had to find the way for themselves. As iin most learning experiments, it was a matter of trial and error. After being placed in the same situation a varying number of times an ant would “learn” the way so that it could escape immediately. When it ,ha,s done this five times without error it was considered to have “learned” the maze,

The temperature was kept const ant for each ant. But those for which the apparatus was heated to between 25 and 29 degrees Fahrenheit, Dr. Hoagland found, learned the way out with about half as many repetitions of the 'experiment as necessnry for those placed in lower temperatures. There was apparently a critical point when , the physico-chemical processes in the ! nervous system which constitute learning acted with much greater rapidity. After “learning” the ant was taken out of the maze apparatus, hut still kept at tv constant temperature. After an interval it was brought back again and the same test repeated to find bow well it remembered what it had learned. The test- of memory was the same as that of lenrning—the numlver OT repetitions necessary before the nut escaped with no unnecessary moves. While those insects kept at temperatures below 25 degrees retained considerable memory. these which bad been kept in temperatures over this point had forgotten so completely that in some oases they required more trials to relearn than had been necessary in the first place. The ant is a cold-blooded • creature whose nervous system presumably responds immediately to any change in the external temperature, so this can