Male rats were trained daily for 20 days in a multiple maze with five choice points in the pathway. To observe the locus of their behavior during training in the maze, electrical information from 12 gates with infrared ray monitors installed along the pathway was recorded remotely. Two parameters were obtained from this record; one was the average time spent in a gate interval, the other was the distance moved per second (speed).
One group of rats was fed ad libitum and the other had its food withheld from evening to the end of training the next morning. Each group was subdivided into three groups for training under different noise conditions, the silent group, the group exposed to noise for one hour before the start of daily training, and the group exposed to noise during daily training. The number of rats in each group was twenty. They were exposed to noise of a wide octave-band at an intensity of 100dB (C).
The results were as follows;
1) A significant inverse correlation was observed between the two parameters.
2) As training progressed under the silent condition, the average time spent in a gate was reduced and the speed rose gradually.
3) These changes were more remarkable in the fasted group than in the group fed ad libitum.
4) No significant changes were observed after the 9th day of training for the average time spent in a gate or after 11th day of training for speed.
5) As training progressed the rising grade of psychomotor activity was inhibited by exposure to noise.
6) This inhibiting effect observed far speed was more remarkable in the group exposed to noise before the start of training than in the group exposed to noise during training. This may have been due to differences in the duration of exposure to noise.
7) Since observational error based on the unequality of each gate interval was included in the average time spent in a gate interval, the difference in the effects of both exposed conditions was unclear.