騒音環境の学習に対する影響に関する研究

抄録

Male rats were trained in a multiple maze with five choice points in the pathway. Their behavior was recorded remotely to remove unnecessary stimuli during the learning. One group of rats was fed adlibitum and the other fasted from evening to the end of the learning period the next morning.
Each group was subdivided into three groups for training under different noise conditions: group I was trained in silence; group II was exposed to wide bound noise at 100 dB(C) for one hour before the start of learning; and group III was exposed to the same noise during learning.
In rats which had been trained for 20 days, the process of learning extinction was then observed in the same maze every four days under noiseless or noisy conditions.
The following items were used as learning indices: the time spent to reach the goal, the number of times non-correct gates were passed, and the time spent between each of the gates.
1. In the fasting rats all three learning indices were lower than in the adlibitum fed rats in group I. (noiseless)
2. Adibitum fed rats of group III (exposed to noise during learning) showed lower learning indices than those in group I, and those in group II (exposed to noise before learning) passed non-correct gates more often than did those in group I.
3. Among the fasting rats, group III showed higher values in the three indices than did the other two groups.
4. In both fed and fasting rats, the learning process from the first gate to the goal was much more disturbed by noise exposure than was that from the starting point to the first gate.
5. Group III rats (exposed to noise during learning) were much more affected than those in group II (exposed to noise before learning).
6. Among the rats (both fed and fasting) which had been trained under noiseless conditions, those exposed to noise during the extinction process showed slower extinction than those undergoing extinction in silence.
7. Among the rats which had been trained under noisy conditions, those fed ad libitum showed slower extinction in silence than in noise. However, in fasting rats, silence hastened extinction while noise slowed it.
These findings suggest that noise affects learning by interfering with information analysis more than with memory, and that exposure to noise during learning severely hampers the learning process.