抄録
It is generally said that the use of visual aids in FLT makes learning efficient. There are some studies that show results contrary to this. This paper is focused on reconsidering the theoretical background of audio-visual methods in FLT. To improve memory is one of the important factors in language learning ; that is, to organize short-term memory into long-term memory. We hold that the process is mediated by the mental imagery. Though many of the concepts of mental imagery still remain to be studied, through Piaget's observation of the development of mental imagery and Paivio's dual-coding theory, it can safely be said that a part of the long-term memory is stored with mental images. On the basis of Paivio's theory, we can define one of the roles of visual aids in FLT as follows: visual aids should be made use of when it is difficult for learners to form images of the language they are learning. Next, we have to discuss whether learning through multiple senses really promotes understanding or the image formation of language materials. In the 1960's Broadbent or Travers and others had doubts about giving learners too many cues in the learning process and stated that, under certain circumstances, there might be interference between language materials and visual aids. We may conclude that in the learning of language itself, visual aids are suitable for learning words or sentences in a high degree of concreteness. However, as the degree of abstractness of words or sentences goes up, it becomes more and more difficult to produce visual aids, and they are apt to be subject to misunderstanding or at worst rejecting appropriate interpretation. In such cases it is far easier for the teacher to provide learners with a verbal explanation to help them form appropriate images about words or sentences they are learning.
