THE ROLE OF MANUAL KINESTHESIS IN BUILDIN G AND IN USING MENTAL REPRESENTATIONS OF BIDIMENSIONAL OBJECTS

From a phylogenetic viewpoint, perceptual information linked to manual activity is an integral part of human thought. Moreover, design offic e operators prefer to draw manually and even manipulate scale models w hen developping objects which are particularly complex. This research is a first attempt to show that kinesthesic activity could, under spec ific conditions, benefit visual treatment of information, in construct ing and memorising representations available for later use. It contras ts with other work, which opposes vision to kinesthesis or, more often , vision to touch. In this way, it is a new direction for research. Tw o distinct experiments attempt to measure the effects of manual explor ation of two dimensional drawn figures in a recognition task. The firs t experiment, taken as an extreme control condition, separates Kinesth esic processes from visual control to find if, even in these restricti ve conditions, the two perceptual modes can help each other. In a firs t phase intended to allow encoding to work, subjects were to construct spatial representations of the objects. Thus, in the vision-kinesthes is condition, they use kinesthesic activity without any direct visual control. Then they are asked to recognize visually the correct respons e among five distractors. The second experiment allows Kinesthesic pro cesses to act under visual control. it includes two phases: an encodin g stage, as in the first experiment; and a second period intended to b e a recall stage in which subjects must again recognize the correct re sponse among distractors. Since, the effects of Kinesthesis are assume d to differ according to subject abilities, in both the first and seco nd experiments several groups were constituted to test this factor, fr om psychology students considered to be an inexperienced population, t o high school engineering students, assumed to be a skilled group with regard to drawing activities. The results show that without visual co ntrol, kinesthesic activity not only does nor make visual work easier, but can even be considered as an interfering task, which disrupts vis ual information treatment. It is proposed that attention is insufficie nt to manage both of the perceptual modes. In the second part of this work, even though we cannot assert that Kinesthesis always helps visua l information treatment, it is shown that in some conditions there is some improvement, especially when the task appears too difficult, when compared with visual performance alone. Kinesthesis seems to be espec ially useful when storing spatial information in memory, for later rec all in a recognition task. These results indicate the potential value of further research along these lines. They also paint to the need for a Computer Assisted Design workstation incorporating art analogical m anual interface.