Letters

Leonardo, Vol. 7, pp. 379-384. Pergamon Press 1974. Printed in Great Britain LETTERS Readers’ commentsare welcomedon textspublishedin Leonardo. Themitors reserve the right to shorten lettersfor reasons of space. Letters should be written in Englishor in French. CONCEPTS OF SPACE IN URBAN DESIGN, ARCHITECTURE AND ART (cont.) Peter F. Smith in his letter (Leonardo 7, 284 (1974)) suggests that visual perception is a binary affair with visual stimuli registering on the occipital region of the neocortex and also making an impact on the midbrain or the ‘limbic system’. He further suggests that as this system operates in parallel with the neocortex and uses quite different criteira, it determines its own mode of space perception. Research so far actually has failed to establish the essential nature of the limbic contribution to psychological experience and behaviour. Although the functional significanceof this region of the brain is not well established, its independent nature implied by Smith is a highly unlikely hypothesis. What has been well substantiated in the literature is that the role of the limbic system is in emotional reaction. The limbic cortex is an important sub-system of the brain, as it is the staging area for the elaboration of emotional expression and implementation of impulses. It is generally agreed that the two-fold function of this sub-system in the process of perception, spatial or otherwise, is to integrate the various sensory impressions and impart to them the quality of feeling-like, dislike, excitement, joy and sadness. The limbic cortex derives and acts upon information in terms only of feelings and where these are intense it is manifested in the form of emotions. Present research findings indicate that the limbic cortex actually receives impulses from the neo-cortical sansory areas and association areas, which contain mainly memories and images. The impulses are compared to similar memories and images from past experience. Only a few somesthetic stimuli rely on no previous memory of an experience, all other images being derived from actual sensory experience. As indicated in my article, images or schemata are learnt and are largely determined by sub-parts of an individual’s culture. Thelimbiccortex is thus at the centre of a circuit and its role is that of appraising stimuli, evaluating possible alternative interpretations of a situation and selecting from a choice of actions where necessary. This part of the brain, only extensively researched in the last 20 years, is connected to all sensory cortical areas and as an appraisal system, mediates in every perception completing the sense experience and giving it personal meaning. On this basis, the limbic cortex would not lead forward its own separate and independent spatial percept. Its appraisal function imparts feelings and emotions in a unitary and not binary process of perception. The limbicsub-systemprovides the locus for evaluating sensory stimuli against culturally determined spatial schemata and, by imparting feeling, explains the emotional differences experienced by individuals of the same culture. N. N. Patricios Dept. of Town and Regional Planning Utiiv.of the Witwatersrand Jan Smuts Ave. Johannesburg, South Africa EXPERIMENTAL AESTHETICS I am in complete agreement with F. Molnar (Leonardo 7, 23 (1974)) about the importance of an experimental aesthetics. I shall conclude my comments by relating my work to the importance of a science of art. Molnar says of Husserl: ‘The knowledge of the truth concerning essence does not contain the least reference to facts and, thus, from essence alone one cannot derive the slightest truth about facts.’ It is certainly true that Husserl distinguishes eidetic investigations from factual ones but it does not follow that an eidetic investigation of the essence of aesthetic experience would be irrelevant to a factual investigation. I might put it like this: From the definite fact that this thing before me is colored I can infer the general fact that it must have some extension. I cannot infer what specificextension it has but I can infer that the color must have some extension. A general fact does not tell one the content of a specific perception, however, it does tell one something about the act of perception, about the essence of perception. Somewhat analogously, Husserl gives some suggestions about the essence of aesthetic perception and...