Role of the Anatomical and Physiological Connections of the tonic-postural body tensions in the perception of the space in mental image

Abstract

We examined the spatial transformations of mental images of 34 participants male and female, undergraduate psychology students, who were asked - while they were looking with closed eyes at a mental image consisting of a table on which an apple was placed - to actively increase the distance between the first sacral vertebra and the 12th dorsal. The participants were previously subjected to a lengthening training of that section of the vertebral column. During the experimental task, while the participant observed the mental image, the experimenter measured in centimeters the lengthening of the sacrum-dorsal tract. Our research considers two interacting characteristics of visual space’s perception both in external real and in imagined space. The first is constituted by concrete objects-stimuli which are visually perceptible and whose extension and mutual distance can be measured; the second has a formless form, i.e. an abstract form without concrete objects, always present, but which every person has full awareness and perceives its presence as a particular form of feelings, projecting it on the external environment. This form of space perception interposes between separate objects and envelops both objects and the observer himself, also defining the horizon of the world. This form is not visually perceivable, if not indirectly, like the distance between the objects. We can name this second component of space as “space-container”. Starting from the reflection that the body as a unitary structure constitutes the first spatial experience, we hypothesize that the integrated proprioceptive perception of muscular tonic activity of the body scaffolding is at the basis of the “perceptual” feeling that characterizes what we named “space-container”. Our hypothesis concerns the idea that the interaction between the two components is cross-modal. In this interaction the visual cerebral representation is connected, both in visual perception and visual imagery with the perception of postural muscular tensions (due to oscillations in muscle tone) of the different body districts directly or indirectly interacting with each other. The tensions are perceptually unified to produce a perception of an unitary feelings. In the present research we focus essentially on the role of isometric variations of relatively stable muscles tone. In conclusion we hypothesize that by modifying the relations between the muscular tensions of the bodily districts of the postural scaffolding, we can modify the visual spatial perception-like relations between the imagined objects. Our results seem to confirm these hypotheses. It is interesting that 23% of the participants observed, during the task, a lifting of the apple from the table.