Chapter 4 - Imaging

Abstract

Imaging techniques play a fundamental role in interpretative sciences such as geophysics and medical diagnosis. In this chapter, I review the concept of imaging from an enlarged perspective with respect to the geophysical (or medical) point of view. My discussion includes philosophical, psychological, physiological, and neurobiological aspects. I clarify from many points of view why imaging is so important in exploration geosciences. Moreover, I discuss the contribution of other senses in creating “mental images” of the reality. I start introducing the main imaging problems in geophysics, mentioning the technology most frequently used for producing pseudoimages of the subsoil. Many of these techniques, such as seismic tomography, are based on the same general principles of brain imaging methods. Despite substantial differences in the two fields of study (geosciences and medical diagnostics), imaging is rooted in the same ancient question of “mental imagery.” Philosophers and scientists have investigated this as a possible background of the thought. Nowadays, modern cognitive sciences provide a robust neurobiological explanation of our brain's ability to create mental images. These are made possible by the topological and structural features of the neocortex, with the fundamental contribution of some specific subcortical nuclei, such as the colliculi. After discussing the neurobiological background of mental maps and images, I show a schematic block diagram for explaining how external stimuli are transformed into mental maps and images. I remark that not only visual stimuli but also other sensorial perceptions are transformed into mental maps. For instance, maps of auditory and somatic information are continuously combined and integrated with visual maps. All these maps represent the crucial elements of basic perception. When properly integrated, they allow high-level cognition. Finally, I discuss analogies, problems, and solutions in geophysical and medical imaging.