This paper gives a phenomenological account of scientific imagination and visualization which focuses on how neuroscientists use diagrams to understand the brain as a multi-level, hierarchically-organized structure. Drawing on the diverse, burgeoning literatures on the pervasive use of diagrams and of the levels metaphor in scientific representation, I give a Husserl-inspired phenomenological account of key experiential structures, such as image consciousness, the eidetic intuition and the figure/ground structure of object-directed experience, which jointly regulate the scientific visualization process. I also draw on Pessoa’s discussion, in The Entangled Brain, of how scientists project a multi-level, hierarchical structure onto the otherwise seamlessly interconnected architecture of brain regions responsible for so-called “lower-level” affective processing and “higher-level” cognition. I offer a phenomenological reconstruction of neuroscientists’ imaginative reliance on the eidetic intuition to generate hierarchically-organized, multi-level images of these brain regions. I then describe how these images guide scientists’ imaginative exploration of the target neural phenomena and constrain the space of possible model-building. I conclude with a reflection on how phenomenology can shed light on the ubiquity of the levels metaphor in the scientific imaginary as it comes to grip with massively entangled systems like the brain. I also explain how my study evinces a fundamental methodological reorientation: by using phenomenology to disclose the foundational role of image-consciousness in science, we reverse the usual explanatory procedure evinced by approaches that seeks to “naturalize” phenomenology by bringing its results into conformity with neuroscience. Instead, in a manner consistent with arguments provided by Thompson, Frank and Gleiser in The Blind Spot, we “phenomenologize” neuroscience by laying bare its experiential presuppositions.
