The Brain and Its Maps: An Illustrative History

The human brain has been studied and mapped in a number of ways since antiquity. This chapter reviews investigative methods and the evolution of human brain maps from ancient times to the present. Special focus is given to the shift in modern history from purely structural mapping, through purely functional mapping, to neuropsychological maps displaying the relation between structure and function. The historical review that begins the chapter presents a number of key findings and investigators, major historical debates and detours in the field, and the more recently developed synergies between clinical treatment, neuropsychological measurement, and technological advancement. An introduction to current brain mapping techniques presents the mechanisms, strengths, and weaknesses of X-ray computed tomography (CT), single-photon emission computed tomography (SPECT), positron emission tomography (PET), electroencephalography (EEG), magnetoencephalography (MEG), transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES), and the various forms of magnetic resonance imaging (MRI). A final section reviews promising current approaches and initiatives in human brain mapping and the value they may add to neuropsychological investigation and the refinement of human brain maps. These relatively new approaches include more advanced statistical analyses, better data management and informatics specialized to handle very large data sets, functional network analysis, nonlinear and chaos/complexity analysis, development of whole-brain connectome maps, and new advances in the imaging of the microstructure of brain cells. This chapter is organized in such a way as to highlight the shifts in preferred metaphors guiding different eras of human brain research–from inert lump of flesh, to a container for mental and spiritual functions, to mechanistic pump, to an information processing computer, to a hyper-connected and mutable network.