The first neuroimaging technique ever is the so-called 'human circulation balance' invented by Angelo Mosso in the 1880s and able to non-invasively measure the redistribution of blood during emotional and intellectual activity. Then, in the early 1900s, a technique called pneumoencephalography was set. This process involved draining the cerebrospinal fluid from around the brain and replacing it with air, altering the relative density of the brain and its surroundings, to cause it to show up better on an x-ray, and it was considered to be incredibly unsafe for patients (Beaumont 8). A form of magnetic resonance imaging (MRI) and computed tomography (CT) were developed in the 1970s and 1980s. The new MRI and CT technologies were considerably less harmful and are explained in greater detail below. Next came SPECT and PET scans, which allowed scientists to map brain function because, unlike MRI and CT, these scans could create more than just static images of the brain's structure. Learning from MRI, PET and SPECT scanning, scientists were able to develop functional MRI (fMRI) with abilities that opened the door to direct observation of cognitive activities. Angelo Mosso and his "human circulation balance" The desire to understand the human mind has been one of the main desires of philosophers throughout the ages. Questions about thoughts, desires, et cetera have drawn psychologists, computer scientists, philosophers, sociologists and the like together into the new discipline of cognitive science. Non-invasive imaging of the human brain has proven invaluable in this context. The very first chapter of the history of neuroimaging traces back to the Italian physiologist Angelo Mosso who invented the "human circulation balance", which could non-invasively measure the redistribution of blood during emotional and intellectual activity. However, even if only briefly mentioned by William James in 1890, the details and precise workings of this balance and the experiments Mosso performed with it have remained largely unknown until the recent discovery of the original instrument as well as of Mosso's reports by Stefano Sandrone and colleagues. These documents suggest that patients would be placed on a weighted table that would tilt as blood flowed to their head, for instance, while concentrating on reading a philosophy book. Remarkably, Angelo Mosso unearthed and investigated several critical variables that are still relevant in modern neuroimaging such as the "signal-to-noise ratio", the appropriate choice of the experimental paradigm and the need for the simultaneous recording of differing physiological parameters.