A my K ind time But even greater advances were yet to come Perhaps nothing has been as important to our understanding of neural function as the late 20th-century development of noninvasive neural-imagining techniques Starting with the development of X-ray computed tomography (CT scans) in the early 1970s, scientists could for the first time work with three-dimensional images – a development that, as Marcus Raichle puts it, “quite literally changed the way in which we looked at the human brain” (Raichle 2008, 120) Many of the modern imaging technologies work by measuring hemodynamic changes, i.e., they measure the changes in blood flow and the levels of oxygenation in the blood following neural activity Though scientific research had revealed an important relationship between blood flow and brain function as early as the 1870s, it took almost 100 years for the significance of this fact to be fully appreciated and implemented for effective neural imaging by way of the development of positron emission tomography (PET) and magnetic resonance imaging (MRI) Finally, one more important step forward occurred in the late 1980s with the development of functional magnetic resonance imaging (fMRI) – a development that opened up a new avenue of research that was almost wholly responsible for the birth of cognitive neuroscience Unlike previous neural imagining techniques, fMRI technology allows for relatively high-resolution images of the brain to be collected very quickly, with a whole brain scan being possible in less than three seconds.2 So how has philosophy of mind in the 20th century been influenced by all of this neuroscientific research? As we have learned more and more about the brain, how has that influenced our philosophical understanding of the mind? Interestingly, some philosophers have suggested that for most of the century it has had very little effect at all.3 In their article on “The Philosophy of Neuroscience” in The Stanford Encyclopedia of Philosophy, John Bickle, Peter Mandik, and Anthony Landreth argue that “actual neuroscientific discoveries have exerted little influence on the details of materialist philosophies of mind.” While granting that the late 20th-century “neuroscientific milieu” has had some sway in discouraging dualism, they note that most 20th-century materialists – including even the empirically oriented identity theorists of the 1950s (see Chapter 2) – have relied very little on actual neuroscientific details Moreover, as they go on to suggest, the rise of functionalism in the 1970s has been accompanied by a neglect of neuroscientific research not only in practice but also in principle Functionalists suggested that mental states are to be understood in terms of their function But since the function of a state does not depend on physical mechanisms in which it is realized, functionalists have tended to think that we cannot understand the nature of mind by way of neuroscience To my mind, however, this pessimistic assessment of the influence that neuroscience has had on philosophy is problematic Granted, philosophers’ continued fixation on c-fibers in discussion of pain (see Chapter 2), even in the face of evidence that this association is overly simplistic, may seem to indicate a clear neuroscientific indifference – and this is how Bickle et al take it.4 But there are