We recently discussed how the term ‘neuroplasticity’ is widely used as if it were a precise scientific concept, when, in fact, it is virtually meaningless on its own. Several commenters suggested that while not scientifically meaningful, it serves as a useful reminder that we no longer think the brain is ‘fixed’ as we did ‘about 20 years ago’. This is also part of the neuroplasticity hype, and, as I’ll demonstrate, discussions of neuroplasticity go back as far as the 1800s.
This is not to say that we haven’t discovered new ways in which the brain changes and adapts. But this hasn’t been a sudden discovery, and it hasn’t solely happened in the last few decades. On the contrary, these discoveries have peppered the last century and this knowledge has been slowly accumulating.
So here’s a hastily gathered list of scientific papers from before 1970 in which neuroplasticity was discussed, found with nothing more than Google Scholar and 30 minutes of time:
A 1896 paper from the Journal of Mental Science that discusses cortical plasticity as the basis of insanity, as well as tackling neural regeneration and recovery of function.
A 1897 paper from The American Journal of Psychology that discusses how “intelligence… enables the organism to make better adaptations. Its neural pre-requisite is plasticity”.
A 1932 study from Brain on recovery of function after brain injury.
A recent paper that reviews neuroplasticity in the work of neuroscientist Ramón y Cajal (1852-1934) who argued for fixed circuits but extensive local plasticity both in structure and function.
A 1943 review article from Brain on recovery from three types of nerve injury that discusses regeneration of nerve fibres.
The transcript of the 1950 Royal Society Ferrier Lecture on “Growth and Plasticity in the Nervous System”.
A 1967 paper from Acta Neurologica Scandinavica reviewing findings in sensory plasticity.
I’m sure there are many more examples that you could find for yourselves.
I suspect the neuroplasticity hype was fuelled by two main things: the 1998 discovery that adults humans have a limited ability to regenerate neurons and the growth of functional brain imaging in both science and the media.
In fact, neuron regeneration accounts for very little of our ability to learn and adapt, but after decades of thinking that ‘we are born with all the brain cells we’re ever going to get before we slowly decline’, it perhaps seems very significant to many and is certainly used in that way in popular discourse.
Functional brain imaging scans are often used as ‘visual proof’ that the brain changes. In reality, neuroimaging, almost by definition, relies on mechanisms that we must at least broadly understand already. But as a tool in popular discourse, it has increasingly come to stand for the brain’s flexibility.
I’m also interested by the fact that ‘neuroplasticity’ is often used in two seemingly contradictory ways.
The first is that it highlights ‘hidden potential’, the second that it highlights ‘hidden vulnerability’. These in themselves are not contradictory but often the message is that ‘we now know that your behaviour is now more susceptible to change than before’ but with an implicit message that once the change has taken place it is more permanent than before. Hence the additional risk or benefit. After all, your brain has changed, right?
To be clear, I am not suggesting that the brain is not flexible or that the discoveries about how the brain changes are not important. It’s simply that neuroplasticity has become a rhetorical device that, in itself, tells us nothing without further explanation.
All neuroscience is the science of how the brain changes and if you’re not being told exactly how this change is taking place, someone is likely wasting your time or trying to pull the wool over your eyes.
Link to previous Mind Hacks piece on neuroplasticity hype.