mind > freud the neuroscientist?

What is it about Sigmund Freud that makes people want to elevate him to the pantheon of greatest ever thinkers? He is always in the top ten of any "most cited scientist" list. In the Time magazine "100" roll-call of the most significant 20th century figures, he was the only neurologist to feature.

Yes, neurologist! Oh alright, Freud is actually famous for his psychological theories. But he began his career as a neurologist. And champions of Freud will be quick to tell you he was on the brink of some brilliant neuroscientific discoveries before he suddenly switched track to develop psychoanalytic therapy.

Freud set out as a medical student at the University of Vienna, eventually becoming a research assistant working with illustrious pioneers of neuroscience such as Ernst Brücke, Theodore Meynert and Jean-Martin Charcot. But it seems he did not impress as Freud published a few papers on aphasia and infantile cerebral palsies before being politely persuaded by his teachers that his future lay in private practice rather than the giddy heights of academia. In 1887, Freud opened his own neurology clinic and seemed destined for a fairly safe, if dull, medical career.

Yet Freud always harboured a megalomaniac streak. He wrote to his future wife that he was looking for a "lucky hit" to propel him into the history books. His first stab was a paper trumpeting the curative powers of a recently refined drug - cocaine. Freud exclaimed it was a remedy for everything from seasickness to diabetes. Well, actually biographers have noted that Freud's megalomania seemed to kick in when he first started prescribing this particular elixir for his own indigestion and depression. Certainly his thinking took on a fevered, sexually-charged, energy from this point.

For a number of years while building up his neurology practice, Freud worked secretly on a grand neuroscientific theory of hysterical mental illnesses. Freud sent hundreds of pages of notes and diagrams to a friend. But his "Project for a Scientific Psychology" was never published, the manuscript being released only posthumously in 1954. In the middle of his efforts, Freud decided abruptly to abandon a brain-based explanation and instead develop his ideas as a psychological theory.

So what of this lost research? Could Freud have revolutionised neuroscience as well? Freud's supporters claim he foresaw many important principles. Way back in the 1890s he was already talking about Hebbian learning in neural networks. He was talking about neural synchrony and feedback. On some accounts, Freud sounds truly a man ahead of his times.

Sad to say, a little investigation soon reveals that Freud's neuroscientific writings are the psycho-sexual mish-mash one might expect. Yes, there is a strong connectionist flavour. But this is only to be expected as Victorian neurology was more sophisticated then generally realised. His own teachers, Brücke and Meynert, let alone many others such as Sigmund Exner, Herbert Spencer and William James, were developing "Hebbian" ideas about associative networks of excitatory and inhibitory neurons - work largely forgotten today.

Where Freud differed was that he saw these networks as having a hydraulic psychic energy. In his theory, there were two classes of neurons. Omega neurons in perceptual and frontal cortex areas vibrated directly to sensory stimuli, creating jangling patterns of conscious experience. A second class of Psi neurons formed unconscious memory networks. As well as trapping memories and ideas in their webs of connections, these Psi cells accumulated inside them a mysterious substance - Q - exuded by the tissues of the body.

So the Psi networks became literally swollen with the body's desires. The pressure released into consciousness the memories for the particular behaviours necessary to satisfy them. But because of the often animal or anti-social nature of the body's desires, the civilised human ego had to find other ways of discharging the constant build up of Q in the brain. Its unconscious energy had to be diverted into the production of oblique fantasy images or various neurotic displacement activities.

The charitable will see the good in Freud's bulging Psi networks. At least he was taking account of the "wet" side of information processing - our embodied values, emotions and needs. And he was definitely a pioneer of a neurocognitive approach to psychiatric problems.

But the question remains: what would have happened to Freud's big ideas if he had actually gone ahead and published them as neuroscience rather than as a collection of rather literary psychological case histories? Perhaps the critical savaging of his notions might have come round rather more violently and swiftly.  But we would also be left without even a single historically important neuroscientist, or former neurology student, it seems.