The Man Who Couldn’t Stop (18 page)

Biology has one clear advantage over philosophy and metaphysics: it can be measured. But it's natural for scientists to measure either the mind or the brain. Even as modern science scoffs at the false premise of dualism, it inadvertently reinforces it. Neurologists work with brain tissue. Psychologists grapple with functions of the mind. Psychiatrists have a foot in both camps; they diagnose problems of the mind and treat them as problems of the brain, which is perhaps why psychiatry is sometimes regarded with suspicion by both sides.

Since the days of Esquirol and Freud, OCD has been viewed as a problem of the mind. Except, of course, OCD wasn't viewed, not in the literal sense, it was conceived, modelled, reimagined. Modern technology, however, now allows the brain to be viewed in the literal sense. And that literal view, some neuroscientists believe, can show us the physical basis of OCD.

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Only a fool or a liar will tell you how the brain works. Even well into the twentieth century, while scientists in other fields could harness technology to split the atom and unravel the molecular structure of DNA, neuroscientists were largely restricted to two types of experiment. They could remove and look at a dead brain, or they could watch for the effects of brutal accidents and dreadful disease on a live brain. The nineteenth-century scientist Paul Broca famously unravelled how the brain processes language with the help of stroke victims who lost the ability to speak. By the 1960s, Canadian neurosurgeon Wilder Penfield made maps of cognitive function with electrical stimulation of the exposed brains of wide-awake epileptic patients he was poised to operate on, to see which part of their bodies activated – the patients might twitch their shoulder or report a memory.

Neuroscience became more high-tech in the 1970s with devices to analyse live brains – an alphabet soup of acronyms. First was the CAT scan, computed axial tomography – which combines X-ray images taken from various directions – and the PET scan, positron emission tomography, which maps radioactively labelled chemicals injected into the bloodstream. Most influential was MRI, magnetic resonance imaging, based on a tool that research chemists had long used to probe molecular structure. The chemists called the technique nuclear magnetic resonance, and one of the first things that doctors did when they started to point the machines at their patients was to drop the word ‘nuclear' from the name. The patients preferred it that way.

MRI uses magnets and radio waves to detect blood. Particularly useful to neuroscientists is functional MRI, which takes lots of scans, one immediately after the other, and so shows how the blood moves. Blood flow in the brain means activity. If one part of the brain shows a greater demand for blood, or in the parlance of MRI studies, ‘lights up', then neuroscientists believe it shows the ‘lit up' part of the brain is more active. If the person whose brain is scanned is engaged in a task at the time, then neuroscientists can claim an association between the task and the region of the brain that lights up. In this way, functional MRI has been used to probe the brain regions associated with love, hate, racism, voting intention, response to adverts and chocolate, and why someone would prefer to drink Coke or Pepsi.

It's a lot easier to look for these regions than to find them. Despite the way these studies are sometimes presented, most don't prove that a certain part of the brain is responsible for a specific activity, thought or intention. The most they can say is that the scan images showed increased activity in that part of the brain at the time, but the pictures say little about cause and effect – whether the area that lit up drives the mental activity under investigation, or if it activates as a consequence of the activity.

There are other weaknesses with this kind of research. Most parts of the brain do different things at different times – the amygdala, for example, plays a role in both sexual arousal and terror – but an MRI scan cannot differentiate between passion and panic. It only tells us when a region is active, or more accurately, more active than normal. So what should we think when the amygdala lights up on an MRI scan when we are shown a picture of Cameron Diaz or Brad Pitt – that we are afraid of them? And then there is the dead fish problem.

In 2005, neuroscientists in California put an Atlantic salmon bought from a local fishmonger into their MRI machine. They showed the dead fish a series of photographs and scanned for its response. ‘The salmon', the scientists later reported, ‘was asked to determine what emotion the individual in the photo must have been experiencing.' It sounds silly, but it's a common and necessary step to calibrate MRI machines and check all is good before human volunteers are introduced. The California scientists tried it with a pumpkin too, because one is about the same size and weight as a human head.

The test samples – animal or vegetable – of course are not supposed to yield results. Yet, when the neuroscientists looked at the output of the scans of the salmon, they found a curious thing. The results appeared to show the salmon thinking. Shown the photographs, parts of its fishy brain had lit up. The rogue signal was down to a technical and statistical glitch, random noise in the way the scanner's computer software processed the signals. The scientists knew this, but rather than throw the scans away, they decided to publish them to alert others to the problem. MRI studies performed without certain statistical precautions, they said, could give out false positive results.

All of this is not meant to undermine the power and usefulness of MRI scans in research, just to show that the results are often not as clear-cut as they might appear. Neuroscientists get cross when journalists ignore the caveats and exaggerate the potential of brain scans to determine how we think and behave, but neuroscientists do it themselves. Some sell MRI scans they claim can help companies market their products, or detect liars.

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It's pretty grim inside an MRI machine. In 2003, as science correspondent for
The Guardian
, I had my brain scanned by MRI as part of a research study at University College London into the way we process information. The scientists were interested in how people can find themselves unable to pronounce certain words. It was nothing to do with my OCD. I wanted to write for the newspaper about how it felt to have a scan, and to take part was the only way they would let me through the doors. Time on those machines is too precious to waste on a tourist.

I remember most the sense of entombment; the metal cage to hold my head still and the magnet itself seemed to brush the end of my nose. And the noise – like I was trapped next to someone who typed a chapter of this book on an old-fashioned clickety-clack typewriter and blew an air horn each time they finished a sentence. Given that experience, I have great admiration for the people with OCD who have agreed to venture into these machines in the name of science, and then allowed scientists to poke their obsessions with a sharp stick.

Strapped inside MRI tubes, people with obsessive fears of contamination have had their hands sprayed with (harmless) water they are told contains drugs. Women with a compulsive need for symmetry have had nail varnish unevenly removed from their fingers. In other experiments, people with OCD have been asked to identify the words that set them off the most – ‘scissors' say, for a mother who feared she would stab her child – and then been forced to listen as the scientists repeat the words back to them over and over again through the loudspeakers of the MRI scanner. All the time, the machines record their torment in pixels.

Hundreds of OCD patients have been MRI scanned over the last decade or so, and had their brains compared to those of normal people, schizophrenics and hoarders. They have been scanned before and after treatment, and while they rest or wrestle with deliberately planted intrusive thoughts. Again and again a consistent picture of OCD emerges – unusual activity in and around a brain region called the basal ganglia.

The basal ganglia is the grape held in your crooked index finger. It is a tightly packed and knotty cluster of tissue at the base of the forebrain. Like most of the brain, exactly what the basal ganglia does, and how, remains largely unknown. But the basal ganglia does seem to play a role in ritual, compulsion and OCD. This was first shown almost a century ago with the work of an Austrian medic called Constantin von Economo, the original flying doctor.

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Von Economo married a princess but he had two passions: psychiatric medicine and aviation. He piloted one of the first fighter aircraft above the Italian front of the First World War in 1916, before he moved to a hospital in Vienna to care for soldiers with head injuries. It was there he saw his first cases of a bizarre disease that would go on to make him famous. Between 1915 and 1926, nearly a million people across the world died in a largely forgotten epidemic. Millions more were left as living statues in a catatonic state, unable to move or speak. Whatever infectious agent caused the disease (and it has yet to be pinned down with any certainty) seemed to attack and inflame the brain, and specifically, post-mortems of victims revealed, the region around the basal ganglia.

Von Economo reported how some patients with the condition – now known formally as encephalitis lethargica and less formally as von Economo's disease or sleepy sickness – reported a strange sensation. They felt compelled to carry out odd movements. In his write-up of 1920, he said: ‘These patients do not say I have a twitch in my hand, but rather as a rule, I
have got to
move my hand that way.'
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He saw a range of tic-like behaviours too. His patients would cluck, hiss and yell. These disturbances, he said ‘were reminiscent of compulsive movements and compulsive actions, with frequently ensuing utterances of speech and trends of thought of a compulsive character'.

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Our brains evolved from the inside out. The clever stuff at the edge, the cortex with its ability to reason, is new in evolutionary terms. The deepest bits of the brain are the oldest. They evolved in some ancestor long before we did and we share these brain units with all the subsequent species that developed later. The basal ganglia is among the deepest and oldest bits of the brain. Birds have a basal ganglia, and so do ugly eels called lampreys, which have been around for more than half a billion years.

Half a billion years is a long time to get something right, and the basal ganglia has its act perfect. It holds set programmes for repetitive, automatic and ritualistic behaviours, any of which a creature can press into service at a moment's notice. A quick response – run! − is usually critical to such situations, so the higher parts of our brain – the middle management, which tend to mull on the pros and cons and just slow everything down – are sidelined. That makes the behaviour directed by the basal ganglia easy to activate and difficult to turn off. When people say that a pattern of behaviour is hardwired into the brain, it's often something that is stored in the basal ganglia.

In that context, it makes sense that OCD could be a problem with the basal ganglia. OCD could be what happens when these programmes go haywire; when they can't be turned off or when they activate at an inappropriate time. That would explain the quasi-instinctive drive in OCD to perform compulsive behaviour. Time and again, scientists see how damage to the basal ganglia can cause OCD-like symptoms. Injuries and diseases such as rheumatic fever, Huntingdon's and Parkinson's can bring on obsessions and compulsions, and so can something as benign as a wasp sting.

Mr V was French. He was 41 in 1968, when he was stung and suffered an extreme reaction. He had immediate convulsions and fell into a coma for twenty-four hours. He recovered, but scans showed he had suffered damage to the basal ganglia. Two years after he was stung, life began to get strange for Mr V. He started to feel an urge to count inside his head, usually to twelve or a multiple of twelve, though he performed more difficult calculations. Sometimes he wagged his finger as he did so; other times he was compelled to switch a light on and off for an hour or more. His psychiatrist noted: ‘When asked about his behaviour he answered that he had to count … that he could not stop … that it was stronger than him.' Once Mr V was found on his knees as he pushed a stone along the ground with his hands – he simply had to push it, he explained.

Then there was Mr E, a 42-year-old Dutchman who suffered a heart attack in 1992, which choked off the oxygen to the base of his brain around the basal ganglia. He survived but started to compulsively whistle, for up to eight hours a day, always the same tune. He wanted to stop, but when he did he felt annoyed and anxious. After listening to him for almost sixteen years, Mrs E sent her husband for treatment.

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Rituals stored in the basal ganglia have been used to explain some of the most puzzling cases of OCD: children who go to bed fine and wake up the next morning with severe obsessions and compulsions. It's a controversial area, but if the scientists and doctors who have investigated these cases are correct then it presents a startling conclusion – OCD can be passed from person to person as easily as a sore throat.

In early 1991, a 10-year-old boy was brought to the US National Institute of Mental Health in Maryland after he seemed to develop OCD overnight. He woke one day with severe obsessive concerns about Aids and other germs, as well as compulsions to clean and hoard. Within two days the boy could not face school, or anything else. He had developed a spitting tic alongside the obsessive thoughts, and jerky, abrupt movements. But the night before his symptoms arrived, his mother said, he had been completely healthy. Well, almost.

She was a medical technologist and she pointed out to the NIMH doctors that, just a couple of weeks before, the boy had been diagnosed with a throat infection; specifically, he had pharyngitis caused by streptococcal bacteria. What's more, the boy's older brother suffered from a tic disorder that waxed and waned, and his most recent bad days, the woman realized, had come after he had been ill with the same throat infection as his younger brother. ‘There had to be a connection,' she said.