Diary of a human 'lab rat'

New Scientist, 08 December 2007

FOR more than a decade, I have been reporting on the big advances in neuroscience. I have talked to the top names, attended their conferences, read their papers and visited their labs, but I have never been on the receiving end of their work - until now. Earlier this year, I volunteered to become effectively blind for a week, as part of a study to test what happens to a brain when it is suddenly deprived of light. This is my diary:


Induction. I report to the Beth Israel Deaconess Hospital in Boston, as instructed. To be honest, I am having second thoughts. I'm not sure I want to be blindfolded. What if I can't hack it? I'm worried I'll wake up in the middle of the night and not know where I am, that I won't be able to find the bathroom, that they'll discover a brain tumour - or worse, a very small, unimpressive brain. Why did I agree to do this?

I realise there is no turning back as I meet the research team. Naomi Pitskell is the study coordinator, Lotfi Merabet will be running the show, and Marina Bedny plans to conduct some pilot tests on me. Over the next few hours they evaluate my hearing, vision and general neurological function. Miraculously, despite last night's insomnia, all is normal.

Others have done this before me, but that isn't much consolation: most were undergraduate students about half my age. I confide to Lotfi my big fear that I will be the subject who definitively pinpoints the age when the human brain can no longer adapt - that I'll lose my sight for good. "That's not going to happen!" he hoots. Yet later, as I re-read the 17-page consent form, I notice that the hospital and staff cannot be held responsible if anything goes wrong.

In the afternoon the team introduce me to some of my tasks. One involves listening to pairs of tones and deciding whether they go up or down. Another requires me to produce verbs to accompany nouns: I hear "dog" and respond "fetch". Then there is the category game. Listing countries is easy, but I am totally stumped on cars and football teams.


Day Zero. Today the researchers are locating my visual cortex. Unfortunately that involves staring at flashing lights - a guaranteed migraine trigger for me. At least obsessing over the impending headache helps me ignore the discomfort of getting into an MRI scanner, which entails lying down on a long plastic tray, having your head locked into a little plastic cage, and being slid into a narrow cylindrical hole. You feel a bit like a CD being popped into a stereo, or a stiff going into storage in the morgue. I lie there motionless for two hours.

By the time I formally check into the hospital, a big snowstorm is blowing in, and the city is coming to a standstill. I am lodged in a special wing reserved for people crazy enough to sign up for research projects and clinical trials. The nurses are friendly. They have seen this all before, and tell me people cope surprisingly well with the blindfold, although one woman did have to be sent home when she was caught peeking at the TV.

Tonight I will be alone, but I learn that down the corridor some hapless soul will soon be staying awake for 88 hours straight for a sleep deprivation study. It puts the blindfolding into context.

I spend the evening playing with my talking clock and practising writing with my eyes closed using my "writing guide". A note is posted on my door: "This is study N-107. When entering this room please announce yourself so our blindfolded subject is not startled." Yikes! What am I getting into?


Day One. I wake early, very anxious. After breakfast I perform the ceremonial last washing of the hair and take a good, hard look around my room to try to imprint it on my memory. At 8.20 Lotfi enters and the blindfolding begins. I slip on the eyemask, with its shiny black plastic front, thick foam backing and Velcro strap. It has cavities carved out of the foam, so I can open my eyes if I want. Then Lotfi wraps an elastic bandage around my head to hold the mask and make sure it is light-proof. He shines a flashlight at potential weakpoints. I can't see a thing.

Now the testing begins in earnest. I do more verbs and lists and tones. There is also a new task, where I have to figure out if there are spaces between rows of raised dots. It's weird, but I don't mind not being able to see them. I don't even miss seeing people.

The crucial next step is a baseline fMRI scan. By comparing this with a similar scan done on day five, the team will be able to see how my brain has adapted to life without visual input. Shortly before noon, Lotfi brings news that the scanner is broken. We have no option but to stop the experiment. They remove my blindfold. We will have to wait and see whether we can start again tomorrow.


Day One - Again. Woo-hoo! The scanner is working. By late morning, with blindfold replaced and a fresh round of cognitive tests behind me, Lotfi helps me down the elevator and into the hospital lobby. With my white cane and head bandaged I am creating a stir. "I hope none of my patients see me with you," he quips. "They'll wonder what I did wrong."

We drive over to Boston University, where all my scans are being done. The scanner is a nicer place without vision. I do tasks like identifying objects by touch, recalling a list of words and generating yet more verbs. The scanner is not entirely fixed yet, and every so often it turns itself off to avoid overheating. When that happens we have to start all over again. I lie still for what feels like hours.

Back at Beth Israel it is time for some transcranial magnetic stimulation. TMS uses magnets to induce tiny electrical impulses that turn off target areas of the brain, so researchers can test whether they are needed in certain tasks. Journalists often give the impression it is quick and easy: far from it. First I have a device strapped to my head so that my brain can be tracked in space, allowing comparisons on day five. Then they use an MRI scan to figure out where the target areas are. This is not quick.

Finally we are ready for the TMS itself. In a trial run on my arm it click-clicks away harmlessly. See? It's nothing. It feels just the same on the first scalp site. Click click click. At the second site it is a bit more like a mean flick of the finger against my skull. The final site, just above my left ear, is altogether less fun - like having a woodpecker perched on the side of your head, pecking once a second for 10 minutes, but without breaking the skin.

Driving back after the scan, I had noticed an intense pinprick of light. It lasted a minute or two then disappeared. Later, there were short-lived and less intense specks, sometimes many at a time, like a distant galaxy. Now it is evening and I am seeing brightly illuminated swimming sperm and slowly swirling firecrackers. At other times there is a grey, textured palette, something like the grainy undersea images from the wreck of the Titanic. When things settle down, I sense the faint glowing haze of a late-summer dusk. I press my talking clock. "It's ten-oh-five pm."

Now it is evening and I am seeing brightly illuminated swimming sperm and slowly swirling firecrackers


Day Two. No more tests until day five now. Instead, I have lessons in navigation - and not a moment too soon. I have already given myself a bloody lip by slamming into a towel rail. Carol Coggio Faherty from the Carroll Center for the Blind in Newton, Massachusetts, teaches me how to protect my head and how to square off so I set off in the right direction from my starting point. I also learn how to use a guide's elbow and my white cane, and, perhaps most importantly, not to feel self-conscious as I grope around.

Eating is distressing. I hunch over my tray and shovel the food in. With utensils, I never know how much is coming, so now I just use my hands. I feel like a caveman. I am not enjoying the flavours or textures at all, and my senses of smell and touch are not coming to my assistance as I had hoped. For instance, biting into a lovely firm piece of cucumber, I discover it is actually a slice of lemon.

The lightshow continues. Jagged shapes, vertical lightning strikes, symmetrical patterns, strings that quiver in time to the music on my CD.


Day Three. I have become very sensitive to my body temperature. I feel it rise dramatically after eating, and I can tell where I am by how cool or warm the air around me is. I have never noticed this before. My sense of smell is also becoming more acute. Perhaps I didn't need that to tell me I could use a shower.

Strange things are happening. A short while ago, a nurse came in while I was listening to music and I didn't hear her say hello. Suddenly I smelled face powder right next to me and leapt up in terror. While talking to the nutritionist, my phone rang. I told my friend to call back and resumed the conversation, only to discover the nutritionist had gone.

I was enjoying the "view" from my window until someone pointed out that the blind was drawn. Even in the middle of the day, my room is in complete darkness.

There is no darkness for me, though. The shapes and flashes have been joined by what look like searchlights, bouncing off waves and patches of thick fog. Flares are set off, illuminating the choppy seas of my brain for an instant. It seems like a desperate cry for help. "Hello visual input! Are you out there!" This sensation is heightened by the sounds of a storm at my window, though I am told the day is sunny and calm. It's hard not to be just a little alarmed.


Day Four. I have noticed a growing pig-headedness. For the past three days I have woken with the confident knowledge that it is 8 am. Each day, the clock disagrees. First 5.35, then 5.30, then today 4.45. Ditto when navigating my room. I square off against the bed and head towards the bathroom. Failing to encounter the anticipated wall, I nevertheless continue confidently until I chance upon the table on the opposite side of the room. It makes me tetchy to discover the room morphing as I walk knowledgeably through it.

Lotfi took me for a stroll around the hospital this afternoon. I was completely comfortable negotiating stairs because I had the glorious handrail. Once back on the flat, however, I felt vulnerable, as though I was perched on a tiny platform - one wrong step and I would hurtle over the edge.

Tonight I had the weird sensation of being able to detect my hand passing in front of my eyes. As I waved it to and fro, it caused a ripple of visual disturbance through the image in my head. I can only assume that in a desperate attempt to see, my visual cortex is taking coordinates from my hand and saying "Look! We have intelligence that something is moving right here. It's yay big with five appendages and it's wagging. Can you find it!" The astonishing implication is that at least part of seeing is knowing what to look for.

I am so ready for this to end. I've finished listening to David Sedaris at Carnegie Hall and have the entire unabridged Thirty-nine Steps under my belt. I hope my brain performs well tomorrow - especially that most important trick of allowing me to see again.


Day Five. Suddenly, everything is very exciting. We're nearly there, and with no major mishaps. We repeat everything we did on day one, including the cognitive tasks, the scanning and the TMS. By 4.30 pm, right on schedule, we are done.

It is time to take the blindfold off. Lotfi sits across from me in my room. It feels like he has rescued me from a kidnapping and is about to debrief me. The blind is down and we are in total darkness. He removes my bandage and puts a towel over my head. I undo the Velcro and take off the mask. I am shocked to see the inside of the towel glowing with light. After a few minutes, I glance down at my thighs. They are like embers. I feel nauseous and have to look up again. After a few minutes, we take the towel off and the room seems bright all around me, despite being in pitch darkness.

Gradually, my eyes adjust and Lotfi raises the blind a centimetre. Within 10 minutes it is drawn all the way up, and everything is bright and crisp, no longer on fire or grainy. There's a problem, though. When I move my head, my eyes are not seeing what my head reports - every snapshot is just a split second behind what it should be.

By 5 pm my vision is almost normal again. An hour later I am at Logan airport. As I enter the departure lounge, I start to cry with relief. With my unwashed hair, hospital bracelet and tears, I must cut quite a picture. People are staring at me again. Still, it is marvellous to be able to see them doing it.

The Human Brain - With one hundred billion nerve cells, the complexity is mind-boggling. Learn more in our cutting edge special report.

The blindfold study

Blind people can do certain things much better than sighted people, such as localise sounds in space and read Braille. Their verbal memory also tends to be better. Brain imaging suggests that they have these talents partly because they call upon the visual cortex - no longer involved in seeing - to help out. Is this some extraordinary adaptation that happens in brains that have grappled with sightlessness for years? Neurologist Alvaro Pascual-Leone at Harvard Medical School suspected not. To test his hunch, in 1997 he began the Blindfold Study.

Over the years, his team has blindfolded dozens of subjects for five days straight to find out just how flexibly and quickly the average brain can respond to blindness. Sometimes they taught people Braille, then tested how well they could recognise the letters through touch alone on day one versus day five. Other experiments have explored whether people's ability to localise sound improves after being deprived of sight.

In both these cases, subjects performed better on day five than day one. Brain scans with fMRI revealed that just like blind people, volunteers were recruiting their visual cortex to carry out these non-visual tasks. What's more, if on day five Pascual-Leone temporarily disabled the visual cortex using TMS, the volunteers were suddenly unable to identify the Braille characters or figure out as accurately where sounds were coming from. TMS had no effect on performance on day one.

All this calls into question the idea that the visual cortex is exclusively visual, Pascual-Leone says. He believes that that part of the brain simply prefers vision, but when vision is not an option, it can draw information from the other senses. His ideas reflect a growing realisation that the human brain is much more flexible than previously thought. It is made to be versatile and adaptable, argues Pascual-Leone, and it doesn't dally when a sense goes AWOL - it just moves on to another.

My brain's contribution to science


The task: On day one of blindfolding, I was presented with cards with lines of tiny raised dots on them. Sometimes I had to say whether there was a gap in the line of dots. Other times I had to decide whether there was a parallel line just next to the main line. It sounds easy but wasn't. The researchers compared my tactile ability on day one and day five.

The results: This was a pilot study, and I was subject number one with no control but, for what it's worth, I did show a dramatic improvement. "You were able to discriminate much smaller gaps and you were able to detect much finer breaks in the offset," researcher Lofti Merabet says.


The task: On days one and five, I listened to numerous pairs of tones. Sometimes the second tone went up in pitch, sometimes down, and I had to indicate which. In many cases it was hard to tell, and my responses felt instinctual.

The results: Again, this was a fledgling pilot study. This time I showed no improvement. The researchers think they may need to make the task more difficult to pick up any subtle changes.


The task: I was given nouns such as "car" and asked to respond quickly with a related verb, such as "drive". In some of these tests, I was zapped with TMS for 10 minutes immediately beforehand to temporarily disable parts of my brain. Other tests were done in a brain scanner.

The results: Again, only a pilot study, but as expected, I did do worse on day five after TMS to disable the visual cortex.


The task: While lying in the brain scanner, I was handed a succession of small objects to grope and identify by touch - things like a plastic spoon and a toy horse.

The results: The researchers were trying to activate a part of my brain known as LO, which lights up when we identify objects by sight. Recent findings, confirmed by the Blindfold Study, indicate that tactile information can also activate LO, suggesting that it couldn't care less where the information is coming from - eyes, fingertips, even ears - so long as it conveys something about shape.

Results from my fMRI scan are not yet in.