Control A Robot With Your Brain?

A paper just out makes the dramatic claim that you can control a robot using thought alone, Avatar style, thanks to a 'mind reading' MRI scanner. But does it really work?

Dutch neuroscientists Patrik Andersson and colleagues bought a robot - an off-the-shelf toy called the 'Spykee' -  which is equipped with Wifi and  a video camera. The controlling human lay in the scanner and real-time fMRI was used to record brain activity. The video feed from the robot was showed on a screen in the scanner, completing the human-robot loop.

Participants controlled the robot with their brain. Specifically, they had to focus their attention on one of three arrows - forward, left, and right - shown on the screen.

During an initial training phase they focussed on each arrow in turn, to provide examples of the resulting brain activity: these were then fed into a machine learning algorithm that learned to recognize the pattern of BOLD activation for each command. Then in the second phase, they could control the robot just by thinking about the correct arrow - the scanner 'decoded' their brain activity and sent the appropriate commands to the bot over Wifi.

None of the elements of this process are new - real time fMRI has been around for a few years, so has machine learning to decode brain activation - but it's the first time they've been put together in this way.

And it's pretty awesome. The participants were able to guide their 'avatar' around a room to visit a number of target locations. They weren't perfectly accurate, and it took 10 or 15 minutes to navigate a few meters of ground... but it worked.

However... were they really using their minds, or just their eyes?

This is my main concern about this paper: participants were told to keep their eyes focussed on the middle of the screen and just mentally focus on the arrows to give commands. If they did indeed keep their eyes entirely stationary, then the patterns of brain activation would indeed represent pure 'thoughts'.

But if they were moving their eyes slightly (even unconsciously), the interpretation would be rather different. Moving their eyes would change the pattern of light hitting their retina, and this would be expected to change brain activation in the visual system of the brain.

So, maybe the fancy fMRI decoding system wasn't reading their mind, it was just acting as an elaborate means of tracking eye movements - which would be much less interesting. If you want to control a robot with your eyes, there are cheaper ways.

Andersson et al acknowledge this issue, and they claim, for various reasons, that this probably wasn't what happened here - but they didn't measure eye movements directly, so it does remain a worry. Eye tracking devices suitable for fMRI are widely available but this study used an ultra-powerful 7 Tesla scanner which, the authors say, made it impossible. So there's more work to be done here.

Andersson P, Pluim JP, Viergever MA, and Ramsey NF (2012). Navigation of a Telepresence Robot via Covert Visuospatial Attention and Real-Time fMRI. Brain topography PMID: 22965825

Dream Action, Real Brain Activation

A neat little study has brought Inception one step closer to reality. The authors used fMRI to show that dreaming about doing something causes similar brain activation to actually doing it.

The authors took four guys who were all experienced lucid dreamers - able to become aware that they're dreaming, in the middle of a dream. They got them to go to sleep in an fMRI scanner. Their mission was to enter a lucid dream and move their hands in it - first their left, then their right, and so on. They also moved their eyes to signal when they were about to move their hands.

Unfortunately, only one of the intrepid dream-o-nauts succeeded, even though each was scanned more than once. Lucid dreaming isn't easy you know. Two didn't manage to enter a lucid dream. One thought he'd managed it, but the data suggested he might have actually been awake.

But one guy made it and the headline result was that his sensorimotor cortex was activated in a similar way to when he made the same movements in real life, during the lucid dream -  although less strongly. Depending on which hand he was moving in the dream, the corresponding side of the brain lit up:

EEG confirmed that he was in REM sleep and electromyography confirmed that his muscles were not in fact being activated. (During REM sleep, an inhibitory mechanism in the brain prevents muscle movement. If the EMG shows activity this is a sign that you're actually partially awake).

They also repeated the experiment with another way of measuring brain activation, NIRS. Out of five dudes, one made it. Interesting this showed the same pattern of results - weak sensorimotor cortex activation during movement - but it also showed stronger than normal supplementary motor area activation, which is responsible for planning movements.

This is rather cool but in many ways not surprising. After all, if you think about it, dreaming presumably involves all of the neural structures that are involved in really perceiving or doing whatever it is you're dreaming about. Otherwise, why would we experience it so clearly as being a dream about that thing?

It may be, however, that lucid dreaming is different, and that the motor cortex isn't activated in this way in normal dreams. I suppose it depends what the dream was about.

That raises the interesting question of what someone with brain damage would dream about. On the theory that dream experiences come from the same structures as normal experiences, you shouldn't be able to dream about something that you couldn't do in real life... I wonder if there's any data on that?

Dresler M, Koch SP, Wehrle R, Spoormaker VI, Holsboer F, Steiger A, Sämann PG, Obrig H, & Czisch M (2011). Dreamed Movement Elicits Activation in the Sensorimotor Cortex. Current biology : CB PMID: 22036177

The Real "Contagion" Virus

Seen Contagion yet?

It's pretty scary. A new epidemic disease comes out of nowhere and starts killing everyone. It infects the brain - victims suffer seizures, or fall into a coma, and die. It spreads like wildfire. Humanity's only hope lies in Lawrence Fishburne and Kate Winslet.

Luckily, that's fiction. But only just.

In the movie, the killer bug is called "MEV-1", but it might as well have been called the Nipah virus, because it was closely based on a real disease of the same name. So much so that this post about Nipah contains movie spoilers.

The Nipah Virus came to the world's attention in late 1998. There was an outbreak of a severe fever accompanied in many cases by encephalitis (viral infection of the brain) in Malaysia and Singapore. 276 patients were recorded. 40% of them died.

In the initial outbreak, there was probably no person-to-person transmission of the virus. Rather, only people who came into contact with Malaysian pigs - mainly farmers and butchers - caught the disease. Over a million pigs were culled in 1999 to try and contain the outbreak, and this seemed to be effective.

But since then, there have been several other smaller Nipah outbreaks in Asia, one almost every year in fact. In some of these, person to person transmission has been detected, notably in Bangladesh and India. The fatality rate in these more recent outbreaks has also been higher (70-90%). Luckily, unlike in the movie, it doesn't seem to be very contagious - so far. Most years have seen only 10 or 12 cases. But who knows what the future holds?

The virus is distantly related to measles, but is much more severe. Symptoms can begin anywhere from 4 days to 2 months after infection, but generally within 1 to 2 weeks. More recent outbreaks seem to have a shorter incubation period. The symptoms include fever, headache, vomiting, seizures, muscular jerks, and altered consciousness (confusion, coma).

Even after the initial infection is over, a minority of patients (4-8%) later suffer a relapse encephalitis. The virus seems able to remain dormant in the body before re-emerging to infect the brain again. Survivors may suffer neurological problems such as epilepsy, movement disorders, fatigue, and others. This is especially common following relapse encephalitis.

Where did it come from? It turns out that various strains of Nipah-like viruses are common in certain bats that inhabit various Asian countries, specifically fruit bats of the Pteropus genus, aka "flying foxes". The bats don't get sick, but infected bats are highly contagious, excreting the virus in their urine.

The virus seems to have made the leap into humans not once but several times, from different kinds of bats. Each outbreak could represent a new crossover event. Often there was an intermediate animal host, such as the domestic pigs in Malaysia .

Nipah is a classic zoonotic disease - it jumps from animals to humans. Zoonoses are scary for two reasons. They're new to humans, so humans haven't had a chance to develop immunity. And they may be especially deadly, because they haven't evolved not to be deadly to us.

Viruses and bacteria don't actually want to kill you. They want you alive, so that you can keeping breathing, walking, having sex, and otherwise spreading them. So pathogens tend to evolve to be less lethal to their primary hosts. Unfortunately, that's only good news if you are the primary host, and in the case of zoonoses, we're not. Bats don't get sick, but we do.

Lo, M., & Rota, P. (2008). The emergence of Nipah virus, a highly pathogenic paramyxovirus Journal of Clinical Virology, 43 (4), 396-400 DOI: 10.1016/j.jcv.2008.08.007

The Almond of Horror

Remember the 90s, when No Fear stuff was cool, and when people still said "cool"?

Well, a new paper has brought No Fear back, by reporting on a woman who has no fear - due to brain damage. The article, The Human Amygdala and the Induction and Experience of Fear, is brought to you by a list of neuroscientists including big names such as Antonio Damasio (of Phineas Gage fame).

The basic story is nice and simple. There's a woman, SM, who lacks a part of the brain called the amygdala. They found that she can't feel fear. Therefore, it's reasonable to assume that the amygdala's required for fear. But there's a bit more to it than that...

The amygdala is a small nugget of the brain nestled in the medial temporal lobe. The name comes from the Greek for "almond" because apparently it looks like one, though I can't say I've noticed the resemblance myself.

What does it do? Good question. There are two main schools of thought. Some think that the amygdala is responsible for the emotion of fear, while others argue that its role is much broader and that it's responsible for measuring the "salience" or importance of stimuli, which covers fear but also much else.

That's where this new paper comes in, with the patient SM. She's not a new patient: she's been studied for years, and many papers have been published about her. I wonder if her acronym doesn't stand for "Scientific Motherlode"?

She's one of the very few living cases of Urbach-Wiethe disease, an extremely rare genetic disorder which causes selective degeneration of the amygdala as well as other symptoms such as skin problems.

Previous studies on SM mostly focussed on specific aspects of her neurological function e.g. memory, perception and so on. However there have been a few studies of her "everyday" experiences and personality. Thus we learned that:

Two experienced clinical psychologists conducted "blind" interviews of SM (the psychologists were not provided any background information)... Both reached the conclusion that SM expressed a normal range of affect and emotion... However, they both noted that SM was remarkably dispassionate when relating highly emotional and traumatic life experiences... To the psychologists, SM came across as a "survivor", as being "resilient" and even "heroic".

These observations were based on interviews under normal conditions; what would happen if you actually went out of your way to try and scare her? So they did.

First, they took her to an exotic pet store and got her to meet various snakes and spiders. She was perfectly happy picking up the various critters and had to be prevented from getting too closely acquainted with the more dangerous ones.

What's fascinating is that before she went to the store, she claimed to hate snakes and spiders! Why? Before she developed Urbach-Wiethe disease, she had a normal childhood up to about the age of 10. Presumably she used to be afraid of them, and just never updated this belief, a great example of how our own narratives about our feelings can clash with our real feelings.

They subsequently confirmed that SM was fearless by taking her to a "haunted asylum" (check it out, even the website is scary) and showing her various horror movie clips, as well as through interviews with herself and her son. They also describe an incredible incident from several years ago: SM was walking home late at night when she saw

A man, whom SM described as looking “drugged-out.” As she walked past the park, the man called out and motioned for her to come over. SM made her way to the park bench. As she got within arm’s reach of the man, he suddenly stood up, pulled her down to the bench by her shirt, stuck a knife to her throat, and exclaimed, “I’m going to cut you, bitch!”

SM claims that she remained calm, did not panic, and did not feel afraid. In the distance she could hear the church choir singing. She looked at the man and confidently replied, “If you’re going to kill me, you’re gonna have to go through my God’s angels first.” The man suddenly let her go. SM reports “walking” back to her home. On the following day, she walked past the same park again. There were no signs of avoidance behavior and no feelings of fear.

All this suggests that the amygdala has a key role in the experience of fear, as opposed to other emotions: there is no evidence to suggest that SM lacks the ability to experience happiness or sadness in the same way.

So this is an interesting contribution to the debate on the role of the amygdala, although we really need someone to do equally detailed studies on other Urbach-Wiethe patients to make sure that it's not just that SM happens to be unusually brave for some other reason. What's doubly interesting, though, is that Ralph Adolphs, one of the authors, has previously argued against the view of the amygdala as a "fear center".

Links: I've previously written about the psychology of horror movies and I've reviewed quite a lot of them too.

Justin S. Feinstein, Ralph Adolphs, Antonio Damasio,, & and Daniel Tranel (2010). The Human Amygdala and the Induction and Experience of Fear Current Biology

The Horror, The Horror (Movies)

Previously, I blogged about how the placebo effect is at work when you watch a horror movie. As part of my... research for this post I watched quite a lot of them. Here are my thoughts on some recent ones. Roughly in order of best to worst. Some minor spoilers, but nothing worse than you'd get from the trailer.

• The Last Exorcism - Very scary, and full of surprises. The trailer makes it look like a shameless clone of The Exorcist; it isn't. Gets Neuroskeptic bonus points for the opening bit where the hero, a preacher who's lost his faith, talks about how he keeps doing "exorcisms" because it's psychologically helpful i.e. a placebo effect.
• The Broken - Inventive, intelligent and creepy. A woman starts seeing her own doppelgänger after a car crash. Neuroskeptic bonus points for mentioning Capgras syndrome, a classic neurological disorder. Well worth watching.
• The Signal - A mysterious TV glitch sends people crazy. But who's actually affected, and who's just been sent crazy by the fact that everyone else is going crazy around them? A clever twist on the zombie apocalypse genre, and manages to be both frightening and funny.
  
• Carriers - An airborne Ebola virus wipes out almost everyone. Four teens try to escape. The characters and acting are pretty blah, but the concept is good, and it's well produced.
  
• Dread - Student film-makers decide to make a documentary about people's worst fears, but one of them is a psychopath, so they end up making a Saw movie. Good, if a bit predictable.
  
• The House of the Devil - An attempt at the kind of anticipation-horror that I talked about in my past post - nothing really happens, but the build-up is tense. Up to a point. Then it goes on for another half hour and gets tedious. Missable.
  
• Tell Tale - Pretty standard slasher, except that the serial killer... is an internal organ! Actually not all that bad, but nothing special.
  
• Mutants - Zombies attack survivors holed up in a hospital. In France. Extremely generic, there is no point in watching this if you've seen, well, any other zombie movie from the past 5 years.
• Mulberry Street - "They're rat people, they're f-king rat people!" Some virus strikes New York, turning people into rat people. Who are also psychopaths. More funny than scary, unintentionally. Apparently this was done on basically zero budget: what's disappointing is that it comes across as quite polished despite that - the budget isn't the problem, the script is.

The Horror, The Horror

You're watching a horror movie.

The characters are going about their lives, blissfully unaware that something horrifying is about to happen. You the viewer know that things are going to end badly, though, because you know it's a horror movie.

Someone opens a closet - a bloody corpse could fall out! Or they're drinking a glass of water - which could be infected with a virus! Or they're talking to some guy - who's probably a serial killer! And so on.

The effect of this - and a good director can get a lot of mileage from it - is that scenes which would otherwise be entirely mundane, are experienced as scary, purely because you know that something scary is going to happen, so you see potential horror in every innocent little thing. An expectation as to what's going to happen, leads to you interpreting events in a certain way, and this creates certain emotions.

In a medical context, that would be called a placebo effect. Or a nocebo effect when expectations make people feel worse rather than better.

The horror movie analogy is useful, because it shows that placebo effects don't just happen to other people. We all like to think that if we were given a placebo treatment, we wouldn't be fooled. Unlike all those silly, suggestible, placebo responders, we'd stay as sick as ever until we got a proper cure.

I wouldn't be so sure. We're always interpreting the world around us, and interpreting our own thoughts and feelings, on the basis of our expectations and beliefs about what's going on. We don't suddenly stop doing this when it comes to health.

Suppose you have the flu. You feel terrible, and you're out of aspirin. You don't think you'll be able to make that meeting this afternoon, so you phone in sick.

Now, clearly, flu is a real disease, and it really does make you feel ill. But how do you know that you wouldn't be able to handle the meeting? Unless you have an extensive history of getting the flu in all its various forms, this is an interpretation, a best guess as to what you'll feel in the future, and it might be too pessimistic.

Maybe, if you tried, you'd get on OK. Maybe if you had some aspirin that would reassure you enough to give it a go. And just maybe it would still have worked even if those "aspirins" were just sugar pills...

Link: See my previous posts I Feel X, Therefore Y and How Blind is Double Blind?

Inception for Dummies

If you haven't watched Inception yet, don't read this post. It's great and I don't want to spoil it for you. So stop. You didn't though, did you, you're still reading this right now. Well, I warned you.

Inception as everyone knows is about people who can hack into other people's dreams to access their subconcious. The plot concerns their attempts to achieve, well, inception - putting an idea into someone's mind, which makes what they usually do, stealing secret ideas, seem easy by comparison.

The problem is that it's easy to plant an idea, but the victim always knows that it's an external imposition - they don't really believe it. Leonardo DiCaprio comes up with the plan of going into the victim's subconcious's subconcious, and planting an emotional idea about his father, in order to lead him to conclude, on his own, that he should break up his father's business empire. I'm not sure what Freud would have thought of this plan.

Could you actually do this? Well. Hacking into people's dreams is high fantasy: we have absolutely no idea how you'd do that, and in the movie the only explanation we get is that it involves fancy machines and unspecified drugs. It's safe to say no-one will be gatecrashing your dream party any time soon.

But here's one way to achieve the same kind of effect, inspired by two recent papers: this one that I wrote about in my last post, finding that electrical stimulation of the hippocampus produces temporary amnesia, and this one covered at Neurophilosophy, finding that stimulating a mouse's lateral amygdala at the same time as playing it a noise makes it fear that noise.

Simple fear conditioning happens in the amygdala, not the hippocampus (although conditioned fear to some partiuclarly complex stimuli, like places, does.) So assuming you were a neurosurgeon with a desire to do some inception and no ethical scruples whatsoever, here's what you might decide to do.

Knock your victim out with a sedative. Keep them unconscious while you implant electrodes in their hippocampus and their amygdala. Wake them up, but make sure that you constantly stimulate their hippocampus to disrupt it, from the moment they awake. This will leave them fully aware, but will mean they'll have no subsequent concious memory of what you do, because such concious declarative memories depend upon the hippocampus.

Now, you condition them to fear something, by showing it to them whilst stimulating their lateral amygdala. (To be honest, you could just give them a slap in the face and it would probably be just as effective - but that would be a bit unrefined. This is a high-tech evil medical procedure, not a common punch-up.) Maybe you could make them scared of the face of a business rival who you don't want them to cut a deal with. Or you could make a terrorist leader abhor the symbols of his own ideology. The possibilities are endless.

Once you're done, sedate them again and return them to their house. Yeah, you'd have to do this all in the course of one night, but no-one said Inception was going to be easy. With any luck, they'll wake up with no concious recollection of anything, but with the emotional conditioning still intact.

The lack of memory is of course crucial: if they remembered what had happened, they'd realize that the conditioning was an external imposition, and wouldn't be swayed by it. And they'd bust you to the cops, obviously. But without that concious knowledge as to the true source of the feelings, they'd have no alternative interpretation of the fear they now feel - they'd take it as their own, and really start to dislike whatever it was you'd made them afraid of, constructing elaborate rationalizations along the way. The dream is real...

The Crazies

I just watched The Crazies, a remake of Romero's 1973 original of the same name, about a small town struck by an outbreak of insanity following a biological weapon accident. It's not for the faint of heart: I was unsettled by a number of the scenes and I watch a lot of horror movies.

Which is to say, it's excellent. It maintains a high pitch of tension through the whole 100 minutes, something that a lot of horror doesn't manage. All too often, I find, a movie will start out scary enough, but then by some point about half way through it's effectively turned into an action movie.

This happens when the nature of the monster/killer/zombies have been revealed and all the protagonists have to do is fight it out - with the uncertainty gone, the horror goes, too. Without giving too much away, The Crazies avoids this trap. (The last great horror movie I saw, Paranormal Activity, does too, although in a very different way).

Of course the real reason I liked this movie is that it's got some neuroscience. The Crazies is (spoilers) about an engineered virus that infects the brain. Early symptoms include fever, blank stares, flattened emotions and stereotypies. This then progresses, over the course of about 48 hours, to psychopathic aggression, at least in some cases, although other victims just become confused. The "crazies" are somewhat like zombies - they have a Zombie Spectrum Disorder, one might say - but they retain enough of their personality and intelligence to be capable of much more elaborate and calculating violence than the average braaaaaaains-muncher, which is what makes them so disturbing.

Could a virus do that? Rabies, notoriously, causes aggression in animals and humans, although the incubation period is weeks rather than days, and aggression is only one of many neurological symptoms of the disease. But maybe an engineered virus could achieve a more specific effect if it was able to selectively infect the area of the brain reported on in this rather scary paper:

The authors report a patient with advanced PD, successfully treated by bilateral stimulation of the subthalamic nucleus, who developed acute transient aggressive behavior during intraoperative electrical test stimulation. The electrode responsible for this abnormal behavior was located within the lateral part of the posteromedial hypothalamic region (triangle of Sano). The authors suggest that affect can be dramatically modulated by the selective manipulation of deep brain structures.

Zombies!

Splinter and Quarantine are both very good horror movies that you might not have heard of. You should watch them, if you like scares - they're both "zombie movies", of a kind, but with enough originality and twists to keep them interesting.

Helpfully, they're both on the iStore. And on torrents, obviously, but neither was big-budget, and the filmmakers deserve your money, so you should really pay for them.

Maybe it's just because I share their interest in brains, but I've always preferred zombie movies to vampire ones. Vampires just aren't scary - at least in most modern portrayals, they're little more than psychopaths with a light allergy. They're too, well, human, to really horrify.

That's not to say there aren't some good vampire movies: Let The Right One In was great, and 30 Days of Night was pretty fun if nothing else - but as horror, which is the genre they always end up in, they just don't work for me.