Am I Attacking Neuroscience?

A New York Times article just out says:

Neuroscience: Under Attack

Under attack by who?

Er... me. And the rest of the usual suspects:

A gaggle of energetic and amusing, mostly anonymous, neuroscience bloggers - including Neurocritic, Neuroskeptic, Neurobonkers and Mind Hacks - now regularly point out the lapses and folly contained in mainstream neuroscientific discourse. 

I had promised not to do any more self-referential posts, but this one wasn't my fault. Just when I thought I was out, they pull me back in.

Anyway, I'm pretty happy with how Neuroskeptic's presented in the article, but not entirely.

The headline is sensationalist - I don't see myself as attacking neuroscience and I don't think any of the others do either. We are trying to defend neuroscience against errors and misrepresentations. My ideal is The Sceptical Chymist, where skepticism helped, rather than undermined, chemistry.

But the job of a headline is to be sensationalist so that's OK. Most of the piece is very good. I'm all on board with this:

Meet the "neuro doubters". The neuro doubter may like neuroscience but does not like what he or she considers its bastardization by glib, sometimes ill-informed, popularizers.

Yet I can't quite go along with this:

A number of the neuro doubters are also humanities scholars who question the way that neuroscience has seeped into their disciplines, creating phenomena like neuro law, which, in part, uses the evidence of damaged brains as the basis for legal defense of people accused of heinous crimes, or neuroaesthetics, a trendy blend of art history and neuroscience.

Admittedly this wasn't directly aimed at me because I'm not a humanities scholar, but I believe that neuroaesthetics and neurolaw are absolutely valid - in theory.

I'm not defending any particular manifestation of those, and I've criticized quite a few. But in the abstract, I see nothing wrong with neuroscience helping to explain those things. It will be difficult in practice, but it's fine to try.

Militarization of Neuroscience?

US military tech hothouse DARPA have an exciting announcement:

Tag Team Threat-recognition Technology Incorporates Mind, Machine
DARPA links human brainwaves, improved sensors, cognitive algorithms to improve target detection...

In what is - to my knowledge - the first example of the direct militarization of neuroscience, DARPA have developed a system in which electrical responses in a human brain are an integral step.

A soldier watches a screen on which, via various cameras, possible battlefield "threats" are shown. The cameras are fancy, and fancy image-recognition algorithms prioritize images that resemble threats - stuff that looks a bit like a tank, an IEDs, etc. But that's just the set-up.

The neuroscience core is that rather than just having a guy watching this screen and pressing a button if he spots something, they have a guy wired up with EEG to record brain activity. The system registers a threat when a picture causes a P300 response.

Now, the P300 is an electrical wave triggered by stimuli that are somehow 'meaningful' to the individual person. If you ask someone to press a button whenever they see a red light, for example, and then show them various lights, red ones will elicit a P300.

Very clever. But it may be too clever for its own good.

We already have a system that can detect the P300. It's the brain. No, most of us don't think of it as in those terms - we think of it as "Oh!" or "WTF?" or "Button press time" - but that response is the P300 (or rather something that precedes it because the P300 takes 300 milliseconds to peak, but you can respond faster than that.)

So why the EEG?

You could program a computer to detect P300s in a guy's brain and set off an alarm. DARPA apparently have. But it would be easier and cheaper to just 'program' the guy's brain to detect the P300 and push an alarm button - by asking him to do that. The human brain is a supercomputer that's been in development for hundreds of millions of years and it's primary job is to detect threats and act on them as quickly as possibly. One day technology might be able to do better but I don't think we're there yet.

DARPA say:

In testing of the full CT2WS kit, the sensor and cognitive algorithms returned 810 false alarms per hour. When a human wearing the EEG cap was introduced, the number of false alarms dropped to only five per hour, out of a total of 2,304 target events per hour, and a 91% percent successful target recognition rate.

All that tells us is that having a human check the pics via EEG is better than having no human involved at all. That's fine, but would a human just checking the pics via a button, be even better? We're not told. Maybe DARPA ran those tests and it really does offer advantages, but off the top of my head I can't think of any, and it wouldn't be the first time that the allure of high-tech neuroscience has blinded smart people to the fact that there's an easier, less sexy solution.

Unless...

OK. This is going to make me sound like a conspiracy nut. But there's one scenario in which the P300 has a decided advantage: unlike a button press, it's involuntary. It would work even if the guy doesn't want to co-operate.

So suppose you've captured a terrorist and you want to know who his terrorist friends are or where they've put the bomb. But he's not talking and Samuel L Jackson is off sick. So you wire him up to this system and show him a bunch of pictures of all the possible suspects or targets on your database. His brain will respond with a P300 to the ones he recognizes.

That would probably work - sometimes - and the P300 is already being trialled in some legal contexts for just that purpose although it's not clear how reliable it is.

So it's just possible that this whole soldier-scanning-the-battlefield story is merely an elaborate front (and perhaps a useful source of crucial calibration data) for a device to allow the CIA to read minds. I warned you it would make me sound crazy. Quick! Pass the tinfoil hat...!

Naomi Wolf's "Vagina"

Naomi Wolf's "Vagina" is full of bad science about the brain - is an article I wrote for the New Statesman. It's about a new book which is... not very good.

I didn't come up with the title by the way, but I do rather like it.

See also the Neurocritic's take.

This Is Your Brain On Management

Have you ever wondered whether how the brains of managers work? New research from a group of German neuroscientists and management experts reveals all: Dissociated Neural Processing for Decisions in Managers and Non-Managers

The results were rather remarkable:

Using fMRI, the researchers found that managers' brains were less active in a number of areas, compared to the brains of non-managers, when doing the same task. By contrast, managerial brains were more active than the others only in one small area (caudate nucleus). See above.

So overall, managers had less brain activation during the task. Does that mean they have defective brains? Could this be a neurobiological explanation for the behaviour of Pointy Haired Boss and David Brent?

Not at all, say the authors. The lower activation in the brains of managers means that they were more efficient:

the managers might have found a more efficient way of sorting the presented words. This might have enabled them to faster decide for their preferred category...  Managers as expert decision-makers would seek to find a rule or heuristic on which they could base their decisions. According to previous studies, this phase of rule identification would involve the caudate nucleus

While non-managers wasted brainpower on thinking through the task with several areas of their cerebral cortex, the managers (so to speak) downsized their neurological expenditure by outsourcing the work to their caudate nucleus, an area responsible for applying a simple but effective rule.

One of the problems with these kinds of group-comparison fMRI studies is that under-activation can equally well be glossed as "deficient" or "efficient". Curiously, it usually ends up being whichever fits with the author's narrative.

That's assuming you agree that the task was about "decision making". It consisted of seeing a long series of pairs of words, one "individualistic" such as 'power' and one "collectivistic" such as 'harmony'. Participants just had to pick which word they liked best. There were no right or wrong answers. I'm not sure what kind of manager would have to do anything like that in real life. Maybe a manager of a fridge magnet poetry manufacturer?

That's also assuming the results are solid. The authors provide few details on the fMRI methods (the main results are said to be "cluster-level corrected at p less than 0.0013", which is an unusual threshold to use and an extremely strict one (0.05 cluster-level is more common; this is about 40 times stricter).

Still. If you do buy these results, the message is: management is literally about using as little of your brain as possible...

Caspers S, Heim S, Lucas MG, Stephan E, Fischer L, Amunts K, and Zilles K (2012). Dissociated neural processing for decisions in managers and non-managers. PloS one, 7 (8) PMID: 22927984

Whole Brain Teaching...?

Oh dear. The Kansas City Star asks: Teachers learn ways to keep students' attention, but are brain claims valid?

Probably not. Unless you're buying a brain scanner or a plush brain, product 'brain claims' are generally just marketing patter. But let's see.

When Chris Biffle called out the word "Class!" Wednesday morning at Walsh University, 450 teachers and administrators yelled back, "Yes!"

"Class class?" he said. "Yes! Yes!" they replied.

"Classity classity," he said.
"Yessity yessity," they chanted back.

Biffle, one of the co-founders of Southern California-based Whole Brain Teaching LLC, is leading a two-day conference about his method. He calls the technique "Class-Yes." Whole Brain Teaching's website says "Class Yes" activates the prefrontal cortex of the brain and "readies students for instruction"...

Whole Brain Teaching reminds me of Brain Gym, a notorious bit of British neuro-nonsense from a few years ago. According to the WBT research page, they have over 50,000 registered teachers and 2 million views of their videos. This also informs us that:

Class-Yes: Our primary attention-getter activates the prefrontal cortex, often called the CEO of the brain... Little if any learning can take place if the prefrontal cortex is not engaged.

while even "mirror neurons" have a role to play:

Mirror: Many brain scientists believe that we learn by mirroring the gestures and activities of others. They have identified mirror neurons scattered throughout the brain that are activated by mimicking the behavior we observe. Our own experience in WBT classroom indicates that when a class mirrors our gestures and, when appropriate, repeats our words, a powerful learning bond is created between students and teachers.

There are lots of problems here, but here's the most fundamental: the theory behind the system seems to be that activating particular parts of students' brains, through a special task, will help them to use that part of their brain when it comes to the actual lesson a few minutes later. But I know of no evidence that bits of the brain "warm up" like that; if anything they're more likely to "wear out" through lack of energy and nutrients although I don't think that's likely either.

If such warm-ups did work, your best bet for activating your primary visual cortex, for example, would be to stare at a rapidly-changing pattern of random colors for a few minutes. That wouldn't improve your vision. It would just give you a headache.

In fact, why not just activate your entire noggin, pharmacologically? Just grab some pentylenetetrazol - a drug that blocks inhibitory signals between brain cells. Snort a few lines of that and if you survive the resulting seizure, go and learn something and see if you're really good at it.

I'm not saying Whole Brain Teaching is useless, I'm not saying anything about the method itself, but the "brain" claims are misleading. Many of the things they recommend are teaching aids and classroom exercises, and no doubt those are helpful. Plus, psychological factors like teacher motivation, student engagement, and a positive atmosphere are vital in learning, and it doesn't matter if you achieve them through neurosciencey gimmicks, they're still going to help... well, except in terms of educating people to spot neurosciencey gimmicks.

But that's teaching. It's nothing to do with the brain.

Mystery Joker Parodies Neuroscience

Someone has created a hilarious spoof paper poking fun at neuropsychoanalysis (but all of fMRI takes some hits too): A Triple Dissociation of Neural Systems Supporting ID, EGO, and SUPEREGO.

Featuring gems such as

• Authors "Steven Z. Fisher and Stephen T. Student" with contact details "mother@amaliastate.edu".
• "Twenty-four healthy participants (all 19-year-old white, male undergraduates who sat near each other in an Introductory Psychology course and were raised in upper middle class suburban New
  England neighborhoods) were scanned but 17 were excluded for not following instructions or falling asleep in the scanner."
• "If you’re like us, you’ve probably been thinking that Social Neuroscience, Neuroeconomics, and Developmental Social Cognitive Affective Clinical Neuroscience are just not cutting edge enough
  anymore. Do not despair. This study represents the first of what is likely to be a productive and active new field of Psychoanalytic Neuroscience."

It really is very funny, but it's also deadly accurate in its highlighting serious problems that plague a certain genre of neuroimaging papers. Who made it? The PDF appeared on Dropbox a couple of weeks ago and, while a few people have Tweeted about it, no-one has claimed ownership, yet.

For the record, it wasn't me.

Do Brain Scans Sway Juries?

Does seeing a criminal's brain affect jury decisions?

Edith Greene and Brian Cahill ask this question in a new study which put volunteers in the position of jurors in a murder trial. The 'defendant' was guilty, but the question was: should they get life in prison, or death?

It turned out that seeing brain scans didn't have much of an effect - but it's not clear how far the results would generalize.

208 mock-jurors were randomly assigned to get different kinds of mitigation information about the accused. Sometimes, all they were told was that he had been diagnosed with schizophrenia, depression and a substance misuse disorder. Others were also given neuropsychological test scores showing that he did poorly on various tests of reasoning and cognition. Finally, some were shown brain scans on top of all that, scans which were described as showing left frontal lobe damage.

All these materials were based on a real 2007 court case.

What happened? When the defendent was said to have been assessed as probably "dangerous" in future, people who were only told his diagnosis of schizophrenia usually sent him to the chair. But when they were given his psychological test scores - showing that he suffered from cognitive impairments - they were far more lenient. Seeing the neuroimages had no effect on top of that.

If the guy was described as posing a low risk of future violence, the verdicts were lenient, no matter what else they were told about him. In the real case, by the way, he got life.

This suggests that brain scans don't exert a seductive allure on jury decisions, at least not over-and-above psych test scores. But I'm not sure how representative the results are. The 'jurors' were all psychology undergrads. Most were Hispanic (63%) females (67%). Are psychology students especially resistant to the allure of brain scans - and/or especially vulnerable to the allure of psychological test scores? No-one knows, but it's surely plausible.

On some level, neuroimaging evidence clearly can influence people's decisions, like any other evidence; lawyers wouldn't bother presenting it otherwise. The question is how much of an impact it has, but that is surely going to depend on the details of the case as well as the juror's background; I'm not sure how much a study like this one, focussing on one example, will be able to tell us.


Greene E, and Cahill BS (2011). Effects of Neuroimaging Evidence on Mock Juror Decision Making. Behavioral Sciences and the Law PMID: 22213023

Scanning The Brain While Looking At Scans

A new study investigated what goes on in the brain when doctors make a diagnosis.

Radiologists use X-rays and other imaging techniques to diagnose diseases - but in this study, they went into the scanner themselves. Brazilian researchers Marcio Melo et al used fMRI to record neural activity while the radiologists were shown an array of chest X-rays.

Some of the scans showed evidence of disease, which the doctors were required to diagnose. There were also two control conditions, in which the stimuli were still X-rays but with little pictures of either animals or letters embedded in them, instead of diseases.

The image above shows how it worked. As well as pneumonia, one patient has a severe case of Alligator Lung, while the other looks like they've got the Influenza 'B' virus.

Now, the point of all this was to compare the mental process of making a diagnosis to that of seeing an object. The idea is that a trained radiologist sees particular diseases in the scans, in the same way that anyone can see an alligator.

Activity during diagnosis, object-recognition and letter naming was very similar (compared to doing nothing); this presumably represents the visual and language areas involved in looking at the image, recognizing what it is, and saying it out loud:

There were some slight differences, with the left inferior frontal cortex and the posterior cingulate cortex being more activated by diagnosis than animals. But this difference disappeared after controlling for the number of different possible descriptions the radiologists reported thinking about for each image.

The authors conclude that

These results support the hypothesis that medical diagnoses based on prompt visual recognition of clinical signs and naming in everyday life are supported by similar brain systems.

Which seems fair enough, although it's important to remember that the diagnoses in this study were quite easy ones. The mean response time was just 1.3 seconds and only 6% of those split-second diagnoses were wrong. Unfortunately diagnosis is not always that easy.

Anyway, this study is all very well, but why stop at chest X-rays? Last year I speculated on the fun neuroscientists could have with a real-time fMRI machine:

You could lie there in the scanner and watch your brain light up. Then you could watch your brain light up some more in response to seeing your brain light up...

We really need to scan people while they're looking at brain scans. Only then will we be able to understand the neurological basis of being a neurologist, and find the brain's looking-at-a-blob blob.

Melo M, Scarpin DJ, Amaro E Jr, Passos RB, Sato JR, Friston KJ, and Price CJ (2011). How doctors generate diagnostic hypotheses: a study of radiological diagnosis with functional magnetic resonance imaging. PloS ONE, 6 (12) PMID: 22194902

Susan Greenfield's Dopamine Disaster

It's Susan Greenfield again.

Continuing her campaign warning of the dangers of modern technology in terms of their effects on the vulnerable brains of the young, the British neuroscientist and Baroness has written another article. This is the latest of many. None of them have been in peer reviewed academic journals.

This one's behind the Great Times Paywall so I can't link to it, but it's called Are video games taking away our identities?

The first part of the article is hard to argue against. Either you'll agree with it or you won't. Personally, videogames as Greenfield describes them bear little resemblance to any games that I've played recently. Similarly for her account of the Internet. But maybe this rings true for some:

Screen images do not depend for their impact on seeing one thing in terms of anything else. Their premium lies invariably in their raw sensory content... we are perhaps heading towards a much weaker sense of identity by engaging in a world where we are the passive recipient of senses and where there is no fixed narrative of past and future but an atomised thrill of the moment. One could even suggest that the constant self-centred readout on Twitter belies a more childlike insecurity, an existential crisis.

Greenfield then moves into discussing the brain, and this is where the science comes in. This is her "home turf" - she's Professor of physiology at Oxford. Yet it's a shambles.

There is one alarm bell ringing, which suggests that increasing 2D screen existence may be having undesirable effects: it is the threefold increase over the past decade in prescriptions for drugs for attention deficit hyperactivity disorder.

While this could be due to changes in doctors’ prescribing procedures, or indeed to a greater recognition and medicalisation of attentional problems, a third possibility could indeed be that if the young brain is exposed from the outset to a world of fast action-reaction, of instant new screen images flashing up with each press of a key, then such rapid interchange might lead to a shorter attention span.

The human condition can be basically divided into two alternating modes, first described by Euripedes... the rational “bread force”, characterised by a strong cognitive take on the world — a personalised past, present and future, in turn related to an active prefrontal cortex and lower levels of the brain chemical dopamine; and the “wine force”, more the state of young children or those adults indulging in “letting themselves go”, in situations perhaps involving wine, women and song, where a strong sensory environment demands less reflection, more passive reaction.

...An increase in physiological arousal can be linked to excessive release of dopamine. Could the screen experience be tilting this ancient balance in favour of the more infantile, senses-driven brain state?

Greenfield says that high dopamine and low prefrontal cortex activity is associated with irrationality and a deficit in attention. Video games are causing a flood of dopamine and causing ADHD. That would make sense, if ADHD was caused by too much dopamine, and if drugs for ADHD reduced dopamine release.

The problem is that it's the exact opposite. Drugs for ADHD increase dopamine release and ADHD is widely believed (although it's controversial) to be caused by a dopamine deficit.

Greenfield then says "We know too that dopamine suppresses the activity of neurons in the prefrontal cortex", but this is a serious oversimplification. Dopamine has complex effects on target neurons. It can inhibit firing, but it can also excite it. It all depends on the conditions. Here's what the authors of an influential scientific review said in 2004: "It is agreed by most researchers is that dopamine is a neuromodulator and is clearly not an excitatory or inhibitory neurotransmitter"

Some say that dopamine helps to "tune" the prefrontal by increasing the signal to noise ratio - more signal, less noise. Here's one of the most cited papers about dopamine and the PFC: Cognitive deficit caused by regional depletion of dopamine in prefrontal cortex of rhesus monkey.

Remember that drugs for ADHD like Ritalin, which are sometimes used illicitly by students without that disorder to help them focus and concentrate, cause dopamine release. If Greenfield were right, it would be the exact opposite.

...[other] people characterised by an underactive prefrontal cortex are those with schizophrenia, this time not due to physical damage but rather a chemical imbalance, in particular an excessive amount of the transmitter dopamine. In schizophrenia, like children, the patient is easily distracted, cannot interpret proverbs, is not strong on metaphor but takes the world literally; it is a vibrant world that can implode on, and overwhelm, the fragile firewall of the schizophrenic mindset.

This again is a serious simplification. Actually, you don't need to be a neuroscientist to work that out. Just recall the earlier bit: Greenfield has said that ADHD is caused by too much dopamine leading to an underactive prefrontal cortex. Now she says that schizophrenia is the same. So why are the symptoms of ADHD completely different from schizophrenia?

Why is it, in fact, that Ritalin and similar dopamine releasing drugs help with ADHD, but can make schizophrenia worse?

As a neuroscientist, I can tell you that we don't really know what's going on with dopamine in ADHD or schizophrenia. There's decent evidence that dopamine is involved in schizophrenia, but not in any straightforward sense. Schizophrenia is now believed to be linked to reduced dopamine in the prefrontal cortex, and too much in other areas.

As for ADHD, remember: the leading theory is that it's about too little dopamine. Not too much.

The only disease that we know certainly is associated with too little dopamine is Parkinson's. Contrary to Greenfield's theory, people with Parkinson's often have cognitive and mood problems as well as the better known difficulties with movements. They're not super intelligent, prefrontal-cortex-wielding geniuses.

I appreciate that an opinion piece in the Times is never going to be a rigorously argued scientific paper, but the fact that Greenfield's article contains several claims which are the exact opposite of the truth (or at least of current scientific thinking) calls her credibility into serious question.

What Is Brain "Activation" on fMRI?

Functional MRI is one of the most popular ways of measuring human brain activity. But what is "activity"?

Fundamentally, neural activity is electical potentials and chemical signals. fMRI doesn't measure these directly. Rather, it measures changes in the oxygen content of blood in different parts of the brain.

The more the brain cells are firing, the more oxygen they use up, although oxygenation actually increases as a kind of compensation for the activity and this increase is what gets measured. The oxygenation changes associated with neural firing is called the BOLD response.

Using fMRI you can measure BOLD and end up with some pretty blobs of activation. But what does it mean for a region of the brain to be activated? Just as no man is an island, no brain region can do anything on its own. Every area gets inputs from other areas, and sends outputs as well.

So if an area gets more active, that could mean one or more of three things:

1. It's sending more outputs
2. It's getting more inputs
3. It's doing more "internal" processing within that area - "talking to itself".

Which of these contributes to BOLD? It's known that number 1 - output from the area in question - is not a major contributor to the fMRI signal, but what about 2 and 3? A 2010 paper that I just came across argues that 80% of the BOLD signal is caused by internal processing, and only 20% is due to input.

They took some rats, and stimulated their whiskers. Using electrodes, they measured blood oxygenation changes in an area called the barrel cortex, which is known to deal with whisker-based sensations (they didn't actually use fMRI, but this would be seen as a BOLD signal if they had.)

But they then added a drug called muscimol to the barrel cortex. Muscimol reduces neuronal firing, but it doesn't affect synaptic input. They show that muscimol strongly reduced the blood oxygenation response, by about 80%. This suggests that 80% of the signal was not caused directly by sensory input to the cortex, but was generated within the cortex.

In many ways this is not surprising: it would be weird if the cortex were just picking up signals and doing nothing with them. However, it's good to be able to put a figure on just how much intra-cortical processing contributes to the fMRI signal. In rats, at any rate.

Harris S, Jones M, Zheng Y, & Berwick J (2010). Does neural input or processing play a greater role in the magnitude of neuroimaging signals? Frontiers in neuroenergetics, 2 PMID: 20740075

You Use Your Partner To Phone And Play Angry Birds. Literally.

WITH lots of weddings expected on Tuesday, people in love across the world are getting ready for their latest fix.

But should we really characterize the intense devotion shown by people in love, as love? A recent experiment that I carried out using neuroimaging technology suggests that love-related terms like “romance” and “soulmates” aren’t scientifically accurate - not compared to a word we use to describe our relationships with our smartphones. That word is “owning an iPhone.”

As a branding consultant, why am I even writing this article for the NYT? Never mind. Earlier this year, I carried out an fMRI experiment to find out whether iPhones were really, truly addictive, no less so than alcohol, cocaine, shopping or video games (sic)... wait, are those last two actually addictive? Whatever, let's just say they are.

In conjunction with the San Diego-based firm MindSign Neuromarketing (kerching! Wait, did I write that, or just think it?), I enlisted eight men and eight women between the ages of 18 and 25. Our 16 subjects were exposed separately to audio and to video of a wife or husband.

In each instance, the results showed activation in both the audio and visual cortices of the subjects’ brains. In other words, when they were exposed to the video, our subjects’ brains didn’t just see their partner, they “heard” them, too. This powerful cross-sensory phenomenon is known as "the brain storing information about people and objects, and retrieving it in response to related stimuli", or "memory" to use the technical term.

But most striking of all was the flurry of activation in the insular cortex of the brain, which has also been associated with seeing an iPhone. The subjects’ brains responded to the sound of their partner as they would respond to the presence or proximity of a top of the range smartphone (with free WiFi in thousands of locations!)

In short, the subjects didn’t demonstrate the classic brain-based signs of addiction when they were shown pictures of their lovers. Instead, they made calls and played Angry Birds on them.

---

The silliness of equating insula activation on fMRI with love and using this to argue that we love our iPhones as a recent crap OpEd in the New York Times did, has been excellently covered over at [Citation Needed], Neurocritic and many others. I'm sure you've heard plenty about this story already.

But let's set aside the fact that loads of other things, by no means limited to disgust and drug addiction, are known to involve the insula in fMRI. Let's assume (as the NYT piece did) that the only two things that had ever been shown to activate the insula were seeing an iPhone and seeing someone you love.

This study still wouldn't show that people love their phones. You could equally well turn the whole thing on its head and argue that it shows that we think of people we love as something to make phone calls with. Hey, the brain activity is the same as when you look at an iPhone.

This might strike you as implausible, but given the fMRI data alone, you have no grounds for saying one interpretation is more or less plausible than the other.

There are countless other interpretations, each equally plausible given the imaging data. Maybe the insula is only about love, and the activation to the iPhone is due to conditioned association (you call people you love on it). Maybe it's about objects you see every day, which includes your phone and people you love. Maybe...

The only reason to prefer any particular interpretation would be because you have evidence from outside neuroimaging - from other areas of neuroscience or psychology. So if you discovered that insula lesions cause people to be unable to fall in love (they don't, as far as I know) then you could make a case for the love interpretation. But only then.

Neuroimaging, on its own, can't tell us anything about the brain. It's like a peek under the hood of your car. If you already know how a car works, you can look under the hood and work out what's going on, and what's gone wrong. But only if you have that prior knowledge. Otherwise, it's just a big set of metal pipes.

To Catch A Predator... With A Brain Scanner?

With the help of an MRI scanner and some child pornography, a new study claims to be able to tell whether someone is a paedophile: Assessment of Pedophilia Using Hemodynamic Brain Response to Sexual Stimuli.

It was an fMRI study of 24 self-identified paedophiles (recruited through a clinic offering anonymous treatment) and 32 male controls. Everyone was shown a series of images of naked men, women, boys and girls. The neural response to child vs. adult images was the main outcome measure.

Respect to the authors for getting that past the ethics committee.

The blob-o-grams above show that the paedophile's brains reacted differently to the control brains, when shown images of naked children, which is not surprising because the brain is what makes you a paedophile (and everything else.)

However, what's more interesting is that by comparing each individual's brain activity to the average activity of the paedophile group and the control group, it was possible to diagnose people as paedophiles or not with high accuracy (90+%).

Plotting the "typical paedophile"-ness of the neural response to girls vs women and boys vs men, the paedophiles (triangles) form a clear cluster. There were also some differences between homosexual and heterosexuals in both groups.

The statistics seem kosher: they used leave-one-out cross-validation to avoid the error of double dipping.

What's not clear is whether this was measuring sexual attraction as such. All it's measuring is how much each person's activity correlated with the paedophile group average. Maybe it's picking up on the shame paedophiles feel over being reminded of what they've done. Maybe the controls were just averting their eyes when the child porn came on.

However, you could say that if you're just interested in the practical business of catching paedophiles, that's academic. More concerning is the question of whether it would be possible to fool the technique. A recent study showed that it's easy to fool a brain scan designed to detect lying.

But let's suppose it does work out. Would that be a good thing? What is "a paedophile", anyway? Is it someone's who's attracted to children, or someone who acts on that attraction?

For example, there are people who are caught with child porn, and who admit they downloaded it, but who deny being attracted to children. The Who shredder Pete Townsend and comedian Chris Langham being two British examples. Both admit downloading illegal images, but say it was for 'research purposes'.

Now it might be possible, using fMRI, to find out if they're telling the truth. Let's suppose it was doable.

So what? Downloading child pornography is a crime - whatever your motivation. Being attracted to children is legal, in itself. So from a legal perspective it should make no difference at all in cases like this.

Of course, we don't in fact go around seeing things from a purely legal perspective. We care whether someone is attracted to children or not. But should we care? Is that fair? You don't choose your sexual orientation. What you choose is whether to break the law by commiting the crime.

There are surely people out there - no-one knows how many - who are attracted the children, and never act on it. Do we want to be able to "catch" them?

Edit: The original version of this post linked to the wrong paper, an older paper by the same authors. This has been fixed now.

Ponseti, J., Granert, O., Jansen, O., Wolff, S., Beier, K., Neutze, J., Deuschl, G., Mehdorn, H., Siebner, H., & Bosinski, H. (2011). Assessment of Pedophilia Using Hemodynamic Brain Response to Sexual Stimuli Archives of General Psychiatry DOI: 10.1001/archgenpsychiatry.2011.130

Violent Brains In The Supreme Court

Back in June, the U.S. Supreme Court ruled that a Californian law banning the sale of violent videogames to children was unconstitutional because it violated the right to free speech.

However, the ruling wasn't unanimous. Justice Stephen Breyer filed a dissenting opinion. Unfortunately, it contains a whopping misuse of neuroscience. The ruling is here. Thanks to the Law & Neuroscience Blog for noticing this.

Breyer says (on page 13 of his bit)

Cutting-edge neuroscience has shown that “virtual violence in video game playing results in those neural patterns that are considered characteristic for aggressive cognition and behavior.”

He then cites this fMRI study from 2006. It's from the same group as this one I wrote about recently.

Breyer quotes this study as part of a discussion of the evidence linking violent video game use to violence. I have nothing to say about this, but I will point out than the fact that violent crime fell heavily in America after 1990, which is when the Super Nintendo and Sega Megadrive were invented.

Anyway, does this study show that playing violent games causes aggressive brain activity? Not exactly. By which I mean "no".

They scanned 13 young men playing a shooter game. The main finding was that during "violent" moments of the game, activity in the rostral ACC and the amygdala activity falls. At least this is the interpretation the authors give.

OK, but even if this neural response is "characteristic for aggressive cognition and behavior", it only lasted a few seconds. There's no evidence at all that this causes any lasting effects on brain function, or behaviour.

The real problem though is that the whole thing is based on the theory that violence is associated with reduced amygdala (and rACC) activity.

The authors cite various studies to this effect, but they don't distinguish between reduced activity as an immediate neural response to violence, as in this study, and reduced activity in people with high exposure to violent media, in response to non-violent stimuli.

This is rather like saying that because having a haircut reduces your total hair, and because bald people have no hair, haircuts cause baldness. Short-term doesn't automatically become long-term.

Besides, the whole idea that amygdala deactivation = violence is a bit weird because they used to destroy people's amydalas to reduce violent aggression in severe mental and neurological illness:

Different surgical approaches have involved various stereotactic devices and modalities for amygdaloid nucleus destruction, such as the injection of alcohol, oil, kaolin, or wax; cryoprobe lesioning; mechanical destruction; diathermy loop; and radiofrequency lesioning...

Lovely. It even worked sometimes, apparantly. Although it killed 4% of people. You can't reduce the activity of a region much more than by destroying it, yet destroying the amygdala reduced violence, or at the very least, didn't make it worse.

The truth is that aggression isn't a single thing. Everyone knows that there are two main kinds, "in cold blood" and "in the heat of the moment". Killing someone in a spontaneous bar brawl is one thing, but carefully planning to sneak up behind them and stab them is quite another.

Just based on what we know about the rare cases of amygdala-less people, I would imagine that destroying the amygdala would reduce violence "in the heat of the moment", which is motivated by anger and fear. The kind of patients who got this surgery seem to have been that kind of violent person, not the cold calculating kind.

So, even if violent video games reduced amygdala activity long term, that would probably reduce some kinds of violence.

Weber, R., Ritterfeld, U., & Mathiak, K. (2006). Does Playing Violent Video Games Induce Aggression? Empirical Evidence of a Functional Magnetic Resonance Imaging Study Media Psychology, 8 (1), 39-60 DOI: 10.1207/S1532785XMEP0801_4

The Brain Is Not Made of DNA

A new paper claims to have found A novel functional brain imaging endophenotype of autism.
They used fMRI to show that the brains of teenagers with autism showed no activation differences to looking at smiling happy faces, or afraid faces, compared to unemotional ones. In teens without autism, there was strong activation in many emotional and face-related brain regions. The unaffected brothers and sisters of the autistic people showed intermediate effects.

This is a fine study. The finding that siblings of people with autism have weakened neural responses to emotional faces is quite important as it suggests that this finding correlates (to some degree) with your position on the autism "spectrum".

The abstract of the paper actually downplays this, and says "The response in unaffected siblings did not differ significantly from the response in autism". However, there was a significant linear trend of group, and looking at the graphs, it's clear the siblings were In The Middle, like Malcolm.


There's plenty more nice things you could do with these results, which is an unusally large and rich dataset (120 people - 40 in each group). You could see, for example, whether siblings tend to be similar in terms of neural response. You could see whether the siblings who are most alike in brain response, are closest in symptoms. Or just look a the structural data on brain size and shape to see if there are characteristic differences between siblings that make one of the autistic and the other not.

There are a few problems. Most of the analyses are subject to the non-independence problem, because they defined their regions of interest based on the areas that showed a significant happy vs neutral face effect in the control group. So it's no surprise that when they generated graphs from these areas, the control group showed the strongest effect. However, they also do whole-brain analyses which avoid this problem and I don't think it undermines the main results.

So it's a decent study. But is this a "biomarker", or "endophenotype", as the title of the paper has it?

These are both hot topics in neuroscience at the moment. As the authors put it (emphasis mine):

An endophenotype is a heritable feature associated with a condition, present in affected individuals regardless of whether their condition is manifested, which co-segregates with the condition in families and which is present in unaffected family members at a higher rate than in the general population.

In such family members, endophenotypes represent instances in which genes associated with a particular condition exert measurable effects in individuals in whom they are insufficient to cause the condition itself...

The promise of characterizing endophenotypes lies in their hypothesized intermediate position between genotype and phenotype... the etiology of the endophenotype is likely to be correspondingly simpler: it can be said to be ‘closer to the level of gene action’.

The idea, in other words, is that if we can find a difference in the brains of people with autism, and their unaffected relatives who (presumably) share some of the same genes, we might have found a mechanism by which the genes ultimately cause the symptoms.

It might be easier, then, to find the genes for brain-not-lighting-up-to-happy-faces, than it will be to find genes for autism. Then once we've found those, we can use them to better understand autism.

My concern is that, while in theory endophenotypes seem "closer to the genetics" because they're "biological" rather than "behavioural", this is just a philosophical illusion based on the idea that the mind is not the brain.

We actually have no idea whether brain-not-lighting-up-to-happy-faces is closer to genetics than autistic behaviour. I'd say that our default assumption should be that everything is exactly the same "distance" from DNA, that is to say, everything is the product of complex interactions between genes and environment.

Some things are under the more or less exclusive control of a small number of genes, and these are called "genetic", but it's important not to assume that just because something's "in the brain", it's probably "more genetic" in this sense. The brain is a product of the environment as well.

If you scanned my brain while playing an audio recording of Urda love poetry, not much would happen. I don't know Urdu. In someone who did speak Urdu, all kinds of language and emotional areas would light up. That doesn't mean Urdu-brain-response is genetic. It's exactly as genetic as speaking-Urdu, which isn't genetic.

Spencer, M., Holt, R., Chura, L., Suckling, J., Calder, A., Bullmore, E., & Baron-Cohen, S. (2011). A novel functional brain imaging endophenotype of autism: the neural response to facial expression of emotion Translational Psychiatry, 1 (7) DOI: 10.1038/tp.2011.18

The NeuROFLscience of Jokes

A new paper in the Journal of Neuroscience investigates the neural basis of humour: Why Clowns Taste Funny.

The authors note that some things are funny because of ambiguous words. For example:

Q: Why don’t cannibals eat clowns?
A: Because they taste funny!

Previous studies, apparently, have shown that these kinds of jokes lead to activation in the lIFG (left inferior frontal gyrus), although it's also involved in processing ambiguity that's not funny, and indeed, language in general.

In this study they gave people fMRI and played them audio clips of sentences that were either funny or not, and that either contained ambiguity or not. Examples of non-funny ambiguity included crackers like this:

Q: What happened to the post?
A: As usual, it was given to the best-qualified applicant.

They found that, relative to straightforward ones, ambiguous sentences led to increased activation in two areas, the lIFG and also the left ITG. That fits with previous work.

By contrast, funny stimuli, whether ambiguous or not, sent the brain into overdrive, with humour causing activation all over a wide range of hilarious areas such as the amygdala, ventral striatum, hypothalamus, temporal lobes and more.

Many of these areas are known to be involved in emotion and pleasure, although some are fairly random such as visual area BA19.

There were strong associations between BOLD signal change and funniness in the midbrain, the left ventral striatum, and the left anterior and posterior IFG.

The problem is, like so many neuroimaging studies, it's not clear what this adds to our understanding of the topic. All this really shows is that linguistic ambiguity activates language areas, and enjoyable stimuli activate pleasure areas (amongst many others); it doesn't tell us why some things are funny.

So more research is needed, and future neuro-humour studies will need a new set of neuro-jokes in order to maximize the laughs. Here's a few I came up with:

Q: Why did the chicken cross the road?
A :Because of activation in the motor cortex, causing muscle contractions in his legs.

Q: What neuroimaging methodology is most useful for studying the brains of cats and dogs?
A: PET scanning.

Knock knock.
Who's there?
John.
I doubt that. The 'self' is an illusion. The concept of 'John' as an individual is incompatible with modern neuroscience.

Bekinschtein TA, Davis MH, Rodd JM, & Owen AM (2011). Why Clowns Taste Funny: The Relationship between Humor and Semantic Ambiguity. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31 (26), 9665-71 PMID: 21715632

Blind Spots & Braintrust

This is a review of two recently published books about ethics: Bazerman and Tenbrunsel's Blind Spots (not to be confused with this one), and Patricia Churchland's Braintrust.

The pair may come from the same publisher (Princeton), but they couldn't be more different.


Blind Spots is a good book. It tells a story in a clear and compelling fashion, which is what a book is for.

The story is that we often act unethically, not because we're faced with ethical questions and decide to pick the "bad" option, but because we fail to see that there is an ethical issue at all.

This is not the same as saying that 'the road to hell is paved with good intentions'. That old phrase warns against trying to be good and, as a result, causing evil, because your plans go wrong. Blind Spots is saying, even if all of your attempts to be good work out just fine, you might still cause evil despite that.

For example, you could be a good employee, who never calls in sick unnecessarily, kind to your friends and colleagues, and a generous charity donor.

Unfortunately, you're an accountant connected to Enron, and your work - ultimately - consists of defrauding innocent people. But of course, you don't think of it like that, because we don't tend to think about things "ultimately".

Which is hard to disagree with. At worst, you could say it's obvious, although I think it's still something we ought to be reminded of. That's not all there is to the book, though: it also discusses how this happens and suggests ways to avoid it within organizations.

For example, the authors give an example of how setting up rewards and punishments to "make people be ethical", can make them less so, by encouraging people to think of the issue as a personal trade-off between gain and loss, rather than an ethical dilemma - what the authors call "ethical fading".

A day-care centre was annoyed at the fact that some parents were picking up their children late. This was antisocial because it meant staff had to work late into the evening.

So they started charging parents a late fee. Not a big one, but enough to send people a message: this is wrong, don't do. But in fact what happened was that late pickups became more common.

Previously, many people were making an effort to be on time, as a matter of principle. Once the fees were in place, it stopped being an ethical issue and just became a financial trade-off: is it worth paying the fee to get an extra hour?

Of course, you could make the fees higher to get around this, but even then, you've caused ethical fading, and you'll be relying on the sanctions from that point on.


Braintrust, by contrast, is just not a good read. The bulk of the book consists of discussions of various neurotransmitters and brain areas and how they may be related to human social behaviour. Oxytocin, for example, may make us behave all trusting and kindly, as it's involved in maternal bonding. There's a long discussion of the neurochemistry of male sexual behaviour in voles.

It's not clear how this is relevant to ethics. Whether it's oxytocin that does it, or something else, and whether voles are a useful model of human behaviour or not, clearly sometimes we trust people and sometimes we don't. That's psychology. And biology can't yet explain it.

Churchland doesn't claim that the various biological concepts that she covers can fully explain anything, and she doesn't vouch that all of these findings are rock solid. Which is good, because they can't, and they're not. So why spend well over half of the book talking about them?

Churchland's big idea seems to be that human morality emerges out of our more general capacity for sociability. Hence all the stuff about oxytocin and "the social brain". OK. But I'd have said that's a given - there's obviously some relation between sociability and morality.

I think there is an interesting idea in here, albeit not very clearly expressed, namely that morality isn't a special function of the brain, but just one of the many forms in which our social cognition can take.

In other words, I think the claim is that ethics isn't just related to sociability, it is sociability. Even asocial animals care about their own welfare, in terms of pleasure and pain; social ones become social when they extend this caring to others; intelligent social animals including humans and maybe some primates also have a system for inferring the motivations and thoughts of others.

At the end of the book, Churchland stops reviewing neuroscience, and starts talking about the implications for philosophy. This is best section of the book, but it's too short.

Churchland makes the interesting point, for example, that when we are considering philosophical "ethical dilemmas", like the famous trolley problems, we may not be applying any kind of ethical "rules" as such. Rather, she thinks that our moral reasoning is pretty much a kind of pattern recognition based on previous experience - like all our other social reasoning.

Someone who'd just read a book about the horrors of Stalinism might tend to adopt an anti-consequentialist, every-life-is-sacred approach. Whereas if you'd just watched a movie in which the hero, reluctantly but rightly, decides to sacrifice one guy to save many other people, would do the opposite. Then the ethical "rules" might be confabulated to cover it.

This is a nice idea. It's open to criticism, but it's a serious suggestion, and one that deserves a decent discussion. Sadly, there isn't one. If only there were more room in the book for this kind of stuff - but oxytocin covers so many pages.

Basically, the good parts of this book are not about the brain at all.

Reading Braintrust is like going on date but then bumping into an annoying friend who insists on coming along for dinner. Jesus, The Brain, you want to say. I like you and all, but seriously, you are getting in the way right now.

Links: Other blog reviews.

My Grandma: Neurophilosopher

John Galliano is the British designer who got videoed being a bit unpleasant and ended up in court on racism charges.


His defence is that he was drunk and/or high. Which from the video he fairly obviously was. But here's an interesting quote from his lawyer:

Some things may have come out of his mouth that didn’t come from his brain.

So where did they come from, then... hmm. Don't answer that.

I doubt that the lawyer was actually trying to say that Galliano's mouth was moving of its own accord or under the control of some other organ. Rather she was expressing the idea that "my brain" in this context doesn't mean, literally, the whole of the grey blob of neurons in my skull.

Rather "my brain" means, roughly, "that part of my brain responsible for rational thought".

My grandmother once talked about a friend who'd had a stroke. She said, as far as I can remember, "Sometimes the stroke means you can't talk or walk, which is bad enough, but sometimes it gets into your brain and that can be really nasty."

Of course she knew that all strokes happen in the brain. What she was saying was that some strokes, but not all, affect the part of the brain responsible for "me" as a person - thoughts, emotions, and so forth.

So, this is all anecdotal evidence, but there seems to be a popular, common-sense temptation to believe in the "me part" of the brain, a tendency which neuroscientists are not immune to and which can lead to dubious conclusions.

I'd love to see someone do a proper study of what non-neuroscientists, ideally people with little exposure to neuroscience like children, think about the brain. A bit like this, but really in depth. I suspect that you'd find that many of the ideas underpinning today's neuroscience had their origins in pre-scientific, common sense intuitions.

We neuroscientists are human, and we have neuro-intuitions too. But if neuroscience has taught us anything, it's not to trust those.

The Unhelpful Brain

A reader pointed me to this study from a few months back which used fMRI to look at the effects of "Coaching With Compassion".

Unfortunately, the authors say at the outset that their paper is "Not to be quoted or reproduced without the expressed permission of one of the authors prior to publication" so I'm not going to... oh, hang on. Have I just broken the rules by quoting that? I hope not. But fair enough.

The paper describes an fMRI study of brain responses to being shown a variety of statements. The participants were students and the statements were about the university experience. They were either positive, negative, or neutral.

The authors found that the human brain responds differently to different kinds of stuff.

That's it. Well that ought to be it. The paper discusses things like Coaching With Compassion, The Ideal Self, and Intentional Change Theory, which are awesome no doubt, but they're not what this study is about.

Here's why. Before getting scanned, the students got two sessions of academic and career coaching. One session was focussed on hopes and goals for the future, dreams, and what they wanted to achieve in their studies. Yes you can! The other session, with a different coach, was all about challenges, fears, and disappointments. Maybe you can't.

The positive and the negative statements in the fMRI bit were based on these coaching interviews. The coach who did the nice bit said the nice statements (via recorded video clips) and vice versa. The positive and negative coaches were randomly assigned to each participant to avoid coach effects, and so on, which is good, the fMRI methodology was fine, and the data analysis looks good.

Who'd have thought it? Different parts of the brain were activated by positive, negative and neutral statements, and these were roughly what you'd expect from previous studies.

The reason this says nothing about coaching is that while participants got coaching beforehand, they all got the same coaching. These statements would have been positive or negative anyway - coaching or no. We don't know what, if any, effect coaching had.

Had half of them been randomized to get coached, and the other half assigned to a "placebo" coaching, say chatting about sports or the weather, then it would tell you something about coaching.

But that wouldn't mean it told you anything interesting about it, and this is the deeper problem with studies like this, of which this is only a good example.

Suppose that you found that positive, Compassionate Coaching made the brain respond more strongly to positive statements, or changed brain activity during decision-making, or whatever. That would be a result, and it might be really strong and statistically very significant, but for the life of me I can't see why you'd care, if you were interested in coaching.

Of course coaching affects the brain, and not just as a side effect: if it works, it'll work via changing the brain, in some way. But everything that changes behaviour changes the brain. That's what the brain does. How it does so is a detail of interest only to neuroscientists.

If you're a coach, or want to get coaching, or want to know whether coaching is effective, then you should look at coaching. The brain will be there, in the background, activating and deactivating happily, but it's not going to help you.

These kinds of studies happen, I think, because there's an inherent allure to seeing "the neural basis of" thoughts and feelings. It seems paradoxical and disturbing: you can't see thoughts! They're made of pixie dust and magic!

In the same way, quantum physics is universally agreed to be "weird". But it's always there, everywhere in the universe, and always has been. We're the weird ones, with our strange conviction that the most everyday thing in the world is really bizarre. God must find quantum physics incredibly boring.

Brains are not quite as commonplace as quarks, but they are at work whenever anyone, or most animals for that matter, does anything. Of course: how else would behaviour happen? We find this odd and fascinating. As a neuroscientist I'm no exception, the allure never "wears off". But that's just us.

Even people trying to be neuro-skeptical often fall into this trap. Here's Steven Rose in book review:

The weird locution – “it was not me; it was my brain that made me do it” – is increasingly used by neuroscientists who are sure that human thought and action are reducible to brain processes, and by legal defence teams pleading diminished responsibility for their clients. The trouble is that this way of speaking – and thinking, if such a term remains permissible – leaves unresolved who is the “me” that the brain drives.”

Well, human thought and action are reducible to brain processes. To deny this or (as is more common) imply that it's unhelpful, but not explain why, gets us nowhere.

The point is that all behaviour is brain activity, and that's why saying "It's brain activity" tells us nothing about any given behaviour. It’s an empty truism, like saying that a fire was started by something hot. Well, duh.