A balanced look at brain scanning

Bioethics think tank The Hastings Center have published an excellent open-access report on ‘Interpreting Neuroimages: The Technology and its Limits’ that takes a critical but balanced look at the use of brain scans for understanding the mind.

They’ve commissioned leading cognitive neuroscientists to write chapters including Geoffrey Aguirre, Martha Farah and Helen Mayberg, as well as having a chapter by some legal folks who discuss whether neuroimaging can teach us anything about moral and legal responsibility.

The chapter by the brilliant Martha Farah is particularly good and takes a level-headed look at the critiques of fMRI and is essential reading if you want to get up to speed on what brain scans are likely to tell us about the mind and brain.

The report is all in academic writing but if you’re a dedicated neuroscience fan, it probably won’t pose too much of a problem.

 

Link to ‘Interpreting Neuroimages: The Technology and its Limits’.

Frozen nightmares

The Devil in the Room is a fantastic short film about the experience of hallucinatory sleep paralysis – a common experience that has been widely mythologised around the world.

Sleep paralysis is the experience of being unable to move during the process of waking – when you have regained consciousness but you’re brain has not re-engaged your ability to control your muscles.

The reason the experience has been widely associated with mythological creatures is because in some people it can lead to intense emotions and hallucinations.

The name ‘sleep paralysis’ is a bit confusing because this also refers to normal sleep paralysis – where your brain disengages control of your muscles during REM sleep to stop you ‘acting out’ your dreams.

The film is part of the Sleep Paralysis Project, which has much more about the experience on their website.
 

Link to ‘Devil in the Room’ on vimeo.

Loving you is easy because you’re beautiful

Neuroscape Lab, we salute your next generation of brain visualisation, that looks like something out of a sci-fi film where the director is a bit obsessed with correctly representing the anatomy of the brain.

They describe the visualisation like this:

This is an anatomically-realistic 3D brain visualization depicting real-time source-localized activity (power and “effective” connectivity) from EEG (electroencephalographic) signals. Each color represents source power and connectivity in a different frequency band (theta, alpha, beta, gamma) and the golden lines are white matter anatomical fiber tracts. Estimated information transfer between brain regions is visualized as pulses of light flowing along the fiber tracts connecting the regions.

But honestly, who cares? It’s a glowing rotating brain with golden streaks of light flowing through it.

In fact, after 25 years, science has finally scanned the brain from The Orb’s ambient techno classic ‘A Huge Ever Growing Pulsating Brain That Rules from the Centre of the Ultraworld’.

It’s as if the rave generation stumbled out of life’s warehouse at 7am and ended up being neuroscientists.
 

Link to Neuroscape Lab’s awesome brain visualisation.
Link to the original Orb track (or the classic Orbital remix)

The Society of Mutual Autopsy

The Society of Mutual Autopsy was an organisation formed in the late 1800s to advance neuroscience by examining dead members’ brains and to promote atheism by breaking sacred taboos.

It included some of the great French intellectuals and radicals of the time and became remarkably fashionable – publishing the results in journals and showing plaster-casts of deceased members brains in world fairs.

In October 1876, twenty Parisian men joined together as the Society of Mutual Autopsy and pledged to dissect one another’s brains in the hopes of advancing science. The society acquired over a hundred members in its first few years, including many notable political figures of the left and far left. While its heyday was unquestionably the last two decades of the century, the society continued to attract members until the First World War. It continued its operations until just before World War II, effectuating many detailed encephalic autopsies, the results of which were periodically published in scientific journals.

The quote is from a fascinating but locked academic article by historian Jennifer Michael Hecht and notes that The Society was partly motivated by self-nominated ‘great minds’ who wanted to better understand how brain structure related to personal characteristics.

It was no backwater project and attracted significant thinkers and scientists. Most notably, Paul Broca dissected brains for the society and had his brain dissected by them, despite apparently never joining officially.

Part of the motivation for the society was that, at the time, most autopsies were carried out on poor people (often grave robbed) and criminals (often executed). The intellectual elite – not without a touch of snobbery – didn’t think this was a good basis on which to understand human nature.

Also, these bodies usually turned up at the dead of night, no questions asked, and no one knew much about the person or their personality.

In response to this, the Society of Mutual Autopsy functioned as a respectable source of body parts and also requested that members write an essay describing their life, character and preferences, so that it could all be related to the shape and size of their brain when autopsied by the other members.

There was also another motive: they were atheists in early secular France and they wanted to demonstrate that they could use their remains for science without consideration of religious dogma.

As with most revolutionary societies, it seems to have fallen apart for the usual reasons: petty disagreements.

One person took exception to a slightly less than flattering analysis of his father’s brain and character traits. Another starting flirting with religion, causing a leading member to storm off in a huff.

In a sense though, the society lives on. You can donate your body to science in many ways after death:

To medical schools to teach students. To forensic science labs to help improve body identification. To brain banks to help cure neurological disorders.

But it’s no longer a revolutionary act. Your dead body will no longer reshape society or fight religion like it did in 1870’s France. The politics are dead. But neither will you gradually fade away into dust and memories.

Jennifer Michael Hecht finishes her article with some insightful words about The Society of Mutual Autopsy which could still apply to modern body donation.

It’s “both mundane – offering eternity in the guise of a brief report and a collection of specimens – and wildly exotic – allowing the individual to climb up onto the altar of science and suggesting that this act might change the world”.
 

Link to locked and buried article on The Society of Mutual Autopsy.

A reality of dreams

The journal Sleep has an interesting study on how people with narcolepsy can experience sometimes striking confusions between what they’ve dreamed and what’s actually happened.

Narcolepsy is a disorder of the immune system where it inappropriately attacks parts of the brain involved in sleep regulation.

The result is that affected people are not able to properly regulate sleep cycles meaning they can fall asleep unexpectedly, sometimes multiple times, during the day.

One effect of this is that the boundary between dreaming and everyday life can become a little bit blurred and a new study by sleep psychologist Erin Wamsley aimed to see how often this occurs and what happens when it does.

Some of the reports of are quite spectacular:

One man, after dreaming that a young girl had drowned in a nearby lake, asked his wife to turn on the local news in full expectation that the event would be covered. Another patient experienced sexual dreams of being unfaithful to her husband. She believed this had actually happened and felt guilty about it until she chanced to meet the ‘lover’ from her dreams and realized they had not seen each other in years, and had not been romantically involved.

Several patients dreamed that their parents, children, or pets had died, believing that this was true (one patient even made a phone call about funeral arrangements) until shocked with evidence to the contrary, when the presumed deceased suddenly reappeared. Although not all examples were this dramatic, such extreme scenarios were not uncommon.

This sometimes happens in people without narcolepsy but the difference in how often it occurs is really quite striking: 83% of patients with narcolepsy reported they had confused dreams with reality, but this only happened in 15% of the healthy controls they interviewed.

In terms of how often it happened, 95% of narcolepsy patients said it happened at least once a month and two thirds said it happened once a week. For people without the disorder, only 5% reported it had happened more than once in their life.

Although a small study, it suggests that the lives of people with narcolepsy can be surprisingly interwoven with their dreams to the point where it can at times it can be difficult to distinguish which is which.

If you want to read the study in full, there’s a pdf at the link below.
 

Link to locked study at Sleep journal (via @Neuro_Skeptic)
pdf of full text.

Heroin, addiction and free will

The death of Phillip Seymour Hoffman has sparked some strong and seemingly contradictory responses. What these reactions show is that many people find it hard to think of addiction as being anything except either a choice or a loss of free will.

The fact that addiction could involve an active choice to take drugs but still be utterly irresistible seems difficult for most people to fathom.

Let’s take some reactions from the media. Over at Time, David Sheff wrote that “it wasn’t Hoffman’s fault that he relapsed. It was the fault of a disease”. On the other hand, at Deadspin, Tim Grierson wrote that the drug taking was “thoughtless and irresponsible, leaving behind three children and a partner”.

So does addiction trap people within its claws or do drug users die from their own actions? It’s worth noting that this is a politicised debate. Those who favour a focus on social factors prefer prefer the ‘trap’ idea, those who prefer to emphasise individual responsibility like the ‘your own actions’ approach.

Those who want to tread the middle ground or aim to be diplomatic suggest it’s ‘half and half’ – but actually it’s both at the same time, and these are not, as most people believe, contradictory explanations.

To start, it’s worth thinking about how heroin has its effect at all. Heroin is metabolised to morphine which then binds to opioid receptors in the brain. It seems to be the effects in the nucleus accumbens and limbic system which are associated with the pleasure and reward associated with the drug.

But in terms of motivating actions, it is a remarkably non-specific drug and it doesn’t directly cause specific behaviours.

In fact, there is no drug that makes you hassle people in Soho for a score. There’s no drug that manipulates the neural pathways to make you take the last 40 quid out of your account to buy a bag of gear. No chemical exists that compels your hands to prepare a needle and shoot up.

You are not forced to inject heroin by your brain or by the drug. You do not become an H-zombie or a mindless smack-taking robot. You remain in control of your actions.

But that does not mean that it’s a simple ‘choice’ to do something different, as if it was like choosing one brand of soft drink over another, or like deciding between going to the cinema or staying at home.

Addiction has a massive effect on people’s choices but not so much by altering the control of actions but by changing the value and consequences of those actions.

If that’s not clear, try thinking of it like this. You probably have full mechanical control over your speech: you can talk when you want and you can stay silent when you want. Most people would say you have free will to speak or to not speak.

But try not speaking for a month and see what the consequences are. Strained relationship? Lost job maybe? Friends who ditch you? You are free to choose your actions but you are not free to choose your outcomes.

For heroin addicts, the situation is similar. As well as the pleasurable effects of taking it, not taking heroin has strong, negative and painful effects.

This is usually thought of as the effects of physical withdrawal but these are not the whole story. These are certainly important, but withdrawing from junk is like suffering a bad case of flu. Hardly something that would prevent most people from saving their lives from falling apart.

For many addicts, the physical withdrawal is painful, but it’s the emotional effects of not taking drugs that are worse.

Most smack addicts have a frightening pre-drug history of trauma, anxiety and mood disorders. Drugs can be a way of coping with those emotional problems in the short-term.

Unfortunately, in the longer-term, persistent drug use maintains the conditions that keep the problems going. Even for those few that don’t have a difficult past or unstable emotions, life quickly become difficult after regular heroin use sets in.

If you can stay high, you’ll be less affected by the consequences of both long-standing problems and your chaotic lifestyle. If you stop, you feel the full massive force of that emotional distress.

It’s vicious circle that is often set in motion by past trauma but requires a meeting with a drug and the right social circumstances. Just taking the drug until you develop tolerance and withdrawal is unlikely to addict most people.

For example, a Vietnam War study found that just under half of soldiers reported trying heroin, 1 in 5 developed full blown dependency while in Vietnam but only about 5-10% of the dependent soldiers continued using when they arrived home. Most said they gave up without any help and only a small minority had ongoing addiction problems.

In fact, some of you reading this may have been addicted to heroin and not known it. Heroin, under its medical name diamorphine, is commonly used as a painkiller after major surgery. It’s not uncommon that patients develop tolerance and go into withdrawal after they leave hospital but just put it down to ‘feeling poorly’ or ‘recovering’.

But for persistent addicts, the ‘short-term solution that maintains the long-term problem’ cycle is not the whole story and it’s important to remember the neurological effects of the drug and how it interacts with, and changes, the brain.

Addiction is associated with difficulties in resisting cravings and making flexible decisions. This is likely to be caused by a combination of genetics, earlier experience and the ongoing impact of the drug and the drug-focused lifestyle – all of which affect brain function.

A recently popular approach is the ‘disease model’ of addiction which says that the brains of those who become addicted are more susceptible to compulsive drug use because of genetic susceptibility and / or brain changes due to early experience that ‘prime’ the brain for addiction.

It’s probably true to say that the extreme version of the ‘disease model’ – which says addiction is entirely explained by these changes and is best characterised as a ‘brain disease’ – is an exaggeration of what we know about the neuroscience of addiction, but this is not to say that neuroscience is not important.

But either way, there is no clear relationship between an aspect of behaviour being best explained in neurobiological terms and not having any control over that behaviour. For example, most genuine addicts usually give up, on their own, without any assistance and don’t relapse. They still have brains, of course.

Unfortunately though, the ‘disease model’ approach is often used precisely because some think it implies addicts have less control, possibly because they feel (probably wrongly) that it is less ‘stigmatising’ to think of heroin users in this way.

Instead, we know that self-efficacy is one of the best predictors of recovery, so denying people’s role in their own decisions just undermines one of their most important tools for recovery – alongside medication, social support and other forms of therapy.

So to say an addict has ‘no choice’ over their actions is just to misunderstand addiction but to pretend these choices are like any others just misses the fact that they can sometimes be impossibly hard decisions.

Unfortunately though, people find it hard to separate any admission of addicts being able to choose their actions from blame and moral accusation.

Blaming someone for their addiction is like shaming someone for being wounded by an abusive partner. Whatever the circumstances that caused the problem, they deserve respect and treatment, and working with them to help them regain control of their circumstances and promote their own autonomy is an important and valuable way forward.

The cutting edge of brain science technologies

National Geographic has an excellent article that gives a tour of some of the latest technologies of neuroscience that are likely to be leading the way in understanding the brain over the next decade.

You can read the full article online but you need to complete a free registration first. A typical publication ploy but, in this case, it’s well worth doing.
 


 

The article is itself fascinating but is also wonderfully illustrated with photos and videos to show exactly how the new technologies allows us to see the brain at work in many different ways.

An excellent guide to the cutting edge of lab brain science.
 

Link to National Geographic article ‘Secrets of the Brain’ (free reg required).
Link to plain text copy of article – no reg required.