The big fight over the neuroscience of dreams

Believer Magazine covers the battle over whether neuroscience has supported or undermined Freud’s theories on dreaming, who suggested that dreams are symbolic expressions of our unconscious mind.

The debate is particularly interesting because it is largely centred around two larger-than-life personalities.

Allan Hobson is a retired Harvard psychiatry professor who did a great deal of neurophysiological work on dreaming and is vehemently anti-Freud, suggesting that dreams are just the higher cognitive centres creating a narrative out of essentially random brain stem activation.

Mark Solms is a psychoanalyst and neuropsychologist who also researches the neuroscience of sleep, and has argued that dreaming heavily involves higher brain centres and involves a different mechanism from sleep itself, suggesting that there may be involvement of symbolic processing from higher cognitive centres.

The two had a famous debate, which has been made available as an oddly ‘Fight Night’ packaged DVD, where they trade blows over the nature of dreaming and the brain. Their dispute has been continued in both popular and scientific publications.

Hobson originally congratulated Solms on his research, but when he discovered that Solms was on the board of the New York Psychoanalytic Institute and was working on an English translation of the complete works of Freud, he stopped writing him friendly letters. He has since altered his own theory to allow for more activity in the forebrain, not just the brain stem as he had originally proposed, but still insists that dreams have no inherent meaning: they‚Äôre the equivalent of Rorschach blots, and analysts or dreamers can make of them what they choose. He’s addressed the controversy in a series of journal publications with titles like “Freud Returns‚ÄîLike a Bad Dream.” Or “In Bed with Mark Solms? What a Nightmare!”

In a somewhat unusual turn of event, Hobson suffered a brain stem stroke in 2001, which seems to have stopped him dreaming, which, he argues, bolsters his claim that dreaming is essentially random activation of the cortex by the brain stem.

However, it’s also notable that the stroke has stopped him sleeping, so the issue remains unresolved.

The Believer Magazine does a great job of capturing the debate, as well as the personalities involved.

Link to Believer Magazine article ‘Hobson’s Choice’.

Brain radiator

The New Scientist Invention blog has a short piece on a recent patent application for a radiator which could be installed over a sensitive area of the brain that would allow it to be cooled and prevent epileptic seizures in susceptible people.

It’s not actually such a wacky idea and previous research has suggested something similar.

A 2003 paper by Steven Rothman and Xiao-Feng Yang suggested that an electrical cooling system could be implanted to detect seizure activity and temporarily cool the area to prevent a full-blown seizure.

Link to NewSci piece on the ‘brain radiator’ (via /.).

Breaking through to the vegetative state

There’s an interesting and in-depth article in The New Yorker on using brain scans to communicate with people who may be trapped in a persistent vegetative state (PVS) – a coma-like condition that can occur after severe brain injury.

The article focuses on the work of Dr Adrian Owen and colleagues who published a key paper [pdf] in Science last year which reported changes in voluntary brain activation in response to verbal request in a patient who was seemingly unconscious when assessed externally.

The research suggests that some of these patients may be misdiagnosed as being unconscious, when, in fact, they are aware of their surroundings but trapped in their immobile bodies.

Needless to say the research has both stirred some primal fears and garnered a great deal of scientific interest.

Recent research by Owen and other neuroscientists may eventually help make diagnoses more accurate, but it is not yet clear how the new brain-scan data will affect the medical understanding of consciousness. As Owen put it, “The thought of coma, vegetative state, and other disorders of consciousness troubles us all, because it awakens the old terror of being buried alive. Can any of these patients think, feel, or understand those around them? And, if so, what does this tell us about the nature of consciousness itself?”

The article goes on to consider what implications this study has for our understanding of consciousness and discusses some other fascinating studies which suggest how disordered brains can give leads into this crucial question.

One important application of this understanding is to work out ways to ‘awaken’ patients in similar states, which includes using implanted brain electrodes to stimulate under-active arousal-related brain areas.

I found the article via Frontal Cortex, which also has some interesting speculation on the possible links between these states and ‘blindsight’.

Link to New Yorker article ‘Silent Mind’.
Link to information on persistent vegetative state.

Biting the mind

Ten-minute philosophy podcast Philosophy Bites has an interview with Prof Tim Crane where he gives an excellent summary of one of the most important topics in contemporary cognitive science – the mind-body problem.

The problem asks how we can reconcile the biological properties of the brain with the subjective mental properties of the mind, because intuitively they seem like quite different things.

One of the most important points often gets lost when people think about this: it is perfectly possible to believe that mind cannot be fully reduced to the function of the brain while still being a materialist – i.e. while thinking that the brain is the only thing that supports the mind and without needing to believe in souls, ghostly spirits, or other non-material things.

How can this be? The key to understanding this is the word ‘reduced’ – i.e. reduction – where one phenomenon is equally well explained by its smaller components.

Importantly, this is a process of fitting theories together. Our idea of heat is equally well explained by our ideas about atoms.

For two things that are understood physically to begin with (e.g. heat and atoms) it works well, but for things that are described using quite different properties, such as thought and the brain, it doesn’t.

Here’s an analogy: when someone plays a recording of a song, everything you experience is carried in the sound waves.

However, you won’t understand why the singer is so in love by looking at the physics of sound, because what is meaningful about the song cannot be fully reduced to physics.

This isn’t a problem of missing detail in the sound. We can measure the sound waves in minute detail. But still, meaning is lost.

The same holds for the mind: even if we could track every single atom in the brain when we have a thought, we might lose meaning when we map the two together.

And if we lose meaning, it means we cannot fully reduce to the mind to the brain. No ghosts, spirits or souls, just a problem of connecting different levels of explanation.

One school of thought, eliminative materialism, argues that this problem highlights the fact that mind-level explanations are inherently unscientific and we should solve the issue by only taking about neuroscience – our subjective experience of the mind is simply wrong and misleading.

Probably the most popular approach at the moment is property dualism – which argues that both mind-level and brain-level explanations may explain how we think and behave but at different levels that may not always be reducible.

This is where there are two type of theories that both attempt to explain something, but in different ways. You can see where, in places, they connect, but they’re not always compatible.

This is different from ‘substance dualism‘, famously invented by Descartes, which says there are two types of substances – the brain, and the soul.

In the recent debates about religion, it’s interesting to see that some people argue that being unable to reduce the mind to the brain is evidence for the God, spirit or soul; while others opposed to religion see any mention of the problem as an indication of support for a non-materialist view.

The key point is that this issue is about how we map theories, not about what sorts of things exist in the universe.

The Philosophy Bites podcast discusses exactly these sorts of issues, particularly with regards to consciousness, perhaps the most well-known example of a problem with mapping the mind to the brain.

Link to Philosophy Bites on the mind-body problem.

SciAmMind on neurotheology and false memories

The new edition of Scientific American Mind is on its way to the shelves and two of the feature articles are freely available online: one on the neuropsychology of mystical experience and the other on one person’s experience of false memories created by the widely discounted ‘recovered memory therapy’.

The article on the neuropsychology of mystical experience covers all the major research studies but has a few niggling omissions.

For example, it mentions that a 2005 attempt by Swedish scientists to replicate Persinger’s induced ‘sensed presence’ studies “failed”, without mentioning that it wasn’t a very good replication – as noted by Persinger himself in a reply in the same journal.

The whole area of neurotheology is interesting because its very presence seems to rile some people, not least because some of the researchers have personal religious beliefs. However, in the field as a whole the mix seems quite healthy.

For example, Beauregard argues in his new book that there is a neuroscientific case for the soul, from reading Newberg’s book Why We Believe What We Believe he seems to be of the ‘there may be something spiritual going on but I’m not sure’ school, whereas, as far as I know, Persinger and Ramachandran are both atheists.

I find Beauregard’s argument a bit bizarre to be honest, as understanding the neuroscience of spiritual experience tells us no more about the existence of the soul than the understanding of vision tells us about the existence of whatever someone’s looking at.

However, this doesn’t stop people using the data to confirm their own beliefs. The article finishes with a lovely example of this from both sides:

Moreover, no matter what neural correlates scientists may find, the results cannot prove or disprove the existence of God. Although atheists might argue that finding spirituality in the brain implies that religion is nothing more than divine delusion, the nuns were thrilled by their brain scans for precisely the opposite reason: they seemed to provide confirmation of God’s interactions with them.

What these studies may show is that spiritual experience is distinct from other sorts of subjective mental states in terms of neurobiology, but they can’t answer metaphysical questions.

The other SciAmMind article discusses the science of memory with regards to one woman’s experience of having false memories of satanic ritual abuse raised by involvement with an unethical therapist.

Other feature articles include stories on Eric Kandell, virtual reality, brain nutrition, IQ and the Flynn Effect, unusual experiences and creativity, and the accuracy of visual perception.

Link to annoyingly titled article ‘Searching for God in the Brain’.
Link to article on false memories entitled ‘Brain Stains’.

Thirteen blue sky psychology experiments

The BPS Research Digest has published the last of the articles in its series on the ‘Most Important Psychology Experiment Never to be Completed’, written by a number of leading psychologists and one over-caffeinated keyboard monkey.

Actually, that goes quite well. I don’t know what I was worried about.

The series has been published an article at a time over the last two weeks, and includes inspired but impossible experiments on the cognition of unborn children, brain optimisation, resisting tyranny, and one inspired by The Truman Show – to name but a few.

They’re all now available online, so have a look and see which of the 13 impossible studies catches your eye.

Link to the most important psychology study that’s Never been done’.

2007-10-05 Spike activity

Quick links from the past week in mind and brain news:

Frederick Frese, legendary Professor of Psychology and Clinical Psychiatry, discusses his life with schizophrenia.

Mathematical modelling of movement finds clear differences between people with and without depression, reports The Economist.

The Moustrap covers a study finding that the brain shows similarities in the way that it handles tunes that violate our expectations of melody, and words that violate our expectations of sentences.

Is Alzheimer’s disease a form of diabetes? A striking hypothesis based on new findings in brain physiology.

The New York Times reports on a new study finding that cognitive behavioural therapy is likely to be a key treatment for depressed children and adolescents.

Retrospectacle discusses the curious case of Phineas Gage.

Britain’s youngest female brain surgeon, Dr (Ms?) Gelareh Zadeh, 35, introduces day-patient neurosurgery to the NHS.

A fantastic child psychology triple bill:

1) Cognitive Daily has another wonderful try-it-yourself article: Infants perceive language sounds differently by age 6 months.

2) Are infants born with a spider detection mechanism? Mixing Memory continues the child psychology theme.

3) Developing Intelligence finds that children produce less false memories with a method that has a strong effect in adults.

Has the digital word altered how the brain reads text? An article in the International Herald Tribune ponders the question.

I am not a number — I am a free man! Raymond Tallis argues that free will is not an illusion in Spiked Magazine.

Furious Seasons notes that drug company Bristol Myers Squibb pays $515 million to the US Department of Justice to settle a case over unauthorised ‘off-label’ promotion of its flagship antipsychotic medication.

Can we selectively reduce the impact of traumatic memories? SciAm’s Mind Matters blog investigates.

Three-Toed Sloth has an in-depth discussion of the debate over whether IQ is inherited. If you’re in a hurry, the summary is at the end.

PsyBlog critiques a recent dodgy news report suggesting that ‘conscientiousness’ may ward off Alzheimer’s.

A rough guide to philosophy and neuroscience

Philosophy is now an essential part of cognitive science but this wasn’t always the case. A fantastic new article, available online as a pdf, describes how during the last 25 years philosophy has undergone a revolution in which it has contributed to, and been inspired by, neuroscience.

The article is by two philosophers, Profs Andrew Brook and Pete Mandik, and it’s a wonderful summary of how the revolution occurred and just how we’ve benefited from philosophers turning their attention to cognitive science.

But it also notes how evidence from psychology and neuroscience is being used by philosophers to better understand concepts – such as perception, belief and consciousness – that have been the concern of thinkers from as far back as the Ancient Greeks.

It’s an academic article, so it’s fairly in-depth in places, but if you want a concise introduction to some of the key issues philosophy of mind is dealing with, and how this directly applies to current problems in the cognitive sciences, look no further.

The scope is wonderfully broad and there’s a huge amount of world-shaking information packed into it.

It’s particularly good if you’re a psychologist or neuroscientist and want a guide to how philosophy is helping us make sense of the mind and brain.

The article will shortly appear in the philosophy journal Analyse and Kritik but the proofs are available online right now.

pdf of article ‘The Philosophy and Neuroscience Movement’ (via BH).

Strippers’ earning potential affected by hormone cycle

A study shortly to be published in the journal Evolution and Human Behaviour found that lap dancers in their most fertile phase of the menstrual cycle earned much more than dancers in the least fertile phase. In contrast, dancers who took the contraceptive pill, which ‘flattens’ the hormone cycle, earned much the same throughout the month.

This adds to the increasing evidence that women’s sexual behaviour changes during their monthly cycle, and that the external signs of this change are picked up by males.

We’ve covered a couple of other studies that have reported that women dress more attractively and show a greater neural response to rewards at their most fertile time.

Other studies have found that the most fertile time is associated with increased facial attractiveness, decreased waist-to-hip ratio, higher levels verbal creativity, a heightened interest in other partners (and a greater ‘protective’ interest from their primary partner) – to name but a few of the effects.

The researchers of the latest study, led by psychologist Prof Geoff Miller, asked 18 dancers to record their menstrual periods, work shifts, and tip earnings for 60 days via a web site.

Although 18 participants is relatively few for a psychology study, they recorded a large amount of data over time – 296 work shifts in total, representing about 5300 lap dances.

Dancers who were not on the contraceptive pill and at their most fertile time earned an average of $70 dollars an hour, twice the $35 average of women at their least fertile phase.

Dancers who took the contraceptive pill, which ‘flattens’ the hormone cycle, didn’t show a peak in earnings when the peak in fertility would normally occur.

The researchers suggest that this is evidence of ‘estrus’ – an external display of peak fertility – seen in almost all other animals but supposedly missing in humans. One theory goes that women have ‘concealed ovulation’ as estrus has been lost during evolution.

But the fact that tip earnings peak during estrus perhaps suggests that men can detect female fertility more accurately than the ‘concealed ovulation’ idea suggests.

They also argue that studying lap dancing may also be a particularly powerful way of understanding change in female sexual attractiveness as the interaction with the men is ‘multisensory’ and there is a clear measure of appreciation – the tips from patrons:

Because academics may be unfamiliar with the gentlemen’s
club subculture, some background may be helpful… Club patrons will often “sample” several different dancers with one lap dance each before picking one for a more expensive multisong bout of dancing. Thus, patrons can assess the relative attractiveness of different women through intimate verbal, visual, tactile, and olfactory interaction, and those attractiveness judgments can directly influence women’s tip earnings, through the number of 3-min dances that patrons request from each dancer.

Link to abstract of scientific study (thanks Matthew!).
Link to write-up from Psychology Today.

Artificial intelligence ‘sees’ visual illusion

A study just published in PLoS Computational Biology has reported that an artificial intelligence system trained to make sense of a simulated natural environment is susceptible to some of the same visual illusions that humans fall for.

In one of these, the ‘Herman grid‘ illusion – illustrated on the right, you may be able to ‘see’ fuzzy patches of grey in the white stripes, despite the fact that there is no grey in the image (click for a bigger version if it’s not clear).

David Corney and Beau Lotto, researchers working in the Lotto Lab (which has a wonderful website by the way), have been training artificial intelligence systems to distinguish surfaces in a simulated natural environment with lots of ‘dead leaf’-like shapes.

When training these sorts of systems, the idea is not to program them with specific rules, but to present an image and let the neural network make a guess.

The researchers then ‘tell’ the AI system whether it is correct in its guess, and it adjusts itself to try and reduce the extent of the error on the next guess. After many learning trials, these sorts of ‘back propagation‘ neural networks can make distinctions between quite complex stimuli.

In this case, Corney and Lotto decided that once the system was fully trained to complete its task successfully, they would test it with some visual illusions experienced by humans.

Interestingly, the AI system was susceptible to the Herman Grid illusion, sensing ‘grey’ where there was none. Other illusions produced similar results.

The fact that both humans and AI system ‘fall’ for the same illusions, suggests that they take advantage of visual abilities that have been shaped by our experience of the visual world.

Link to paper in PLoS Computational Biology (thanks Matt!).
Link to study write-up from the university’s news site.
Link to Lotto Lab website (with loads of cool images and demos).

Pioneers of psychology

Oklahoma State University’s online psychology museum has launched an exhibit to commemorate African American Pioneers of Psychology. It’s an excellent resource but they’re missing some photos and you might be able to help.

The photo on the left is of Dr Inez Prosser. She earned her PhD in educational psychology from the University of Cincinnati in 1933.

She did some of the earliest research into the effect of racial segregation on academic achievement.

There have been many more African-American psychologists who were working in the USA as far back as the 1920s and the new ‘Pioneers of Psychology’ site is collating their history.

Unfortunately, it’s missing photos for Drs Robert Prentiss Daniel and John Henry Brodhead.

If you think you can help out with photos of either of the above, or have additional information on any of the people featured in the exhibit, I am sure the curators would love to hear from you.

Link to African-American Pioneers of Psychology Website (via AHP).

Personality types, as you’ve never seen them before

Someone’s created some satirical descriptions of the personality types classified by the Myers-Briggs personality test, that include categories such as ‘The Egghead’, ‘The Conman’ and ‘The Evil Overlord’.

The Myers-Briggs isn’t used so much by research psychologists, largely because it isn’t as reliable as some of the newer ‘Big Five‘ personality measures which dominate the field.

It is not unusual for people to fill one in themselves though (there are many versions online) and get a rating of whether they are Extroverted or Introverted, Sensing or iNtuitive, Feeling or Thinking, Judging or Perceiving.

Each of these gets compressed into a short letter string, and each is supposed to represent some particular personality type.

This new satirical interpretation of the personality types makes a sly commentary on some of the more outlandish descriptions you can read online.

ESFP: The National Enquirer Headline

An ESFP is a spontaneous, outgoing, charismatic, fun-loving person like the guy you used to room with in college–you know, the one who was found floating face-down in the reservoir with the homecoming queen’s underwear in his teeth.

The strongest element of the psychological makeup of an ESFP is his easygoing, impulsive approach to life. ESFPs often build their careers out of dating supermodels, being involved in scandals, and appearing regularly in such newspapers as “The National Enquirer” and “The Weekly World News.” ESFPs often die in bizarre circumstances, usually involving jealous boyfriends, exotic dancers, escaped pythons, feather boas, and falls from the penthouse floor of high-rise apartments; those who don’t, usually die of veneral diseases.

Link to satirical Myers-Briggs interpretation (via MeFi).
Link to good Wikipedia page on the Myers-Briggs.

‘Self-silencing’ may affect women’s health

The New York Times discusses recent findings suggesting that not expressing feelings during marital arguments is bad for women’s health, but not for men’s.

The article draws on the results of a study that followed over 3,500 people and looked at both the quality of their marriage and whether they developed heart disease.

Interestingly, the overall level of marital satisfaction and total number of disagreements were not related to heart problems.

However, women who “self-silenced” during conflict with their spouse, compared with women who did not, had four times the risk of dying. This was not the case with men.

The tendency to bottle up feelings during a fight is known as self-silencing. For men, it may simply be a calculated but harmless decision to keep the peace. But when women stay quiet, it takes a surprising physical toll.

“When you’re suppressing communication and feelings during conflict with your husband, it’s doing something very negative to your physiology, and in the long term it will affect your health,” said Elaine Eaker, an epidemiologist in Gaithersburg, Md., who was the study’s lead author. “This doesn’t mean women should start throwing plates at their husbands, but there needs to be a safe environment where both spouses can equally communicate.”

Other studies led by Dana Crowley Jack, a professor of interdisciplinary studies at Western Washington University in Bellingham, Wash., have linked the self-silencing trait to numerous psychological and physical health risks, including depression, eating disorders and heart disease.

Keeping quiet during a fight with a spouse is something “we all have to do sometimes,” Dr. Jack said. “But we worry about the people who do it in a more extreme fashion.”

Nevertheless, men are not without their seemingly gender specific health risks. The study found that men with wives who were upset by work were almost three times more likely to develop heart disease.

The study is another example of how mental and physical health are completely intertwined.

Link to NYT article ‘Marital Spats, Taken to Heart’.
Link to abstract of scientific study.

How the brain generates private thoughts

The Spanish Journal of Psychology has an interesting English language article [pdf] on the neuropsychology of private thoughts – still one of the most mysterious and poorly understood aspects of our mental life.

Neuropsychology is especially good at looking at how differences in brain function relate to objectively observable behaviour. Private thoughts are quite hard to study in this way, because they are essentially subjective.

Sometimes, of course, we make our private thoughts ‘public’ by talking to ourselves, and, it seems, this is something we learn to do during childhood.

Infants seem unable to ‘think to themselves’ and instead ‘talk to themselves‘ when solving problems, usually vocalising the most tricky or novel aspects of the situation. As we grow, we develop the ability to internalise this speech, and can eventually have a purely internal monologue.

Understanding inner speech is also important because it becomes distorted in psychotic disorders such as schizophrenia.

People with psychosis can experience effects like ‘thought insertion’, where they experience external thoughts being inserted into their stream of consciousness, or ‘thought withdrawal’, where thoughts seem to be removed from the mind.

This suggests that there must be something that the brain uses to identify thoughts as self-generated, and that this perhaps breaks down in psychosis, so we can have the uncanny experience of having thoughts that don’t seem to be our own.

Why we would need this is an interesting question, as surely all thoughts would be our own.

However, the Spanish Journal of Psychology article notes that inner speech often activates areas of the brain also used for ‘outloud speech’, suggesting that it may be a sort of internal action.

Being able to distinguish bodily movements caused by something external (someone moving your arm) and movements caused by our own will is very important, and, perhaps, this is the sort of mechanism that becomes disturbed for what were originally movements, but have become internalised as we ‘think to ourselves’.

pdf of ‘A Neurocognitive Approach to the Study of Private Speech’.
Link to SciAm article on private speech in children.

Illusory motion with waves of almonds

I’ve just found a visual illusion that gives a striking impression of motion from a static image. It’s entitled ‘this picture is not animated’, which, like anything eye-catching on the internet, immediately made me check whether it was or not.

With many of these sorts of illusory motion images, you can ‘stop’ the motion by simplying viewing them through a very small aperture.

Putting a pin through a piece of paper and viewing it through the hole does the trick, but so does making a small viewing hole with your fingers.

As you can see yourself, the picture stops ‘moving’ when viewed like this, but starts again as soon as you view it normally.

This also prevents stars from twinkling when you view them at night. The traditional explanation of ‘star twinkle’ is that the light gets bounced around as it travels through the atmosphere, giving it the twinkling effect.

In fact, by looking at them through a small hole, you’re preventing any effects caused by your eyes moving about.

The fact that the illusion stops moving and the stars stop twinkling when you do this, suggests that the way our eyes scan across the visual scene is an important part of why we see the false movement in these sorts of images.

Because of this, you can ‘speed up’ and ‘slow down’ the false movement in the visual illusions by changing how often you move your eyes.

UPDATE: Thanks to celeriac for posting a link to a scientific paper which explains this effect.

Link to striking movement illusion.