The dark matter of the brain

Discover Magazine has an excellent Carl Zimmer article on glial cells. They make up the majority of the brain’s volume but they get relatively little attention from the neuroscience community who would rather focus on the seemingly more lively neurons.

There’s a traditional format for these stories, that says that we used to think that glial cells were just ‘scaffolding’ for the brain that gave protected padding for the neurons, but now we are on the verge of a breakthrough in understanding what they do.

Here’s one from New Scientist in 1994, and a pdf of another from Scientific American in 2004.

One difficulty has been integrating the action of glial cells into the popular cognitive model of the brain that suggests that it works as an information processing device.

While there have been various discoveries about the biological function of glia, this is the first article I’ve read which gives a clear idea of how one type of glial cell, the astrocyte, might be involved in information processing.

For some brain scientists, these discoveries are puzzle pieces that are slowly fitting together into an exciting new picture of the brain. Piece one: Astrocytes can sense incoming signals. Piece two: They can respond with calcium waves. Piece three: They can produce outputs—neurotransmitters and perhaps even calcium waves that spread to other astrocytes. In other words, they have at least some of the requirements for processing information the way neurons do. Alfonso Araque, a neuroscientist at the Cajal Institute in Spain, and his colleagues make a case for a fourth piece. They find that two different stimulus signals can produce two different patterns of calcium waves (that is, two different responses) in an astrocyte. When they gave astrocytes both signals at once, the waves they produced in the cells was not just the sum of the two patterns. Instead, the astrocytes produced an entirely new pattern in response. That’s what neurons—and computers, for that matter—do.

If astrocytes really do process information, that would be a major addition to the brain’s computing power. After all, there are many more astrocytes in the brain than there are neurons. Perhaps, some scientists have speculated, astrocytes carry out their own computing. Instead of the digital code of voltage spikes that neurons use, astrocytes may act more like an analog network, encoding information in slowly rising and falling waves of calcium. In his new book, The Root of Thought, neuroscientist Andrew Koob suggests that conversations among astrocytes may be responsible for “our creative and imaginative existence as human beings.”

Obviously this is based on the idea that we need to fit new biological findings into the computational model, rather than fitting our model of the mind into the biology, but that’s a whole different battle.

Link to Discover article ‘The Dark Matter of the Human Brain’.

Empty glass, empty promise

Photo by Flickr user DeeJayTee23. Click for sourceThere’s a neat study in the August edition of the Journal of Abnormal Psychology on how alcohol can make us feel fully committed to goals we know we have no chance of achieving.

Alcohol breeds empty goal commitments

J Abnorm Psychol. 2009 Aug;118(3):623-33.

Sevincer AT, Oettingen G.

According to alcohol-myopia theory (C. M. Steele & R. A. Josephs, 1990), alcohol leads individuals to disproportionally focus on the most salient aspects of a situation and to ignore peripheral information. The authors hypothesized that alcohol leads individuals to strongly commit to their goals without considering information about the probability of goal attainment. In Study 1, participants named their most important interpersonal goal, indicated their expectations of successfully attaining it, and then consumed either alcohol or a placebo. In contrast to participants who consumed a placebo, intoxicated participants felt strongly committed to their goals despite low expectations of attaining them. In Study 2, goal-directed actions were measured over time. Once sober again, intoxicated participants with low expectations did not follow up on their strong commitments. Apparently, when prospects are bleak, alcohol produces empty goal commitments, as commitments are not based on individuals’ expectations of attaining their goals and do not foster goal striving over time.

Link to PubMed entry for study.

Footage of neurosurgery from 1933

The Wellcome Trust is putting its archive of medical films online which includes some fascinating footage of some 1933 neurosurgery to remove a tumour from the frontal lobe.

The film says the tumour is a tuberculoma. While we typically link tumours to cancer, the name also refers to other types of abnormal growths.

In this case, it’s an abnormal growth caused when tuberculosis (TB) reaches the brain and leads to an infected mass that can have a similar effect – damaging the cortex by taking up space where the brain should be.

Because TB can be treated effectively with antibiotics, tuberculomas are now very rare in the West, but they are still unfortunately quite common in parts of the developing world where access to medical care is limited.

The Wellcome archive footage is from a time where TB was much more common and shows how surgeons of the days would have removed the mass and how the patient is left after recovery.

Link to Wellcome archive footage of 1933 brain surgery.

Weaponized drugs: armed and delirous

Today’s Nature has a fantastic article about how psychoactive drugs are being developed into a new generation of chemical weapons design to have specific psychological effects on the enemy.

This has long been part of military research (see the famous and unintentionally hilarious footage of British troops being given LSD presumably from the 1950s) but the effects of the mind altering weapons have generally been thought to be too unpredictable and largely restricted to the lab.

However, the Nature article argues that as our knowledge increases and specific biochemical pathways in the body are discovered, chemical and biological weapons are likely to be deployed that target highly selective biological mechanisms to incapacitate and disable.

Some researchers are actively facilitating the development of new chemical weapons. For example, a research group from Pennsylvania State University in University Park has identified several drug classes as potential non-lethal agents or ‘calmatives’, including benzodiazepines and alpha2-adrenoreceptor agonists, as well as individual drugs such as diazepam and dexmedetomidine…

Those who support the development of incapacitating agents often argue that using them in conflict situations stops people being killed. Historical evidence suggests otherwise. At the Nord-Ost [Moscow theatre] siege, for instance, terrorists exposed to the fentanyl mixture were shot dead rather than arrested. Likewise, in Vietnam, the US military used vast quantities of CS gas ‚Äî a ‘non-lethal’ riot-control agent ‚Äî to increase the effectiveness of conventional weapons by flushing the Viet Cong out of their hiding places.

The piece notes that the current international laws on chemical and biological weapons do not address this form of armament which are typically marketed under the ‘non-lethal weaponry’ banner.

From past experience, including the fact that the fentanyl-based ‘incapacitating’ gas seemed to have killed the majority of people during the Moscow theatre siege, it is likely that they will be used in anything but a non-lethal manner.

Link to Nature ‘Biologists napping while work militarized’.

The vibratory chair for Parkinson’s disease

There’s a curious historical snippet in the latest edition of Neurology about how the famous French neurologist Jean-Martin Charcot designed a shaking chair for patients with Parkinson’s disease after they reported sleeping better after a train or carriage ride.

The most obvious symptom of Parkinson’s disease is tremor and name first given to the condition, by James Parkinson in his famous essay, was the ‘shaking palsy’.

While Charcot’s 19th century contemporaries had tried ‘vibration therapy’ here and there, he was the first to systematically apply it to patients with Parkinson’s and found it helped with stiffness, discomfort and poor sleep.

Later Gilles de la Tourette, a one-time student of Charcot, developed the treatment into a type of electrical vibrating hat to specifically apply a 600 rpm treatment ‘directly’ to the brain.

The treatment was seemingly forgotten for many years but recently it has been revived and studies have found modest benefits for vibration therapy in Parkinson’s disease.

Link to paper.
Link to PubMed entry for same.

Booze memory of waiters in Buenos Aires

Photo by Flickr user Sarah Severson. Click for sourceThe Guardian’s Improbable Research column covers a clever study on the incredible memory of waiters in Buenos Aires who can take orders from a large table of customers without writing anything down.

Instead of coming up with some abstract computerised lab task, the researchers tested their drink ordering skills and then swapped places to test how they were remembering all the orders.

Eight customers sat at a table, and ordered drinks. When the waiter brought the beverages, the scientists tallied up how many were served to the people who had ordered them, and how many delivered to someone else. All the waiters performed admirably.

The customers later ordered more drinks, then switched seats before the waiter returned. This produced dreary results. The scientists tried this on nine waiters, only one of whom consistently delivered drinks to the right people.

Interviewed afterwards, waiters said they generally paid attention to customers’ locations, faces and clothing. They also disclosed a tiny trick of the trade. They “did not pay attention to any customer after taking a table’s order, as if they were protecting the memory formation in the path from the table to the bartender or kitchen.”

Link to Improbable Research column on the study.
pdf of scientific paper.
Link to PubMed entry for same.

No one expects Encephalon 74

Edition the 74th of the Encephalon psychology and neuroscience writing carnival has just hit the net, this time hosted by Neuronarrative with a Monty Python twist.

A couple of my favourites include one from Neurospeculation on a clever clapping test for hemispatial neglect that originated from class of high school students and another from Sharp Brains on preparing society for the cognitive age.

There’s a lot more where that came from, and a couple of Monty Python sketches thrown in for good measure. Enjoy!

Link to Encephalon 74.

The chill of the bass

Photo by Flickr user jon madison. Click for sourceI’ve just found this wonderful short paper on emotional peaks and ‘chills down the spine’ in response to music. I didn’t realise the area had been investigated and apparently there is a small literature on these most sublime of experiences.

The paper is brief, accessible and is available online as a pdf but the abstract gives a great summary:

Chills as an indicator of individual emotional peaks

Ann N Y Acad Sci. 2009 Jul;1169:351-4.

Grewe O, Kopiez R, Altenmüller E.

Chills (goose bumps) have been repeatedly associated with positive emotional peaks. Chills seem to be related to distinct musical structures and the reward system in the brain. A new approach that uses chills as indicators of individual emotional peaks is discussed. Chill reactions of 95 participants in response to seven music pieces were recorded. Subjective intensity as well as physiological arousal (skin conductance response, heart rate) revealed peaks during chill episodes. This review suggests that chills are a reliable indicator of individual emotional peaks, combining reports of subjective feelings with physiological arousal.

Right, where’s that Miley Cyrus CD.

pdf of scientific paper.
Link to PubMed entry for same.

Standing together against combat trauma

There is probably no more hostile environment to mental health treatment than the military. Recently, a new treatment method has been widely adopted by the UK Armed Forces and, perhaps for the first time in history, officers are requesting it in droves.

In major wars since the 20th century more fighters have been lost to psychiatric casualties than bodily injuries but psychiatrists and psychologists are still mistrusted by the corps.

It was explained to me rather tactfully that “soldiers are not necessarily the most psychologically minded of individuals” and it is likely a combination of the macho culture and conditioning to deal with discomfort by sheer grit that casts mental strain as weakness in the military.

This has made both mental health problems and their treatment a source of significant stigma in one of the professions most likely to cause trauma and breakdown in its employees.

Trauma Risk Management or TRiM was first developed by the Royal Marines, one of the UK’s most hardened battle corps, and trains key members to recognise signs of mental strain in their comrades and provides support at the level of the unit.

It’s a wonderfully conceived approach as it takes advantage of the esprit de corps, the intense group bond that forms between fellow soldiers, but which also makes them wary of accepting help from ‘outsiders’.

But it also avoids the practice of sending in outsiders to provide ‘debriefings’ after traumatic incidents which have been found, in many cases, to make the trauma worse.

A recent paper [pdf] published in Journal of the Royal Army Medical Corps outlines the TRiM approach. Non-medical mid-level soldiers are trained to assess their colleagues after a potentially traumatic event and look for risk factors for poor-coping, provide information on which psychological reactions to expect, give informal support and know when to refer to specialist medical staff.

More widely the approach aims to change attitudes to mental distress by making it both an acceptable topic and another form of operational training.

And it is clear that there is a currently a need for a different approach, particularly it seems, in the US military.

A recent review of post-traumatic stress disorder (PTSD) in soldiers deployed to Iraq found that, seemingly uniquely, US soldiers show increased levels of the disorder one year after returning from the war zone. This is exactly the opposite pattern to that which is typically seen in other soldiers and civilians.

Science writer David Dobbs has received a lot of flak for suggesting that the system that provides mental health treatment to US veterans is unintentionally encouraging long-term disability but the figures suggest he may be right.

TRiM could be an effective counter-measure to mental illness in the military and it is certainly popular. It is also being adopted widely in the civilian emergency services, but it remains under-researched.

The recent paper on TRiM notes that a trial is currently being run by the UK Ministry of Defence and preliminary results suggest cautious optimism although we still await the first published study its effectiveness when deployed on the ground.

In light of the lack of evidence, it’s perhaps a little worrying that TRiM is being increasingly flashed around as a PR-friendly talisman of good practice whenever the military’s mental health credentials are questioned and it has also now become the basis of a minor training industry.

Nevertheless, the simple fact that it has been accepted and requested by the armed forces themselves is a significant advance for military psychiatry.

pdf of ‘Trauma risk management (TRiM) in the UK Armed Forces’

Sulci against the head bangers

One of the mysteries of the human brain concerns why the surface is wrinkled into ‘ridges’ and ‘trenches’. We covered some of the theories a couple of weeks ago but a new study in the Journal of Biomechanics suggests a completely different take – the rippled surface protects against the effects of head injury.

The research team created a 3D computer model of the brain taken from an MRI brain scan (top) and then generated a second model (bottom) but with the sulci (the ‘trenches’) smoothed out.

They then took each model and simulated a few smacks upside the head from different directions. As well as ‘striking’ the head head on, the researchers also simulated blows causing ‘rotation’.

This is where the brain moves as if it is pivoting around a point. For example, if you look straight on and loll your head from side to side, your brain is following the path of a ‘coronal rotation’. These sorts of blows are known to be a particular cause of tears in the white matter, your brain’s ‘cabling’.

It turns out that a brain with sulci on the surface suffers significantly less strain when the head is struck. And this isn’t just for areas near the surface.

The sulci also had a protective effect almost everywhere, including deep brain structures like the brain stem and the corpus callosum.

So it seems that having a wrinkly brain may be a good protective measure for when your head has to bounce off a hard surface.

Link to paper ‘Can sulci protect the brain from traumatic injury?’
Link to PubMed entry for same.

Time to face the muzak

Newsweek has an interesting article about the science behind the infuriating muzak that plays while you’re on hold in a telephone queue.

The article made me realise what probably should have been obvious, that telephone queuing systems are a multi-million dollar industry and psychologists have been employed to research the best way to stop you hanging up.

When of the most interesting bit is where the article touches on the use of music to alter customers’ perception of passing time.

Kellaris says that while musical distraction often causes time to feel like it’s passing more quickly, particularly dull, or overly familiar, music can actually make the wait feel longer. Familiar music may act as a sort of “Zip file,” says Kellaris, referring to the common format computers use to compress large volumes of data into a smaller package.

“If you hear an excerpt of a familiar piece of music, it might cue recall of the entire piece.” Kellaris also cautions that numerous factors, including mindset and setting‚Äîand in one of his studies, even gender‚Äîdetermine the effect that background music has on us. “Time on hold seemed shortest for women exposed to alternative rock and for men exposed to classical music,” he says.

And there are apparently a number of studies which have tested exactly this, including two intriguing ones I found after my interest was sparked.

The article also notes that a major factor in keeping people in a queue is the perception that they are progressing by giving customers’ feedback on their position on time to destination.

Link to Newsweek article ‘On Hold And In Hell’.

Desperately seeking something

Slate magazine has an article on “how the brain hard-wires us to love Google, Twitter, and texting” which has become remarkably popular but buys into the dopamine myth and misapplies it to the nebulous concept of ‘information’.

The piece is, on the surface, quite appealing because it seems to give a more sophisticated account of the dopamine = pleasure myth of old, suggesting instead that dopamine really equals seeking and it’s the system that motivates us to search out rewards.

There is a some truth in this, as one of the several theories of the dopamine system is that it works as a reward prediction system, based on evidence that dopamine neurons in the ventral tegmentum fire when a neutral event (like a beep) comes shortly before a reward (like food) but disappears when the beep keeps happening without any food arriving.

This theory is not without its problems by the way, and it shouldn’t be assumed that this is really how it is.

The article rambles on a bit about the distinction between pleasure and seeking, experiments on dopamine and motivation, and then falls off a cliff:

Ever find yourself sitting down at the computer just for a second to find out what other movie you saw that actress in, only to look up and realize the search has led to an hour of Googling? Thank dopamine….

Panksepp says a way to drive animals into a frenzy is to give them only tiny bits of food: This simultaneously stimulating and unsatisfying tease sends the seeking system into hyperactivity.

Berridge says the “ding” announcing a new e-mail or the vibration that signals the arrival of a text message serves as a reward cue for us. And when we respond, we get a little piece of news (Twitter, anyone?), making us want more.

So we’ve gone from the neurobiology of dopamine in rats rewarded by food pellets to the “ding” of an email arriving. Science!

The crucial issue is the question of what counts as a reward. In almost all of these articles, it is assumed that Google and Twitter work as rewards because they are ‘information’.

But as far as the brain is concerned, ‘information’ encompasses all input from the senses. When you look a tree searching for unusual patterns in the bark, you are getting information and rewards. We could just as easily rewrite the article as “how the brain hard-wires us to love forests, trees, and curious patterns in the bark”.

You could, of course, and the article would be equally as (in)valid scientifically, but you’d never get it in the media because there’s currently a market for faux science internet scare stories but not hand-wringing over the addictive potential of trees.

But apart from these cultural issues, the article confuses primary (or natural) rewards and secondary (or learnt) rewards. Primary rewards are things like food, sex and escape from pain. They’re acquired from evolution, essential for our survival and universal. Secondary rewards are things like money, praise and well… anything else and that’s because we have to learn secondary rewards.

There’s nothing innately rewarding about a crumpled bit of coloured paper but we’ve learnt to link money to our innate primary rewards.

In contrast, the article makes a leap between mostly animal studies that have looked at the neurobiology of primary reward prediction and misapplies it to digital technology as if receiving ‘information’ is equivalent to a rat receiving a food pellet when it’s hungry.

But the concept of ‘information’ is orders of magnitude more abstract because there is nothing innately rewarding about a sensation. It depends on how we interpret the sensation or, in information terms, its content.

For example, the article implies that ‘novel’ and ‘unpredictable’ digital information is rewarding but if this is the case, why do we dislike spam so much? The explanation lies in why that information is meaningful and this goes way beyond misapplied ideas about the dopamine reward system.

We are not motivated to seek any information, otherwise I’d never take my eyes off the sky. The meaning and relevance is key.

In other words, if you want to explain compulsive behaviour you need to explain how the behaviour has become rewarding and this could be as varied and different as human nature itself.

The ‘dopamine reward system’ explanation is one of the most widely abused and misapplied scientific theories in the popular press. Be wary when anyone can’t explain why it is relevant.

Link to Slate article ‘Seeking’.

On the extremes of eminent reasonableness

I’ve just come across a brilliant 1966 sketch about a psychiatrist from Peter Cook and Dudley Moore’s classic comedy series Not Only… But Also.

Peter Cook plays a psychiatrist who takes his reasonable acceptance of his patient’s behaviour to the extreme with Dudley Moore as his comic foil.

It’s actually a parody of a technique in psychotherapy called “unconditional positive regard” in which the therapist accepts the person’s behaviour, experiences and emotions, good or bad, without judging the person’s core value as a human being.

This was originally developed by psychologist Carl Rogers as part of a humanistic or person-centred approach to psychotherapy.

While few therapists would consider themselves purely Rogerian in their approach nowadays, his general assumptions are now widely used in all forms of psychological treatment. Probably as a result he has been voted the most influential psychotherapist twice over the last 50 years.

Apparently he’s been so influential that he even influenced Pete and Dud’s comedy.

By the way, I picked up the link from the Twitter stream of @mariapage, a Greek student who consistently posts interesting and eye-opening psychology links. Thanks!

UPDATE: I’ve discovered this wasn’t the only psychiatrist sketch Pete and Dud did. There’s footage of another brilliant parody available here. In this one, Peter Cook makes looks of banal pseudo-Freudian observations about the state of Dudley Moore’s relationship with his wife. There’s also a great piss-take of behavioural therapy.

Link to The Psychiatrist sketch from Peter Cook and Dudley Moore.

2009-08-14 Spike activity

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

Why do ethicists steal more books than other people? ABC Radio National’s Philosopher’s Zone talks to Eric Schwitzgebel about his brilliant philosophical research project.

The New York Times has an article on delusions of identity after brain injury. Doesn’t say very much except they exist but an interesting topic nonetheless.

Listen to Ben Goldacre doing a fantastic job of countering Susan Greenfield’s scaremongering over internet addiction on ABC Radio National’s The Science Show.

To wit: Susan ‘digital brain damage / attention span armageddon / generation ADHD’ Greenfield take note. Newsweek reports that teen novels are more popular than ever.

Reuters reports on the University of Pennsylvania’s Neuroscience Boot Camp.

Chocolate consumption increases in people Parkinson’s disease, according to research covered by Dr Shock.

BBC News covers researching finding that people with more symmetrical faces are less likely to suffer mental decline in old age. See an earlier Mind Hacks piece for more on links between face structure and brain function

Dieting could lead to a positive test for cannabis reports New Scientist, but only if you’ve been previously smoking cannabis.

The British Medical Journal has a meta-analysis of 372 (wow) double blind antidepressant RCTs finding that they slightly increase suicide risk in younger people. Furious Seasons has great coverage as always.

Radiotherapy for brain cancer has long-term cognitive effects, reports BBC News.

Bad Science has some excellent coverage of a study on how beliefs flow through science literature.

Would have covered this ourselves if it’d not been picked up by the big boys. If you’ve not read it already, the BPS Research Digest has an excellent piece on how time perception is linked to anger.

Scientific American has an interview with Judith Rich Harris, the influential psychologist who argues that parents have a minimal influence on children’s social development in comparison to their peers.

Facebook reinforces jealousy in jealousy-prone people according to a study covered by PsychCentral.

Optimistic women live for longer, according to BBC News who seem to have raised their game this week.

3 Quarks Daily has a first hand account of sleep paralysis. Some slightly shaky neuroscience but well worth a read.

Anthropologist Richard Wrangham mongers his ‘the invention of cooking as the cause of hominid brain expansion’ theory on Edge.

Dr Petra discusses the American Psychological Association’s recent statement on the futility of ‘gay conversion therapy’.

A project to map every brain connection in five years time has been announced by the American National Institute of Health. An overview and commentary by Neurophilosophy’s Mo Costandi are published in Seed Magazine which brings it down to earth a little.

The Journal of Cognitive Neuroscience has an interesting paper on a neurocomputational model for cocaine addiction (thanks Will!). Only runs in the toilets apparently.

Studying babies can tell us about some of the most challenging philosophical questions according to an article in Salon.

Cognitive Daily finds a wonderful study on how adaptation to distorted faces doesn’t transfer between male and female faces suggesting they may be processed differently.

Congenitally blind people distinguish between living and nonliving things in the <a href="
“>same visual brain areas as sighted people, according to a new study covered by Science News.

The Psychiatric Times has a response by the DSM-V critics accused by the American Psychiatric Association of being motivated by wanting to sell more of their books on the earlier version. It’s the debate that keeps on giving.

A study on the neural cartography of the clitoris is covered (if that’s the right word) by The Neurocritic.

The archaeology of language

ABC Radio National’s Ockham’s Razor has a short but thoroughly fascinating programme on how human pre-history and cultural change can be uncovered through the study of languages. It’s an eye-opening insight into how patterns in our language are relics of our past and how they can be a window into the interplay of societies.

The presenter is linguist Claire Bowern who does most of her research in the field. Bowern particularly studies the languages of the Aboriginal peoples of Australia and how they’ve interacted with each other and with English.

She gives the example of various ‘loan words’, such as koala or kangaroo, used in English but adopted from native speakers.

Loan words like this show us that there were enough contacts between Aboriginal people and settlers for the settlers to learn the names of local animals in those languages, rather than making up their own names. However, the loans are mostly confined to plants, animals and environment terms, and this tells us something about the depth and type of contact between the two groups. The European settlers did not adopt Aboriginal kinship terminology, for example, or other cultural terms.

We might compare this to the English wholesale adoption of French legal terms like judge, jury and trial, following the Norman Conquest. Many of the loans of Aboriginal words in English come from the Sydney region; it’s therefore reasonable to assume that this was the place that European settlers first came into contact with animals like koalas and dingos.

It really is like archaeology for language as she often has to uncover quirks of languages that are spoken only in remote places and then builds of picture from feint traces left by past generations.

Link to Ockham’s Razor on ‘Language and prehistory’.

Seeing what we want to see in our friends

Photo by Flickr user davy 49. Click for sourceThe Boston Globe has an interesting piece on how bad we are at judging our friends’ beliefs, opinions and values but why we tend to assume they match with our own.

The article covers various examples of this effect, but it mentions a finding from a shortly to be published study finding that the most socially connected people are typically the least accurate at judging their friends’ attitudes:

A similar effect arises when people are asked questions about right and wrong rather than politics. Recent research by Francis Flynn, a psychology professor at Stanford, and Scott Wiltermuth, a doctoral student there, looked at people in tight-knit workplace and graduate-school settings.

The researchers found that people assumed, often unquestioningly, that their responses to a series of ethical dilemmas were shared by the majority of their close colleagues. In reality they often were not. More strikingly, it was the more socially connected among the test subjects who were more likely to be wrong.

The article has a bit of a quirk, however, by supposedly explaining “Psychologists call this projection: in situations where there‚Äôs any ambiguity, people tend to simply project their feelings and thoughts onto others”.

Except, they don’t. The effect discussed by the article, where we over-estimate the extent to which people share our own mindset, is called the false consensus effect.

Projection is a unverified psychological defence mechanism where people supposedly misperceive psychological states in other people that, in reality, they have themselves but unconsciously want to hide from their conscious mind.

This was a concept originally developed by Sigmund Freud and systematised, along with a range of other ‘defences mechanisms’, by Anna Freud in her landmark book The Ego and the Mechanisms of Defence.

However, as with the majority of defences proposed in psychoanalysis, the basic process has been experimentally verified but the defence aspect (it’s the unconscious hiding the unthinkable from us) has not.

Link to Globe article ‘What you don‚Äôt know about your friends’.