Elvis in potato chip neuroscience

A new study just published in Cerebral Cortex on the neuroscience on how we see meaningful information in unpatterned visual scenes, seems a little fixated on Elvis.

The study concludes:

Future studies of the neural processing relevant to pareidolia and to meaning more generally may provide novel insights into how the organization of conceptual processing differs across individuals (see also Pizzagalli et al. 2001), thereby addressing the question of what neurocognitive architecture is necessary to see a potato chip not just as a tasty snack but as the embodiment of Elvis.

They even include a photo of the potato chip (proper spelling: crisp) that supposedly contains the image of The King which you can see above.

Unfortunately, I can’t see it, which I suspect means my brain has been ruined by the overuse of Fidonet as a child.
 

Link to Elvis obsessed neuroscience study.

The dreams and hallucinations of cloistered monks

French sleep scientists have studied a group of monks who have virtually no contact with the outside world and have taken a vow of silence.

The monks are of scientific interest owing to the tradition of having two sleep periods per night interrupted by a 2-3 hour prayer and psalm reading session.

The research group were interested in how the sleep-regulating circadian rhythm adjusts to this two sleep system.

It turns out that the automatic rising and falling of body temperature seemed to sync with the two-period sleep patterns but that the monks still had sleep problems (difficulty sleeping, waking, daytime sleepiness).

This suggests that they were not fully adjusted, even after decades of practice (the researchers report that “They all used several (two to six) alarm clocks”!)

Delightfully, the monks were also asked about their tendency to hallucinate and about the content of their dreams.

Although only ten individuals were studied, the answers are oddly appropriate for members of a silent, closed order.

Six monks had experienced mild (n = 4, ringing of the cell door at sleep offset or of the alarm clock, feeling that someone hit them briefly in the back, waking-up during the second sleep while mentally singing psalms) and moderate (n = 2, nightmarish, prolonged feeling of a demoniac presence at sleep onset after Matins) sleep-related hallucinations vs. one control (p = .06). Occasional nightmares were more frequent in monks than in controls.

All monks reported dreaming more often after than before the Matins [midnight prayers in between the two sleep periods], and to have conversations in their dreams. These conversations were rare (n = 3), hard to understand (n = 2), or frequent (n = 5). As for prayers, six monks were able to pray while dreaming, although it was rare, whereas two others dreamt of acts of piety, or imagined a disrupted liturgy, and finally two of them dreamt they were never monks.

 

Link to locked study. Not very charitable really.

A history of the mid-life crisis

Scientific American’s Bering in Mind has a fantastic article on how the concept of the mid-life crisis was invented and whether it has any evidence behind it beyond the occasional inadvisable pair of cycling shorts and sudden interest in cheesy sports cars.

It turns out that the idea of the ‘mid-life crisis’ is surprisingly new – first touted in 1965 – but was invented to refer to a crisis of creativity in geniuses – rather than a sudden urge to dye one’s greying hair.

There isn’t actually any evidence that middle age is more of a time of crisis than any other period of life, but the concept has stuck.

In the decades since Jacques and Levinson posited their mostly psychoanalytic ideas of the midlife crisis, a number of more empirically minded psychologists have attempted to validate it with actual data. And with little success. Epidemiological studies reveal that midlife is no more or less likely to be associated with career disillusionment, divorce, anxiety, alcoholism, depression or suicide than any other life stage; in fact, the incidence rates of many of these problems peak at other periods of the lifespan.

Adolescence isn’t exactly a walk in the park either—as a teen, I’d worry so much about the uncertainties of my future that I vividly recall envying the elderly their age, since for them, no such uncertainties remained. Actually, old people—at least Swiss old people—aren’t fans of the “storm and stress” of adolescence, either. Freund and Ritter asked their elderly respondents which stage of their lives they’d prefer to return to, if they could. Most said middle age.

From another point of view, of course, the concept could also be a socially convenient way of helping to curtail certain behaviours in men when their actions are no longer thought to be age appropriate.

That’s my theory and I’m sticking to it.
 

Link to Bering in Mind on the mid-life not so crisis.

Game not over

The Guardian covers a new study on how video games can persist in our perception as fleeting hallucinations in an effect labelled ‘game transfer phenomena’.

Unfortunately, the study has been published in an obscure journal which means I’ve not been able to read it in full, although the write-up quotes the lead researcher, Mark Griffiths:

“The academic literature goes back to 1993,” says Griffiths. “There was a case of a woman who had auditory hallucinations; she just couldn’t get the tune of the game she was playing out of her head – it was very intrusive. But what came out of our pilot research were lots of different experiences, some that were auditory, some visual and some were tactile. We had the example of a teacher who dropped his pen and immediately reached for a joypad button to retrieve it, as though he were in a game.

“Most of the experiences were neutral and often quite positive. We distinguished between what we call automatic GTP, which are almost like reflexes or classically conditioned responses, and those where players deliberately take elements out of the game and work them into their day-to-day routines.”

Needless to say, the tabloids got carried away and ran with ‘gamers losing touch with reality’-type stories although it sounds like the authors of the study were probably a little over-enthusiastic with their own descriptions.

Despite this, it sounds like an interesting study describing how conditioned responses and perceptual expectations learnt in video games might be get triggered in other situations.

I knew someone would get round to studying those weird thoughts about Tomb Raider at some point.
 

Link to Guardian article on ‘game transfer phenomena’

Your face in every flower

Billie Holiday sings about the phenomenon of seeing meaningful patterns in vague or non-connected visual information in her well-known track The Very Thought of You

Scientifically, these effects are known as pareidolia or apophenia.

However, the song notes that the perceptual biases are induced by love and, of course, ‘The Very Thought of You’.

I see your face in every flower
Your eyes in stars above
It’s just the thought of you,
The very thought of you, my love

For those tempted to connect these experience with Billie Holiday’s heavy drug use, which can cause these forms of misperception both through their immediate and long-term effects, it’s worth noting that the song was not written by her and was covered by a number of famous jazz artists, of which Holiday was perhaps the most famous.
 

Link to Holiday’s version of the song on YouTube.
Link to information on the song on Wikipedia.

Inner visions of seven dimensional space

I’ve just found an amazing 2002 article [pdf] from the American Mathematical Society about blind mathematicians.

I was surprised to learn that the majority work in geometry, supposedly the most ‘visual’ discipline, and fascinated to learn that they generally believe the experience of sight puts people at a disadvantage because it locks us into a perception-led view of space.

This can be a problem in geometry because it regularly works in problems that involve more than three dimensions or requires an understanding of objects from all ‘angles’ simultaneously.

Alexei Sossinski points out that it is not so suprising that many blind mathematicians work in geometry. The spatial ability of a sighted person is based on the brain analyzing a two-dimensional image, projected onto the retina, of the three-dimensional world, while the spatial ability of a blind person is based on the brain analyzing information obtained through the senses of touch and hearing. In both cases, the brain creates flexible methods of spatial representation based on information from the senses. Sossinski points out that studies of blind people who have regained their sight show that the ability to perceive certain fundamental topological structures, like how many holes something has, are probably inborn…

Sossinski also noted that sighted people sometimes have misconceptions about three-dimensional space because of the inadequate and misleading twodimensional projection of space onto the retina. “The blind person (via his other senses) has an undeformed, directly 3-dimensional intuition of space,” he said.

There is not any maths in the article but it is written for mathematicians so it contains lots of mysterious sentences like “Morin first exhibited a homotopy that carries out an eversion of the sphere in 1967”.

However, the article is also a fantastic history of blind mathematicians and has lots of quotes from current leaders in the field who explain who their supposed disability lets them better understand the maths of three and more dimensions.

Even for those without a maths background it’s an amazing insight into some remarkable people.
 

pdf of ‘The World of Blind Mathematicians’ (via @tiempoasm).

In search of invisible violence

NPR Radio covers an amazing inattentional blindness experiment that investigated how easy it is to miss a vicious beating in the street – after a policemen was convicted of ignoring an attack during a pursuit.

Inattentional blindness is the phenomenon where we don’t notice something seemingly obvious because we are paying attention to some other details.

It was most famously demonstrated by the ‘gorillas in our midst’ experiment where observers asked to count the number of passes between basketball players fail to notice a man in a monkey suit walking though the action.

Following a policeman’s conviction for supposedly ‘keeping quiet’ about a beating that he ran past while in pursuit of someone else, the same researchers wanted to know whether people asked to follow a jogger and monitor their behaviour would miss a simulated attack in the street.

Then about a minute in the run, slightly off to the side, [researchers] Chabris and Simons had three students stage a fight.

“We had two students beating up a third, punching him and kicking him and throwing him to the ground,” Chabris says.

The question was whether the students would see the fight, and under the conditions — nighttime — that most closely resembled [policemen] Conley’s experience. The numbers were shockingly low.

“Only about a third of the subjects reported seeing the fight that we had staged,” says Chabris.

It’s a brilliant piece of applied research, a great report with an amazing backstory, and the full text of the study is available online if you want more details.
 

Link to NPR report.
Link to full text of study.

Alice through the crooked glass

Not Exactly Rocket Science covers a fascinating study where participants felt they were the size of a doll or had expanded to giant proportions simply by using a headset, a camera and a bit of foot stroking.

In a typical experiment, a volunteer is being stroked while wearing a virtual reality headset. She’s lyng down and looking at her feet, but she doesn’t see them. Instead, the headset shows her the legs of a mannequin lying next to her.

As she watches, Bjorn van der Hoort, one of Ehrsson’s former interns, uses two rods to stroke her leg, and the leg of the mannequin, at the same time. This simple trick creates an overwhelming feeling that the mannequin’s legs are her own. If the legs belong to a Barbie, she feels like she’s the size of a doll. If the legs are huge, she feels like a 13-foot giant.

Van der Hoort performed this illusion on almost 200 people. Questionnaires revealed that they did indeed think of the mannequins as their own body parts. Familiar objects didn’t break the spell. When van der Hoort threatened the mannequins’ legs with a knife, the volunteers’ skin broke into a worried sweat, as if their real bodies were in danger. If he touched the doll’s legs with a pencil or his finger, the recruits thought they were being prodded by giant objects. Rather than feeling like dolls in a normal world, they felt like normal people in a giant world.

The researchers Not Exactly Rocket Science dub this the ‘Alice illusion’ after the changes in size experienced by the heroine in Alice in Wonderland.

These experiences can also be experienced as part of ‘Alice in Wonderland Syndrome’ which is usually associated with migraines or epilepsy (although they can occur without any brain disorder) likely due to them affecting the brain’s system for understanding the body’s relation to the surrounding space.

Temporary body-warping experiences are being created in the lab, however, in healthy normal folks and with surprisingly simple tricks.

The Not Exactly Rocket Science piece covers the latest delightful example.
 

Link to NERS on the ‘Alice illusion’.
Link to full text of scientific study.

Hearing the voices of colours

A spectacular case of psychosis, rather oddly described as ‘Methamphetamine Induced Synesthesia’, in a case report just published in The American Journal on Addictions.

The report concerns a 30-year-old gentleman from the Iranian city of Shiraz with a long-standing history of drug use who recently started smoking crystal:

Six months PTA [prior to admission] (October 2009), he started smoking methamphetamine once a day, and gradually increased the frequency to three times a day.

Two months PTA (January 2010), he developed symptoms of auditory and visual hallucinations (seeing fairies around him that talked to him and forced him to conduct aggressive behavior), self-injury, and suicidal attempts.

He developed odd behaviors such as boiling animal statues. He was hearing the voices of colors, which were in the carpet. Colors moved around and talked to each other about the patient. He also saw the heads of different kinds of animals gathering on a board, and they talked to him.

Finally, his mother brought him to the emergency room of Ebnecina Psychiatric Hospital in Shiraz.

The authors are using the term ‘synaesthesia‘ very liberally as it usually refers to an experience in one sense automatically triggering sensations in another – such as numbers having specific colours or tastes.

I’m not sure that ‘hearing the voices of colours’ necessarily qualifies as this could as much a delusion (a distorted belief) or a hallucination (that isn’t specifically tied to seeing the colours) rather than a genuine synaesthetic experience.

As the authors didn’t investigate any further and only have the gentleman’s word for his experiences, it’s a little hard to say.

However, it’s also worth noting that our concept of synaesthesia is no longer tied to ‘crossing of the senses’ as synaesthesia for increasingly meaningful things is being discovered.

Only recently, two confirmed and tested cases of ‘swimming-style synesthesia’ were reported in the journal Cortex where different colours were reliably triggered by the sight of people doing different swimming strokes.
 

Link to locked case report of ‘meth-induced synaesthesia’.

Poetic sensitivities

Perceptual psychologists have long been interested in limen – the threshold at which a stimulus becomes detectable. The following limen for the different senses, expressed in everyday terms rather than in terms of physical quantities, have a certain poetry to them. I got this information via email as a scan of an (unknown to me) textbook. I reproduce them here for your enjoyment:

Approximate absolute sensitivities, expressed in everyday terms:

Vision – A candle flame seen at 30 miles on a dark, clear night
Hearing – The tick of a watch under quiet conditions at 20 feet
Taste – One teaspoon of sugar in two gallons of water
Smell – One drop of perfume diffused into the entire volume of a three-room apartment
Touch – The wing of a bee falling on your cheek from a distance of one centimeter

Exact values vary between individuals and even from moment to moment with the same individual. Source: Galanter, E. (1962). Contemporary psychophysics. Holt, Rinehart, Winston.

A misperceptive critic

It’s not often that hallucinations indulge in media criticism, but this case of Charles Bonnet syndrome recently published in the journal Optometry is a delightful exception.

Everyone, it seems, is a critic, including perceptual distortions generated by, in this case, macular degeneration.

A 79-year-old man presented to the clinic with intermittent hallucinations of 6 months’ duration before this visit. He reported it occurred mostly in the evening, when he saw visions of road maps, Christmas wreaths, and faces that blocked his television screen. The faces were not of people known to him and often had elaborate hats or headdresses. When he rode in a car, he often saw houses that he knew were not truly present, and when he watched his favorite celebrity television dancing show, he saw multiple dancers rather than the 2 actually dancing. He was not disturbed or frightened by these hallucinations; he knew that they were not real. On the contrary, he felt they were amusing and reported they were often more entertaining than what was actually on television.

 

Link to PubMed entry for case report.
Link to DOI entry for same.

An illusory tribute

Richard Gregory was a much loved and hugely influential perceptual psychologist who passed away earlier this year.

Tom just alerted me to a wonderfully appropriate visual palindrome on his page of remembrance where his name reads perfectly well when either the ‘right way up’ on when ‘turned on its head’.

If you can’t see it or don’t believe it, go to the site and click the corner to see the image rotate.

A small but charming tribute to a man who used visual illusions to demystify perception.
 

Link to Richard Gregory tribute site.

The vision thing

The ever-interesting Oliver Sacks is interviewed on NPR’s Fresh Air where he discusses cases from his new book on the extremes of visual perception.

If you’re a fan of Sacks’ work, like me, this programme is an absolute treat as the conversation ranges from the science of misrecognition to his own quite recent experiences of visual distortion caused by a type of tumour, a melanoma, which developed in his eye.

Needless to say, there are plenty of interesting diversions on the way and some quite personal moments interwoven with discussion on themes from The Mind’s Eye – which is apparently out today.

The NPR website has an excerpt from the book if you want a taster and Sacks is also about to start a brief book tour hitting a few cities in the US.
 

Link to NPR interview with Oliver Sacks.

Sensory blending

The BBC’s science series Horizon just broadcast a fantastic edition on perception, illusions and how the senses combine with each other to the point of allowing us to integrate artificial new senses.

If you’ve got a healthy interest in psychology, the first half of the programme discusses several important but well-known effects like the rubber hand illusion, colour context changes and the McGurk effect, in light of what they reveal about the perceptual system.

Even if you’re familiar with these concepts, its worth watching as they’re so well presented, but its the second half of the programme which really stands out.

It has several brilliant examples of where people have begun to integrate new information into their sensory world: a blind mountain biker who has learnt to echolocate by making clicks with his mouth, helicopter pilots flying purely by spatial information conveyed to them by vibrations, a belt that allows the wearer to feel where magnetic north is at all times, and so on.

Some of the programme is clearly inspired by an excellent book on unusual sensory and perceptual integration that I’m reading at the moment called See What I’m Saying. It’s by psychologist Lawerence Rosenblum whose name you may recognise as we’ve featured some great pieces from his Sensory Superpowers blog before on Mind Hacks.

If you’re in the UK, you can use the BBC’s iPlayer website to watch the programme online, although rumour has it that there’s a working torrent over at the Pirate Bay.
 

Link to Horizon edition on BBC iPlayer.
Link to index page of programme on the Pirate Bay.

The ’68 comeback perceptual

Elvis makes a fleeting comeback, accompanied by a milk drinking chimp and some well-dressed mice, in the hallucinations of a patient with Parkinson’s disease who is described in a case study published in the Southern Medical Journal.

He had compulsive gambling behavior and multiple hallucinations (visual and auditory). Visual hallucinations were simple (shapes of shadows, animal shapes like a raccoon, a cat, and a dog) and complex (a woman sitting next to him in car, two well-dressed little mice running around, a chimpanzee drinking his milk standing next to his lunch table in a restaurant, and Elvis Presley standing outside his door in his white coat and white trousers without a guitar). Once while fishing, he saw his dead uncle standing next to him and his uncle said, “It’s not going to work.” Auditory hallucinations were also both simple (incomprehensible sounds) and complex (like his uncle talking to him, nonspecific symphony, and constant melody of chimes). All hallucinations were associated with intact insight and were nonthreatening.

Although the patient was diagnosed with Parkinson’s, which is known to trigger hallucinations, it is likely they were caused as much by the dopamine-boosting medication than by the effects of the disease itself.

The patient was taking quite a selection, reportedly prescribed “a combined regimen including carbidopa/levodopa 25/100 mg four times a day (q.i.d.); carbidopa/levodopa 50/200 mg sustained release three times a day (t.i.d.) with a half tablet in the morning; entacapone 200 mg 5 times a day; pramipexole 1mg q.i.d. with 1.5 mg at bedtime (h.s.); amantadine 100 mg twice a day (b.i.d.); and clonazepam 1mg h.s.”

Despite the perceptual distortions encouraged by the meds, the patient is quoted as saying “It is the best control I have had of my motor functions in a long time” and refused to discontinue any of the treatments.
 

Link to PubMed entry for case study (via @anibalmastobiza).