Newly Discovered

How blind people see

Blind people have revolutionised our view on vision. Biology text books still teach us that vision functions roughly as light hitting the eyes where special cells – rods and cones – turn it into neural signals. These travel to the back of the head, the visual cortex, for brain processing leading to something we experience as ‘seeing’. Some blind people have offered a completely new picture. They see without visual cortex. They see without rods or cones. They see without experiencing ‘seeing’.

Stevie Wonder

Wearing sunglasses might impair vision – in the blind.

The visual cortex lies right at the back of the head and it is – as the name suggests – responsible for vision. If you lose it, you can’t see anymore. This happened to a partially blind patient only known by his initials DB, a man brought to scientific fame in 1974 by an article in the journal Brain. In it, Lawrence Weiskrantz and colleagues describe how DB is asked to say whether he is presented an X or an O in an area of his visual field where he is blind. DB performs more than 80% correct despite only guessing.
What happened when DB was told about his visual abilities? ‘[H]e expressed surprise and insisted several times that he thought he was just “guessing.” [H]e was openly astonished’ (p. 721). This phenomenon has been termed blind-sight and it is very unlike normal vision. It is usually much worse but there are exceptions. For example, DB is actually better at ‘blind-seeing’ very faint lines compared to his intact visual field or normal people’s vision (Trevethan et al., 2007). This rules out all sorts of concerns about blindsight such as the suggestions that DB might be lying or falsely describing degraded vision as no vision at all. Unusually good performance can hardly be faked.
If blind-sight is possible without visual awareness or visual cortex, is it also possible without the eye’s rods and cones which turn light into neural signals? Interestingly, yes. Back in 1995 a team led by Charles Czeisler reported an unusual finding in three blind people whose eyes were damaged due to various diseases. When a bright light was shone in their face, they had less melatonin – a hormone related to the sleep cycle – in their blood. Probably a little known cell type – called intrinsically photosensitive retinal ganglion cells – turned light into neural signals and generally helps us synchronize our sleep-wake cycle with the day-night cycle.
A new article by Vandewalle and collagues shows what the potential of this newly discovered cell type is. They tested three blind people with eye damage and simply asked ‘is there a light or not?’ If a light was on for ten seconds, all three ‘guessed’ significantly differently from chance. This is remarkable as these people reported not seeing anything, electrical brain potentials following light flashes were curiously absent and their eyes were undoubtedly damaged.
When looked at together, these phenomena offer a new picture of the visual system. In the text-books you see a linear picture roughly like this:
light –> rods/cones in the eye –> visual cortex –> rest of brain
A new model is needed because a remarkable range of behaviours can still be performed when the middle elements of this account are removed. Instead of a linear picture we need a collection of parallel pathways all using light to influence the brain. The blind-sight pathway proves that circumventing the visual cortex is possible. People without rods/cones prove that not even these cells are needed to make use of light.
And now imagine that vision is one of the best-understood systems in the brain. If even vision can offer such surprises it is difficult to imagine what other brain systems hide below the surface. However, going ‘below the surface’ also comes with a considerable cost. Ask blind people what they see and they simply say ‘nothing’. Their residual abilities are hidden from them. It takes careful psychological testing to make them aware of what they can do.
So, how do blind people see? Some of them see without even knowing it.

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Czeisler CA, Shanahan TL, Klerman EB, Martens H, Brotman DJ, Emens JS, Klein T, & Rizzo JF 3rd (1995). Suppression of melatonin secretion in some blind patients by exposure to bright light. The New England journal of medicine, 332 (1), 6-11 PMID: 7990870

Trevethan CT, Sahraie A, & Weiskrantz L (2007). Can blindsight be superior to ‘sighted-sight’? Cognition, 103 (3), 491-501 PMID: 16764848

Vandewalle G, Collignon O, Hull JT, Daneault V, Albouy G, Lepore F, Phillips C, Doyon J, Czeisler CA, Dumont M, Lockley SW, & Carrier J (2013). Blue Light Stimulates Cognitive Brain Activity in Visually Blind Individuals. Journal of cognitive neuroscience PMID: 23859643

Weiskrantz L, Warrington EK, Sanders MD, & Marshall J (1974). Visual capacity in the hemianopic field following a restricted occipital ablation. Brain : a journal of neurology, 97 (4), 709-28 PMID: 4434190
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Figures:

1) By Antonio Cruz/ABr (Agência Brasil.) [CC-BY-3.0-br (http://creativecommons.org/licenses/by/3.0/br/deed.en)%5D, via Wikimedia Commons

ResearchBlogging.org

Music training boosts IQ

There are more and more brain training companies popping up which promise the same deal: improved intelligence. While there are doubts about their results, another sort of brain training has existed since the beginning of humanity: music. The evidence for its effectiveness is surprisingly strong.

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Music Lesson, 1936

Brain training in the 1930’s.

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Over the years, researchers have noticed that people who have taken music lessons are better on a wide range of seemingly unconnected tasks. Just look at this impressive list:

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Mathematics (across many different tasks; Vaughn, 2000)
Reading (understanding a written text; Corrigall & Trainor, 2011)
Simon task (quickly overcoming an easy, intuitive response in order to do a task right; Bialystok & DePape, 2009)
Digit Span (repeating a long list of random digits; Schellenberg, 2011)
Simple Reaction Time (pressing a button as soon as possible; Hughes & Franz, 2007)

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None of these tasks has anything to do with music classes. What is it that makes music lessons correlate with them? It could just be the socio-economic background: the more well-off or well-educated the parents the better the education of their children, including their music education (e.g., Corrigall et al., 2013). However, one can adjust for these differences with statistical tricks and the general picture is that the family background cannot fully explain the advantage musically trained children have on all sorts of tasks (e.g., Corrigall & Trainor, 2011; Schellenberg, 2011). If not family background, then what is underlying the music children advantage?

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Füssli: Liegende Nackte und Klavierspielerin

Brain training in the 18th century. I am referring to the left lady.

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Another contender is a common factor making some people good on all sorts of seemingly unrelated tasks and other people bad on nearly any task. This factor is called ‘g’ or general intelligence. An indeed, people who have enjoyed a musical education score higher on intelligence tests than people who did not. This has been shown across the globe: North America (Schellenberg, 2011), Europe (Roden et al., 2013), Asia (Ho et al., 2003†). The consistency across age groups is also impressive: 6-11 year olds (Schellenberg, 2006), 9-12 year olds (Schellenberg, 2011), 16-25 year-olds (Schellenberg, 2006). So, what holds these tasks and music education together is general intelligence. But that just opens up the next question: what causes this association between general intelligence and music lessons?
Music lessons cause higher intelligence
The most exciting possibility would be if music lessons actually caused higher intelligence. In order to make such a claim one needs to take a bunch of people and randomly assign them to either music lessons or some comparable activity. This random assignment ensures that any previous differences between music and non-music children will be equally distributed across groups. Random chance assignment at the beginning of the experiment ensures that any group differences at the end must be due to the whether children took music lessons during the experiment or not. Glenn Schellenberg did exactly this experiment with over 100 six-year-olds in Toronto (2004). Over a period of one year the children who learned to play the keyboard or to sing increased their IQ by 7 points. Children who were given drama lessons instead or simply no extra-curricular activity only increased by 4 points (likely because they started school in that year). A similar study which recently came out of Iran by Kaviani and colleagues (2013) replicates this finding. After only three months of group music lessons, the six-year-old music children increased their IQ by five points while children who were not assigned to music lessons only improved by one point. Across studies music lessons boost IQ.
It is worth reiterating how impressive this effect is. It has been found across three different music teaching approaches (standard keyboard lessons, Kodály voice lessons, Orff method). It has been replicated with two different sorts of intelligence tests (Wechsler and Stanford-Binet) as well as most of their subscales. It even came up despite the cultural differences between testing countries (Canada, Iran).
The take-home message couldn’t be any clearer. Music lessons are associated with intelligence not just because clever or well-off people take music lessons. A musical education itself makes you better across many tasks generally and on IQ tests specifically. No other ‘brain training’ has such a strong evidence base. Music is the best brain training we have.

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Eros and a youth

Ancient Greek brain training. I am referring to the gentleman on the right.

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Bialystok E, & Depape AM (2009). Musical expertise, bilingualism, and executive functioning. Journal of experimental psychology. Human perception and performance, 35 (2), 565-74 PMID: 19331508

Corrigall KA, Schellenberg EG, & Misura NM (2013). Music training, cognition, and personality. Frontiers in psychology, 4 PMID: 23641225

Corrigall, KA, & Trainor, LJ (2011). Associations Between Length of Music Training and Reading Skills in Children Music Perception: An Interdisciplinary Journal,, 29 (2), 147-155 DOI: 10.1525/mp.2011.29.2.147

Ho YC, Cheung MC, & Chan AS (2003). Music training improves verbal but not visual memory: cross-sectional and longitudinal explorations in children. Neuropsychology, 17 (3), 439-50 PMID: 12959510

Hughes CM, & Franz EA (2007). Experience-dependent effects in unimanual and bimanual reaction time tasks in musicians. Journal of motor behavior, 39 (1), 3-8 PMID: 17251166

Kaviani H, Mirbaha H, Pournaseh M, & Sagan O (2013). Can music lessons increase the performance of preschool children in IQ tests? Cognitive processing PMID: 23793255

Roden, I, Grube, D, Bongard, S, & Kreutz, G (2013). Does music training enhance working memory performance? Findings from a quasi-experimental longitudinal study Psychology of Music DOI: 10.1177/0305735612471239

Schellenberg EG (2004). Music lessons enhance IQ. Psychological science, 15 (8), 511-4 PMID: 15270994

Schellenberg, EG (2006). Long-Term Positive Associations Between Music Lessons and IQ Journal of Educational Psychology, 98 (2), 457-468 DOI: 10.1037/0022-0663.98.2.457

Schellenberg EG (2011). Examining the association between music lessons and intelligence. British journal of psychology, 102 (3), 283-302 PMID: 21751987

Vaughn, K (2000). Music and Mathematics: Modest Support for the Oft-Claimed Relationship Journal of Aesthetic Education,, 34 (3/4), 149-166 DOI: 10.2307/3333641

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Notes:

† Effect only marginally significant (0.05<p<0.1)

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images:

1) By Franklin D. Roosevelt Presidential Library and Museum [Public domain], via Wikimedia Commons

2) By Johann Heinrich Füssli: Liegende Nackte und Klavierspielerin, via Wikimedia Commons

3) attributed to the Penthesilea Painter, between circa 460 and circa 450 BC, via Wikimedia Commons
ResearchBlogging.org

Are some languages easier than others?

‘Long time no see’ is something I heard repeatedly in Britain even though it totally violates all the English grammar I learned at school. Clearly, Brits should correct this expression originating from Chinese Pidgin English rather than adopt it. The reason it entered common usage anyway is at the heart of why you might find English a lot easier to learn than the other British languages like Welsh or Gaelic. In a nutshell: when you learn English, it learns something from you as well.

Three years ago Gary Lupyan and Rick Dale published a (freely available) paper in which they looked at over 2,000 languages across the globe and quantified how difficult they are, e.g. by looking at their morphological complexity. Morphological complexity refers to how difficult it is to say a word in its correct form (‘went’ rather than ‘go-ed’). Its simpler counterpart is usually the use of more words to say the same thing (compare the sometimes irregular past like ‘gone’ with the always regular future ‘will go’). Using these principles Lupyan and Dale could show that languages which are spoken by more people tend to be simpler. Why?
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When languages grow big, they tend to get simple.
When languages grow big, they tend to get simple.
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Lupyan and Dale hypothesise that languages with more speakers also include more people who learned it when they were no longer children. As an adult, when you are not that good at learning a language anymore, you make yourself understood without speaking perfectly. Over time, these mistakes and simplifications are adopted by the language simply because difficult things never get learned by a new generation of learners. They are just forgotten. In some sense, the language learns what it can expect from its learners and what not. This drive towards simplification is a lot less strong when only expert language learners, i.e. children, are responsible for language transmission.
This year, a new study got published which directly looked at the proportion of adult second language learners in a given community rather than just assume it from the community size, as Lupyan and Dale did. Christian Bentz and Bodo Winter looked at case marking which is another pain to learn. In many languages around the world the Who does What to Whom pattern is not expressed through word order, like in English, but instead through case marking on words (similar to difference in roles marked by ‘he – him – his’). It turns out that on average languages which managed to retain a case system only have 16% of its speakers learn it after childhood, while the comparable number for no-case languages is 44%. Adults are bad at learning grammatical case systems, so it is forgotten if many adult learners speak the language.

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Melting Pot, English, Foreign Language, L2

His forebearers shaped English. As does he.

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So, yes, some languages are indeed easier. Learning them is a lot simpler. The reason being that language is not an invention of a single person. Instead, it is a communication tool shaped by the people using it. When Chinese people started using English they made many mistakes, some of them got adopted like ‘Long time no see’. Notice how it uses very little morphology, i.e. the words are all like you would find them in a dictionary, and no case at all (by that time English no longer had a full case system).
Follow the path of other adult language learners and you will meet with less resistance.
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Bentz C, & Winter B (2013). Languages with more second language learners tend to lose case Language Dynamics and Change, in press

Lupyan G, & Dale R (2010). Language structure is partly determined by social structure. PloS one, 5 (1) PMID: 20098492

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Figures:
1) adapted from Lupyan & Dale, 2010, p. 7
2) By Eneas De Troya from Mexico City, México (Melting Pot  Uploaded by russavia) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons

ResearchBlogging.org

The mysterious appeal of too loud music

Felix Baumgartner jumps

What would your next step have been?

At 39km above planet earth, would you have made Felix Baumgartner’s step off the platform? It was very dangerous, no doubt. But is this the reason why you wouldn’t have? People engage in many dangerous things. And I am not talking about skydiving. I mean the ordinary, every day kind of danger. Surely, some dangers can hardly be avoided, say road traffic (which is the leading cause of death for people in my age group). For others there is no obvious non-dangerous equivalent. But what if there was an activity with no practical value, which could easily be carried out without danger, but which nonetheless millions of people worldwide engage in? Listening to too loud music is such an activity.

Is this an exaggeration? Surely, if loud music was really dangerous, people would avoid it. Make no mistake, the scientific consensus clearly lays out the danger. Round about half the people exposed to music professionally show some hearing loss. Researchers have found worrying hearing impairments in classical musicians, rock/pop musicians, and music bar tenders. And the danger is not limited to professionals. The majority of rock concert attendees experience temporary auditory problems such as tinnitus or being hard of hearing. You are actually a daredevil when you listen to too loud music.
But this behaviour is not limited to your typical daredevil characters à la Felix Baumgartner. People flock to very loud concerts. Even toddlers prefer fast and loud music over slow and quiet music. Perhaps the clearest example for loudness’s paradoxical appeal is the band Sun 0))). Their music is without discernible rhythm, harmony or melody. Pure loudness. And still, they are successful. Hear for yourself:
The Sun 0))) concert is a good example of the mysterious attraction of too loud music but it may also offer clues for understanding why people subject themselves to it. Actually, not just this band’s concerts are too loud. Most concerts are. And so are night clubs. This is not the place to go to for a quiet night out. This is where you want energy, fun and excitement. It turns out that this is exactly what loud music is associated with. An Australian research team led by Roger Dean showed that the perceived arousal of music – whether a classical piece or Sun 0))) like noise – followed its loudness profile. Sweet melody or not, when people go out they want energetic music. And this music happens to be loud.

Beyond going out – why listen to too loud music when sitting still?

However, such an explanation can only be part of the answer. We have all seen the person on the bus with his headphones in or were annoyed by the colleague on the next desk with his music choice permeating the office through his headphones. These people are not out dancing. They look pretty low energy, if anything. And still they put their hearing at risk.
Neil Todd and Frederick Cody from the University of Manchester may offer a solution to the puzzle. They found that loud tones not only activate our sense of hearing but also our sense of balance. This happens because the nice distinction between these two modalities does not work for a structure in the ear called the saccule. It responds to head movements as well as rather low sounds. Through this structure muscles automatically react, explaining why deaf people’s muscles can nonetheless react to loud clicks whereas vestibularly impaired people’s can’t. Todd and Cody found the saccule to start reacting around the so called ‘rock’n’roll’-threshold of 105 dB. Is it just a coincidence that the beat of club music is typically in the tonal range and at the loudness level of the saccule? Could it be that the enjoyment of too loud music works through the same mechanism as the pleasure derived from baby swings, roller coasters and head banging? If so, the fun of skydiving and too loud music listening may have more in common than generally thought.
The inner ear: vestibular system (balance), auditory system (hearing) and the saccule (balance and hearing)

Yellow: Hearing. Brown: Balance. The saccule is neither.

The greatest mystery surrounding too loud music, though, are not people seeking it in quiet environments such as the bus or the office. The strangest thing is the appeal of too loud environments even when one plugs the ears. It has become more and more common to go to rock concerts with ear plugs. The obvious question is why people don’t just refrain from going to rock concerts all together and wait until concert organisers realise that they overdid it with the decibel levels.

Seeking intimacy through loudness

The final piece of the puzzle could be an idea exemplified in research done by Russo and colleagues from Ryerson University. They found that ordinary people could successfully distinguish piano, cello and trombone tones which they never heard but instead only felt on their backs. Even deaf people were able to do this. This research suggests that, yet again, the involvement of a second modality explains too loud music seeking. Hearing and vision are often grouped together because they reveal distant information. Smell, taste and touch, on the other hand, are intimate sensations only available when directly interacting with an object or person. If someone sees or hears your fiancé(e) you may not mind. But imagine if someone tried to touch or even taste him/her? There is something intimate about touch and perhaps we seek this intimacy when trying to immerse ourselves in music. Incidentally, this is also what was advertised as the novelty of Felix Baumgartner’s jump. For the first time someone can say what it felt like to break the sound barrier. Previously, people only knew what it sounded and looked like. Somehow, this was not enough. We are curious about what he will report because we attach so much importance to the immediacy of touch. For ‘touching’ music, we need loud music as our skin is a poor substitute for the sensitive ears. Through the sense of touch music can cease to be felt at a distance and, instead, become a much more personal full body experience.
Has the mystery been solved? It seems as if modern psychology offers a range of explanations for why a perfectly avoidable but harmful activity is pursued by millions of people. Loud music offers a level of energy, fun and intimacy which soft music just can’t match. If you listen to too loud music, you have more in common with daredevils like Baumgartner than you thought.
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Dean, R.T., Bailes, F., & Schubert, E. (2011). Acoustic intensity causes perceived changes in arousal levels in music: an experimental investigation. PloS one, 6 (4) PMID: 21533095

Lamont, A. (2003). Toddlers’ musical preferences: musical preference and musical memory in the early years. Annals of the New York Academy of Sciences, 999, 518-9 PMID: 14681176

Russo, F.A., Ammirante, P., & Fels, D.I. (2012). Vibrotactile discrimination of musical timbre. Journal of experimental psychology. Human perception and performance, 38 (4), 822-6 PMID: 22708743

Todd, N.P. McAngus, & Cody, F.W. (2000). Vestibular responses to loud dance music: A physiological basis of the ‘rock and roll threshold’? Journal of the Acoustical Society of America, 107 (1), 496-500 DOI: 10.1121/1.428317

Zhao, F., Manchaiah, VK., French, D., & Price, S.M. (2010). Music exposure and hearing disorders: an overview. International journal of audiology, 49 (1), 54-64 PMID: 20001447

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Images:

1) Photograph by: Felix Baumgartner, Twitter via the Vancouver Sun

2) The Vestibular System by Thomas Haslwanter via Wikimedia

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Risk vs. Opportunity across the life-span: Risky choices decline with age

Risk taking is somewhat enigmatic. On the one hand, risky choices in every day life – like drug abuse or drink driving – peak in adolescence. Never again in life is the threat to die from easily preventable causes as great. On the other hand, in laboratory experiments this risky choice peak in adolescence is absent. Instead, the readiness to take a gamble simply goes down the older you are. How can we explain this paradox? Perhaps, we should look at a tribe in the Amazon rain forest for answers.

A group of psychologists from Duke University led by David Paulsen looked at risk taking in the laboratory. Participants had the choice between either a guaranteed mediocre reward (say, four coins) or a gamble with a 50/50 chance of getting a low (e.g., two coins) or a high (e.g., six coins) reward. This is reminiscent of many choices we face in life: do you prefer ‘better safe than sorry’ or ‘high risk/high gain’? As you can see in their figure below, Paulsen and colleagues found adolescents to be greater risk seekers than adults. No matter how risky the gamble, adolescents choose it more often compared to adults.
risk taking across age groups

‘Better save than sorry’ vs. ‘High risk – high gain’

Paradoxically, children are even more risk prone than adolescents. Moreover, the riskier the gamble the greater the difference to older people. Paulsen and colleagues have trouble explaining why risky choices in the laboratory do not show an adolescent peak which so many real world behaviours show. Could it have to do with laboratory risk being clearly defined while real world risk is unknown? Is it peer influencing which drives real world riskiness but is absent in the laboratory? Is there more thrill in real risk taking while lab experiments are so boring that thrill seeking doesn’t come into play?
Perhaps. However, one explanation – which I, personally, found totally obvious – is not even discussed. Risky choices decline with age, true. But the opportunity to make risky choices increases with age. In Western society there are both explicit laws as well as implicit norms that prevent children from the opportunity to take risks. Take as an example alcohol abuse. Many people perceive a party without alcohol as mediocre. With alcohol, however, you take a gamble between doing something very regrettable (read, low reward) or having the time of your life (read, high reward).
Amazon rainforest

Where to test an alternative explanation: the real world.

How does this play out across the life span? It is inconceivable to serve beers at children’s birthday parties. However, the older you are the more you choose yourself what is served at your parties. When you are a young adolescent this increased risk taking opportunity meets a still high (but declining) risk taking readiness and you get wasted.
So, with age, risk taking goes down because the opportunities to take risks do not get more after a certain age while the readiness to take these risks still declines. The outcome would be a peak in real life risk taking at adolescence despite a linear decline in risky choices, i.e. exactly the observed pattern.
This interaction between risk taking opportunities and risk taking readiness is nicely illustrated by a native American tribe Dan Everett described in his very readable book Don’t Sleep, There are Snakes. The Pirahã do not have the Western notion of childhood. Everett writes that ‘children are just human beings in Pirahã society, as worthy of respect as any fully grown human adult. They are not seen as in need of coddling or special protections.’ (p.89). As a consequence, ‘there is no prohibition that applies to children that does not equally apply to adults and vice versa’ (p.97).
What does this mean for child alcohol consumption on the infrequent occasions when alcohol is available to the tribe? This episode gives the answer (p. 98):
Once a trader gave the tribe enough cachaça [alcohol] for everyone to get drunk. And that is what happened. Every man, woman and child in the village got falling-down wasted. Now, it doesn’t take much alcohol for Pirahãs to get drunk. But to see six-year-olds staggering with slurred speech was a novel experience for me.
So, perhaps this solves the paradox. The laboratory results were unrealistic by Western standards because they gave children a choice which they usually do not have: sure reward or gamble? Once you look at societies that do give children this choice you see that the laboratory results line up better with real life.
There is much to be learned by going beyond the laboratory and looking at the real world. The entire real world.

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Everett, D. (2008). Don’t sleep, there are snakes. London: Profile Books

Paulsen, D.J., Platt, M.L., Huettel, SA, & Brannon, E.M. (2012). From risk-seeking to risk-averse: the development of economic risk preference from childhood to adulthood. Frontiers in psychology, 3 PMID: 22973247

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images:

1) as found in Paulsen et al. (2012)

2) By Jorge.kike.medina (Own work) via Wikimedia Commons

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Improving Eye-Witness testimony by undoing false memories

Diana, Princess of Wales

Diana ten years before a certain false memory started spreading.

Do you remember August 31st, 15 years ago? Diana, Princess of Wales, died in a car crash in Paris along with her partner Dodi Fayed and others. Do you remember seeing the video of the crash? If so, you share that memory with 44% of the participants James Ost and colleagues recruited in 2002 in Britain.

This memory is false.
There is no such video. False memories are not a fringe problem, they are more widespread than one likes to think. Less than three months after the 9/11 attacks in 2001 in New York then US president George W. Bush claimed to have seen the first plane hit one of the Twin Towers. Afterwards, he claimed, he had entered a class room and had eventually been told about the second plane.
And I was sitting outside the classroom waiting to go in, and I saw an airplane hit the tower—the TV was obviously on, and I use[d] to fly myself, and I said, ‘There’s one terrible pilot.’
George W. Bush as quoted in Greenberg, 2004, p. 363
TV channels are usually not very good in predicting terrorist attacks and September 11th was no exception. The first plane hitting the World Trade Center was not shown on live television. The person who was preparing for war as a response to the attacks apparently had a false memory of them.
Marvin Anderson

Marvin Anderson was found guilty of rape due to a false memory. He spent 15 years in prison. Read his story: here.

If these examples are a chilling reminder of just how bad human memory is, consider that in 72% of wrongful convictions – which are later overturned by DNA evidence – eyewitness misidentification was a factor (Innocence Project). The unreliability of eye-witness memory is a widespread problem. New research coming out of Germany and Britain by Aileen Oeberst and Hartmut Blank (article in press) offers a way of overcoming false memories.
Their participants were shown a film of a car chase and heard a short summary of the action. The summary changed two small details but was otherwise correct. When asked in a subsequent questionnaire about the film these changed details were more likely to be misrembered than unchanged details which the summary of the film correctly represented. This finding is called the misinformation effect – a false memory is created through information received after a piece of information has been memorised. This is likely what happened to George W. Bush: the first plane hitting the World Trade Center was indeed shown on TV but only much later. A later viewing changed his memory of an earlier event.
After completing the questionnaire participants were told about the true purpose of the experiment, that details were changed between film and summary, and that they should fill in the questionnaire again. Now, the misinformation effect could no longer be found. Further experiments suggest that people no longer tried to remember a single detail (‘What happened to the car?’) but instead engaged in a more elaborate task of retrieving one or two memories from different sources (‘What happened to the car in the film rather than the summary?’).
Still, usually memories need to be retained for longer than 15 minutes. How do the findings change with a five week gap between implanting the false memory and trying to abolish it? The misinformation effect could still be reduced simply by telling people five weeks after getting film and summary that the two did not entirely match. Introducing a more elaborate questionnaire further improved memory. It leads to better performance because people are told in detail which manipulated details to consider carefully and it asks where they have a piece of information from.
The authors hesitantly suggest these changes to eye-witness testimony: 1) remind them that ‘they might have encountered additional information relevant to a witnessed event from various post-event sources (e.g. other witnesses, the media, etc.) and that some of this information may have been inconsistent with their own perceptions and memories.’ 2) ‘ask people not only for event details but also for (possibly contradictory) post-event information, and also […] explicitly ask for the source of every remembered detail.’ By making the remembering process more elaborate than a simple ‘Tell me what you know’ one can help people remember correctly.
The implications for what we mean by ‘memory’ are intriguing. Depending on what task you set people, they remember things differently. Apparently, constructing a memory from bits and pieces scattered in the mind is highly dependent on the situation we are in. The reason why we are not aware of this is because the brain plays a trick on us: a memory always feels somehow real, genuine, and personal. Even that of Diana’s crash video.
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Greenberg, D.L. (2004). President Bush’s False ‘Flashbulb’ Memory of 9/11/01 Applied Cognitive Psychology, 18, 363-370 DOI: 10.1002/acp.1016

Oeberst, A., & Blank, H. (2012). Undoing suggestive influence on memory: The reversibility of the eyewitness misinformation effect Cognition DOI: 10.1016/j.cognition.2012.07.009

Ost, J., Vrij, A., Costall, A., & Bull, R. (2002). Crashing Memories and Reality Monitoring: Distinguishing between Perceptions, Imaginations and ‘False Memories’ Applied Cognitive Psychology, 16, 125-134 DOI: 10.1002/acp.779

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Images:

1) By Rick (Princess Diana, Bristol 1987) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons

2) via Innocence Project: http://www.innocenceproject.org/Content/Marvin_Anderson.php

ResearchBlogging.org

Mimicking infants rather than adults – how infants choose their models.

The infant academy by Joshua Reynolds

The infant academy by Joshua Reynolds

Parents are often afraid of what happens once their children hit puberty and stop emulating their parents. Recent research suggests that this fear should start a lot earlier: in infancy. Of course, infants need their parents to learn but they need other infants when it comes to imitating things they already know.

Two recent articles by Zmyj from the Ruhr university in Bochum and colleagues present convincing evidence to back up infants’ occasional preference for peer imitation. First, when presented with videos of people playing with novel toys in familiar ways, fourteen month olds imitate a peer more than an older child aged 3.5 or an adult. Secondly, when presented with similar videos of people performing simple gestures (banging on the table, waving, clapping…) they again imitated a 14 month old more often than an older child or an adult.
These results are curious because at this age infants typically spend more time with their parents than with other infants. Furthermore, as far as imitation is used to learn new things the infants should prefer adults who are more knowledgeable. When it comes to novel actions the learning objective does actually prevail. Switching on a new lamp with the head or building a rattle is more likely to be copied from an adult model rather than an infant model (Seehagen & Herbert, 2011; Zmyj, Daum et al., 2012).
When it comes to infant-infant imitation, it may come out of a desire to belong to the same social group as the model, a sort of precursor to facebook’s Like button. Infant-adult imitation, on the other hand, may be more like a student-teacher relationship.
This set of studies powerfully shows that age matters to infants. They copy the behaviour of others depending on how old the model is and what sort of behaviour is shown. This sort of reasoning was long thought to be beyond 1 ½ year olds. Recent evidence, however, shows that infants play a more active part in choosing who to emulate than you may think.
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Seehagen, S.,, & Herbert, J.S. (2011). Infant Imitation From Televised Peer and Adult Models Infancy, 16 (2), 113-136 DOI: 10.1111/j.1532-7078.2010.00045.x

Zmyj, N., Aschersleben, G., Prinz, W., & Daum, M. (2012). The Peer Model Advantage in Infants’ Imitation of Familiar Gestures Performed by Differently Aged Models. Frontiers in psychology, 3 PMID: 22833732

Zmyj, N., Daum, M.M.,, Prinz, W.,, Nielsen, M.,, & Aschersleben, G. (2012). Fourteen-month-olds’ imitation of differently aged models Infant and Child Developement, 21 (3), 250-266 DOI: 10.1002/icd.750

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image: By Joshua Reynolds (jundurrahman.files.wordpress.com) [Public domain], via Wikimedia Commons
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Is it safe to talk while driving? – Partly depends on what you talk about.

World Health Organization reports about road safety are mind boggling: about 1.2 million people die on the world’s roads every year. For people of my age (15 to 29 year olds) it is the leading cause of death.

A rather recent addition to laws designed to reduce these numbers was the adoption of compulsory hands-free devices for mobile phones. Their safety value is easy to understand. When you look at a mobile phone display you cannot simultaneously look at the road. Similarly, using your hands for typing and using them for steering are at least partly incompatible actions.
mobile phone use while driving

How mobile phone use impairs sight and hands.

From a psychological point of view the current law tries to ensure that visual input channels (eyes) and motor output channels (hands) remain undisturbed. But what about the brain areas which control these channels?
This is the question recently investigated by Bergen from UC San Diego and colleagues. They put undergraduates in a driving simulator giving the impression of a motorway with steady traffic and a car in front of the driver breaking from time to time. Simultaneously, the driver had to judge simple true/false statements from the motor domain (e.g., “To open a jar, you turn the lid counterclockwise.”), the visual domain (e.g., “The letters on a stop sign are white.”), or the abstract domain (e.g., “The capital of North Dakota is Bismarck.”). As a baseline condition, people were just asked to say “true” or “false” several times.
Why choose such questions? There is both behavioural and brain-imaging evidence that language comprehension involves the simulation of what was said. This set of findings is often summarised as embodied cognition and its take-home message is something like this: in order to understand it, you mentally do it. For example, to answer a motor question, you use your brain areas doing motor control and make them simulate what it would be like to open a jar. Based on the outcome of this simulation you answer the question.
So, will visual or motor questions affect driving differently than abstract questions because the former engage the same brain areas as those needed for driving while the latter don’t? The alternative would be that asking anything distracts because general attention gets pulled away from driving.
The results go both ways. First, one measure was affected by the true/false statements but not by which kinds: quickly breaking when the car in front breaks. The time it took to do so was longer if any sort of question was asked compared to baseline. This suggests that domain general mechanisms were interfered with through language, e.g., attention.
Liza minelli driving

Was she a safe driver? May depend on whether she talked and if so about what.

Second, one measure was affected by what kind of statements had to be judged:generally holding a safe distance to other cars. This distance was greater if visual questions were asked compared to abstract questions and compared to baseline. A similar, albeit not as clear, pattern emerged for motor questions. It looks as if participants were so distracted by these kinds of questions that they fell behind their optimal driving distance. This suggests that a task such as keeping a safe driving distance which requires visual working memory (compare ideal distance to actual distance) and corrective motor responses (bring ideal and actual distances closer together) is influenced by language comprehension through mental simulation.
On the one hand, the scientific implications are quite straight forward. Bergen and colleague’s results suggest that those low level perception and action control areas which are needed for quick reactions are not what embodied cognition is about. Instead it seems like embodied cognition happens in higher perceptual and motor planning areas. Furthermore, the whole embodied cognition idea gets quite a boost from a conceptual replication under relatively realistic conditions.
On the other hand, the practical implications are somewhat controversial. Because talking in general impairs quick reactions by the driver, even hands-free devices pose a risk. This danger is compounded by talking about abstract topics since the driving distance is reduced compared to visual topics.
The authors refrain from saying that any sort of conversation should be prohibited. Passengers share perceptual experiences with the driver and can adjust their conversations to the dangerousness of the situation. Mobile phone contacts can’t do this. But what if you want to be really really safe? Well, cut your own risk of dying and take public transport. There you can chat and cut your death risk by 90% (bus) or even 95% (train or flight) compared to car travel (EU numbers).
London bus

A safe way to travel.

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Bergen, B., Medeiros-Ward, N., Wheeler, K., Drews, F., & Strayer, D. (2012). The Crosstalk Hypothesis: Why Language Interferes With Driving. Journal of experimental psychology. General PMID: 22612769

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images:

1) By Ed Brown as Edbrown05 (Own work) [CC-BY-SA-2.5 (www.creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons

2) By Alan Light (Flickr) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons

3) By Original author was User:Kameragrl at Wikitravel Shared, transferred to Commons by User:Oxyman (http://wikitravel.org/shared/Image:London_Bus.jpg) [CC-BY-SA-1.0 (http://creativecommons.org/licenses/by-sa/1.0)%5D, via Wikimedia Commons

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Psychological principles as guidelines for effective PowerPoint presentations

A presentation using Powerpoint. Corporate pre...

How good can it get?

You probably wouldn’t have much difficulty if I asked you to imagine a bad PowerPoint presentation. Nowadays one sits through so many of them that confusing, boring or annoying slide shows are sometimes perceived as the norm rather than the exception. A research team from the universities of Stanford, Amsterdam and Harvard headed by Stephen Kosslyn explains how to do it better. In order to reap off the benefits and avoid the pitfalls of visual aids, presenters should think about avoiding weaknesses of human information processing and play on the strengths of such processing.

 
Kosslyn and colleagues see the task of the audience viewing a PowerPoint presentation as composed of three steps: a) information needs to be acquired, b) information needs to be processed, c) information needs to be connected to knowledge. They derive eight principles that a presenter should follow based on this analysis.
 .
a) encoding, i.e. acquiring information and turning it into a usable form
1) Discriminability: make it easy for the audience to discriminate colours, letters, sizes, line orientations etc.
2) Perceptual Organisation: group things effectively in the visual space you’ve got
3) Salience: use large perceptual differences to guide attention to what is IMPORTANT
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b) working memory: holding information in mind in order to integrate it online
4) Limited Capacity: understanding breaks down once too much information has to be retained
5) Informative Change: when something perceptual changes, this change has to mean something
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c) accessing long term memory: connect the new information with knowledge in order to extract meaning.
6) Appropriate Knowledge: avoid as much novel concepts, jargon or symbols as possible
7) Compatibility: the meaning of a message needs to be compatible with its form
8) Relevance: provide neither too much nor too little information
.
These principles may look very obvious but they are frequently violated. From an internet sample of slide shows it became clear that on average a PowerPoint presentation violates six principles at least once. Some principles were nearly always ignored: 1) discriminability, 4) limited capacity, 5) informative change.
Now, one may argue that these principles are simply guidelines that lay people are unaware of. No wonder they get violated. However, in a subsequent laboratory experiment participants were 80% correct in choosing a non-violating slide and rejecting a bad one. Moreover, when asked to say why one slide was better, more than 80% of the correct choices were appropriately justified.
So, this study is about what one already knows but still ignores when designing a slide show. The authors use a backdrop of psychological literature to predict what sorts of principles should guide PowerPoint presentations. What they, unfortunately, fail to do is to empirically test each principle’s impact on presentation understanding and memory. As such, this study simply presents a set of guidelines, says that presentations usually violate guidelines and that most people are aware of these violations. How important the guidelines are to begin with remains unclear.
The main take-home message is that the more work a presenter does for his/her audience, the more the audience can tune into the content of the presentation. For my part I am always guided by a more memorable principle:
Look around the room and search for the newbie or the bored one or the least intelligent listener. S/he is your target audience.
For a complete list of useful rules which may help you and especially your audience, see the appendix of Kosslyn and colleagues’ paper.
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Kosslyn S.M., Kievit R.A., Russell A.G., & Shephard J.M. (2012). PowerPoint® Presentation Flaws and Failures: A Psychological Analysis Front. Psychology, 3 DOI: 10.3389/fpsyg.2012.00230

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Images:

1) Photo credit: Wikipedia

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