Glimpsed at last - the life of neuropsychology's most important patient

Leborgne's brain

Monsieur Leborgne, nicknamed Tan Tan, for that was the only syllable he could utter (save for a swear word or two), died in the care of the neurologist Paul Broca in Paris on April 17, 1861. Arguably the most important case in the history of neuropsychology, Leborgne's death coincided with a debate raging in scholarly circles about the location of language function in the brain. When Broca autopsied Leborgne's brain, he observed a malformation on the left frontal lobe - "Broca's area" - and concluded this was the site of speech production, a moment that the historian Stanley Finger has described as a "key turning point in the history of the brain sciences".

Broca was far from being the first person to propose that speech function is located in the frontal lobes, but crucially, the evidence from Leborgne helped him persuade the academic community. For centuries experts had believed mental functions were located in the brain's hollows; that the cortex ("husk" in Latin) was little more than a rind of tissue and blood vessels. Today, problems producing language are still termed Broca's aphasia in recognition of Broca's landmark contribution, although Broca in fact named Leborgne's problems aphémie (meaning “without speech”). The Greek term “aphasia” (also meaning “speechlessness”), adopted by medicine, was coined in Broca's day by the physician Armand Trousseau.

Far more is known about Gage's life

In terms of the historical record, Leborgne is like a mirror opposite of Phineas Gage - another of neuropsychology's legendary cases. The story of Gage's life and infamous accident, in which a tamping iron shot through his brain, has been researched in-depth, inspiring books, poems, YouTube skits and snowmen makers along the way. Yet relatively little is known about the brain damage Gage suffered because no autopsy was performed when he died and his brain was never preserved (that hasn't stopped scientists from attempting to simulate the likely damage).

In contrast, Broca was careful to save Leborgne's brain for posterity. He decided against a full dissection, performing a surface examination only. Today the preserved organ is housed at the Musée Dupuytren museum in Paris, where Broca placed it. The brain has been scanned numerous times using modern methods (e.g. PDF), allowing detailed analysis of the location and nature of any lesions. We now know that the frontal lobe damage to Leborgne's brain was more extensive and deeper than Broca had realised based on his superficial examinations. But, contra the situation with Gage, while we are well-informed about Leborgne's brain, before now his identity and life story have remained largely mysterious. Broca's medical notes revealed little.

Thankfully, in a new paper, Cezary Domanski at Maria Curie-Sklodowska University in Poland has used archive registers in France to uncover hitherto unknown detailed biographical information about Monsieur Leborgne. Born in Moret-sur-Loing - the picturesque town that inspired Monet and other impressionists - "Tan's" full name was Louis Victor Leborgne. He was the son of Pierre Christophe Leborgne, a school teacher, and Margueritte Savard. He had three older siblings, Lucille, Pierre and Anne, and two younger siblings, Arsene and Louise.

An epileptic since his youth, it was Leborgne's loss of speech that led to him being hospitalised at age 30. Unmarried, he ended up spending the remaining 21 years of his life in hospital. Before this incapacitation through illness, Domanski tells us Leborgne was a "formier" in Paris, a kind of skilled craftsman who made the wooden forms used by shoemakers in their work.  Together with the information on Leborgne's family, this news corrects at least one historical myth. The oft-told idea that Leborgne "was an uneducated illiterate from the lower social class should once and for all be deemed erroneous," writes Domanski.

Based on his inquiries, the Polish historian offers an intriguing speculation - given that Leborgne's birthplace of Moret was home to several tanneries, Domanski wonders if his repeated utterance of Tan was somehow connected to childhood memories of the pretty town.

"One thing remains certain," Domanski concludes, "The memory of the disease and cause of death of 'Monsieur Leborgne' proved far more enduring than the story of his life, which was deemed irrelevant even when the patient was still alive. It is time for Louis Victor Leborgne to regain his identity ...".

In 2009, out of the blue, a photograph was discovered of Phineas Gage. I wonder if we will ever look upon an image of Leborgne?

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Domanski CW (2013). Mysterious "Monsieur Leborgne": The Mystery of the Famous Patient in the History of Neuropsychology is Explained. Journal of the history of the neurosciences, 22 (1), 47-52 PMID: 23323531

--Further reading-- 
500 Francs Says Language Is Housed in the Frontal Lobes!
Speaking without Broca's area
Broca’s area: Nomenclature, anatomy, typology and asymmetry

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

Introverts use more concrete language than extraverts

Your personality is revealed in the way you speak, according to new research. Introverts tend to use more concrete words and are more precise, in contrast to extraverts, whose words are more abstract and vague.

Many previous studies have looked at the links between personality and language, but usually this has been about the content of what different personalities choose to talk about. It's been shown, for example, that extraverts are more likely to talk about family and friends, and to use words like "drinks" and "dancing", which makes intuitive sense given that people matching that personality type are expected to spend more time socialising.

Camiel Beukeboom and his co-workers took a different tack, asking 40 employees (19 women; average age 34 years) at a large company in Amsterdam to describe out loud the same five photos depicting ambiguous social situations. Participants were told that "there are no right or wrong answers" and given as long as they wanted to describe each photo. Their answers were recorded and transcribed for later coding. Three days later, the participants also completed a personality questionnaire.

Participants who scored higher in extraversion tended to describe the photos in terms that were rated by an independent coder as more abstract. For example, they used more "state verbs" (e.g. Jack loves Sue) and adjectives, and they admitted to engaging in more interpretation - describing things that were not directly visible in the pictures. On the other hand, the higher a person scored in introversion, the more concrete and precise their speech tended to be, including more use of articles (i.e. "a", "the"), more mentions of numbers and specific people, and making more distinctions (i.e. use of words like "but" and "except").

The differences make sense in terms of what we know about social behaviour and the introvert-extravert personality dimension, with the introverted linguistic style being more cautious, and the extravert style being more casual and vague.

The researchers said their results have far-reaching implications because we know based on past research that the contrasting speech styles are interpreted differently. For instance, they said behaviour described in abstract terms, in the style of an extravert (e.g. Camiel is unfriendly), is usually attributed to personality, as opposed to the situation, and therefore interpreted as enduring, more likely to occur again, yet harder to verify. By contrast, behaviour described in more concrete terms, in the characteristic style of an introvert (e.g. Camiel yells at Martin), tends to be interpreted as situation-specific, and as more believable.

"Thus an introvert's linguistic style would induce more situational attributions and a higher perception of trustworthiness than an extravert's style," the researchers said.

The findings also complement past research showing how conversations between two introverts usually involve discussing one topic in more depth whereas two extraverts dance around more topics in less detail.

"By talking at different levels of abstraction, extraverts and introverts report information differently," the researchers concluded, "and induce different recipient inferences, memories, and subsequent representations of the information exchanged."

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Beukeboom, C., Tanis, M., and Vermeulen, I. (2012). The Language of Extraversion: Extraverted People Talk More Abstractly, Introverts Are More Concrete. Journal of Language and Social Psychology DOI: 10.1177/0261927X12460844

--Further reading--
The links between bloggers' personalities and their use of words.

Post written by Christian Jarrett for the BPS Research Digest.

We think more rationally in a foreign language

One of psychology's major contributions has been to document the myriad ways our thinking is sent haywire by a series of biases. Investigations into the ways and means to combat these biases have lagged behind, but that's starting to change. Now a team of researchers at the University of Chicago has reported that people are immune to two key biases when they think in their second, less familiar language.

The first half of the investigation involved well-established framing effects. Participants were told that 600,000 people were at risk from a deadly disease. They were then presented with the same decision framed differently. In one condition, they chose between a medicine (A) that would definitely save 200,000 lives versus another (B) that had a 33.3 per cent chance of saving 600,000 people and a 66.6 per cent chance of saving no one. In another condition, the participants chose between a medicine (A) that meant 400,000 people will die versus another (B) that had a 33.3 per cent chance that no one will die and 66.6 per cent that 600,000 will die.

The gamble in each condition is effectively the same, but numerous studies have shown that people are systematically influenced by the way the choice is framed. In the first condition, the gains of A are made salient, and people tend to prefer the certainty of that option. In the second condition, A's losses are made more salient and people prefer to take the risk of medicine B.

Boaz Keysar and his team showed that dozens of native English speakers showed the typical framing effect when they completed the task in English, but not when they completed the task in their second, classroom-learned language of Japanese. It was a similar story with native Korean speakers - they showed no framing effect when they completed the task in English. And it was the same again with native French speakers when they completed the task in their second language of English. A follow-up study added a third inferior option to the decision task and confirmed that participants weren't just choosing at random when taking part in their second language.

The second half of the investigation focused on loss aversion. We're typically affected emotionally twice as much by losses as we are affected positively by gains of equivalent size. So, presented with a series of bets on the toss of a coin, with the chance to win $1.50 or lose $1, people will tend to shy away from the bet even though the cold logic of probability theory suggests they'll win out in the long run. Keysar and his colleagues gave native English speakers $15 in cash to play 15 rounds of this game, with the chance to keep the balance of their wins and losses at the end. The key finding was that the players were far more willing to gamble when they played the game in their second language of Spanish.

The researchers aren't entirely sure why speaking in a less familiar tongue makes people more "rational", in the sense of not being affected by framing effects or loss aversion. But they think it may have to do with creating psychological distance, encouraging systematic rather than automatic thinking, and with reducing the emotional impact of decisions. This would certainly fit with past research that's shown the emotional impact of swear words, expressions of love and adverts is diminished when they're presented in a less familiar language.

The findings have important implications for international internet research - psychological measures could vary according to whether participants are answering in their mother tongue or in a second language learned later in life. More generally, the researchers said the findings could have ramifications for real life. "People who routinely make decisions in a foreign language rather than their native tongue might be less biased in their savings, investment, and retirement decisions, as a result of reduced myopic loss aversion," they concluded. "Over a long time horizon, this might very well be beneficial."
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Boaz Keysar,, Sayuri L. Hayakawa, and Sun Gyu An (2012). The Foreign-Language Effect, Thinking in a Foreign Tongue Reduces Decision Biases. Psychological Science DOI: 1177/0956797611432178

Post written by Christian Jarrett for the BPS Research Digest.

There are two kinds of bilingual brain

How do bilinguals avoid confusing the two languages they speak? One idea is that there's a kind of language switch that inhibits one tongue whilst the other is in use. A new investigation by researchers in Finland suggests that such a system probably applies to what they call "Dominant Bilinguals", who learned a mother tongue first before acquiring a second language later in life. But they don't think such a system exists for what they call "Balanced Bilinguals", who grew up speaking two languages. In the brains of Balanced Bilinguals, the researchers say, the two languages seem to be fully intertwined.

Maija Peltola and her colleagues used an ingenious way to investigate bilingual brains, based around the way vowel sounds are perceived in Swedish and Finnish. Just as the boundaries between colours are arbitrary (the spectrum of light is continuous, yet we talk about colours as discrete categories), the boundaries between vowel sounds are too, and these boundaries vary from one language to another.

Peltola's team focused on two sounds that are categorised as two different vowels in Finnish, but which are seen as the same vowel in Swedish. The main task of their bilingual participants was to listen to pairs of sounds and judge whether they were the same vowel sound or if one was different from the other. Crucially, the participants performed this test twice, a week apart: once in Swedish and once in Finnish. Their brains were scanned with EEG throughout.

Two types of participant took part: one group of 12 Balanced Bilinguals had starting acquiring Finnish and Swedish simultaneously from birth at home; the other group of Dominant Bilinguals were Finnish university students studying Swedish - they'd been raised with Finnish as their mother tongue, then started learning Swedish at age 12 and had developed an extremely high proficiency in the language.

An initial finding was that the Balanced Bilinguals were slower and less systematic in where they located the Finnish vowel boundaries, suggesting that they suffered interference from the Swedish interpretation of sounds. This was supported by the EEG recordings. Confronted with two different vowel sounds in Finnish, an early spike of negative electrical activity from the brain (known as the mismatch negativity; MMN), which is associated with the perception of a different vowel category, was slower to peak in the brains of the Balanced Bilinguals.

Moreover, the amplitude of this MMN, in response to the same pair of sounds, varied dramatically in the Dominant Bilinguals, depending on whether they were performing the task in Swedish or Finnish. This suggests their brains were treating the same sounds differently depending on which language "mode" they were in. By contrast, for Balanced Bilinguals, this early spike of electrical activity to the vowel sounds was the same in both language contexts. This suggests that early on ("pre-attentively" was the researchers' term), their brains were treating the sounds the same, regardless of which language they were supposed to be speaking.

According to Peltola and her colleagues, all this suggests that there are two ways for bilingualism to operate in the brain. Dominant Bilinguals seem to be able to "switch off" irrelevant sounds in accordance with the language they're currently using, even if those sounds are recognised by their more dominant, mother tongue. "This implies the existence of two functionally separable phonological systems," the researchers said. In contrast, Balanced Bilinguals don't keep their two languages apart. Their language systems "are so intertwined," the researchers said, "that exemplars from both inventories are automatically activated regardless of language context."

Taken altogether, the researchers said this shows that "Balanced Bilinguals have one uniform speech sound system for the processing of their two maternal languages [mother tongues], whereas Dominant Bilinguals have two separate phonological inventories." A question for future research is whether Dominant Bilinguals keep their two systems separate via inhibitory processes or even via distinct cortical areas supporting the two languages.

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Peltola, M., Tamminen, H., Toivonen, H., Kujala, T., and Näätänen, R. (2012). Different kinds of bilinguals – Different kinds of brains: The neural organisation of two languages in one brain. Brain and Language, 121 (3), 261-266 DOI: 10.1016/j.bandl.2012.03.007

Further reading: Tongue-tied: When bilinguals switch languages involuntarily.
Change your personality, learn a new language.
Second language changes the way bilinguals read in their native tongue.

Post written by Christian Jarrett for the BPS Research Digest.

What do kids know about wisdom?

A wise person once said that intelligence is knowing that tomatoes are a fruit; wisdom is knowing not to put them in fruit salad. You might have a different idea about what constitutes wisdom. When adults are asked what wisdom is, their answers tend to fall into five recurring categories: a cognitive component based around intelligence; insight (the ability to find original solutions); a reflective attitude; concern for others; and real-world problem-solving skills.

But before now, no-one has investigated what children understand by wisdom and how this changes as they get older. Judith Glück and her colleagues have surveyed 461 children (aged six to ten years) at two schools in rural Austria. Ideas about wisdom are obviously prone to cultural variation, but these new findings provide us with some useful initial clues as to how children think about this slippery concept.

The children were asked a mixture of closed and open-ended questions. For example, they were asked to write a few lines on what a wise person is like and they also read a list of 23 adjectives, indicating which ones applied to a typical wise person.

Overall, just over 70 per cent of the kids said they knew the term "wisdom", rising from 43 per cent of the youngest to 92 per cent of the oldest year group. The majority of the children said they'd encountered the term in books, in conversations at home and in TV shows or films.

In contrast to adults, these children tended to focus mostly on the outward aspects of wisdom - especially cleverness (fluid intelligence, rather than concrete knowledge), and concern for others. There was an association with age here - all the children tended to mention the social aspect of wisdom, but a far greater proportion of the older than younger children mentioned the intelligent aspect. Older children were also more likely to link wisdom with older-age. Unfortunately the paper provides few examples of the kind of open-ended answers given by the children, despite the teasing title of the article.

More internal or abstract aspects of wisdom were apparently rarely mentioned by the children, including: having a reflective attitude, solving problems with original insight; having real-world problem-solving skills; and perspective taking. "Presumably such aspects are not yet part of the spontaneous 'psychological repertoire' of children at this age," the researchers said.

Unsurprisingly, given that it prompted them, the children's understanding of wisdom was more precocious when using the adjective list, with the children tending to tick items like "pensive" and "sensitive", as well as terms like "friendly" and "clever", which they'd mentioned in their open-ended answers.

Asked to name a wise person, the children were extremely generous, most often mentioning a grand-parent or a parent. Religious figures or figures from the media were rarely mentioned. The children showed a gender bias in their nominations, with boys being more likely to name male figures and girls being more likely to name females. Boys were also more likely to identify wise people as "astute" and girls to identify them as "beautiful" - perhaps a consequence of gender-stereotypes in the kind of media they were exposed to.

"We conclude from our findings that a basic understanding of the concept of wisdom is developed in and even before the elementary school years," the researchers said. "However, especially the more complex aspects of the concept get much more differentiated in subsequent development."

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Glück, J., Bischof, B., and Siebenhüner, L. (2012). “Knows what is good and bad”, “Can teach you things”, “Does lots of crosswords”: Children's knowledge about wisdom. European Journal of Developmental Psychology, 1-18 DOI: 10.1080/17405629.2011.631376

Post written by Christian Jarrett for the BPS Research Digest.

Babies can tell whether you made a mistake or not from the tone of your voice

For decades, psychologists have been trying to find out when and how children develop the ability to step outside of themselves and understand other people's minds. Piaget, the great Swiss developmental psychologist, had children study a model of the mountains around Geneva and describe what the scene would look like from another perspective. His results led him to conclude that children younger than about seven are stuck with an ego-centric perspective. Since then, with ever more ingenious techniques, psychologists have demonstrated that even infants as young as one year old have a rudimentary sense that other people have a mind, perspective and intentions of their own. Betty Repacholi and Alison Gopnik, for example, observed how 18-month-olds would choose to feed an adult disgusting broccoli, rather than yummy crackers, if they'd seen the adult enjoying the dreaded vegetable earlier.

Now Elena Sakkalou and Merideth Gattis have performed a study looking specifically at the role of prosody in the ability of infants to infer whether an adult intended to perform an action or made a mistake. Prosody refers to the sing-song, rise and fall of speech - its tempo and fluctuating pitch. It's the quality of speech we can hear through a wall or ceiling. We might not be able to distinguish any of our next-door neighbour's actual words, but we can still get a sense of the mood and emotion of what they're saying.

This study combines what we know about the importance of prosody to children's learning, with what we know about their emerging ability to think about other people's minds and intentions. For example, past research has shown how mothers use prosody to convey approval and prohibition, and that 5-month-olds smile more in response to the former.

Sakkalou and Gattis first replicated an earlier study by showing that infants aged 14 to 18-months can use an adult's vocal utterances, specifically including the words "There" vs. "Whoops", to infer whether they intended an action or not. Twenty-eight toddlers saw an experimenter perform two actions on a toy (for example, pushing it or rolling it), one of which was accompanied by the word "There" as if the action were intended; the other by "Whoops". Given a chance to handle the toy themselves, the infants were more likely to imitate the action that was accompanied by the word "There" - as if they knew that it had been a deliberate action.

Next, Sakkalou and Gattis analysed the prosody of the experimenter utterances: "There" and "Whoops". The former was characterised by higher amplitude, longer duration and falling pitch; the latter by a rising pitch contour. The earlier experiment was then replicated with 56 more toddlers (mean age 16 months), but this time the words "There" and "Whoops" were replaced with the Greek words "Nato" and "Ochi" (or vice versa). Crucially, the words signifying a mistake or intentional action were always delivered with the prosodic profile established earlier as being associated with a mistake or intended action. The toddlers were raised in English-speaking homes so there's no way they could have known the meaning of the words. Nonetheless, the toddlers older than 16 months still imitated more "intentional" actions than accidental actions on the toys, thus suggesting strongly they were able to use the way the words were said to infer which actions were intended and which were accidental.

It's important to note that the "mistake" vs. "intent" prosodic patterns in the current study do not map simply onto approval/ disapproval - they were more complex, which could explain why it was only the older toddlers who could interpret the difference. This fits with other research showing that infants' preference for different types of vocalisations changes as they develop, with older infants preferring prosodic patterns that direct their attention whereas younger infants prefer comforting prosody.

"We propose that infants' understanding of vocal patterns supports their growing understanding of intentions," Gattis told The Digest. "Together these two forms of understanding shape the development of imitation and communication."

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Sakkalou, E., and Gattis, M. (2012). Infants infer intentions from prosody. Cognitive Development, 27 (1), 1-16 DOI: 10.1016/j.cogdev.2011.08.003

Post written by Christian Jarrett for the BPS Research Digest.