Posts Tagged ‘cerebral cortex’

Don’t forget to remember this – The Irish Times – Wed, Mar 30, 2011

March 30, 2011 Leave a comment

Don’t forget to remember this – The Irish Times – Wed, Mar 30, 2011.

How does our memory work? What’s the difference between remembering how to ride a bike and recalling people’s names? Is it possible to improve your memory? An exhibition in the Science Gallery is looking for the answers, writes BRIAN O’CONNELL

REMEMBER A NAME but can’t match it with a face? Good with numbers but useless at childhood recollections? Led by Prof Shane O’Mara of Trinity College, Memory Lab is a month-long experience at Science Gallery in Trinity College, which invites the public to take part in a range of scientific experiments aimed at examining how our memory works.

Brainpower: a rational guide to the myths – The Irish Times – Thu, Mar 24, 2011

March 24, 2011 Leave a comment

Brainpower: a rational guide to the myths – The Irish Times – Thu, Mar 24, 2011.

In the new Hollywood thriller, ‘Limitless’, Bradley Cooper plays a failing writer who uses a top-secret ‘smart drug’ to unlock his brain’s potential. SYLVIA LEATHAM asks TCD neuroscientist Prof Shane O’Mara for a reality check on how the brain works.

Trinity College Institute of Neuroscience Strategic Plan 2010-2016

November 11, 2010 Leave a comment

Blogging has been light recently because of the usual term-time stuff. However, we have launched our Institute of Neuroscience Strategic Plan (also available via google docs).

See here for the Trinity press release and TCIN Strategic Plan Nov 2010 Final for the summary presentation pdf.

The graphics are fantastic, and the plan itself is short and sweet.

A quote:

Our animating ethos rests on the belief that major and fundamental research problems are best solved by combining research strengths across disciplines and levels of analysis.

Combining our strengths in this way will allow us to deliver major scientific discoveries of great consequence for human health, welfare and knowledge.

Table of Contents:

  1. Why Explore the Brain? [Our short, simple answer: ‘Understanding the structure and functions of our brains brings us a good way along the path of understanding ourselves as humans. Progress in understanding the nervous system materially benefits human health, welfare and knowledge.‘]
  2. Trinity College Institute of Neuroscience Mission
  3. Transformative Neuroscience
  4. Context
  5. Trinity College Institute of Neuroscience Today
  6. Trinity College Institute of Neuroscience Tomorrow
  7. Research Focus 1: Synapses, Cognition and Behaviour
  8. Research Focus 2: Neuropsychiatry and Neurodevelopmental Disorders
  9. Research Focus 3: Neurodegeneration, Neuroprotection and Neuroplasticity
  10. Platform Technologies: Imaging and Neural Engineering
  11. Innovation
  12. Education
  13. Contribution to Society and Outreach
  14. Future Opportunities
  15. Measuring Impact: Hard and Soft Metrics
  16. Final Thoughts

Read it!

Loss aversion and ‘thinking’ about the house price collapse (in Ireland and further afield)

September 4, 2010 Leave a comment

There has been a dramatic collapse in house prices in many parts of the world, including Ireland, which has seen prices come down by 40% or so on average since the peak a few years ago (and more to come, according to some economists). The market is now very slow-moving, and probably as bad as it ever has been. And given past patterns, will probably take a decade to recover. Jonah Lehrer has a fantastic post on the pervasive phenomenon of loss aversion in human cognition which must underpin at least some of the problems in the market, because of the aversion and indeed pain caused by recognising losses quickly.

Key quote: “The pain of a loss was approximately twice as potent as the pleasure generated by a gain. Furthermore, our decisions seemed to be determined by these feelings. As Kahneman and Tversky put it, “In human decision making, losses loom larger than gains.”

[Blog reproduced in full]

The Real Estate Collapse By Jonah Lehrer

The news on the housing front is bleak and getting bleaker. The New York Times posts a graph that captures the trend:

Obviously, a stew of forces are at work here. There is the end of the federal tax credit, and the crappy employment news, and the shadow inventory of foreclosed homes. But I think the dismal housing data also reflects a systematic human bias: loss aversion. The phenomenon was first identified by Daniel Kahneman and Amos Tversky in the mid-70s, after they gave their students at Hebrew University a simple survey asking them whether or not they’d accept a variety of different bets. The psychologists noticed that, when people were offered a gamble on the toss of a coin in which they might lose $20, they demanded an average payoff of at least $40 if they won. The pain of a loss was approximately twice as potent as the pleasure generated by a gain. Furthermore, our decisions seemed to be determined by these feelings. As Kahneman and Tversky put it, “In human decision making, losses loom larger than gains.”

Consider this scenario:

The U.S. is preparing for the outbreak of an unusual Asian disease, which is expected to kill 600 people. Two alternative programs to combat the disease have been proposed. Assume that the exact scientific estimates of the consequences of the programs are as follows: If program A is adopted, 200 people will be saved. If program B is adopted, there is a one-third probability that 600 people will be saved and a two-thirds probability that no people will be saved. Which of the two programs would you favor?

When this question was put to a large sample of physicians, 72 percent chose option A, the safe-and-sure strategy, and only 28 percent chose program B, the risky strategy. In other words, physicians would rather save a certain number of people for sure than risk the possibility that everyone might die. But what about this scenario:

The U.S. is preparing for the outbreak of an unusual Asian disease, which is expected to kill 600 people. Two alternative programs to combat the disease have been proposed. Assume that the exact scientific estimates of the consequences of the programs are as follows: If program C is adopted, 400 people will die. If program D is adopted, there is a one-third probability that nobody will dies and a two-thirds probability that 600 people will die. Which of the two programs would you favor?

When the scenario was described in terms of deaths instead of survivors, physicians reversed their previous decision. Only 22 percent voted for option C, while 78 percent of them opted for option D, the risky strategy. Most doctors were now acting just like Frank: they were rejecting a guaranteed gain in order to partake in a questionable gamble.

Of course, this is a ridiculous shift in preference. The two different questions examine identical dilemmas; saving one third of the population is the same as losing two thirds. And yet, doctors reacted very differently depending on how the question was framed. When the possible outcomes were stated in terms of deaths – this is the “loss frame” – physicians were suddenly eager to take chances. They were so determined to avoid any alternative associated with a loss that they were willing to risk losing everything.

The same irrational quirk is now playing out in the U.S. housing market. Look, for instance, a 2001 paper by the economists Christopher Mayer and  David Genesove. They studied the Boston condominium market of the early 1990s, which was one of the most spectacular real estate busts in recent decades. Between 1989 and 1992, Boston condo prices fell by nearly 40 percent. This meant that, for the vast majority of condo owners, they could only sell their home at a steep loss.

Classical economics assumes that people will adjust to the new reality. They’ll realize that the market has changed, and that they made a costly mistake. But that’s not what happened. In their paper, “Loss Aversion and Seller Behavior: Evidence From the Housing Market,” Mayer and Genesove found that, for essentially identical condos, people who had bought at the peak of the market (between 1989-1992) listed their properties for nearly 35 percent more than those who had bought after the collapse. Why? Because they couldn’t bear to take a loss.

The end result, of course, is that these overpriced properties just sat there, piling up like unwanted inventory. According to the economists, less than 25 percent of the properties bought during the condo bubble sold in less than 180 days.

I’d argue that the same thing is happening right now, except on a nationwide scale. The housing market will only recover when we get over our collective bias, and realize that home prices have fallen and aren’t coming back (at least not anytime soon). Our irrationality got us into this mess – we binged on credit cards and took out unreasonable loans and mistook a bubble for a boom – and the only way we’re going to get out of it is to see through a new set of irrational quirks, which prevent us from fully equilibrating to our new financial reality. Sometimes, the wisest thing to do is cut our losses and run.

More at Wired.

Current Directions Special Issue on Schizophrenia Now Open Access

September 4, 2010 Leave a comment

Something that is worth noting. There is a lot of high profile Irish research on schizophrenia (see this and this, for example).

Dear APS Colleague,

The Special Issue of Current Directions in Psychological Science on Schizophrenia has been getting so much attention that, in special arrangement with our publisher SAGE, we have just made the issue completely Open Access. Below are open links, along with a brief introductory video from Special Issue Guest Co-Editor (and noted Schizophrenia researcher) Elaine Walker providing an interesting historical overview of the field:

Please feel free to pass this on to anyone you like – friends, colleagues, students. We already have heard of APS members making these papers required readings as a part of their Fall classes. Thanks to Current Directions Editor Randy Engel for commissioning what will surely become a classic set of reviews.

Best, Alan

APS Executive Director
Mark A. Geyer

Neurodevelopment and Schizophrenia: Broadening the Focus

Elaine Walker, Dan Shapiro, Michelle Esterberg, and Hanan Trotman Prenatal Factors in Schizophrenia

Suzanne King, Annie St-Hilaire, and David Heidkamp Current Research on the Genetic Contributors to Schizophrenia
Michael F. Pogue-Geile, and Jessica L.Yokley Schizophrenia Course, Long-Term Outcome, Recovery, and Prognosis

Thomas H. Jobe and Martin Harrow

From The Skeptic: Top Ten Myths of Popular Psychology

September 3, 2010 Leave a comment


Top Ten Myths of Popular Psychology

Virtually every day, the news media, television shows, films, and Internet bombard us with claims regarding a host of psychological topics: psychics, out of body experiences, recovered memories, and lie detection, to name a few. Even a casual stroll through our neighborhood bookstore reveals dozens of self-help, relationship, recovery, and addiction books that serve up generous portions of advice for steering our paths along life’s rocky road. Yet many popular psychology sources are rife with misconceptions. Indeed, in today’s fast-paced world of information overload, misinformation about psychology is at least as widespread as accurate information. Self-help gurus, television talk show hosts, and self-proclaimed mental health experts routinely dispense psychological advice that is a bewildering mix of truths, half-truths, and outright falsehoods. Without a dependable tour guide for sorting out psychological myth from reality, we’re at risk for becoming lost in a jungle of “psychomythology.”

Myth #1: We Only Use 10% of our Brains

Whenever those of us who study the brain venture outside the Ivory Tower to give public lectures, one of the questions we’re most likely to encounter is, “Is it true that we only use 10% of our brains?” The look of disappointment that usually follows when we respond, “Sorry, I’m afraid not,” suggests that the 10% myth is one of those hopeful truisms that refuses to die because it would be so nice if it were true. In one study, when asked “About what percentage of their potential brain power do you think most people use?,” a third of psychology majors answered 10%.1 Remarkably, one survey revealed that even 6% of neuroscientists agreed with this claim!2 The pop psychology industry has played a big role in keeping this myth alive. For example, in his book, How to be Twice as Smart, Scott Witt wrote that “If you’re like most people, you’re using only ten percent of your brainpower.”3

There are several reasons to doubt that 90% of our brains lie silent. At a mere 2–3% of our body weight, our brain consumes over 20% of the oxygen we breathe. It’s implausible that evolution would have permitted the squandering of resources on a scale necessary to build and maintain such a massively underutilized organ. Moreover, losing far less than 90% of the brain to accident or disease almost always has catastrophic consequences.4 Likewise, electrical stimulation of sites in the brain during neurosurgery has failed to uncover any “silent areas.”

How did the 10% myth get started? One clue leads back about a century to psychologist William James, who once wrote that he doubted that average persons achieve more than about 10% of their intellectual potential. Although James talked in terms of underdeveloped potential, a slew of positive thinking gurus transformed “10% of our capacity” into “10% of our brain.”5 In addition, in calling a huge percentage of the human brain “silent cortex,” early investigators may have fostered the mistaken impression that what scientists now call “association cortex” — which is vitally important for language and abstract thinking — had no function. In a similar vein, early researchers’ admissions that they didn’t know what 90% of the brain did probably fueled the myth that it does nothing. Finally, although one frequently hears claims that Albert Einstein once explained his own brilliance by reference to 10% myth, there’s no evidence that he ever uttered such a statement.

You could lots more to this list: having a stroke is not consequence free, for example. Losing part of your brain is generally irrevocable, and requires lots of rehabilitation (unless you are Lisbeth Salander of course, in which case all will be well, even after being shot in several parts of your brain simultaneously!).

The rest of the list is at the link above.

For the art-loving neuroscientist: From Scientific American – Michelangelo’s secret message in the Sistine Chapel: A juxtaposition of God and the human brain

Douglas Fields has a very interesting post at Scientific American – seems Michelangelo has hidden in many of his Sistine Chapel paintings illustrations of the dissected central nervous system:

At the age of 17 he began dissecting corpses from the church graveyard. Between the years 1508 and 1512 he painted the ceiling of the Sistine Chapel in Rome. Michelangelo Buonarroti—known by his first name the world over as the singular artistic genius, sculptor and architect—was also an anatomist, a secret he concealed by destroying almost all of his anatomical sketches and notes. Now, 500 years after he drew them, his hidden anatomical illustrations have been found—painted on the ceiling of the Sistine Chapel, cleverly concealed from the eyes of Pope Julius II and countless religious worshipers, historians, and art lovers for centuries—inside the body of God.This is the conclusion of Ian Suk and Rafael Tamargo, in their paper in the May 2010 issue of the scientific journal Neurosurgery.

The brainstem dissection looks convincing to me, and most especially the pons and medulla, but as Fields notes: ‘The mystery is whether these neuroanatomical features are hidden messages or whether the Sistine Chapel a Rorshach tests upon which anyone can extract an image that is meaningful to themselves. The authors of the paper are, after all, neuroanatomists. The neuroanatomy they see on the ceiling may be nothing more than the man on the moon.’

Concealed Neuroanatomy in Michelangelo’s Separation of Light From Darkness in the Sistine Chapel,” by Ian Suk and Rafael J. Tamargo in Neurosurgery, Vol. 66, No. 5, pp. 851-861.

Neuroanatomy, bullets and brain damage in ‘The Girl With the Dragon Tattoo’ [The Millennium Trilogy by Stieg Larsson]

April 3, 2010 1 comment

Like at least 27 million other people, I bought and read all three volumes of the late Stieg Larsson’s Millennium trilogy (The Girl with the Dragon Tattoo, The Girl who Played with Fire, and The Girl who Kicked the Hornet’s Nest). All three books are in the current top ten best sellers in Ireland. I’ve also been to see the first film of the series (in Swedish, with English subtitles). The books are all a bit daft, but hugely enjoyable and compulsively readable – Larsson must have had great fun dreaming up the cast of variously weird, wonderful, and way-out characters in these books. The film was enjoyable too, if you like stark, grey, colour-desaturated Swedish landscapes with the occasional ageing and semi-crazed nazi, vicious intrafamily feuds, intergenerational inheritors of murderous traditions and dreary, near-endless rain and snow (seems I do). The lead female character, Lisbeth Salander, something of a social misfit (perhaps with a mild case of Asperger Syndrome), is an accomplished computer hacker and is reasonably skilled in martial arts and the use of golfclubs to demotivate murderers from the object of their predatory desires.

Towards the end of second volume of the series, Lisbeth is shot in the head with a .25 calibre gun (she survives). Larsson describes the wound thus (p 550, Quercus paperback edition):

“The third bullet caught her about two centimetres below the top of her left ear… The lead came to rest in the grey matter about five centimetres beneath the cerebral cortex by the cerebrum.”

In volume three, two medics work to save her and remove the bullet. One operates, the other (who claims to have a certain amount of alcohol on board), observes and makes suggestions. On page 9 (again Quercus paperback edition), the bullet wound is now described as ‘Entry wound just above the left ear’ (hmm). On page 11, one asks the other for a diagnosis. The reply is: ‘It entered at the temple, and the stopped about four centimetres into the brain. It’s resting against the lateral ventricle’. A conversation ensues about bone fragments and their potential for damage. One medic says the bone fragments are the cause  for concern, as they might kill her, as they are embedded in brain tissue. The other then remarks they are in the part of the brain associated with ‘numbers and mathematical capacity’, eliciting a sceptical response. (However, a bullet this deep in the brain would surely give anyone pause for thought, even if they were somewhat under the influence of alcohol).

But, reading all this as a neuroscientist, makes me give a sceptical response too; the various descriptions of  where the bullet has travelled really make little sense at all. If she was shot two centimetres below the top of the ear (but presumably not through the pinna, the outer part of the ear), how does the bullet end up passing through the temple? The neuroanatomical description of the bullet trajectory makes no sense either. The bullet is described as ‘to rest in the grey matter about five centimetres beneath the cerebral cortex by the cerebrum’. However: the grey matter is what comprises the cerebral cortex; the cerebrum is merely the term for what is usually referred to as ‘the brain’ (excluding the brain stem and cerebellum).

Five centimetres into the brain is quite a distance into the brain, and would likely cause enduring damage to a variety of functions (depending on location – but the bullet location varies!). If the bullet is close to or above the ear, then it can’t be close to the lateral ventricle, which is in a distinctly different location. There is a part of the brain associated with numerical and mathematical capacity (well, there must be) – it is usually regarded as the left parietal lobe (and the subregion of the angular gyrus) in right-handed individuals. Damage to this region is associated with the syndrome of acalculia, the loss of the ability to use and manipulate numbers. Again, this all a bit of distance from the three different places in the brain that poor Lisbeth has been shot with the one bullet! If the bullet has travelled five centimetres into the brain (assuming the top of the ear description is the accurate one), then depending on the trajectory, it just might have passed through the angular gyrus, travelling in a straight line toward the corpus callosum, or perhaps up a bit to posterior cingulate or anterior retrosplenial cortex (all midline structures). If it travelled at a downward angle, then it gets a lot more complicated. It won’t get near the lateral ventricle in either case; there is, instead, a wide choice of structures (both thalamic and non-thalamic) for the bullet to compromise.

What’s the lesson here? I’ve no idea (except that I should get out more, perhaps).