Monday, January 30, 2006

Improving law through neuroscience

The insights from brain science has the potential to alter the making and practice of law. But how and why? What is so special about brain science that gives it this potent source of change?

Let's reverse that question by asking: what is so good about our current models about human thought, motivation and behaviour that makes us certain that our laws reflect the most correct view of human behaviour? I thought so; I don't feel the slightest confident that our current models of the mind are merely good enough (by our scientific standards).

Luckily, our models are improving -- from day to day, some would say. It's definitely not a linear progress, IOW that each new publication makes an added improvement to our understanding. The battle of theories are still dominating the field, so whether you choose to go with Damasio or Rolls on the issue of decision making, it will have an influence on the laws you make. But whatever use we make of such models, be it law systems, educational practices or child rearing, we should use the most up to date and most supported models.

This is suggested in a thorough and comprehensive (and very long) article by Owen Jones and Timothy Goldsmith. Jones and Goldsmith argue that better understanding of the biology of behaviour makes better laws. I won't brag with reading the entire document, but I will do. If I stumble across anything especially important (which is likely) I'll drop a note.

------------------------------------------
Here is the abstract. Get the full article here (PDF).
See also a story in Medical News Today

LAW AND BEHAVIORAL BIOLOGY
Owen D. Jones & Timothy H. Goldsmith

Society uses law to encourage people to behave differently than they would behave in the absence of law. This fundamental purpose makes law highly dependent on sound understandings of the multiple causes of human behavior. The better those understandings, the better law can achieve social goals with legal tools.

In this Article, Professors Jones and Goldsmith argue that many long-held understandings about where behavior comes from are rapidly obsolescing as a consequence of developments in the various fields constituting behavioral biology. By helping to refine law’s understandings of behavior’s causes, they argue, behavioral biology can help to improve law’s effectiveness and efficiency.

Part I examines how and why law and behavioral biology are connected.
Part II provides an introduction to key concepts in behavioral biology.
Part III identifies, explores, and illustrates a wide variety of contexts in which behavioral biology can be useful to law.
Part IV addresses concerns that sometimes arise when considering biological influences on human behavior.

Saturday, January 28, 2006

More on neuroprosthetics

If you downloaded the radio programme on neuroprosthetics that Thomas mentions in a post below, you'll want to also hear the January 13 version of BBC's excellent radio show Science Frontier. Here's the presentation of the programme, to be found at Radio 4's web-site:

People with nerve or limb injuries may one day be able to command wheelchairs, prosthetics and even paralysed arms and legs by "thinking them through" the motions.

As researchers overcome the technical and biological hurdles to begin the first human trials, Peter Evans examines how capturing brain output could allow fully paralysed patients to interact with the world.

The idea behind the research is to insert a computer between pathways in the brain and the world outside, which have been broken due to neurological injuries or diseases.

At Duke University's Center for Neuroengineering in North Carolina, Professor Miguel Nicolelis has created an artificial bypass to carry brain signals to an activator, which produces the movement the person is thinking about.

Thanks to a tiny implant in the motor cortex, monkeys have been able to control a robotic arm, just by thinking about making the movement.

Researchers at Brown University in Rhode Island have taken things a step further by working with a tetraplegic man.

They have found that the patient's motor cortex still transmits the same electrical signals a non-paralysed person uses to control their muscles, even though the connections themselves are broken.

The research team has captured these signals using microelectrodes, and built the technology to allow him to carry out basic tasks by moving a cursor around a computer screen.

For the patient, carrying out these simple activities represents a significant improvement in the quality of his life.


You can find a stream of the programme here.

Friday, January 27, 2006

Meeting of Minds report out

Throughout 2005 126 EU citizens participated in something called the "Meeting of Minds", learning about neuroscience and debating what to do with our ever increasing knowledge about the brain. Here is how the project is described on its web-page www.meetingmindseurope.org:

Meeting of Minds. European Citizens’ Deliberation on Brain Science is a two-year pilot project led by a European panel of 126 citizens. A partner consortium of technology assessment bodies, science museums, academic institutions and public foundations from nine European countries launched this initiative in 2004 with the support of the European Commission.

The initiative will give European citizens a unique opportunity to learn more about the impact of brain research on their daily lives and society as a whole, to discuss their questions and ideas with leading European researchers, experts and policy-makers, put them in touch with fellow citizens from other European countries and make a personal contribution to a report detailing what the people of Europe believe to be possible and desirable in the area of brain science and what they recommend policy-makers and researchers to be aware of for future developments in this field.

Through this approach, the Meeting of Minds initiative wishes to meet EU calls for greater public involvement in the debate on future research, technological decision-making and governance.

The results of their deliberation is now out in the form of a report which can be downloaded here. The 126, now neuro-wize, citizens recommend 36 policy initiatives concerning the practical use of our knowledge about the brain. The majority of these suggestions are pretty dissapointing, merely reflecting various general medical concerns. They do, however, raise two brain-specific issues. (1) First, they suggest that it should be illegal for police, courts, and other official institutions, to use brain scans as information about citizens. (2) Second, they argue for a more public discussion as to what exactly constitutes normal behaviour, and what counts as a mental decease. Both excellent problems that we will certainly return to her at Brainethics in coming posts.

But why, oh why, hasn't this report received more press, at least in the European media?

Wednesday, January 25, 2006

More compassionate through meditation?

Apparently the Dalai Lama is a science buff. For some years now he has lend out munks to Richard Davidson, an expert on emotion, who is currently studying what happens when these monks meditate. In 2004 Davidson and his colleagues published a paper in PNAS showing a difference in neural activity in buddhist monks compared to a control group when measured with EEG. Personally, I don't see this as very surprising. Tons of evidence is pointing to the fact that ekspertise in some field correlate with some change to the brain. The big question is: Exactly what kind of change are we talking about? More neurons, different connections, an elevated influx of neurotransmitters, or something else? Unfortunately, EEG can't tell us anything about what is different about the monks' brains. Also, registrering a difference in brain activity doesn't tell us much about putative functional differences. Buddhists claim that they have been able to evolve a more compasionate attittude towards other people through their meditating. Maybe. But it is surely somewhat premature to conclude that meditation actually have such power to make us all more compassionate. Although, of course, it may turn out to be true.

On it's website Wired has a story about the relation between the Lama and Davidson. It also reports on the furore surrounding the Dalai Lama's visit to the Society for Neuroscience conference in November. Get it here.


References

Geirland, J. (2006): Buddha on the Brain. Wired. Issue 14.02.

Lutz, A. et al. (2004). Long-term meditators self-induce high-amplitude synchrony during mental practice. Proceedings of the National Academy of Sciences, 101, 16369-16373.

Ekman, P., Davidson, R.J., Ricard, M. & Wallace, B. Alan. Buddhist and psychological perspectives on emotions and well-Being. Current Directions in Psychological Science, 14, 59-63.

Tuesday, January 24, 2006

Fusiform -- not alone

One of the important basic discussions in congitive neuroscience is that of the fusiform face area (FFA). The FFA has been suggested as a part of the fusiform gyrus that is solely dedicated to face perception. The rationale is that faces have been evolutionary special and selected for, and that the FFA is an evolved module specifically dealing with faces.

As the story goes, researchers such as Isabel Gauthier and her colleagues have demonstrated that the FFA is also active when study participants are asked to discriminate between different types of birds and cars and even when participants become expert at distinguishing computer generated nonsense shapes known as greebles. These activations were not as profound as those seen when subjects perceived faces, but they still demonstrate a less clear-cut role of the FFA. At the Human Brain Mapping 2005 in Toronto , Canada, we saw Gauthier and Nancy Kanwisher battle it out, and it is clear that this is by no means a settled issue. The selectivity and encapsulation of neuro-cognitive modules is one of the hot topics in modern cognitive neuroscience, though even in its infancy it was a much debated issue. Just take John Hughlings Jackson's (1882/1932) famous and excellent quote:

"I am neither a universalizer nor a localizer...In consequence I have been attacked as a universalizer and also as a localizer. But I do not remember that the view I really hold as to localization has ever been referred to. If it is, it will very likely be supposed to be a fusion of, or a compromise of recent doctrines"

In a recent study reported in Neuropsychologia by Steeves et al., the FFA does not seem to be sufficient to produce face recognition. Well, that does not come as such a surprise maybe, since we do know that face perception is the result of processes starting in the retina. But the whole idea is that the FFA is something special for face processing. But Steeves et al.s study show that the FFA is part of a larger network, and that face processing consists of many different steps and subprocesses. Their patient study of D.F., combined with fMRI studies demonstrate that
  1. For gross detection of face-nonface decitions, the FFA does not seem necessary although it can be activated. For this, the occipital face area (OFA) seems to do the work.
  2. For face identification -- i.e. recognising a familiar face -- the FFA is involved, but still involves a network of different modules (including the OFA)
In short, Oma und Opa get your OFA going, too. Here is the article's abstract, but you can get the article here (PDF):

The fusiform face area is not sufficient for face recognition: Evidence from a patient with dense prosopagnosia and no occipital face area

Steeves et al.

We tested functional activation for faces in patient D.F., who following acquired brain damage has a profound deficit in object recognition based on form (visual form agnosia) and also prosopagnosia that is undocumented to date. Functional imaging demonstrated that like our control observers, D.F. shows significantly more activation when passively viewing face compared to scene images in an area that is consistent with the fusiform face area (FFA) (p < 0.01). Control observers also show occipital face area (OFA) activation; however, whereas D.F.'s lesions appear to overlap the OFA bilaterally.

We asked, given that D.F. shows FFA activation for faces, to what extent is she able to recognize faces? D.F. demonstrated a severe impairment in higher level face processing—she could not recognize face identity, gender or emotional expression. In contrast, she performed relatively normally on many face categorization tasks. D.F. can differentiate faces from non-faces given sufficient texture information and processing time, and she can do this is independent of color and illumination information. D.F. can use configural information for categorizing faces when they are presented in an upright but not a sideways orientation and given that she also cannot discriminate half-faces she may rely on a spatially symmetric feature arrangement.

Faces appear to be a unique category, which she can classify even when she has no advance knowledge that she will be shown face images. Together, these imaging and behavioral data support the importance of the integrity of a complex network of regions for face identification, including more than just the FFA—in particular the OFA, a region believed to be associated with low-level processing.

Monday, January 23, 2006

Reward processing and extrovert behaviour

Yesterday I mentioned that brain scientists are actively investigating the neural processes underlying personality differences in behaviour. A very nice example of this research is to be found in the latest issue of Cognitive Brain Research. Michael Cohen and his colleagues linked personality testing, fMRI and genetic analysis to look into how personality may correlate with different neurocognitive ways of handling an economic game. Here is the abstract:

Psychologists have linked the personality trait extraversion both to differences in reward sensitivity and to dopamine functioning, but little is known about how these differences are reflected in the functioning of the brain's dopaminergic neural reward system. Here, we show that individual differences in extraversion and the presence of the A1 allele on the dopamine D2 receptor gene predict activation magnitudes in the brain's reward system during a gambling task. In two functional MRI experiments, participants probabilistically received rewards either immediately following a behavioral response (Study 1) or after a 7.5 s anticipation period (Study 2). Although group activation maps revealed anticipation- and reward-related activations in the reward system, individual differences in extraversion and the presence of the D2 Taq1A allele predicted a significant amount of inter-subject variability in the magnitudes of reward-related, but not anticipation-related, activations. These results demonstrate a link between stable differences in personality, genetics, and brain functioning.

Note how juxtaposing the various types of data effectively unveil insights into brain activity we would have no possibility of gaining using just one method. Combining behavioural, imaging, and genetic data, will probably soon become the gold standard of cognitive neuroscience.

Reference

Cohen, M. et al. (2005): Individual differences in extroversion and dopamine genetics predict neural reward responses. Cognitive Brain Research 25: 851-861.

Sunday, January 22, 2006

Animal personality

Today's NY Times Magazine has a rather fascinating story about research on animal personality. Although eradicated by behaviourism, the notion that others animals than ourselves display various personality types - timid, bold, aggresive, etc. - is becoming increasingly accepted in the worlds of biology and psychology. Researchers such as Sam Gosling - visit his site for in-depth research papers on the topic - are pondering why personalities exist at all; why aren't the behavioural profile of the members of an species just uniform and similar? The answer may be that it is advantageous to have a repertoire of behavioral traits around if the milieu of a species should change. In some niches bold members will have a survival edge, in others cautious members will be better of.

Unfortunately, the article doesn't go into the issue of what brain processes underlie personality traits. This kind of research is also booming, though. So, perhaps we may hope to see a follow-up article on this topic as well.

Reference

Siebert, C. (2006): The Animal Self. New York Times Magazine, January 22 issue.

Thursday, January 19, 2006

Critical remarks about art in the brain

An online published paper by John Hyman provides a thorough criticism of two major contributors to the emergent field of neuroaesthetics, V.S. Ramachandran and Semir Zeki.

Art and Neuroscience

From the article:

I want to discuss a new area of scientific research called neuro-aesthetics, which is the study of art by neuroscientists. The most prominent champions of neuro-aesthetics are V.S. Ramachandran and Semir Zeki (fig. 1). They have both made ambitious claims about their work. Ramachandran says boldly that he has discovered ‘the key to understanding what art really is’, and that his theory of art can be tested by brain imaging experiments, although he is vague about the experimental design. And Zeki, who originally coined the term ‘neuro-aesthetics’, claims to have laid the foundations for understanding ‘the biological basis of aesthetic experience’

(...)

The main defect in the work I have discussed is that both authors propose extravagant generalizations about art – all art is caricature; all great art is ambiguous – and then discuss a small number of examples, which are chosen to illustrate the generalization they favour and not to test it. Would Zeki or Ramachandran tolerate this procedure in their own subject? I expect they’d laugh at it. How easily we shrug off our academic training when we take the brave step outside the furrows we were taught to plough!

Read the full article.

iHuman on podcast

There is a most interesting question being posed at the ABC The Science Show:

"What are the implications of the latest advances in neural prosthetics?"

THE SCIENCE SHOW with Robyn Williams - iHuman
Saturday 14 January, Midday, repeat Monday 16 January, 7pm

What are the implications of the latest advances in neural prosthetics, electronic implants and robotics for humankind? It started with attachments to the body - the watch, the hearing aid - now we are working with nerves and the brain, having the brain operate motors and activators. Combining man and machine can be used to save lives, but where does it end?

Download the mp3 file directly here (mp3 file) or get the transcript here.

Men's vengeful brains

While trying to digest the overwhelming yet so short conference on Imaging Genetics in Irvine, I find myself just tapping into some of the latest headlines. This little piece in New Scientist on sexual differences in revenge sounds interesting.

From the New Scientist article:

Tania Singer of University College London and colleagues used a functional magnetic resonance imaging (fMRI) machine to analyse the brain activity of 32 volunteers after their participation in a simple game, called the Prisoner's Dilemma.

The game allows players to cooperate or double-cross one another, and so fosters camaraderie or enmity between players. Following the game, participants were placed inside an fMRI machine and then saw their fellow players zapped with electricity. The activity in their brain was recorded as they watched.

The scans revealed changes in activity as players who had cooperated got zapped, compared with those who had double-crossed them in the game. The results suggest that men get a much bigger kick than women from seeing revenge physically exacted on someone perceived to have wronged them.

So it seems possible that there are sexual differences in how men and women choose their revenge. It does not show, however, that men are more vengeful. But they seem to react more to see their opponents being punished.

Red the full story here and visit Dr. Tania Singer's homepage to read more.

Monday, January 16, 2006

2006: Year of the Neanderthals

This year it is 150 years ago that miners in the German Neander Valley lucked upon 16 fossils that turned out to belong to a different homo species. The Neanderthals are of special interest to the study of the homo sapiens brain, being bigger in average volume, but (presumably) different in function. Since brains doesn't fossile there are really only two ways of studying this difference: (1) through comparing the DNA of the two species, and (2) through what has been called cognitive archeology - the deduction of how the Neanderthal mind must have been organized through an examination of archeological evidence such as diet, technology and social structure.

If you happen to read German this article in Die Zeit kicks off the Neanderthal year. In July Bonn will host a big conference on the Neanderthals. Its web-site has a number of interesting papers on-line.

Sunday, January 15, 2006

Mirror neurons

On a hot summer day 15 years ago in Parma, Italy, a monkey sat in a special laboratory chair waiting for researchers to return from lunch. Thin wires had been implanted in the region of its brain involved in planning and carrying out movements.

Every time the monkey grasped and moved an object, some cells in that brain region would fire, and a monitor would register a sound: brrrrrip, brrrrrip, brrrrrip.

A graduate student entered the lab with an ice cream cone in his hand. The monkey stared at him. Then, something amazing happened: when the student raised the cone to his lips, the monitor sounded - brrrrrip, brrrrrip, brrrrrip - even though the monkey had not moved but had simply observed the student grasping the cone and moving it to his mouth.

The researchers, led by Giacomo Rizzolatti, a neuroscientist at the University of Parma, had earlier noticed the same strange phenomenon with peanuts. The same brain cells fired when the monkey watched humans or other monkeys bring peanuts to their mouths as when the monkey itself brought a peanut to its mouth.

Later, the scientists found cells that fired when the monkey broke open a peanut or heard someone break a peanut. The same thing happened with bananas, raisins and all kinds of other objects.

"It took us several years to believe what we were seeing," Dr. Rizzolatti said in a recent interview. The monkey brain contains a special class of cells, called mirror neurons, that fire when the animal sees or hears an action and when the animal carries out the same action on its own.

By now mirror neurons is a well-known story. However, if you are not up to speed Sandra Blakeslee has a nice story in NY Times giving a short run-down of the story so far. (The quote above is from that article.) Afterwards, you will probably enjoy a visit to the homepage of the Physiology Lab at Parma University. That's the home of many of the pricipal investigators working on the mirror neuron cells, including Giacommo Rizzolatti, Leonardo Fogassi, and Vittorio Gallese. They have a lot of their research papers on-line.

I'm chiefly mentioning this because I'm going to put up the next installment in my little series on the neurobiology of culture in a few days. (See the first part here.) Here, mirror neurons play a vital part, and you may want to get a head start!

Friday, January 13, 2006

Hardwired Behavior

This book from Cambridge University Press looks interesting. I haven't actually read it yet, but the new issue of Nature has a rather positive review of it. A brief passage from the review:

Laurence Tancredi’s book Hardwired Behavior powerfully presents science that shows the gross inadequacy of the binary terms we often use to talk about the genesis and character of complex human behaviours. He writes: “Our brain structures are not immutable; they are susceptible to change for the better and change for the worse.” Indeed, much of the research he discusses rests on this neuroplasticity. He reports on research showing that talk therapy can produce neuronal changes. His chapter on gender differences suggests that changing social conceptions of the roles of women “will inevitably affect the biology of their brains over time”. He reports on research showing that rats deprived of nurture at birth fail to express a gene that is correlated with their ability to handle stress. And he refers several times to a fascinating study by Avshalom Caspi and colleagues (Science 301, 386–389; 2002), which found that the likelihood of children becoming antisocial as adults is a function of both their genomes and their experiences. As Tancredi observes, this finding “emphasizes the interactive nature of genes and environment, nature and nurture”.

Tancredei, L. (2005): Hardwired Behavior. What Neuroscience Reveals About Morality. Cambridge University Press.
Publisher's description.

Tuesday, January 10, 2006

Adult dendritic growth

Until recently anatomists were convinced that humans are born with all the neurons they are ever going to own. In the first years of life, some of theses neurons are then pruned due to a dynamic selection process. From then on, the only serious change to the brains was thought to come from cell death or inflicted lesions.

Not so. The brain actually continues to rebuild itself throughout life. For instance, new cells are born in the hippocampus. And a new study from a group at MIT demonstrates that adult dendrites of non-pymidal neurons are able to expand their branches. Here's the abstract:

Despite decades of evidence for functional plasticity in the adult brain, the role of structural plasticity in its manifestation remains unclear. To examine the extent of neuronal remodeling that occurs in the brain on a day-to-day basis, we used a multiphoton-based microscopy system for chronic in vivo imaging and reconstruction of entire neurons in the superficial layers of the rodent cerebral cortex. Here we show the first unambiguous evidence (to our knowledge) of dendrite growth and remodeling in adult neurons. Over a period of months, neurons could be seen extending and retracting existing branches, and in rare cases adding new branch tips. Neurons exhibiting dynamic arbor rearrangements were GABA-positive non-pyramidal interneurons, while pyramidal cells remained stable. These results are consistent with the idea that dendritic structural remodeling is a substrate for adult plasticity and they suggest that circuit rearrangement in the adult cortex is restricted by cell type–specific rules.

The paper was published in PLoS Biology which means it is open-access. Go grap it!

Lee, WCA. et al. (2006): Dynamic remodeling of dendritic arbors in GABAergic interneurons of adult visual cortex. PLoS Biol 4(2): e29.

Monday, January 09, 2006

Sorry babe, blame it on my D1-receptors!

The most recent issue of Nature Neuroscience contains a truly amazing study by the Thomas Insel-group. Insel and his colleagues have for many years studied pair-formation in prairie voles. Earlier, they have demonstrated that dopamine transmission within the nucleus accumbens (Nacc) facilitates partner-preference formation (i.e., that the infusion of dopamine into Nacc makes male pairie voles seek out female mates). In this new paper, they demonstrate that the rostal shell of Nacc actually contains two different dopaminergic receptors that perform functionally different jobs. One type, called D2, facilitates the approach behavior associated with the formation of a pair-bond. The other, D1, maintains that bond, by antagonizing the activity of the D2-receptors. This "faithfulness" is expressed behaviourally by the male voles figthing off other female voles than the partner. Crucially, D1-receptors are upregulated after the pair-bond has been formed. In other words: the male vole's brain changes with having a relationship - it, figuratively speaking, becomes faithful. Thus, the behavioural process of finding a mate, establishing a relationship and keeping it going depends upon a complicated molecular process in parts of the prairie vole's reward system. This result opens at least two exiting new avenues of ressearch: (1) Will we find the same functional system in the human brain? What is the genetic reason for a vole having more or less D1-receptors, i.e. being able to form long lasting pair-bonds?

I personally wouldn't be surprised if Insel one day receives the Nobel prize. Being the director of NIMH shouldn't hurt!


Aragona, B. et al. (2005): Nucleus accumbens dopamine differentially mediates the formation and maintenance of monogamous pair bonds. Nature Neuroscience 9: 133-139.

More on the Sapir-Whorf hypothesis

The problem with arm-chair hypotheses such as the Sapir-Whorf idea that the language you speak determines how you think, is that they are all-or-nothing contentions. Either language determines thought, or it doesn't. Either the mind is innate, or it is the result of nurture. Things tend not to be so clear-cut. In the next issue of Trends in Cognitive Science Paul Kay and Terry Regier review research done on colour perception - an old Whorfian theme. Turns out that colour naming and colour cognition is neither strictly universal, nor strictly language specific. Say Kay & Regier:

The ‘Whorfian’ debate over color naming and colorcognition has been framed by two questions: (1) Is color naming across languages largely a matter of arbitrary linguistic convention? (2) Do cross-language differences in color naming cause corresponding differences in color cognition? In the standard rhetoric of the debate, a ‘relativist’ argues that both answers are Yes, and a ‘universalist’ that both are No. However, several recent studies, when viewed together, undermine these traditional stances. These studies suggest instead that there are universal tendencies in color naming (i.e. No to question 1) but that naming differences across languages do cause differences in color cognition (i.e. Yes to question 2). These findings promise to move the field beyond a conceptually tired oppositional rhetoric, towards a fresher perspective that suggests several new questions.

This review nicely complements the study Thomas mentions below.


Kay, P. & Regier, T. (In press): Language, thought, and color: recent developments. Trends in Cognitive Science, to appear.

Sunday, January 08, 2006

Brushing up the brain

While we're at it with cosmetic neurology, there is also a nice article by Chatterjee freely available in Neurology. I think the conclusion in this paper says it all:

"In this paper, I have raised issues about cosmetic neurology that our profession will encounter. We may have our personal opinions on the correctness of such “treatments,” but do we have a stand as a profession? We can anticipate facing questions where separating principle from prejudice is not easy and for which there are no easy answers. To make these questions concrete, I invite readers to consider their own views on the following questions:
  1. Would you take a medication with minimal sideeffects half an hour before Italian lessons if it meant that you would learn the language more quickly?
  2. Would you give your child a medication with minimal side effects half an hour before piano lessons if it meant that they learned to play more expertly?
  3. Would you pay more for flights whose pilots were taking a medication that made them react better in emergencies? How much more?
  4. Would you want residents to take medications after nights on call that would make them less likely to make mistakes in caring for patients because of sleep deprivation?
  5. Would you take a medicine that selectively dampened memories that are deeply disturbing? Slightly disturbing?
Such questions are not simply thought experiments. Patients and advocacy groups encouraged by direct advertising to consumers will raise them. How will you respond to these “patients” when they turn to you as the gatekeeper in their pursuit of happiness?"

Remember to take your Targacept

In the growing field of cosmetic neurology, an approach that seeks to enhance the brain's workings, one branch seeks to develop new drugs that not only help those suffering from memory disorders such as dementia. The question is, if it works in these patients, how would it work in healthy individuals? Several studies on both humans and other primates and mammals now show that our memories CAN be enhanced through pharmacological interventions.

So, now it can be done. Question is: should we do it? I think your answer partially depends on how you view how our brains are constructed and how they work. It seems to me that most people think that the brain (our mind) is more or less are naturally given, and highly adaptive mechanisms. To a certain extent, this is true. However, as Martin's piece on Dehaene's showed, the brain is not a perfect machinery but has inherent and many flaws and shortcomings. memory is a good example. How often have you tried to remember the name of a person standing in front of you -- remembering YOUR name? Or where your put your keys? Simple examples, yes. But they show that our memory is not perfect, at least not as perfect as we'd want it to be (sometimes). Just think of that 8-hours exam you read up to, just for sitting there trying to remember a piece of vital information for a key question.

So are there any memory pills out there? The piece below discusses how Targacept works on the nicotine receptor. To know a bit more on one role of this receptor system, you may also read Nancy Woolf's article in Science & Consciousness Review.

_/_/_/_/_/_/_/

Targacept compounds show long-lasting improvement in cognition

Winston-Salem, NC, June 30, 2005 – In a review of research to be published in the July issue of Trends In Pharmacological Sciences, Targacept compounds were reported to have a beneficial effect on cognition well after they were no longer present in the central nervous system. For example, in preclinical animal studies, Targacept's compounds TC-1827 and TC-1734 improved cognitive performance for up to 15 and 18 hours, respectively, though the compounds were appreciably metabolized and eliminated in less than an hour.

The authors postulate that the compounds' long duration of effect arises from their ability to normalize levels of acetylcholine, a key neurotransmitter for modulating cognition. This mechanism of action contrasts with currently marketed drugs for conditions marked by impaired learning and/or memory, which can increase, but not normalize, neurotransmitters involved in cognitive processing.
(...)

Read more at Targacept.com

Friday, January 06, 2006

The economic mammal

How are economic decisions made? How and why are we social? According to the traditional economic , humans are rational and self-regarding beings. Not so, says recent advances in neuroeconomics, the scientific multidisciplinary approach that studies how we make choices and act socially. On the contrary, our social interactions are thought as driven by strategic (mostly unconscious) incentives. At the least we should not think of ourselves as rational beings that are constantly choosing our own behaviour consciously. This also relates to my ongoing "dethronement" idea, especially step III.

A new article in Science by Colin Camerer and Ernts Fehr presents aspects of this discussion.


_/_/_/_/_/_/_/_/

Science 6 January 2006:
Vol. 311. no. 5757, pp. 47 - 52
DOI: 10.1126/science.1110600

Review

When Does "Economic Man" Dominate Social Behavior?

Camerer and Fehr
The canonical model in economics considers people to be rational and self-regarding. However, much evidence challenges this view, raising the question of when "Economic Man" dominates the outcome of social interactions, and when bounded rationality or other-regarding preferences dominate. Here we show that strategic incentives are the key to answering this question. A minority of self-regarding individuals can trigger a "noncooperative" aggregate outcome if their behavior generates incentives for the majority of other-regarding individuals to mimic the minority's behavior. Likewise, a minority of other-regarding individuals can generate a "cooperative" aggregate outcome if their behavior generates incentives for a majority of self-regarding people to behave cooperatively. Similarly, in strategic games, aggregate outcomes can be either far from or close to Nash equilibrium if players with high degrees of strategic thinking mimic or erase the effects of others who do very little strategic thinking. Recently developed theories of other-regarding preferences and bounded rationality explain these findings and provide better predictions of actual aggregate behavior than does traditional economic theory.

Read more

Wednesday, January 04, 2006

Science's dangerous ideas

Every year renowned literary agent John Brockman asks a group of prominent scientists a question and posts their answers at his web-site The Edge. This years question is "what is your dangerous idea". In his reply, French neuroscientist Stanislas Dehaene raises the question of neuro-enhancement. As was the case with the Nation article mentioned below, neuro-enhancement is most often viewed as a dubious affair - potentially dangerous and socially unfair. Dehaene, in contrast, is very much in favour of it. We tend to overlook, he writes, just how inherently limited our brain is. If possible, we should do something about this limitation. An excerpt from his reply:

As we gain knowledge of brain plasticity, a major application of cognitive neuroscience research should be the improvement of life-long education, with the goal of optimizing this transformation of our brains. Consider reading. We now understand much better how this cultural capacity is laid down. A posterior brain network, initially evolved to recognize objects and faces, gets partially recycled for the shapes of letters and words, and learns to connect these shapes to other temporal areas for sounds and words. Cultural evolution has modified the shapes of letters so that they are easily learnable by this brain network. But, the system remains amazingly imperfect. Reading still has to go through the lopsided design of the retina, where the blood vessels are put in front of the photoreceptors, and where only a small region of the fovea has enough resolution to recognize small print. Furthermore, both the design of writing systems and the way in which they are taught are perfectible. In the end, after years of training, we can only read at an appalling speed of perhaps 10 words per second, a baud rate surpassed by any present-day modem.

Nevertheless, this cultural invention has radically changed our cognitive abilities, doubling our verbal working memory for instance. Who knows what other cultural inventions might lie ahead of us, and might allow us to further push the limits of our brain biology?



Read all the - many interesting - answers here.

Language helps vision

There is no doubt that there are hemispheric differences in the brain. We know that in most people, the left hemisphere is dominant for language production. Damage to the left lateral prefrontal cortex produces the well-known expressive aphasia. On the other hand, language comprehension is seen to involve both hemisphere, or at least that the hemispheric asymmetry is lower.

So much for language. But does language influence the way we perceive things? According to the old Sapir-Whorf hypothesis there is a systematic relationship between the grammatical language a person speaks and how that person both understands the world and behaves in it. In other words, language influences thought. But does language influence "direct" perception as well?

In a recent study in PNAS, Gilbert and colleagues from the Ivry Lab demonstrate that language may play a role in perception. Below is a quote from Nature with further link to the full version. The original article by Ivry can be found here.

_/_/_/_/_/_/_/_/

The language-loving left hemisphere of the brain can spot different colours faster than it can identify different shades of the same colour.

Our perception of colours can depend on whether we view them from the left or the right, scientists have found. They say this demonstrates how language can alter the way we see the world.

The idea that language can affect cognition is not new. In the 1930s, the American linguist Benjamin Lee Whorf proposed the controversial hypothesis that the structure of language affects the way people think. Later studies have hinted that this may be true in some circumstances (see 'Tribes without names for numbers cannot count'). But whether language affects our perception of the world has remained an open question.

Richard Ivry of the University of California, Berkeley, and colleagues suspected that separating out the effects of visual input to the right and left brain hemispheres might yield some clues. Language is processed mainly in the left hemisphere of the brain, which also deals with signals from the left side of the retinas in both our eyes.

Because light from objects to our right falls mainly into the left-hand area of our retinas, the researchers hypothesized that colours to the right would feel the influence of language more keenly. Conversely, objects on our left side activate the right hemisphere of the brain, so the effect of language would be minimal.

Full Text at Nature

Tuesday, January 03, 2006

The Convergence of Brain Structure and Function

A special issue of Anatomy and Embryology is out, dedicated to the issue of brain structure vs. function. It has several interesting articles, such as the developmental dynamics of the primate brain, historical antecedents to the current structure-function debate, and mirror neurons in the brain. The list of interesting articles is long.

Find the special issue here.

Monday, January 02, 2006

The plastic brain - reviews

The journal Science has an issue dedicated to brain development and brain plasticity. Models of the brain have changed from viewing plasticity as something occurring only at the early developmental stages to a view stressing a life-long plasticity of the brain. As a result, we need new understandings of how the brain works at all ages, and if there are qualitative stages or changes in the brain between different life age stages, e.g. in how genes are expressed. Neither the mind or its fatty counterpart should be seen as stable over time, and significant changes occur even in the oldest age; changes that are not attributable to degeneration only. even old brains can learn.

_/_/_/_/_/_/_/_/

Neuroscience: Systems-Level Brain Development

Peter Stern and Pamela J. Hines
Full article

Our brains show the highest degree of plasticity during the early phases of life. However, not all is lost as we advance in years. A certain level of flexibility and adaptability will be with us throughout life. To fully understand the operations and functions behind these processes, it is not enough to concentrate solely on the molecular and cellular components and their interactions. Nor, at the other end of the spectrum, is the study of higher cognitive functions sufficient: It is often too remote to provide comprehensible mechanistic insight. The leap from cells to thought seems almost infinitely complex, yet every growing child manages to make it. Somewhere in this middle ground, between molecular components and psychology, lie the means by which familial and educational experiences intersect with developmental biology to shape cognitive abilities and personalities. We have thus decided to focus on the systems level instead. This approach has been extremely successful over the years and provided us with a wealth of novel and sometimes astonishing insights. (...)

Nation article on neuroethics

Neuroethics is slowly beginning to get some attention from the non-academic press. One of the persons responsible for this emerging interest is Martha Farah who has written a number of papers on neuroethics. (Find them here at her homepage.) She has also been instrumental in establishing the Neuroethics Centre at the University of Pennsylvania which has an informative webpage. Recently, she has been named an action editor at the Journal of Cognitive Neuroscience, charged with the task of including papers on neuroethics in the journal.

In the January 9 issue of the journal The Nation Kathryn Schulz has a piece on neuroethics where she interviews Farah and Neuroethics Centre director Arthur Caplan. The article focuses on the two most basic ethical problems that neuroscientific research raises. (1) Implications of insights into brain function. Can the ability to probe people's brains be misused? (As Thomas mentions below, neuroimaging could possibly become a mandatory part of job interviews.) Should our understanding of agency change the legal system? (2) Neuroenhancement. When we come to understand the molecular processes governing the brain this knowledge could potentially be used to change the way people's brains work. This possibility is of course already a reality, with psychopharmacology leading the race, but it will continue to grow in importance. Who should have access to such enhancing drugs and surgery? What part of our mind and personality should be exempt from outside meddling?

In the last part of the article Schulz raises a third ethical problem which has received somewhat less attention. Being a liberal or progressive journal, The Nation is prone to see technological fixes as more dubious than more basic social changes. However, the idea of changing people through social changes pressuposes a plastic idea of the brain: People's values can be changes through their environment. Opposed to this view is "human nature" contention that we are born with a specific set of cognitive faculties that are only malleable to a very small degree. This old nature vs. nuture question is alive and well and concerns our very self-image: What is a human being? Neuroethics should be encouraged to take up such basic philosophical question as well.


Reference

Schulz, K. (2006): Brave neuro world: The ethics of the new brain science. The Nation (January 9, 2006).

You are your amygdala

Show my your amygdala size and I'll tell you who you are! In a study by Omura, Constable & Canli in the November 2005 issue of NeuroReport (see abstract + links below), the sizes of the right and left amygdalae were compared to assessment of the levels of extraversion and neuroticism. The results indicated that the smaller your right amygdala is the more neurotic you are. A larger left amygdala correlated with being more extravert.

How long before your job application includes a mandatory brain scan? Well, as soon as there is only a correlation between amygdala size and personality inventory subscales then the personality subscales is cheaper to use. But psychological tests are prone to errors and the time of assessment. A brain scan is more objective, since your brain does not alter its shape (dramatically) from day to day. But the amygdala might not be the only place one could test. Depending upon the job we could add brain scans for working memory, visual perception, empathy and social reasoning. It might not be here just yet, but it might very well be within our reach to do this.

The term 'head-hunting' can indeed get a new meaning.


_/_/_/_/_/_/_/_/

Neuroreport. 2005 Nov 28; 16(17): 1905-8

Using high-resolution magnetic resonance imaging and voxel-based morphometry in 41 healthy individuals, this study evaluated the association between the personality traits of extraversion and neuroticism, on the one hand, and individual differences in localized brain volume and gray matter concentration, on the other, with a special focus on the amygdala. Extraversion was positively correlated with gray matter concentration in the left amygdala, whereas neuroticism was negatively correlated with gray matter concentration in the right amygdala. Given that neuroticism is a risk factor for depression, our finding offers one explanation as to why prior structural imaging studies of depressed patients (which did not control for personality) produced conflicting findings. Furthermore, our data are consistent with the view that amygdala reduction seen in depressed patients precedes the onset of the disease, rather than being a consequence of the illness.

The making of false memories


For many years researchers in cognitive neurscience have known that episodic memory does not work like a tape recorder or a computer hard drive. Recollection of events is not a simple replay from a fixed store. Rather, episodic memory (and memory in general) is today seen as a dynamic - even fragile - reconstruction process. As a consequence, errors can happen, and they do. One of these kinds of recall errors are false memories. But what are the mechanisms behind false memories? Why do things go wrong? In a paper by Lampinen et al. false memories are studied experimentally. They shed light on two special features in false memories; borrowing and vividness.

The mere existence of false memories are serious news for the use of eye witness testimonies, even for victims of violent acts such as rape. If memories cannot be treated as true, but are unstable, influenced by the context in which it is recalled, how can we make use of it at all. Vivid false memories, as described by Lampinen et al., attest that even if a person is certain about his memory about an event they can be false.

The discussion of false memories also applies to the publication of memory's "shaky trace" (PDF) a couple of years ago. It's an interesting finding that memories can be altered and even deleted at the time of retrieval. Put into more practical terms; depending on how you ask your question you will get different answers from memory. What keeps the same is that the person feels that the memory is genuine.

_/_/_/_/_/_/_/_/_/_/_/

Compelling Untruths: Content Borrowing and Vivid False Memories

by James Michael Lampinen et al.
Journal of Experimental Psychology: Learning, Memory, and Cognition - Volume 31, Issue 5 , September 2005, Pages 954-963''

Abstract False memories are sometimes accompanied by surprisingly vivid experiential detail that makes them difficult to distinguish from actual memories. Such strikingly real false memories may be produced by a process called content borrowing in which details from presented items are errantly borrowed to corroborate the occurrence of the false memory item. In 2 experiments using think-out-loud protocols at both study and test, evidence for content borrowing occurred for more than half of the false remember judgments participants reported. The present study also provides evidence consistent with recollection rejection and distinctiveness playing a role in false-memory editing.

ScienceDirect

Sunday, January 01, 2006

Our inner ape

Below I discuss the continuity of the human and chimp brains. I also briefly mentioned the much exiting research being done these years on chimp behaviour. One of the primatologists leading this research effort is Frans de Waal. The Guardian just published a review of his latest book Our Inner Ape. Read it here.

Musicians are different from you and me

You probably knew this already, but now it has been proved: Musicians are different from you and me. Mounting evidence suggests that playing an instrument will literally change your brain to the point, even, of altering your motor system macroanatomically in some cases. In a forthcoming paper in NeuroImage Marc Bangert and his colleagues demonstrate that musicians also use their brains in a different manner. They imaged a group of musicians and a group of non-musicians using fMRI while either listening passively to a piano sequence or arbitrarily pressing the keys on a soundless piano keyboard. They then looked for differences in brain activity between the two groups in accomplishing these two tasks.

The passive listening task yielded more activation in the professional pianist group in premotor and motor cortex, in BA 10, in left inferior and superior temporal gyrus, and in left Broca’s area. The key-pressing task yielded extraordinary activity in the pianists in the medial frontal and precentral gyri, in dorsolateral PFC, in Broca’s area, and parts of the limbic system.

Bangert & Co afterwards performed a conjunction analysis, singling out the areas active more so in the pianist group in both tasks. According to the abstract of the papers

This network is comprised of dorsolateral and inferior frontal cortex (including Broca’s area), the superior temporal gyrus (Wernicke’s area), the supramarginal gyrus, and supplementary motor and premotor areas.

It is hardly surprising that professional pianists recruit a network of brain processes different from that of novices when playing. But that they also listen to music in a different manner – at least using a different neurocognitive system in their brains – is very interesting news. Could it be that their phenomenal experience is also different?


Reference

Bangert, M. et al. (in press): Shared networks for auditory and motor processing in professional pianists: Evidence from fMRI conjunction. NeuroImage, to appear.