We know a great deal about the relative genetic and environmental influences on average intelligence and on learning disabilities, but far less about the role of genes in exceptional cognitive ability – in lay terms, what we might call genius or innate talent.A new "mega-analysis" of 11,000 twin pairs, aged between 6 and 71, has helped to plug that gap. The results suggest that genes exert a significant influence on exceptional cognitive ability, similar in magnitude to their influence on the normal range of intelligence. The findings challenge versions of the "discontinuity hypothesis" – the idea that the relative contribution of nature and nurture changes for exceptional ability.Claire Haworth and colleagues, of the newly-established Genetics of High Cognitive Abilities (GHCA) consortium, combined data from six studies, involving twins from four countries – the UK, Netherlands, Australia and United States. Combining so much data altogether allowed them to restrict their analyses to participants in the top 15 per cent for intelligence performance, whilst still maintaining enough power for statistical tests.By comparing intelligence differences between pairs of identical twins (who share all their genes) and non-identical twins (who share half their genes like normal siblings), the study showed that genetic differences explained approximately half the variation found in high intelligence, whilst shared environmental factors - those experienced by both twins in a pair, such as education and parenting style - explained just 28 per cent of the variation. The remaining influence is down to unique environmental influences (experienced by one twin but not the other) and other unknown factors.The observed level of genetic influence on exceptionally high intelligence is similar to that found by the researchers for the normal range of intelligence in the same sample of twin pairs, and supports the idea that exceptional cognitive ability is on a continuum with the normal range of intelligence, and is likely subject to the same genetic and environmental influences. However, final proof that the same genes affect high intelligence and the normal distribution won’t be found until specific genes are identified through DNA testing of gifted and control participants.It should be noted that the cited contributions of genes and the environment aren’t necessarily fixed. Rather these estimates reflect the amount of variation explained by genetic and environmental factors for this particular group of twin participants at one particular time. The generalisability of the findings are, however, enhanced by the large size and cross-national nature of the sample. Another caveat is that investigating the top 15 per cent of intelligence test performers may not be high enough to capture any influences that uniquely affect exceptional cognitive ability."We hope that our study, the many interesting and unanswered questions about high cognitive ability, and the importance of studying the high end of the distribution of ability as well as the low end, will stimulate much-needed research on the genetics of high cognitive ability," the researchers said._________________________________Haworth, C., Wright, M., Martin, N., Martin, N., Boomsma, D., Bartels, M., Posthuma, D., Davis, O., Brant, A., Corley, R., Hewitt, J., Iacono, W., McGue, M., Thompson, L., Hart, S., Petrill, S., Lubinski, D., & Plomin, R. (2009). A Twin Study of the Genetics of High Cognitive Ability Selected from 11,000 Twin Pairs in Six Studies from Four Countries. Behavior Genetics, 39 (4), 359-370 DOI: 10.1007/s10519-009-9262-3... Read more »
Haworth, C., Wright, M., Martin, N., Martin, N., Boomsma, D., Bartels, M., Posthuma, D., Davis, O., Brant, A., Corley, R.... (2009) A Twin Study of the Genetics of High Cognitive Ability Selected from 11,000 Twin Pairs in Six Studies from Four Countries. Behavior Genetics, 39(4), 359-370. DOI: 10.1007/s10519-009-9262-3
A great story made its way onto the interwebz lately. The Daily Mail reports:"A 10-year-old girl born with half a brain has both fields of vision in one eye, scientists said today. The youngster, from Germany, has the power of both a right and left eye in the single organ in the only known case of its kind in the world."University of Glasgow researchers used Functional Magnetic Resonance Imaging (fMRI) to reveal how the girl’s brain had rewired itself in order to process information from the right and left visual fields in spite of her not having a whole brain."BBC News goes further with:"In the case of the German girl, her left and right field vision is almost perfect in one eye. Scans on the girl showed that the retinal nerve fibres carrying visual information from the back of the eye which should have gone to the right hemisphere of the brain diverted to the left ... 'Despite lacking one hemisphere, the girl has normal psychological function and is perfectly capable of living a normal and fulfilling life. She is witty, charming and intelligent.'"Get that? The only known case in the world where brain plasticity (the ability of the brain to reorganise itself after injury) is displayed for all to see. Plasticity doesn't always work this way, there are many cases where plasticity effects haven't achieved the mark of restoring all or most of the impaired brain function. Epilepsy patients, for example, who undergo a hemispherectomy (removal of a half of a brain) in order to prevent the onset of severe seizures, among other things tend to lose an entire field of vision in both eyes; they only see people and objects in one half of their visual field, as in the illustration below:Neither was this a case of brain injury; the anonymous girl (known only as 'AH') failed to adequately develop her cerebral right hemisphere in the womb. As a result, she is without a right-brain and also without the use of her right eye. She also has a slight left-hemiparesis (weakness affecting half of the body) but close to normal vision in both hemifields of her normal left eye.In a study published by the Proceedings of the National Academy of Sciences (PNAS), a team led by Lars Muckli of the University of Glasgow used fMRI to investigate how the visual cortex had remapped itself. In a healthy individual, the cerebral cortex contains "maps" for vision, sound, motion and touch, which develop and modify over time dependent on several factors including genetic cues and neural activity. In the mammalian brain (that is, human brain) the visual cortex is made up of distinct sections dealing with vision, the main one being an area known simply as 'V1', the primary visual cortex. 'V2' deals with quarterfield representations in the area of vision, effectively dealing with the 'up' and 'down' areas of both the right and left hemispheres of vision, while 'V3' is a structure in front of V2 that, among other things, performs a supporting role for V2. There is also the question of retinotopic maps, a direct mapping of the spatial arrangement of the retina, located in visual structures including the cortex and thalamus.As per materials provided by the University of Glasgow, "visual information is gathered by the retina at the back of the eye and images are inverted when they pass through the lens of the pupil so that images in your left field of vision are received on the right side of the retina, and images from the right are received on the left." The part of the retina close to the nose is known as the nasal retina whereas the other part is referred to as the temporal retina, being in proximity to the temples. Both halves transmit received information through separate nerve fibres. In a normal situation, the nerve fibres of the nasal retina cross over in the optic chiasm, a brain structure located at the bottom of the brain near the hypothalamus, and are processed by the hemisphere on the opposite side. The nerve fibres of the temporal retina remain in the same hemisphere (ipsilateral), meaning that the left and right visual fields described earlier are processed by opposite sides of the brain.[DIGRESSION]Vision is not the only modality to be processed in this strange way. It actually reflects the larger processing activities of the intact brain which tends to process all other modalities in opposite sides of the brain. To wit, touch and hearing for example that is "entered" into the right side of the body (right body, right ear) are processed by the left-brain, and touch/hearing entered into the left body/ear is processed by the right-brain. This is generally referred to as contralateral processing, when input is processed by the 'opposite' half of the brain. Those inputs processed by the 'same' side of the brain is known as ipsilateral processing. For more information, please read about Basic Visual Pathways.[/DIGRESSION]The MRI scan displays the complete lack of a right-hemisphere: The optic chiasm is shown here (top l-r) in the transverse and enlarged transverse planes, and (bottom l-r) in the coronal and saggital planes. A rudimentary optic nerve is pointed out in the enlargement by the green arrow but with no discernible optic tract, and it can also be seen how the left-hemisphere is spilling over into the right-domain. The vacant right-hemisphere is filled with cerebrospinal fluid (CSF).In AH's fascinating case, it was found that the nasal retinal nerve had connected to her left-brain. A possible interpretation for AH's condition is suggested by the authors: The lack of a right-brain prevented an opposite connection from being made, which led the optic nerve fibers to "connect" with ipsilateral structures instead.Remembering that normal cases require a crossing in the optic chiasm, and AH's connections were essentially ipsilateral, how exactly does AH see both visual fields with only one eye? After all, if the entire right hemisphere is missing, AH should see only the left hemifield. The answer lies with the Lateral Geniculate Nucleus (LGN), a structure that is embedded deep in the thalamus and which processes visual information from the retina. In AH, both the nasal and temporal retina would need to be mapped onto the LGN to allow for the processing of both hemifields. Again a similar suggestion of ipsilateral projections were presented as being the solution, instead of the usual contralateral connections, and that a mirror-symmetric representation of the hemifields would be received and processed by the thalamus. Similar cases have been seen in achiasmatic dogs where optic nerve fibres terminated in the ipsilateral LGN.'Islands' were also found to have formed in the left-hemisphere to deal especially with processing of the left hemifield, to compensate for the missing right-brain activity.The loss of AH's right-hemisphere was discovered at age 3 when she was treated for brief seizures and twitching taking place on her left side. It is speculated that the right-brain failed to develop between Day 28 and Day 49 of embryonic development. Despite the situation, she is able to engage quite capably in activities that require a fair amount of balance, such as riding a bicycle or roller-skating. Truly an extraordinary case in more ways than one.For a professional view, please see Dr. Steven Novella's entry on this case.---------------------------------------------------------------------... Read more »
Muckli, L., Naumer, M., & Singer, W. (2009) Bilateral visual field maps in a patient with only one hemisphere. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.0809688106
There are a number of strategies people use to keep their mates their own. Find out what these behaviors are and how they impact relationships.... Read more »
SHACKELFORD, T., GOETZ, A., & BUSS, D. (2005) Mate retention in marriage: Further evidence of the reliability of the Mate Retention Inventory. Personality and Individual Differences, 39(2), 415-425. DOI: 10.1016/j.paid.2005.01.018
New Zealand’s most iconic reptile, the tuatara, is currently regarded as two separate species – Sphenodon guntheri, which is found naturally only on North Brother Island in Cook Strait, and Sphenodon punctatus, which are found on other islands in Cook Strait and off the north-east coast of the North Island. However research just published [...]... Read more »
Hay, J., Sarre, S., Lambert, D., Allendorf, F., & Daugherty, C. (2009) Genetic diversity and taxonomy: a reassessment of species designation in tuatara (Sphenodon: Reptilia). Conservation Genetics. DOI: 10.1007/s10592-009-9952-7
I received a disappointing email yesterday from a colleague at the Children's Hospital of Eastern Ontario Research Institute pointing me to this article on transit fees in the City of Ottawa (where I currently live, work, and go to school). The article describes a recent change which makes all students 28 and older ineligible for City of Ottawa "student" transit fares. This will mean that many graduate students, medical students, and even "mature" undergraduate students will now have to pay the regular adult fare, which ads up to an extra $240/year. According to this article on the Ottawa Citizen website "Council approved the change as a way to save money and balance the budget". The city expects this change to bring in a meagre $220,000, but would cost many students more than half a month's rent over the course of a year.... Read more »
Lachapelle, U., & Frank, L. (2009) Transit and Health: Mode of Transport, Employer-Sponsored Public Transit Pass Programs, and Physical Activity. Journal of Public Health Policy. DOI: 10.1057/jphp.2008.52
Urgh, exams. The epic ‘true-false-no idea’ multiple choicers of my undergraduate days are not a distant enough memory for me. The whole ‘get it right, get 1 point’, ‘get it wrong, lose 1 point’ approach always seemed horrendously unfair, regardless of the statistical basis for the strategy (i.e. examiners don’t want to reward people that [...]... Read more »
Kelly, S., & Dennick, R. (2009) Evidence of gender bias in True-False-Abstain medical examinations. BMC Medical Education, 9(1), 32. DOI: 10.1186/1472-6920-9-32
Digital industries continue to wage an unwinnable war against the people and organisations that illicitly copy, share, and sell their products, whether DVD rips, DRM-free music files, or pirated software. But, while arguments about lost revenues, performing rights, and the rest of it rage, at least digital copyright theft is not usually a matter of [...]%%Counterfeit Drugs%% is a post from: Sciencebase Science Blog... Read more »
Derek L Bosworth. (2009) Counterfeiting in global pharmaceuticals sector: its consequences and management. International Journal of Intellectual Property Management, 3(4), 343-356. DOI: 10.1504/IJIPM.2009.026911
Everyone knows that the MHC is in the MHC, right? Well, it’s not necessarily so.
That’s not as tautological as it sounds. MHC (major histocompatibility complex) can refer to either the protein complex, or to the genomic region. In most species the genes encoding MHC proteins are clustered together into a distinct region [...]... Read more »
Siddle, H., Deakin, J., Coggill, P., Hart, E., Cheng, Y., Wong, E., Harrow, J., Beck, S., & Belov, K. (2009) MHC-linked and un-linked class I genes in the wallaby. BMC Genomics, 10(1), 310. DOI: 10.1186/1471-2164-10-310
What is cyberbullying?
Cyberbullying techniques use modern communication technology to send derogatory or threatening messages directly to the victim or indirectly to others, to forward personal and confidential communication or images of the victim for others to see, and to publicly post denigrating messages
Cyberbullying has been in the news mostly for children and young adults. There [...]... Read more »
Privitera, C., & Campbell, M. (2009) Cyberbullying: The New Face of Workplace Bullying?. CyberPsychology , 2147483647. DOI: 10.1089/cpb.2009.0025
The research community is rapidly reproducing the past ten years of stem cell technology demonstrations, using induced pluripotent stem (iPS) cells this time around. You'll recall that iPS cells are normal cells - usually skin cells - reprogrammed to act as though they are stem cells. The methodology is well within reach of any laboratory previously working on stem cells, and many research groups have dived into the fray since the first publication of the reprogramming method. Rapid progress has been made in a very short time, a characteristic state of affairs for biotechnology these days. As a recent paper shows, iPS researchers have reached the point of demonstrating regeneration of damaged hearts in mice. Non-scientists might prefer the press release to the original paper: The ultimate goal is to use iPS cells derived from patients to repair injury. Using a person's own cells in the process eliminates the risk of rejection and the need for anti-rejection drugs. One day this regenerative medicine strategy may alleviate the demand for organ transplantation limited by donor shortage, the researchers say. ... The Mayo Clinic team genetically reprogrammed fibroblasts via a "stemness-related" human gene set to dedifferentiate into an iPS cell capable of...... Read more »
Nelson, T., Martinez-Fernandez, A., Yamada, S., Perez-Terzic, C., Ikeda, Y., & Terzic, A. (2009) Repair of Acute Myocardial Infarction With Induced Pluripotent Stem Cells Induced by Human Stemness Factors. Circulation. DOI: 10.1161/CIRCULATIONAHA.109.865154
An ongoing debate today is the relative contribution of total body fat and waist-hip ratio to evaluations of female body attractiveness. Converging research has tended to support a more significant role for total body fat (as measured by BMI or VHI) than for WHR. Using a novel eye tracking methodology, Cornelissen, et.al. (2009) have found [...]... Read more »
Cornelissen, P., Hancock, P., Kiviniemi, V., George, H., & Tovée, M. (2009) Patterns of eye movements when male and female observers judge female attractiveness, body fat and waist-to-hip ratio. Evolution and Human Behavior. DOI: 10.1016/j.evolhumbehav.2009.04.003
RESEARCHERS at the University of California, Berkeley have developed a microscope attachment which enables a standard mobile phone with a camera to be used for high-resolution clinical microscopy. Daniel Fletcher and his colleagues describe the CellScope in a paper published today in the open access journal PLoS One, and demonstrate that it can be used to capture high quality bright field images of the malaria parasite and sickle blood cells, as well as fluorescence images of cells infected with the bacterium that causes tuberculosis. The device could potentially become an important tool for medical diagnostics in the developing world, where resources are limited and laboratory facilities scarce, but where mobile phone networks are ubiquitous. Read the rest of this post... | Read the comments on this post...... Read more »
Breslauer, D. N. et al. (2009) Mobile Phone Based Clinical Microscopy for Global Health Applications. PLoS One, 4(7).
If you're interested in the link between religion and mental health, there's a new open access review in the Canadian Journal of Psychiatry. It's by Harold Koenig, who's one of the world's leading experts on religion and mental health.His conclusion: religious people are less likely to be depressed, anxious, or attempt suicide. The evidence is mostly cross-sectional – showing that depressed people are less likely to be religious, for whatever reason. But there are also a number of longitudinal studies, showing that people who are religious are less likely to become depressed in the future.For people with psychotic delusions, the picture is more complicated. They are frequently highly religious, but the longitudinal studies suggest that psychosis comes first.Koenig's conclusion, that religion can help to reduce symptoms of anxiety and depression, isn't terribly surprising. But what jumps out from the review is how many questions are left unanswered. For example,What's the magnitude of the effect? Is it big enough to make any meaningful difference? How does it compare with other factors that influence depression? Is it effective in severe depression, or just in mild depression (where placebos are also highly effective)?Is it religious beliefs, or attendance, or simply the much more vague concept of 'spirituality' that is important? Koenig's review doesn't really distinguish between them, probably because, historically, studies into the effects of religion didn't tend to.What does it all mean for the treatment of mental illness? In an accompanying paper, Marilyn Baetz and John Toews try to unpack this conundrum - and they fully admit that they don't have much to go on.They do give some practical advice, but even that demonstrates just how confusing this field can be for the unwary. They reckon that you can treat depression by encouraging a spirit of altruism, gratitude and forgiveness.It's sound advice, no doubt. But I think that most atheists would rankle at the idea that these fall under the heading of 'religious and spiritual' interventions!So we really are still a very long way away from answering the key question. To boil it down, I want to know whether it's possible to treat depression by prescribing a dose of religion. And if it is, then is it more effective than other treatment options?If it turns out that a good way to treat depression is to pack people off to their local imam, then that really will raise some interesting ethical issues!_______________________________________________________________________________________This work by Tom Rees is licensed under a Creative Commons Attribution-Share Alike 2.0 UK: England & Wales License.... Read more »
Rees, TJ. (2009) Is Personal Insecurity a Cause of Cross-National Differences in the Intensity of Religious Belief?. Journal of Religion and Society. DOI: http://moses.creighton.edu/JRS/2009/2009-17.html
The Eye-in-the-Sea camera will be freshly baited with a frozen sea lion carcass in a camera deployment set for August 14th, in the deep Monterey Canyon. Mark your calendars and tune in to the Ocean Research Conservation Organization (ORCA) website for updates on the event. The ever fascinating Dr. Edie Widder, the ORCA President, will [...]... Read more »
by Nestor Lopez-Duran PhD in Child-Psych
I was just reading a study that examined the proposed pathways from sleep problems in preschool children to behavioral disruption during the day. Specifically, a team from the MINDS institute at UC Davis was interested in exploring some possible reasons that could explain why sleep problems often lead to behavioral dysregulation during the day. The [...]... Read more »
Goodlin-Jones, B., Tang, K., Liu, J., & Anders, T. (2009) Sleep problems, sleepiness and daytime behavior in preschool-age children. Journal of Child Psychology and Psychiatry. DOI: 10.1111/j.1469-7610.2009.02110.x
[Originally posted in November 2006]
The recent controversial shooting of an unarmed black man in New York has generated terrible grief and perhaps justifiable anger. But if officers honestly believed the man was armed and intended to harm them, weren't they justified in shooting?
Perhaps, but an important additional question is this: were they predisposed to believe he was armed simply because he was black? Consider this quick movie:
Click to play (QuickTime required)
It will flash two pictures. One man is armed, the other unarmed. Who do you shoot? I've primed you to think about race, so it's not really a fair test. If you were a police officer who believed his life to be in danger, would you respond in the same way? (You can use the slider to see which man really was armed.)
In 2003, a team led by J. Correll flashed random photos of white and black faces, some superimposed with guns, others with harmless items such as cell phones and wallets. They asked college students to press one key indicating "shoot" the suspect, and another indicating "don't shoot." The students were more likely to mistakenly fire at black faces that were unarmed compared to unarmed white faces.
But what about police officers? With their special training and rules about when to fire, perhaps they will do better. A study by E. Ashby Plant and B. Michelle Peruche tested police officers on a similar task. Read the rest of this post... | Read the comments on this post...... Read more »
Ashby Plant, E., & Michelle Peruche, B. (2005) The Consequences of Race for Police Officers' Responses to Criminal Suspects. Psychological Science, 16(3), 180-183. DOI: 10.1111/j.0956-7976.2005.00800.x
If you’ve ever taught an online course, or used a discussion board feature in any class, you may have wondered as I did whether to require students to respond to other students. Also, should I, as the instructor, respond to all the students’ posts or does that inhibit other students from responding? An article by [...]... Read more »
An, H., Shin, S., & Lim, K. (2009) The effects of different instructor facilitation approaches on students’ interactions during asynchronous online discussions. Computers , 53(3), 749-760. DOI: 10.1016/j.compedu.2009.04.015
Hana Kucera has always had an interest in science. Kucera credits her scientific fascination to her parents who first introduced her to the observation, exploration and study of living things in their natural habitats. She graduated from British Columbia’s Simon Fraser University in 2004 with a B.Sc. in Biology. As a Master’s student at the University of New Brunswick in the fall of 2004, Kucera began her research in Dr. Gary Saunders’ lab studying the diversity of marine intertidal seaweeds of Canada using variation in DNA barcode sequences. Kucera subsequently transferred to the PhD program, where she is currently finishing the “last bits of lab work” to complete her PhD.... Read more »
Kucera, H., & Saunders, G. (2008) Assigning morphological variants of Fucus (Fucales, Phaeophyceae) in Canadian waters to recognized species using DNA barcoding. Botany, 86(9), 1065-1079. DOI: 10.1139/B08-056
Unilateral neglect (UN) is a debilitating cognitive deficit following traumatic brain injury with long-term implications to both the person affected and the health care system. In the United States, UN affects up to 200,000 stroke survivors, with the incidence and severity of UN increasing with age. However, UN is rarely recognized by the health care [...]... Read more »
Wee, J., & Hopman, W. (2008) Comparing Consequences of Right and Left Unilateral Neglect in a Stroke Rehabilitation Population. American Journal of Physical Medicine , 87(11), 910-920. DOI: 10.1097/PHM.0b013e31818a58bd
I’ve discussed the concept of vaporware on Sciencetext before. Vaporware is software promised by a company that never seems to be released. Games, operating systems, upgrades…dozens of companies are guilty of producing vaporware. Often it’s down to technical problems, occasionally it’s a marketing ploy.
What about the opposite of vaporware? Software that gets released on to [...]Post from: David Bradley's Sciencetext Tips and Tricks
%%Testing is as Easy as Alpha, Beta, RC%%
Testing is as Easy as Alpha, Beta, RC... Read more »
Bagchi, T. (2009) Risks in software development with imperfect testing. International Journal of Advanced Operations Management, 1(1), 1. DOI: 10.1504/IJAOM.2009.026522
Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.
If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.
Research Blogging is powered by SMG Technology.
To learn more, visit seedmediagroup.com.