Sudip Ghosh, MD – Brain Blogger http://brainblogger.com Health and Science Blog Covering Brain Topics Wed, 30 May 2018 15:00:03 +0000 en-US hourly 1 https://wordpress.org/?v=4.9.6 How to Recharge the Batteries in our Brain http://brainblogger.com/2011/03/31/how-to-recharge-the-batteries-in-our-brain/ http://brainblogger.com/2011/03/31/how-to-recharge-the-batteries-in-our-brain/#comments Thu, 31 Mar 2011 12:00:34 +0000 http://brainblogger.com/?p=6310 In recent years, sleep has been less of an enigma than it was in the 70s and 80s. Memory consolidation is now well known as the prime reason why we actually need sleep, but there is still a lot of controversy regarding the exact mechanism by which sleep alters the learning characteristics of the brain. While the effects of long-term sleep deprivation are much better studied and characterized, the role of napping as opposed to deep slumber has been the subject of a recent study.

Researchers at the University College of Berkley, California, studied in particular the role of the traditionally neglected non–REM phase of sleep in the learning process on a group of 44 volunteers, by subjecting them to rigorous tasks aimed at the hippocampus in particular — memorization. During the non-REM phase of sleep (where there is no rapid eye movement or REM), sharp spikes of electrical activity called sleep spindles were recorded from hippocampal region. Normally, these spikes occur about a 1000 times per night, and are thought to be associated with the process analogous to scrubbing the hippocampus free of short-term memory traces, and helping further short-term memory at accumulation once we wake up. In this study, half of the subjects were allowed to have a 90 minutes nap in between two heavy learning sessions in the afternoon and in the evening. These sleep spindles were noted in the above group, and they typically demonstrated better learning in the evening session, compared to the other half who were not allowed to sleep.

One of the important implications of the study is that non-REM sleep serves an important purpose than commonly thought — recharging the brain for learning. Concomitantly performed electroencephalogram (EEG) studies mapping the brainwaves of the participants showed that there was a distinct correlation between the amount of sleep spindles and the quality of learning soon afterwards. These spikes where seen selectively in the hippocampus, also looping to the prefrontal cortex, the two parts of the brain that are thought to be the key areas involved in learning. Walker, the lead researcher of this study published in a recent edition of Current Biology, stated that sleep selectively restores critical learning functions of the brain. In their opinion, non-REM sleep deprivation typically seen in the older population may account for the reduced memorization capacity during learning. Perhaps it also points out that in chronically sleep deprived individuals, learning performance is justifiably diminished.

But what is the exact mechanism at the cellular level by which sleep affects our learning?

This remains a controversial area within neurology at present and the debated theory of synaptic pruning is a leading candidate with some recent experimental evidence. This theory was first proposed nearly seven years ago by Cirelli and Tononi, neurobiologists based at the University of Wisconsin-Madison, which is essentially based on the idea that when awake, the synapses within our brain grow stronger and proliferate leading to a form of neurological saturation. During sleep there is a massive downscaling of such synaptic connections, thus freeing up nerve cell resources for further learning once we are awake. Despite some supporting evidence in fruit flies and fishes, this theory needs further verification before it is accepted as a general model of how learning occurs in humans. Nevertheless it can explain some of the features of the non-REM sleep enhancement of learning ability seen in the subjects of the UC Berkley study published this earlier this year.

Does sleep therefore help in pruning and unentangling the nerve endings in our brain?

Perhaps time will tell.

References

Mander, B., Santhanam, S., Saletin, J., & Walker, M. (2011). Wake deterioration and sleep restoration of human learning Current Biology, 21 (5) DOI: 10.1016/j.cub.2011.01.019

Tononi, G. (2003). Sleep and synaptic homeostasis: a hypothesis Brain Research Bulletin, 62 (2), 143-150 DOI: 10.1016/j.brainresbull.2003.09.004

]]>
http://brainblogger.com/2011/03/31/how-to-recharge-the-batteries-in-our-brain/feed/ 9
Mind your Immune System http://brainblogger.com/2010/07/12/mind-your-immune-system/ http://brainblogger.com/2010/07/12/mind-your-immune-system/#comments Mon, 12 Jul 2010 12:00:41 +0000 http://brainblogger.com/?p=5043 Another significant piece in the mind-body puzzle comes from this new study where obsessive-compulsive behavior in mice was cured by a bone marrow transplant.

A rare form of a genetic disorder in mice causes a “hair pulling” disorder, very similar to its human counterpart trichotillomania. In their new findings published in Cell, Mario Capecchi and his team at Salt Lake City, Utah found that the basis of this psychological aberration was a reduced population of microglia, which are the immune system cells in the brain. These cells have been long known to be the brain’s scavenger system, playing a vital role in clearing breakdown products and microbes, but its surprising that its depletion leads to a specific form of behavioral disorder.

The genetic mutation responsible was pinpointed to the Hox8 gene, which belongs to a family of genes that determine body plan and architecture in all vertebrates, apart from regulating development and growth of organs. The brain microglia cells are thought to originate from the bone marrow, and are the only brain cells that express this gene — thus they are thought to play a key role in the brain’s development.

The study found that if bone marrow containing Hox8 expressed stem cells (early forms which give rise to microglia) were transplanted to affected mice, their hair pulling disorder was cured within four months. By contrast when bone marrow from affected mice was transplanted into normal ones, the disorder appeared in normal ones.

Apart from the fact that this is the world’s first reported behavior transplant, this finding is an important landmark in our understanding of the genetic basis of behavior. To what extent are our behaviors pre-determined by our immune system and our mine interconnected? To what extent does a malfunction of one lead to problems with the other?

To quote Capecchi,

We know a lot more about the immune system than we know about our brain. We know almost nothing about how the brain works and less about how drugs work. If we say the immune system is important, this opens up a whole new vista of things we can do simply because we know more about the immune system.

References

Chen SK, Tvrdik P, Peden E, Cho S, Wu S, Spangrude G, & Capecchi MR (2010). Hematopoietic origin of pathological grooming in Hoxb8 mutant mice. Cell, 141 (5), 775-85 PMID: 20510925

]]>
http://brainblogger.com/2010/07/12/mind-your-immune-system/feed/ 8
Why Infidelity May Not Be Cheating Anymore http://brainblogger.com/2008/11/11/why-infidelity-may-not-be-cheating-anymore/ http://brainblogger.com/2008/11/11/why-infidelity-may-not-be-cheating-anymore/#comments Tue, 11 Nov 2008 14:37:27 +0000 http://brainblogger.com/?p=1738 Cheating implies some sort of deviation form the norm — staying faithful. But as new research suggests, the chances of infidelity in a relationship now varies between 40 and 76%; and this implies that infidelity itself could be the new norm.

“It’s very high,” according to researcher Genevieve Beaulieu-Pelletier, a PhD candidate at the Universite de Montreal’s Department of Psychology and author of this new study. According to her findings, people with avoidant-attachment styles are particularly likely to have multiple sexual encounters, and they are afraid of intimacy. She collated her results from two different studies, one on 145 students and the other on 270 adults with the same results.

CoupleThe explanation for avoidance-attachment is often sought in childhood, as a direct result of inadequate parenting. In adult life, in order to prevent commitment-phobia many of these individuals in relationships cheat to reassure themselves of their own space and freedom. As a followup to the previous studies, two further studies revealed that the number one motive quoted as a reason for infidelity was a conscious will to distance oneself from commitment and one’s partner.

Does this imply that frighteningly, large segments of humanity have become attachment avoidant, which could increasingly become a universal trend. It is quite possible that things may shape that way in the future with increased emphasis on personal freedom, and less on one’s ties with the community and family. The study found that men and women were equally likely to display infidelity, and for exactly the same reasons.

With such high numbers of self-confessed “cheats” in the study, it is clear that infidelity no longer provokes the same kind of moralistic sentiments than it used to, even 50 years ago. And if it becomes an accepted norm, it might well usher in the next step in our social evolution — universal attachment — avoidance.

Reference

Infidelity dissected: New research on why people cheat. University of Montreal, September 8, 2008.

]]>
http://brainblogger.com/2008/11/11/why-infidelity-may-not-be-cheating-anymore/feed/ 7
The Scent Trail – Encoding Memory http://brainblogger.com/2008/10/24/the-scent-trail-encoding-memory/ http://brainblogger.com/2008/10/24/the-scent-trail-encoding-memory/#comments Fri, 24 Oct 2008 15:54:44 +0000 http://brainblogger.com/?p=1732 Marcel Proust’s 3,200 page novel À la recherche du temps perdu has in it the famous scene where dipping pastry into his tea flooded him with his childhood memories. It was the odor which provoked it, and it has gone into psychoanalytical literature as the most famous literary evidence of the power of scents in retrieving long-lost memories.

In a recent controlled study over sleeping mice at the Duke University Medical Center, neuroscientists Stephen Shea and Richard Mooney have tried to elucidate the cellular and molecular basis of how memory of scents are locked up in the brain, only to be retrieved later years afterward, and provoking a strong recall of original incidents. While asleep the animals were administered electric shocks which triggered noradrenaline release; at the same time strong odors were presented to their noses: of food and urine of other mice. The study published in a recent edition of Neuroscience is an important milestone in our understanding of odor-processing.

White flowersLater when awake, the introduction of the same odors provoked distinct behavioral changes, proving that in the presence of adrenaline, odors are codified as memory traces, even though they were asleep. It was an earlier hypothesis which this study lends support to, that noradrenaline plays an important role in preserving memories of scents due to processing in the olfactory bulb in both humans and mice. Long lasting memories are very important for social bonding and this study may have implications for understanding how long lasting memories are linked with emotion. While odors are thought to be extremely important in the social behavior of many animals, in humans its role is still not well understood. Part of this is due to the fact that in humans, the cerebral cortex has assumed an over-riding importance compared to the brains of animals lower down the evolutionary scale.

However, there are many amongst us who remain Proustian at heart, and odors are emotionally important. The waft of Mother’s rhubarb pie may remain an important link to her in the future, long after she is gone.

Reference

S. D. Shea, L. C. Katz, R. Mooney (2008). Noradrenergic Induction of Odor-Specific Neural Habituation and Olfactory Memories Journal of Neuroscience, 28 (42), 10711-10719 DOI: 10.1523/JNEUROSCI.3853-08.2008

]]>
http://brainblogger.com/2008/10/24/the-scent-trail-encoding-memory/feed/ 3
Killer Anti-Oxidant Vitamins: When Excess Could Be Exceedingly Dangerous http://brainblogger.com/2008/04/28/killer-anti-oxidant-vitamins-when-excess-could-be-dangerous/ http://brainblogger.com/2008/04/28/killer-anti-oxidant-vitamins-when-excess-could-be-dangerous/#comments Mon, 28 Apr 2008 14:24:44 +0000 http://brainblogger.com/?p=822 Vitamin E today ranks as the second highest single vitamin consumed in the world after vitamin C, following well organized marketing campaigns extolling its anti-oxidative properties. Anti-oxidation is today a key marketing buzzword for the growing market segment of anti-aging dietary supplements, although how it affects human life spans is poorly understood. According to Wellcome Trust [1] there is no evidence in humans that anti-oxidative vitamins (A, C and E) slows aging; only in laboratory mice have they led to a sight increase in lifespan. Nevertheless, these vitamins are widely sold today without prescription as tablets, fish oils and capsules across chemists, superstores and even eBay.

Brand new research [2] from a study of over 77,000 people has shown that higher than recommended doses of Vitamin E can lead to a “significant” increase in the risk of developing lung cancer, irrespective of whether they smoked or not. The strength of the findings was somewhat unexpected — a 7% rise in lung cancer for every extra 100 mg of Vitamin E taken daily for 10 years. With an average daily Vitamin E supplement of 400 mg, this could mean a 28% excess risk for someone to develop lung cancer taking just one pill a day.

An important question is: do we need Vitamin E supplementation at all on top of an average diet? The UK Food Standard Agency website estimates daily dietary requirements of Vitamin E to be just 4 mg for men and 3 mg for women. It also mentions that not enough is known about the side-effects of high-dose vitamin E supplements, and that 540 mg or less a day is “unlikely” to be harmful. This new study could change all that.

While the protective effects of Vitamin E against heart disease and many forms of cancer are acknowledged, dietary deficiency is rare today [3]. This is mainly related to the fact that vitamin E intake in modern diets is mainly dependent on polyunsaturated fatty acids, and with diets rich in vegetable oils and green leafy vegetables, the amount of daily vitamin E intake could well exceed 20-40 mg — just a tablespoon of sunflower oil has 6 mg, while wheatgerm oil has 20 mg or so.

Do we actually need any extra vitamin E supplements if we can make up for our daily requirement through diet? An editorial from the American Journal of Clinical Nutrition in 2006 [4] concluded that intervention studies did not support a beneficial effect of antioxidant supplements, and there was a growing body of evidence that with anti-oxidant vitamins, “just enough” was more than adequate. About 15 mg per day of Vitamin E was enough to provide us with maximum protection against chronic disease, according to the journal.

Death ValleyThe debate about Vitamin E supplementation as a potential cause of premature death is however not new. In 2004, the Times [5] reported the results from a John Hopkins study [6] that pooled the result of 19 studies on vitamin E supplementation worldwide. The study found that doses of 400 international units (IU) of Vitamin E, “often the equivalent of a single capsule were associated with a 10% increased risk of death.” Ominously, the study found that many people were taking as much as 400-800 mg of Vitamin E a day. Even the Lancet had earlier estimated that out of a million people taking Vitamin E supplements, 9,000 were expected to die premature deaths.

The question therefore is not “if,” but rather “how much.” Supplementation can increase the intake of Vitamin E by up to a hundred times of that of daily requirements, and as the latest study shows, the increase in risk of lung cancer can also be substantial. Dietary adjustment can well increase our intake of Vitamin E to well above our recommended daily allowances. The question therefore remains: is it at all justifiable to use “killer” doses of a supplement that has no demonstrable benefits at all above its physiological limits?

References

1. Wellcome Trust. Anti-ageing treatments.

2. Byers, T. (2007). Nutrition and Lung Cancer: Lessons from the Differing Effects of Foods and Supplements. American Journal of Respiratory and Critical Care Medicine, 177(5), 470-471. DOI: 10.1164/rccm.200711-1681ED

3. British Nutrition Foundation. (2004). Vitamins.

4. Traber, M.G. (2006). How much vitamin E? … Just enough! American Journal of Clinical Nutrition, 84(5), 959-960.

5. Lister, S. (2004). The vitamin boost that could cause early death. TimesOnline.

6. MILLER, E., PASTORBARRIUSO, R., DALAL, D., RIEMERSMA, R., APPEL, L., GUALLAR, E. (2005). Meta-Analysis: High-Dosage Vitamin E Supplementation May Increase All-Cause Mortality. ACC Current Journal Review, 14(5), 17-17. DOI: 10.1016/j.accreview.2005.04.017

]]>
http://brainblogger.com/2008/04/28/killer-anti-oxidant-vitamins-when-excess-could-be-dangerous/feed/ 5
How Yoga Improves Balance in the Elderly http://brainblogger.com/2008/04/24/how-yoga-improves-balance-in-the-elderly/ http://brainblogger.com/2008/04/24/how-yoga-improves-balance-in-the-elderly/#comments Thu, 24 Apr 2008 14:33:12 +0000 http://brainblogger.com/?p=862 Alternative_Medicine2.jpgAmongst older adults aged 65 and over, falls are the leading cause of non-fatal injuries and hospital admissions. It is estimated that at least one-third of adults above 65 experience serious falls in their lifetime. The cause of falls in the elderly is often multi-factorial, and no definite cause is ascertainable in the vast majority. Quite often balance system in-coordination is pointed out, but as an integrated system, balance relies on inputs from various sources: vision, cerebellar responses, joint senses and even basic spinal reflexes.

YogaA new study from Temple University’s Gait Study Center has found that Yoga helps with both balance and stability, and effectively reduces the chance of major falls in the elderly. Dr. Jinsup Song and his colleagues at the School of Podiatric Medicine and the College of Health Professions studied the effects of a specifically designed Iyengar Yoga program on 24 volunteers — women in the over-65 age group. After completing the nine week program, all participants reported a faster stride, an improvement in single leg stance and confidence in walking and balancing and improved flexibility in the lower limbs. In addition, participants became much better at how to redistribute pressure through the soles of their feet.

Some participants even reported improvement in their pain symptoms as a result of reduced stress on their arthritic joints. In addition, the study found that participants reported a more optimistic, focussed, goal-oriented view of life. For the elderly, this means a vastly improved confidence in balancing themselves and increasing their mobility, which in turn helps to prevent falls.

Perhaps this study elegantly demonstrates that falls in the elderly are often a result of disuse of their balance capabilities, which can be greatly enhanced through professional programs.

Reference

Song, J., Newton, R., Yun, J.S., Heilman, B., Zoltick, E. (2008). Gait Study Center. Gait and Clinical Movement Analysis Society Proceedings.

]]>
http://brainblogger.com/2008/04/24/how-yoga-improves-balance-in-the-elderly/feed/ 3
Functional MRI: Emerging Uses for Neurological Diseases – Part 2 http://brainblogger.com/2008/04/03/functional-mri-emerging-uses-for-neurological-illnesses-part-ii/ http://brainblogger.com/2008/04/03/functional-mri-emerging-uses-for-neurological-illnesses-part-ii/#comments Fri, 04 Apr 2008 06:52:11 +0000 http://brainblogger.com/?p=825 Neuroscience_Neurology.jpgDespite the fact that functional MRI was discovered in the early 90’s, scientific research related to its clinical applications is still at an early stage. The first paper on the use of functional MRI (fMRI) in Alzheimer’s disease came out as late as 1999. Today, fMRI is being intensively studied in a number of other clinical areas like dyslexia, epilepsy, mood and anxiety disorders, pain management, rehabilitation after stroke and schizophrenia. Though the application of fMRI in routine neurological practice is still some years away, already our understanding of these disorders and knowledge about mapping progression and treatment effects with fMRI is rapidly progressing.

Alcohol and substance abuse, for example is another developing area. Studying the effect of pharmacological substances on MRI blood flow patterns is spearheaded by the rapidly growing area of pharmacological MRI (phMRI). Updated models of craving and addiction incorporating fMRI criteria demonstrate that over the course of addiction, as it becomes chronic, an orderly change in brain blood flow patterns sets in, as more and more areas get involved.

Pre-surgical planning with functional neuroimaging has been undergoing evaluation over the past few years, particularly in cases involving resections of brain tumors and arterio-venous malformations, as well as in surgery for epilepsy. One important problem with these procedures is the collateral damage inflicted by surgery on vitally important structures and tracts in the vicinity of the lesion. By a pre-operative fMRI evaluation, it is relatively easy to visualize what cognitive, motor or sensory functions are likely to be impaired following the resection, and counsel the patient accordingly. In addition a pre-operative ‘functional’ map might guide surgeons to limit the extent of damage by making them aware of the proximity of functionally important areas. One study found pre-surgical fMRI useful in 89% of tumor and 91% of epilepsy surgical patients.

The future for fMRI is bright. While the technology is still improving, there is a lot of research that needs to be done, along with statistical validation of brain maps from various sources. But it is already leading to a paradigm shift in our understanding of how the brain works in real-time, and perhaps for the first time, we have developed a visual probe in to our minds. As the logical next step, we are standing on the threshold of a new approach to the clinical practice of neurology and its allied behavioral sciences.

References

Ogawa, S. (1990). Brain Magnetic Resonance Imaging with Contrast Dependent on Blood Oxygenation. Proceedings of the National Academy of Sciences, 87(24), 9868-9872. DOI: 10.1073/pnas.87.24.9868

Small, S.A., Perera, G.M., DeLapaz, R., Mayeux, R., Stern, Y. (2001). Differential regional dysfunction of the hippocampal formation among elderly with memory decline and Alzheimer’s disease. Annals of Neurology, 45(4), 466-472. DOI: 10.1002/1531-8249(199904)45:4<466::AID-ANA8>3.0.CO;2-Q

PORRINO, L., SMITH, H., NADER, M., BEVERIDGE, T. (2007). The effects of cocaine: A shifting target over the course of addiction. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 31(8), 1593-1600. DOI: 10.1016/j.pnpbp.2007.08.040

]]>
http://brainblogger.com/2008/04/03/functional-mri-emerging-uses-for-neurological-illnesses-part-ii/feed/ 4
The Brain-Road Link: New Evidence on Cell Phones and Driving http://brainblogger.com/2008/03/28/the-brain-road-link-new-evidence-on-cell-phones-and-driving/ http://brainblogger.com/2008/03/28/the-brain-road-link-new-evidence-on-cell-phones-and-driving/#respond Fri, 28 Mar 2008 16:29:50 +0000 http://brainblogger.com/2008/03/28/the-brain-road-link-new-evidence-on-cell-phones-and-driving/ Neuroscience_Neurology2.jpgLaw enforcers now have all the proof they need for tougher anti-cell phone measures for drivers, as the latest published neurological study shows that there is a 37% reduction in parietal cortex activity with driving. Arguments that there are many among us who can multi-task well have taken a back seat in recent studies involving driving and mobile phone listening.

An University of Oregon Study in 2005 found that complex skills like driving do not only include motor skills, but also staying receptive of visual and spatial cues from minute to minute. It estimated that conversing on the cell phone can increase a driver’s response time by up to 800 milliseconds, and at 60 miles per hour that could mean a significantly higher risk to drivers responding to road hazards.

This new study from Carnegie Mellon, reported in a recent issue of Brain Research however takes it a step further. It suggests that it just might not be enough to use voice-activated systems or hands-free kits for road safety — we have to put our brains too on the road. Carried out on 29 volunteers, the study measured changes in brain blood flow patterns using functional MRI (fMRI) as they simulated driving realistically in the laboratory.

There was a 37% reduction in blood flow through the parietal cortex as a result of driving, which is the seat of spatial sensation and navigation in the brain. For drivers a reduction in spatial awareness could prove fatal, as their ability to carry out defensive and avoidance maneuvers at high speeds could be seriously compromised. In fact, a significant deterioration in the quality of driving was noticed in the study — even though the participants were only “listening”. Listening and driving depend on so different parts of the brain, that the neuronal circuits are bound to experience a “clash of interests” so to speak, when it comes to blood flows and activity. The study also found significant deficits in the occipital cortex, which could be linked to visual inattention of the road ahead — another potentially dangerous factor.

Well, not much of an argument over this study I believe, even if you are an excellent, proven multi-tasker.

References

Lien, M., McCann, R.S., Ruthruff, E., Proctor, R.W. (2005). Dual-Task Performance With Ideomotor-Compatible Tasks: Is the Central Processing Bottleneck Intact, Bypassed, or Shifted in Locus?. Journal of Experimental Psychology: Human Perception and Performance, 31(1), 122-144. DOI: 10.1037/0096-1523.31.1.122

Carnegie Mellon Study Shows Just Listening To Cell Phones Significantly Impairs Drivers. Carnegie Mellon University – Press Release.

]]>
http://brainblogger.com/2008/03/28/the-brain-road-link-new-evidence-on-cell-phones-and-driving/feed/ 0
The “Art” of Being Smart http://brainblogger.com/2008/03/25/the-art-of-being-smart/ http://brainblogger.com/2008/03/25/the-art-of-being-smart/#respond Tue, 25 Mar 2008 18:38:46 +0000 http://brainblogger.com/2008/03/25/the-art-of-being-smart/ Neuroscience_Neurology.jpgA three-year multicenter study called Learning, Arts, and the Brain is finally close to solving the problem of whether art makes us smarter or whether smarter people are drawn to arts.

The question is not purely rhetorical, as in recent years educationists have debated about the relevance of arts in modern school curricula; whether music, drama and dance education should be given an equal emphasis compared to more mainstream science and humanities subjects. In particular some of the key issues raised were related to the attention skills and processes of memory retrieval that is unique to those who appreciate art, and can be put to use in other areas of academics as well.

The study led by Dr Michael Gazzaniga (famous for his work on split-brain research) of the University of California at Santa Barbara utilized brain scanning and behavioral studies to examine a number of questions in this regard. An interest in the arts has been found to lead to high levels of attention that improves performance in many other areas. In particular music training leads to memory enhancement in several unrelated areas too. A link has been found in children between music training and ability in geometrical representation of concepts and ideas, apart from development of neural pathways for phonological awareness. Phonologically aware children have been shown to develop superior learning skills and language skills.

On the other hand, learning to dance is also distinctly advantageous as it leads to a better capacity for learning complex patterns of behavior. The other important find in this study, involving seven universities, was the presence of candidate genes that are responsible for our individual differences in affinity for art. In adults dopamine-related genes have been found to be associated with an interest in the aesthetics and “open” personalities, as artists often are.

It would appear then that art is a deeply neurological phenomenon — much more than most of us think.

Reference

Michael S. Gazzaniga. Learning, Arts, and the Brain. The Dana Consortium Report. 2008.

]]>
http://brainblogger.com/2008/03/25/the-art-of-being-smart/feed/ 0
Functional MRI: A Radiological Window into the Mind – Part 1 http://brainblogger.com/2008/03/19/functional-mri-a-radiological-window-into-the-mind-part-1/ http://brainblogger.com/2008/03/19/functional-mri-a-radiological-window-into-the-mind-part-1/#comments Wed, 19 Mar 2008 14:22:14 +0000 http://brainblogger.com/2008/03/19/functional-mri-a-radiological-window-into-the-mind-part-1/ Neuroscience_Neurology.jpgFunctional MRI (fMRI) is one of the most widely used experimental tools in neuroscience today, which allows us to study blood flow patterns to different parts of the brain during a given task. For example during solving mathematical problems, a typical fMRI pattern is seen. Recently however, psychological theories are being tested, and a broader picture of how the mind works is emerging.

One of the criticisms traditionally faced by psychology as a scientific discipline is the lack of objective data, to back up theories of the mind. For instance, proving the “existence” of the subconscious mind is difficult, although intuitively, the model is widely accepted.

A recent study (1) published on the subject of how knowledge is organized in our mind shows how powerful functional MRI scanning can be, as a tool to prove or disprove psychological theories. It has long been debated whether the human brain perceives living beings as a separate category than the non-living objects (concept domain), or whether, after taking into account the various features like shape, movement, and color (feature domain), it then decides whether it is living or not amongst other attributes. As several objects were presented to a group of 21 participants, detailed fMRI studies were performed of the degree of activation of different parts of the brain, while a yes/no questionnaire designed to test their understanding of concepts versus features was simultaneously analyzed. The results showed with a high degree of statistical significance that human brains organize concepts according to descriptive linguistic features, with the majority using the dominant left half of the brain, and not according to pre-existing conceptual domains of broad categories.

The issue of whether a picture of a “standard” brain from brain scan data can lead us to a “Theory of the Mind” was discussed by Harvard neuroscientist Rebecca Saxe in her paper Why and how to study Theory of Mind with fMRI. (2) Central to our radiological window in to the human mind is the concept of “Regions of Interest” or ROI, which does not presuppose that distinct areas of the human brain have specific “thinking” roles. Rather, a distinct mental activity sets off a pattern of brain activity that involve many areas on the cortex that are close by, or separated widely. In Saxe’s own research she found that while experimental subjects were reading different kinds of stories — appearance, bodily sensations, or thoughts — blood flow patterns on fMRI were distinctly different for the genre of the story, but this difference in patterns were consistent across all the subjects. What fMRI has therefore provided for us is the insight that the number of patterns of activation for different tasks is limitless, but broad patterns do exist. The bigger picture will only emerge after a lot of studies comparing sets of ROI from different experiments are pooled together, providing a clearer picture of how the mind functions through a dynamic, constantly changing network of regions across the brain.

References

1. MARQUES, J., CANESSA, N., SIRI, S., CATRICALA, E., CAPPA, S. (2008). Conceptual knowledge in the brain: fMRI evidence for a featural organization. Brain Research, 1194, 90-99. DOI: 10.1016/j.brainres.2007.11.070

2. SAXE, R. (2006). Why and how to study Theory of Mind with fMRI. Brain Research, 1079(1), 57-65. DOI: 10.1016/j.brainres.2006.01.001

]]>
http://brainblogger.com/2008/03/19/functional-mri-a-radiological-window-into-the-mind-part-1/feed/ 12
Follow the Leader – Insight into Human Decision Making http://brainblogger.com/2008/03/08/follow-the-leader-insight-into-human-decision-making/ http://brainblogger.com/2008/03/08/follow-the-leader-insight-into-human-decision-making/#comments Sat, 08 Mar 2008 13:31:09 +0000 http://brainblogger.com/2008/03/08/follow-the-leader-insight-into-human-decision-making/ Psychiatry_Psychology2.jpgScientists at Leeds University, England believe that they have found the answer to how a lot of our unconscious actions are generated — by simply following our herd of brethren!

A new study demonstrates that it only takes about 5% of people to have a decisive influence on the direction that a crowd of people would take, and the rest simply follow. Prof. Jens Krause a behavioral ecologist, with PhD student John Dyer, designed a series of experiments at Leeds where groups of people were asked to walk around randomly in a large hall. Within the group, a selected few participants received more detailed instructions about how and where to walk. Participants were not allowed to communicate with any another person but had to stay within an arms length of each other.

The study showed these “snake-like patterns” people unconsciously adopted, as they began following others without being unaware that they were doing so. In a way, they had adopted a consensus decision, but being totally unaware of it. The study used different crowd sizes to assess the leader-to-follower ratios at each level, and it soon emerged that the bigger the crowd size, the smaller the number of decision makers required. In large crowds of 200 or more, 5% of the group was enough to influence the direction in which it traveled!

“There are many situations where this information could be used to good effect,” Prof. Krause of the University’s Faculty of Biological Sciences stated in a recent interview. “At one extreme, it could be used to inform emergency planning strategies and at the other, it could be useful in organizing pedestrian flow in busy areas.”

According to Prof. Krause, the study started as part of studying animal grouping behaviour, and as it convincingly demonstrates, there are strong parallels between human crowds and animal flocks, which might be instinctual.

But on a metaphorical plane, does this study explain phenomena like fashion fads and opinion shifts too?

Reference

DYER, J., IOANNOU, C., MORRELL, L., CROFT, D., COUZIN, I., WATERS, D., KRAUSE, J. (2007). Consensus decision making in human crowds. Animal Behaviour,75(2), 461-470. DOI: 10.1016/j.anbehav.2007.05.010

]]>
http://brainblogger.com/2008/03/08/follow-the-leader-insight-into-human-decision-making/feed/ 2
Is it the Brain or the Game? Gender Differences in Gaming http://brainblogger.com/2008/03/06/is-it-the-brain-or-the-game/ http://brainblogger.com/2008/03/06/is-it-the-brain-or-the-game/#comments Thu, 06 Mar 2008 18:06:20 +0000 http://brainblogger.com/2008/03/06/is-it-the-brain-or-the-game/ Neuroscience_Neurology.jpgNew research findings from the Stanford University proves that men find playing video games more rewarding. This wouldn’t appear surprising to the millions of console and PC gaming widows worldwide, but this gives us an opportunity to have a look at the good old chicken-and-egg conundrum in the context of arriving at sweeping generalizations on gender difference issues on the basis of imaging alone.

The abstract of the study (1) recently published in Psychiatric Research begins with the statement “Little is known about the underlying neural processes of playing computer/video games, despite the high prevalence of its gaming behavior, especially in males.” The study carried out on 11 men and women, on a “simplified” computer version of a game involving clicking on balls moving away from the centre of the screen in an attempt to gain “territory” on the screen, which was the object of winning. It concluded that men were more motivated to win territory, and therefore performed better despite the fact that both groups perfectly understood the objective of the game. (2) Functional MRI imaging performed at the time showed that the men’s meso-cortico-limbic centers, traditionally considered the brain’s “reward center” were more activated as they were winning. The authors concluded that territorial dominance is hardwired in the male brain, which is why men enjoy playing and winning computer games more than women.

While the study and its conclusions have a lyrical simplicity to it, observations from the real world contradict the hypothesis. Data from the ESA (3), dedicated to research of the trends in the video gaming industry, reveal the steady increase in the number of women gamers over the years. Currently, 38% of American videogame players and 48% of gaming parents are women. Gaming for women is not always about winning — consider the fact that 70% of the players of Sims, considered by some to be the most successful game ever are women; the game focuses on the intricacies of relationships and urban life. (4) Two recent reports are also worth mentioning – first, a recent report from the Australian gaming industry (5) that women are the fastest growing market segment along with old adults in a rapidly changing gaming demography. In Japan, in what has been described as a “seismic shift” (6), women gamers have actually overtaken their male counterparts with newer consoles like the Wii and DS, both from Nintendo. Lifestyle games on cookery, personal grooming and simulated sports are at the heart of the boom.

Reconciling the Stanford study and industry statistics is not easy: I suppose that the design of any psychosocial experiment largely determines its outcome under its unique circumstances, but is not necessarily applicable to real life. If we take video gaming out of its narrow context of two teenage geeks furiously clawing their consoles in a death match to outbid each other, to its broader modern context, I do think that the problem why men have “traditionally” found video games more rewarding, lies in the games themselves which have focused on competition and visuospatial skills.

But there are many ways of firing our meso-cortico-limbic centers when it comes to video gaming — it depends mostly on the games we choose as well as what the industry is designing for us.

References

1. HOEFT, F., WATSON, C., KESLER, S., BETTINGER, K., REISS, A. (2008). Gender differences in the mesocorticolimbic system during computer game-play. Journal of Psychiatric Research, 42(4), 253-258. DOI: 10.1016/j.jpsychires.2007.11.010

2. Video games activate reward regions of brain in men more than women, Stanford study finds. Stanford School of Medicine – News Release. 2008.

3. The Entertainment Software Association

4. Darren Waters. Games industry is ‘failing women’. BBC News. 2008.

5. Gaming on the rise. The Sydney Morning Herald. 2008.

6. Leo Lewis. Nintendo’s women gamers could transform market. Times Online. 2008.

]]>
http://brainblogger.com/2008/03/06/is-it-the-brain-or-the-game/feed/ 3
Why Some Men, Like Women, Cannot Read Maps Too http://brainblogger.com/2008/03/01/why-some-men-like-women-cannot-read-maps-too/ http://brainblogger.com/2008/03/01/why-some-men-like-women-cannot-read-maps-too/#comments Sat, 01 Mar 2008 13:14:46 +0000 http://brainblogger.com/2008/03/01/why-some-men-like-women-cannot-read-maps-too/ Anti_Stigmatization2.jpgI never quite got around to write the sequel to Barbara and Allan Pease’s evocative work (1), although I had figured out a nice name for it, “Why men don’t use makeup, and women can’t Sumo wrestle.” Not to make fun of the genetic determinists who study gender differences, but to drive home the whole nature-nurture point on this issue: men and women have evolved to be different. But not in its restricted Darwinian sense, but in the current expanded evolutionary contexts as well — social, psychological and politico-economic.

However, as I have closely followed the sexual dimorphism debate over the years, I am of the opinion that although there is irrefutable scientific evidence that there are important differences in the way male and human brains function, they are not significant enough to justify any role stereotyping in humans on a purely biological basis. Women can become Sumo wrestlers if they wanted to and they do these days; in fact Japan held its first-ever official women’s Sumo wrestling championship in 1997 breaking away with the age-old tradition of keeping women away from the arena, even as spectators. Women in the 20th century have been fairly successful as “father role models,” despite significant opposition to the idea from orthodox quarters.

Recent behavioral research has focussed on the gay male brain, and one such recent study (2) from the Queen Mary Hospital, University of London has reported that when it comes to spatial navigational abilities, gay men’s performance tend to equal that of women, which under laboratory conditions, is worse compared to straight men. In the computer-simulation study carried out on 140 volunteers, gay men, straight women and lesbians shared the same weaknesses when it came to tasks that required spatial navigational abilities. I can accept that as a possible explanation why there are so few women who aspire to be fighter pilots, while arguing of course that current combat aviation technology is still not quite as gender-neutral as one can hope for. But in the above case, the reaction of the British press all across the UK to this research finding was simply hilarious.

For example The Telegraph, a national daily ran its story “Women and gay men are worst drivers,” without justifying their assertion. Worse, an accompanying picture was captioned, “Be afraid: gay men or women could be behind the wheel of any car.” Despite the fact that in Britain women are universally acknowledged as safer drivers, and pay less insurance than men (indeed in my household, both our cars are insured in my wife’s name, quite legally of course). Here is a classic demonstration of the pitfalls of illogical stereotyping through misinterpretation of research findings — life skills in modern human society are too complex to be evaluated on the basis of laboratory tests of simple behavioral tests alone. Dr. Rahman, the senior author agrees that “the headlines splashed across the British press about driving were completely taken out of context.”

Behavioral psychology is valuable in numerous aspects, but we must be cautious about jumping to conclusions. And I have always acknowledged that at least in my family, my wife is the better driver.

References

1. Why Men Don’t Listen And Women Can’t Read Maps: How We’re Different and What To Do About It: How We’re Different and What to Do About It. Barbara and Allan Pease. Orion. March 2001.

2. Rahman, Q., Koerting, J. (2007). Sexual orientation-related differences in allocentric spatial memory tasks. Hippocampus, 18(1), 55-63. DOI: 10.1002/hipo.20375

]]>
http://brainblogger.com/2008/03/01/why-some-men-like-women-cannot-read-maps-too/feed/ 1
The Chattering Brain – How Chronic Pain Throws our Cortex out of Sync http://brainblogger.com/2008/02/26/the-chattering-brain-how-chronic-pain-throws-our-cortex-out-of-sync/ http://brainblogger.com/2008/02/26/the-chattering-brain-how-chronic-pain-throws-our-cortex-out-of-sync/#comments Tue, 26 Feb 2008 15:15:06 +0000 http://brainblogger.com/2008/02/26/the-chattering-brain-how-chronic-pain-throws-our-cortex-out-of-sync/ Neuroscience_Neurology2.jpgA new study from the Northwestern University’s Feinberg School of Medicine has provided important clues to how chronic pain might throw our lives out of gear by affecting many areas of the cerebral cortex. Worse, if left unchecked, it could lead to irreversible damage to the interconnection between the neurons, leading to permanent changes in the way our brain functions.

Using functional MRI (fMRI) scanning, Dante Chialvo, lead author and associate research professor of physiology at the Feinberg School, compared the brain activation patterns of people with chronic low back pain to a group of pain-free volunteers while both groups were visually tracking a moving object on computer screens. The study showed that although the pain sufferers performed the task well, they were using their brain in a very different way compared to the normal control group.

With normal brains, when the subject concentrated on one task, like visual tracking, only a few areas of the brain were activated, while the other areas were ‘silent’ from a neurological point of view. This is a state of equilibrium, known as the resting state of the brain, as the different areas of the brain co-operate to give ‘rest’ to each other, while only a few relevant areas are active.

In contrast in the brains of the group with chronic pain, this co-operative resting state was typically absent, and the neurons kept on firing indefinitely without periods of rest. Dr Chialvo’s work suggests that in chronic pain, this continued firing prevents normal interneuronal connections and damages the brain, causing functional alterations. He hypothesizes that this overactive brain firing in chronic pain sufferers could affect their mood, producing chronic depression and a host of other neurological abnormalities seen with chronic pain. In the future in chronic pain sufferers, simply treating pain might be inadequate, as this study implies. Chronic pain may be much more of a whole-brained phenomenon than we once thought.

Reference

Baliki, M.N., Geha, P.Y., Apkarian, A.V., Chialvo, D.R. (2008). Beyond Feeling: Chronic Pain Hurts the Brain, Disrupting the Default-Mode Network Dynamics. Journal of Neuroscience, 28(6), 1398-1403. DOI: 10.1523/JNEUROSCI.4123-07.2008

]]>
http://brainblogger.com/2008/02/26/the-chattering-brain-how-chronic-pain-throws-our-cortex-out-of-sync/feed/ 2
Extinction Fears of the Red-Headed Homo Sapien http://brainblogger.com/2008/02/17/extinction-fears-of-the-red-headed-homo-sapien/ http://brainblogger.com/2008/02/17/extinction-fears-of-the-red-headed-homo-sapien/#comments Sun, 17 Feb 2008 15:02:59 +0000 http://brainblogger.com/2008/02/17/extinction-fears-of-the-red-headed-homo-sapien/ About 4% of the world’s population possess the recessive gene for red hair, and actually 2% are redheads, as a result of a mutation that arose in Northern Europe several thousand years ago. Scientists have been divided in their opinion about whether the red headed population is headed for extinction in an age of global mingling.

Jacob Silverman reported his findings in Are redheads going extinct:

Red hair is caused by a mutation in the MC1R (melanocortine 1 receptor gene)… Because it’s a recessive trait, red hair can easily skip a generation. It can then reappear after skipping one or more generations if both parents, no matter their hair color, carry the red hair gene.

That is a slightly reassuring view, as it implies, that the gene will stay in the population. But most genes are clustered in certain populations, and intermarriage in communities ensures that the prevalence of recessive genes do not get diluted. But with increasingly multicultural populations in the West, where red hair genes are mostly concentrated, some scientists are afraid, redheads as a phenotype could become extinct within a 100 years.

Leading the redhead preservation brigade is the social networking site Redhedd.com, which insists on dating and breeding amongst redheads exclusively, to preserve mankind’s red heritage. It is aggressive in its stance, compared to more moderate devoted sites like Redhead Passions and Realm of the Redheads, and proclaims in its manifesto that its primary object is to “save the redheads.”

“In order to save redheads we have to mingle redheads with redheads, to concentrate the two genes that make red hair”, instructs the site founder in 2007 — Steve Warrington of Ann Arbor, Michigan.

Last August, National Geographic ran the story where “ginger” was predicted to be extinct in a 100 years or so. The gene initially had a positive survival effect by increasing the body’s ability to synthesize Vitamin D in the presence of sunlight, particularly in the northernmost latitudes with relatively less sunlight. But in the era of dietary fortification, it has lost its usefulness, and even makes carriers more prone to cancer and heat and cold-related pain.

But for those red head preservationists not to be put off by such trivial counterarguments, statistically the best place to preserve their heritage is Scotland, where apparently 40% of the population carry the gene and 13% actually have red hair.

]]>
http://brainblogger.com/2008/02/17/extinction-fears-of-the-red-headed-homo-sapien/feed/ 6