Post List

  • May 19, 2010
  • 07:59 AM
  • 383 views

Modest Men Get Sorely Trashed

by Ultimo167 in Strong Silent Types

Moss-Racusin et al. (2010) begin to describe the backlash dished out to modest men, for being presumably weak and insecure, but then stop short and ask for more. ... Read more »

  • May 19, 2010
  • 07:51 AM
  • 1,057 views

Does Oral Sex Confer An Evolutionary Advantage? Evidence From Bats

by Jason Goldman in The Thoughtful Animal

Regular readers of this blog know that while I think studying animal cognition, behavior, and communication is (sometimes) fun and (always) interesting, the real importance - the why should I care about this - is because by understanding animals, we can attempt to learn more about ourselves.

I've written about this before. Here are the relevant excerpts:
When human adults show complex, possibly culture-specific skills, they emerge from a set of psychological (and thus neural) mechanisms which have two properties:
(1) they evolved early in the timecourse of evolution and are shared with other animals, and,
(2) they emerge early in human development, and can be found in infants and children, as well as adults.

Three questions necessitate a comparative evolutionary approach (or, minimally, are enriched by such an approach):
(1) Is a given trait unique to humans?
(2) Does the acquisition of a given trait depend on uniquely human abilities?
(3) What functional problem does a given trait solve, and did it evolve for this particular function?

That the first question necessitates a comparative approach should be obvious. If comparative data indicate that even only one other species possesses the trait in question, then the question shifts a bit, and we have to determine whether the trait is homologous (depending on the same mechanisms), or homoplastic (depending on distinct mechanisms that presumably evolved independently). How can we distinguish homology from homoplasy? We look for signatures, or common features. For example, face processing in humans shows behavioral signatures (e.g. degradation when faces are inverted) and neural signatures (localized cortical activations). Those same features have been found in various monkey species that have been tested in face processing tasks, and this provides one piece of evidence for homology.

The third question distinguishes among the original function of a trait and the way it is currently used. Language, for example, allows us to recombine a finite set of elements in essentially infinite patterns to create meaning. Did this capacity evolve to facilitate communication, or for some other purpose? Assume that chimpanzees, for example, do not show evidence of this mechanism in their communication, but DO exhibit this mechanism for arithmetic computation. This might suggest that this ability evolved for number, and was then "re-purposed" by humans for communication. Of course, it is also possible that this capacity evolved independently in chimpanzees and in humans, but this seems less likely given the relatedness of our two species.

I used cognitive examples above, but of course these questions and methods of investigation apply to behavior more generally (especially since cognition and behavior are only different by virtue of different levels of analysis).

If oral sex offends you, the time to click away is now. Otherwise, read on. Read the rest of this post... | Read the comments on this post...... Read more »

Tan M, Jones G, Zhu G, Ye J, Hong T, Zhou S, Zhang S, & Zhang L. (2009) Fellatio by fruit bats prolongs copulation time. PLoS ONE, 4(10). PMID: 19862320  

  • May 19, 2010
  • 06:23 AM
  • 618 views

Mary Poppins was right: a spoonful of sugar DOES help the medicine go down

by Helen Jaques in In Sickness and In Health

A new study has found that giving children up to one year old a sweet solution before jabs reduces the pain of the immunisation, providing a scientific basis for Mary Poppins’ maxim that “a spoonful of sugar helps the medicine go down.”
The meta-analysis looked at fourteen randomised controlled trials that assessed the effects of oral [...]... Read more »

  • May 19, 2010
  • 05:36 AM
  • 802 views

Can a fear of blushing be cured in a weekend?

by Christian Jarrett in BPS Research Digest

You may have heard of weekend workshops in creative writing or first aid but what about a weekend course to reduce your fear of blushing? Could such a brief, intensive intervention help people for whom a dread of turning red ruins their social lives and undermines their success at work? According to a new, preliminary study - the answer is a tentative Yes.Samia Chaker and colleagues recruited through adverts in a German pharmacy magazine 27 people with social phobia, and in particular a fear of blushing. The weekend course began on a Friday at 2pm and ran until 9pm the following evening.The focus was on 'task concentration training'. Research has shown that a fear of blushing develops through and is worsened by excess focus on the self. A person feels self-conscious, they redden, they feel the warmth in their cheeks and the cycle of self-focus is perpetuated. Through reading stories, role-playing and watching themselves on video, the participants practiced turning their focus away from themselves and to the task at hand - be that the words of a conversational partner or the reading of a story. The participants were also given advice on how to practice re-directing their attention over the coming six weeks, first in non-threatening situations and then in more difficult social contexts. At the end of the weekend compared with at baseline, 37 per cent of participants showed clinically significant improvement in their fear of blushing. By six month follow-up this had risen to 56 per cent of the sample. Improvements were greater in those who said they had practiced re-focusing their attention in difficult situations in the weeks following the weekend workshop.The results are only preliminary: the lack of a control group is a major limitation as is the inability to tease out the most important parts of the intervention. However, feedback from the participants showed the course to have been well-received and worthwhile of future investigation. 'The time-efficient nature of such an intensive treatment could hold great appeal and practicality for working professionals who are short on time, those who prefer a less "therapy-like" experience, or individuals with geographic restrictions,' the researchers said. _________________________________Chaker S, Hofmann SG, & Hoyer J (2010). Can a one-weekend group therapy reduce fear of blushing? Results of an open trial. Anxiety, stress, and coping, 23 (3), 303-18 PMID: 19557558Earlier on the Digest: Thinking that you're blushing makes you blush even more. The puzzle of blushing (open access article in The Psychologist).

... Read more »

  • May 19, 2010
  • 05:35 AM
  • 2,629 views

Towards a Focal Consensus in Cognitive Neuroscience: Databases and Meta-Analyses

by The Neurocritic in The Neurocritic

Moving right along with our timely, fast-paced, cutting edge blog coverage from the CNS 2010 Annual Meeting [held last month], the first symposium urged the field to advance beyond the current piecemeal single-study approach to neuroimaging by moving Towards a cumulative science of human brain function.1 Building comprehensive, structured, and searchable databases (Van Essen, 2009) and using meta-analytic tools (Wager et al., 2009) were proposed to be key methods aimed at achieving this goal.In his talk, prolific neuroanatomist Dr. David Van Essen (of primate visual cortex wiring diagram fame)2 discussed SumsDB (Surface Management System Database), "a repository of brain-mapping data (surfaces & volumes; structural & functional data) from many laboratories."---------------Talk 2: Lost in Localization – But Found with Foci!David Van Essen; Washington University in St. LouisMore than 50,000 studies related to functional imaging of the human brain have been published in recent decades. Of these, more than 10,000 report key experimental data (centers of fMRI activation foci, etc.) in tables of stereotaxic coordinates (‘foci’) in one or another standardized atlas space. To aid in mining this extensive literature, we developed the SumsDB database, which supports storage, visualization, and searching of many types of neuroimaging data. SumsDB includes a Foci Library that currently contains 40,000 foci from ~1,400 published studies. This includes comprehensive coverage of five major journals and almost 15% of the relevant literature. Foci searches can be based on many criteria (e.g., cortical area or region, spatial coordinates, functional criteria, or disease condition). Search results can be viewed online (WebCaret) or downloaded for offline visualization and analysis using Caret sofware. As the Foci Library continues to expand, through contributions from curators and volunteers alike, it will become increasingly valuable as a way to efficiently access the burgeoning neuroimaging literature.---------------Van Essen emphasized the importance of maintaining a central repository of neuroimaging foci, the 3D localization of peak activations in x, y, z coordinates (Fox et al., 1985). He and his lab have established SumsDB, which currently contains 50,000 foci from 1,700 studies, a relatively small fraction of the literature (see figure below).Fig. 1 (Derrfuss & Mar, 2009). Total number of published fMRI studies reporting coordinates by year and number of studies included in current coordinate databases. One impediment to having more complete coverage of the literature is how labor intensive it is to add new articles to the database (30-60 min per paper after 5-10 hr training), as lamented by Derrfuss and Mar (2009) in their Comments and Controversies article in NeuroImage. Because of the effort involved, many in the neuroimaging community haven't been particularly motivated to participate in the project. In in his reply (2009) to Derrfuss and Mar, Van Essen listed the benefits of voluntary data entry duties:submitting foci from publications of your own lab will increase their visibility, through data mining initiated in SumsDB or NIF [Neuroscience Information Framework];submitting relevant studies from your research subfield will facilitate cross-study comparisons and promote broader awareness of research in that area;individual contributors are recognized by ‘provenance’ assignments for each study (or version) entered into SumsDB.SumsDB libraries can also be used to store foci and study collections for ongoing projects that are not yet published. (Data in these libraries are not made public until requested by the submitter and then vetted by a curator in the Van Essen lab to insure conformance to basic metadata description standards.)And what a great classroom project for graduate students and highly motivated undergraduates! (suggested Van Essen, 2009). Greater participation is essential, however. But who wants to do all that work for free?An attractive and feasible model is for one or two individuals (students, postdocs, or knowledgeable technicians) from each of many laboratories to enter data published by their own laboratory plus selected topics related to that lab's research interests. For example, if 50 volunteers each added ~20 studies per year (15–30 h per volunteer, including training), the current rate of submission would approximately double, and about half of the relevant literature would be covered in ~5 years.But even more appealing, a semi-automated data entry system for SumsDB is under development...What does one do with all that data? In the next talk, Dr. Tor Wager discussed meta-analysis, a statistical technique for summarizing quantitative research. Why is it important to combine results across multiple studies (Wager et al. 2007)?Meta-analysis is an increasingly popular and valuable tool for summarizing results across many neuroimaging studies. It can be used to establish consensus on the locations of functional regions, test hypotheses developed from patient and animal studies and develop new hypotheses on structure–function correspondence. It is particularly valuable in neuroimaging because most studies do not adequately correct for multiple comparisons; based on statistical thresholds used, we estimate that roughly 10–20% of reported activations in published studies are false positives. The 'Quick-Search' function in SumsDB can be used to retrieve foci of interest from all papers in the database. For example, one can search by anatomical area (Fig. 1B) or by research topic (Fig. 1C). Searches can also be performed by task, function, disorder, etc.Adapted from Fig. 1 (Van Essen, 2009). ... Read more »

  • May 19, 2010
  • 05:30 AM
  • 1,120 views

H1N1 measures ‘bought valuable time’ in Vietnam

by Wellcome Trust in Wellcome Trust Blog

Though some consider the precautionary measures taken during the H1N1 swine flu epidemic to have been excessive, ‘better safe than sorry’ was an understandable position for health officials to take. That stance is justified to some degree by the results of a study published today in PLoS Medicine. The analysis of the first few months [...]... Read more »

  • May 19, 2010
  • 05:30 AM
  • 823 views

How many minutes a day should you exercise?

by Yoni Freedhoff in Weighty Matters

I don't think there's a one size fits all answer.Last week the Canadian Society for Exercise Physiology (CSEP) and ParticipACTION released their new recommendations that saw their minimum recommended amounts of exercise drop to 60 minutes a day for children and 90-150 minutes a week for adults.I was critical of their press release. I felt that by providing specific numbers and omitting calls to action to change the environment it perpetuated the notion that sloth is a disease of the individual, and by extension for many, that so too is weight and that the solution is increased personal responsibility. To me it seemed akin to the NRDC and Greenpeace putting out a press release about cleaning up the oil in the gulf of Mexico without a call to action for oil rig regulation reform and a call to actually plug the leak.A friend and colleague emailed me to tell me that they felt I had been too harsh and that my post misconstrued the press release because I focused on the fact that the minimums had dropped while ultimately the report strongly encourages people to do more than the minimums. They also felt that having evidence-based guidelines for exercise was a good thing and mentioned that they felt evidence-based guidelines were something I ought to support given my call for evidence to be applied to Canada's dietary guidelines.That led to an interesting email exchange (we're still friends) and given they read into my post intentions that weren't there, I figure it's best to flesh them out here.So let me start by saying that I do not believe that society has recently been afflicted with an epidemic of laziness. People haven't changed, the world has, and to steal a line from Dr. David Katz, it used to be that calories were scarce and physical activity was unavoidable while today physical activity is scarce and calories are unavoidable.Consequently I feel that press releases that simply focus on how many minutes a day everyone supposedly ought to be exercising fail to address the root cause of exercise deficiencies - the world we live in.Cheap cars, suburbia, non-walkable neighbourhoods, irrational fears of child abductions, always on electronic tethers to work, constant chauffeuring of kids to activities, the Internet, video game consoles, hundreds of television channels, big box malls, etc. If we want people to take responsibility for exercising, I think we need to ensure we do our very best to empower them to do so and that means changing the world.Elementary school children aren't lazy, they're just faced with a different environment than we were when we were kids and consequently their weights have risen. While my take on the literature is that the rise is more due to intake increases rather than output decreases, when it comes to exercise people always tend to focus on the "when we were kids we used to play outside" argument. Yes we used to play outside, but the alternative then was staying home with our parents and playing with them, talking to them, or doing chores, whereas now more attractive alternatives abound. Kids, like adults are consumers of both time and pleasure. If there's a behaviour that's more fun, they're likely to choose it and many find playing video games, surfing the net, instant messaging, and iPhones, to be more entertaining than a ride around the block, a game of cops and robbers or hopscotch in the driveway.I also disagreed that a fair comparison can be drawn between the utility of evidence-based exercise recommendations and evidence-based dietary recommendations. I disagreed there because the simple fact of the matter is that more exercise is good, any exercise is good and all exercise is good. Whether it's formal gym based exercise, playing with your kids, gardening in your yard or shoveling snow in the winter, simply put, it all counts, it's all good for you and doing more is better. The same certainly can't be said for food and consequently having more specific guidelines with food is much more of a necessity.My friend felt that my assertion that the personal responsibility focus should simply be on getting people to exercise more rather than providing them with a specific number to shoot for was flawed and perhaps overly simplistic.My thinking's pretty straightforward. It stems from SMART goal setting, which suggests that while goals should certainly be specific, goals should also be both realistic and attainable. What's realistic and attainable for one person may not be for another and frankly telling sedentary children or adults that they need to at a minimum exercise for 60 minutes a day isn't likely either.More importantly though, I wonder if we'd be better off simply encouraging people to exercise more because that's more likely to have an actual impact than specific minute based minimum targets.People should be encouraged to find small bouts of lifestyle based or more formalized exercises, with the recommendation being that every 5-10 minutes count.Certainly the literature would suggest that multiple short bouts of exercise have many of the same health benefits as you'd get from more discrete large bouts of exercise, but perhaps more importantly research might suggest that people encouraged to find short bouts of exercise in fact do more exercise overall than folks trying to find those big blocks of time.One such study, conducted in 1995 by John Jakicic and colleagues found that women encouraged to find multiple 10 minute bouts of exercise, exercised more frequently and with greater total duration than women who were trying to carve out 40 minute blocks of time for exercise.Undeniably more is better, but why paralyze people with huge chunks of minimum more?One argument my friend made, and it's a theoretical one, does fairly refute my post from a few days ago. They wondered whether or not CSEP and ParticipACTION would have been permitted to make specific governmental calls to action in their press release. They wondered whether or not the involvement of the Public Health Agency of Canada would have precluded any criticism of governmental inaction. I don't know the answer to those questions and indeed it's possible that they were muzzled and while if true it might help to explain the omission, it doesn't help change my most basic concern.Press releases are by their nature picked up by the press. The press by its nature is busy and with rare exceptions doesn’t spend tremendous amounts of time researching back stories to succinctly worded press releases. While ParticipACTION may be involved with the Active Health Kids Report Card that does indeed include governmental calls to action as part of its 80 pages of commentary, the average reporter isn't going to dig that up to include it in their coverage of this story.Consequently absent the call to action to government in the press release on exercise, what the CSEP/ParticipACTION press release does, along with provide recommendations as to how many minimum minutes of exercise are necessary, is continue to perpetuate the myth, a dangerous one at that, that individuals themselves are the problem, and not their environment. And while I don't for a moment believe that CSEP or ParticipACTION set out purposely to do so, press releases and calls to action which embolden the flawed notions that inactivity and weight are diseases of the individual have the unintended consequence of hamstringing efforts for the dramatic environmental reforms we so desperately need by taking attention off of the cause and focusing it only on the consequences.So my answer to the question of how many minutes a day should you exercise? As many minutes as you can enjoy, and every single one of them count.Murphy MH, Blair SN, & Murtagh EM (2009). Accumulated versus continuous exercise for health benefit: a review of empirical studies. Sports medicine (Auckland, N.Z.), 39 (1), 29-43 PMID: 19093694Jakicic JM, Wing RR, Butler BA, & Robertson RJ (1995). Prescribing exercise in multiple short bouts versus one continuous bout: effects on adherence, cardiorespiratory fitness, and weight loss in overweight women. International journal of obesity and related metabolic disorders : journal of the International Association for the Stud... Read more »

  • May 19, 2010
  • 05:12 AM
  • 967 views

Cold weather limits potential range of Burmese python invasion

by Rob Goldstein in Conservation Maven

The well-publicized invasion of Burmese pythons in the United States is unlikely to spread farther north than south Florida according to a new study by scientists from the National Wildlife Research Center...... Read more »

Avery, M., Engeman, R., Keacher, K., Humphrey, J., Bruce, W., Mathies, T., & Mauldin, R. (2010) Cold weather and the potential range of invasive Burmese pythons. Biological Invasions. DOI: 10.1007/s10530-010-9761-4  

  • May 19, 2010
  • 02:17 AM
  • 1,513 views

French – the brand

by Ingrid Piller in Language on the Move

Installment #6 in the mini-series on multilingual signage
Multilingualism sells! Some forms of multilingualism that is. In the world of marketing, languages operate like brands: they are a signifier for something else but they are devoid of substance. To phrase it in Marxist terminology: the exchange value of languages has in some contexts come to overshadow [...]... Read more »

  • May 19, 2010
  • 01:34 AM
  • 895 views

The Neurogenesis theory of depression and a little guy called CREB

by Evil Monkey in Neurotopia

Sci wishes she could begin this post with something clever. But she has a cold. Suffice it to say that this paper is cool and interesting. And also, as Sci has a cold, I expect all of you to read this post out loud to yourselves in suitably stuffy, gluey Sci-voices.


(*sniff*)

Gur et al. "cAMP Response Element-Binding Protein Deficiency Allows for Increased Neurogenesis and a Rapid Onset of Antidepressant Response" The Journal of Neuroscience, 2007.

(Yeah, yeah, the title is long and scary. Worry not, Sci will 'splain.)

And this paper is especially good because it allows Sci to write a post on a topic she's been meaning to get to even since she did a depression series way back when: the neurogenesis theory of antidepressant responses.

So here we go. And a new neuron is born.


(From Bumpy Brains. Sci thinks the rendition of diapers as glia is hilarious.) Read the rest of this post... | Read the comments on this post...... Read more »

  • May 19, 2010
  • 01:11 AM
  • 730 views

a possible link between pesticides and ADHD

by Tal Yarkoni in citation needed

A forthcoming article in the journal Pediatrics that’s been getting a lot of press attention suggests that exposure to common pesticides may be associated with a substantially elevated risk of ADHD. More precisely, what the study found was that elevated urinary concentrations of organophosphate metabolites were associated with an increased likelihood of meeting criteria for [...]... Read more »

  • May 19, 2010
  • 12:48 AM
  • 562 views

Atlatls to Bows: A Very Strange Atlatl from Washington State

by teofilo in Gambler's House

Sometime in the early 1950s a wooden object was dredged from the mouth of the Skagit River, north of Seattle.  It ended up in the possession of Mr. and Mrs. Edwin Johnson, residents of the nearby town of La Conner.  In 1952 the Johnsons showed it to two local archaeologists, Herbert Taylor of Western Washington [...]... Read more »

Taylor, H., & Caldwell, W. (1954) Carved Atlatl from Northwest Coast. American Antiquity, 19(3), 279. DOI: 10.2307/277136  

  • May 19, 2010
  • 12:00 AM
  • 611 views

Evidence-Based Health Law Calls for Measured Laws

by Paul Statt in Paul Statt Communications

How can you measure the impact of a law? The Obama administration, for example, recently called for an “evidence-based” approach to the writing of laws and policies that affect the public’s health in matters of drug abuse. But applying the scientific method to an evaluation of a law’s impact requires a rigorous approach to measurement. In “Measuring Law for Public HealthEvaluation Research,” published in the June 2010 Evaluation Review, Charles Tremper, Sue Thomas and Alexander C. Wagenaar provide researchers good guidance for legal researchers. ... Read more »

Tremper, C., Thomas, S., & Wagenaar, A. (2010) Measuring Law for Evaluation Research. Evaluation Review, 34(3), 242-266. DOI: 10.1177/0193841X10370018  

  • May 18, 2010
  • 11:43 PM
  • 717 views

Applying Reliability Theory to Aging

by Reason in Fight Aging!

Reliability theory is, put very simply, a way of modeling and predicting the failure modes and mean time to failure of complex systems with many redundant parts subject to wear and tear. Reliability theory has seen a great deal of use in the electronics industry, amongst many others, but the human body is also a complex system that can be considered in these terms. Looking at our life spans and age-related illnesses in the context of reliability theory and the accumulating failure of redundant systems can add a great deal to our understanding of aging and our expectations for longevity science. In recent years there has been more interest in this topic amongst aging researchers. I'm sure that Leonid Gavrilov and Natalia Gavrilova, who produced some of the important papers in this space, will be pleased to see that more researchers are now rigorously applying reliability theory to aging and longevity: Aging in mouse brain is a cell/tissue-level phenomenon exacerbated by proteasome loss Biological aging is often described by its phenotypic effect on individuals. Still, its causes are more likely found on the molecular level. Biological organisms can be considered as reliability-engineered, robust systems and applying reliability theory to their...... Read more »

Mao L, Roemer I, Nebrich G, Klein O, Koppelstaetter A, Hin SC, Hartl D, & Zabel C. (2010) Aging in mouse brain is a cell/tissue-level phenomenon exacerbated by proteasome loss. Journal of proteome research. PMID: 20469937  

  • May 18, 2010
  • 11:05 PM
  • 1,464 views

Dopamine, Mental Illness and Creativity

by Maria P. in noustuff

A new study by researchers at the Swedish medical university Karolinska Institutet supports the hypothesis that there is a link between mental illness and creativity. More specifically, they showed that highly creative people – with high scores in divergent thinking – had a lower density of D2 receptors in their thalamus than less creative people. [...]... Read more »

de Manzano, Örjan, Cervenka, Simon, Karabanov, Anke, Farde, Lars, & Ullén, Fredrik. (2010) Thinking Outside a Less Intact Box: Thalamic Dopamine D2 Receptor Densities Are Negatively Related to Psychometric Creativity in Healthy Individuals. PLoS ONE. info:/

  • May 18, 2010
  • 08:24 PM
  • 926 views

The incredible leaf-tailed geckos (gekkotans part V)

by Darren Naish in Tetrapod Zoology

Before I start, allow me to announce that Tet Zoo merchandise is now available! So far, I've only used the Tet Zoo logo for these products, but I might produce additional designs in time.





Anyway... welcome to another article in the Tet Zoo gekkotan series. I really want to get through to the end without too many distractions (like amphiumas, wayward grey whales, manatees, white rhinos, giraffe-necked tortoises), otherwise I might never finish. Look what happened with toads and temnospondyls - so much work left to do! Anyway... by now, the generalities of gekkotan diversity, biology and behaviour will be familiar to you, and in this article I want to talk very briefly about one of the most remarkable kinds of geckos: namely, the fabulous leaf-tailed geckos (Uroplatus) of Madagascar [image above of U. fimbriatus by Piotr Naskrecki]. Read the rest of this post... | Read the comments on this post...... Read more »

  • May 18, 2010
  • 07:40 PM
  • 1,022 views

Bycatch Claims Sea Turtles By the Millions

by Scott A. in Thriving Oceans

It’s an article packed full of potential contention as it speaks to a variety of issues involving fisheries management.  So thank God we are dealing with a charismatic marine species or we just may be contemplating their extinction.  But then again, perhaps we are doing just that since all 7 species of marine turtles are [...]... Read more »

Wallace, B., Lewison, R., McDonald, S., McDonald, R., Kot, C., Kelez, S., Bjorkland, R., Finkbeiner, E., Helmbrecht, S., & Crowder, L. (2010) Global patterns of marine turtle bycatch. Conservation Letters. DOI: 10.1111/j.1755-263X.2010.00105.x  

  • May 18, 2010
  • 07:17 PM
  • 373 views

Up (and Down) the Creek

by Journal Watch Online in Journal Watch Online

Yangtze River dolphin maintained large range before extinction

... Read more »

Turvey, S.T. et al. (2010) Spatial and temporal extinction dynamics in a freshwater cetacean. Proceedings of the Royal Society B. info:/10.1098/rspb.2010.0584

  • May 18, 2010
  • 06:59 PM
  • 645 views

Ghrelin after Gastric Banding vs. Sleeve Gastrectomy

by Maureen McCormick in GourMind

In the last post, we discussed differences in ghrelin production after gastric bypass and sleeve gastrectomy. Today the studies we are going to consider describe the effects of gastric banding and sleeve gastrectomy on ghrelin and weight loss variables.Langer et al. randomly assigned (love it!) 20 patients to either gastric banding or sleeve gastrectomy. The groups were well-matched on demographics and medical co-morbidities. The researchers measured plasma ghrelin levels at 4 time periods: preoperatively, 1 day after surgery, 1 month after surgery, and 6 months after surgery. The results are consistent with what we saw in the last post, specifically, that the sleeve gastrectomy produced a significant, immediate and long-term decrease in plasma ghrelin levels. Most ghrelin is produced by the stomach in an area called the gastric fundus, and that part is simply removed by the sleeve gastrectomy. No more fundus, much less ghrelin.And what about the banding? No change in ghrelin was seen after 1 day, but a significant increase occurred after 1 month and 6 months. Again, this is consistent with other studies we have examined . . . weight loss by dieting or other surgical techniques results in an increase in ghrelin. This is one way to understand yo-yo dieting and what used to be called the setpoint theory of body weight.Himpens et al. compared other variables in 2 groups of randomly assigned (about to swoon!) patients, namely, weight loss, loss of feeling of hunger, loss of craving for sweets, new diagnoses of gastroesophageal reflux disease (GERD), and surgical complications. Can you guess the results? Based on what we are learning about ghrelin, you might predict that the only significant differences would be in weight loss and loss of feeling of hunger . . . and you would be right. Specifically, sleeve gastrectomy patients had lost significantly more weight than the gastric banding patients after 1 year and 3 years, and they felt significantly less hunger at the same time points.And the researchers like this as a working hypothesis . . . that decreased ghrelin production results in appetite suppression and weight loss. However, they also introduce another mechanical factor, the effect of gastric emptying on appetite, and they associate this change with the new anatomy of the stomach after sleeve gastrectomy. I need to read up on this, and maybe consult someone who knows more about this than I do, and get back to you.The take-away message I want to send to everyone who struggles with their weight is this . . . there are serious and likely redundant biochemical mechanisms that are working to maintain your weight where it is. Sometimes, when it seems like your appetite has a mind of its own, maybe it does. Lighten up on yourself. Keep working to maintain health-promoting behaviors, but don't beat yourself up for being human.Langer, F., Reza Hoda, M., Bohdjalian, A., Felberbauer, F., Zacherl, J., Wenzl, E., Schindler, K., Luger, A., Ludvik, B., & Prager, G. (2005). Sleeve Gastrectomy and Gastric Banding: Effects on Plasma Ghrelin Levels Obesity Surgery, 15 (7), 1024-1029 DOI: 10.1381/0960892054621125Himpens, J., Dapri, G., & Cadière, G. (2006). A Prospective Randomized Study Between Laparoscopic Gastric Banding and Laparoscopic Isolated Sleeve Gastrectomy: Results after 1 and 3 Years Obesity Surgery, 16 (11), 1450-1456 DOI: 10.1381/096089206778869933... Read more »

  • May 18, 2010
  • 06:49 PM
  • 588 views

Multimodal Investigation of Reading in Children: More from Brem and Colleagues

by Livia in Reading and Word Recognition Research

Accessibility: Advanced



Last time we read an article from Brem and colleagues that compared word processing in adolescents (age 15-17) and adults (19-30). In follow-up paper from 2009, Brem expanded the report to include children (9-11).



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