Neuroscience posts

April 5, 2013
08:16 AM
102 views

“Genetic Test for Autism” Criticized

by Neuroskeptic in Neuroskeptic_Discover

Last year, there was quite a bit of excitement over a “Genetic Test To Predict Risk for Autism”. The test was revealed in a paper in Molecular Psychiatry, by Australian researchers Skafidas and colleagues. The claim was that a statistical classifier could spot patterns of genetic variation that differed between people with autism and healthy [...]... Read more »

Belgard, T., Jankovic, I., Lowe, J., & Geschwind, D. (2013) Population structure confounds autism genetic classifier. Molecular Psychiatry. DOI: 10.1038/mp.2013.34

April 5, 2013
05:58 AM
158 views

Memories of near death experiences (NDE): more real than reality?

by Perikis Livas in Tracing Knowledge

University of Liège researchers have demonstrated that the physiological mechanisms triggered during NDE lead to a more vivid perception not only of imagined events in the history of an individual but also of real events which have taken place in their lives! These surprising results – obtained using an original method which now requires further investigation – are published in PLOS ONE.... Read more »

The University of Liège Press Release. (2013) Memories of near death experiences (NDE): more real than reality?. The University of Liège News. info:/

April 4, 2013
04:47 PM
281 views

Binge Eating: When Should We Call It An “Addiction”?

by Liz in Science of Eating Disorders

Hello Science of Eating Disorders readers! This is a guest post by Liz. Liz is a PhD Candidate in Psychology at the University of Toronto. You can read more about her research, interests, and eating disorder history on her “About” page.
And the usual “disclaimer”: Please keep in mind that I (Tetyana) give as much freedom as possible to guest writers and contributors to write about their own interests and viewpoints. That means that we don’t all necessary agree; there is no joint agenda. My primary reason for wanting more contributors is to widen the content, vary the writing styles, and negate the individual biases we all have. Our desire to understand, translate, and summarize peer-reviewed ED literature is what we all share in common.
The recent New York City soda ban controversy has contributed to increased discussion about the “addictive” properties of sugar and its contribution to the obesity epidemic. While I do not deny that there is an overabundance of high-sugar/high-fat foods in the societal milieu, and that the rewarding properties of these foods encourages …

You May Also Like:
Dopamine and Anorexia Nervosa: Tackling the Myths – Part I (Intro)
Dopamine and Anorexia Nervosa: Tackling the Myths – Part II (Contradictory Findings in Preclinical Studies)
Dopamine and Anorexia Nervosa: Tackling the Myths – Part IV (Treatment with Antipsychotics)

... Read more »

Boggiano, M., Turan, B., Maldonado, C., Oswald, K., & Shuman, E. (2013) Secretive food concocting in binge eating: Test of a famine hypothesis. International Journal of Eating Disorders, 46(3), 212-225. DOI: 10.1002/eat.22077

Corwin, R., Avena, N., & Boggiano, M. (2011) Feeding and reward: Perspectives from three rat models of binge eating. Physiology , 104(1), 87-97. DOI: 10.1016/j.physbeh.2011.04.041

Stice, E., Figlewicz, D., Gosnell, B., Levine, A., & Pratt, W. (2012) The contribution of brain reward circuits to the obesity epidemic. Neuroscience . DOI: 10.1016/j.neubiorev.2012.12.001

April 4, 2013
11:26 AM
99 views

Neurons and New Newt Legs

by TheCellularScale in The Cellular Scale

Salamanders are amazing and mystical creatures. Salamanders and their amazing leg-growing superpower (source)Not because they can survive in fire (they can't), but because they can regrow amputated limbs.A paper in 2007 investigates exactly what neural signals are required for this amazing superpower. Newt Amputee (Kumar et al., 2007)This paper brings together two interesting things about salamander (newt) leg growth.1. The salamander arm 'knows' where it was cut. If it is cut at the wrist it only grows a hand (paw?...foot?), if it is cut at the shoulder, it grows the whole leg/arm. So one question is HOW does the arm know?The answer is surprisingly simple: there is a small protein called Prod 1 that is highly concentrated at the shoulder and progressively decreases along the arm. This protein could tell the new bud of growing cells where it is, and what it should grow into.and2. To regenerate, the arm needs intact nerve endings at the point of the cut. That is, the nerve fiber that goes down the arm has to be attached to the nervous system. If the nerve is cut further up than the arm cut, the arm will not regenerate.Kumar et al., 2007 Author Summary FigureKumar et al. (2007) found a molecule that ties these two interesting things together, completing the newt leg regeneration story. They find a molecule, nAG (n for newt and AG for anterior gradient) which binds to Prod 1, and is secreted by the nerve sheath (the Schwann cells that surrounds nerve fibers).They show that when they cut the nerve further up the arm (denervation), they don't get nAG expression and they don't get limb regeneration. But, when they artificially supply nAG, (see D and E above), the amputated and denervated limb starts to grow. This is a really neat 'rescue experiment' suggesting that the reason the nerve is necessary for regeneration is because it triggers nAG release which binds to Prod 1 and says "GROW".One thing that they don't do (because genetically manipulating salamanders is not really a thing yet) is remove nAG, but keep the nerve intact. This would show that the only important thing the nerve fiber is doing is triggering nAG.This study is also a small step towards limb regeneration in humans, not because injecting nAG into an amputated human limb could regenerate it (It couldn't), but because the more we understand about how the system works, the more likely we can figure out a way to engineer a similar system in humans. © TheCellularScaleKumar A, Godwin JW, Gates PB, Garza-Garcia AA, & Brockes JP (2007). Molecular basis for the nerve dependence of limb regeneration in an adult vertebrate. Science (New York, N.Y.), 318 (5851), 772-7 PMID: 17975060... Read more »

Kumar A, Godwin JW, Gates PB, Garza-Garcia AA, & Brockes JP. (2007) Molecular basis for the nerve dependence of limb regeneration in an adult vertebrate. Science (New York, N.Y.), 318(5851), 772-7. PMID: 17975060

April 4, 2013
03:30 AM
138 views

Nutraceuticals for Alzheimer’s disease

by Usman Paracha in SayPeople

Alzheimer’s disease (AD) is the neurodegenerative disorder that affects the brain leading to dementia. It usually occurs late in life.

Reason behind the Alzheimer’s disease:

Researchers found senile plaques and components of the plaques such as amyloid beta peptide (Abeta), which is a proteolytic fragment of the amyloid precursor protein, and neurofibrillary tangles in the brain lesions as the basic diagnosis of the AD.

Plaques found in the brain are found to be the cause of the damage to the cholinergic neurons found in the basal forebrain of the AD patients.

Drugs of choice for Alzheimer’s disease:

Among the drugs of choice for AD are donepezil HCl and tacrine, which are cholinesterase inhibitors, rivastigmine and galantamine, which are inhibitors of the breakdown of acetylcholine and memantine HCl, which is the glutamate regulator. Even the drugs of choice come with the side effects such as dizziness, headache, nausea, vomiting and insomnia.

Nutraceuticals for Alzheimer’s disease:

Recently researchers have found that many types of spices, fruits, medicinal plants and vegetables could have potential anti-oxidant activity and could help against AD.

Curcumin, yellow curry spice, has anti-oxidant and anti-inflammatory properties and could help against neurotoxic and genotoxic agents. Technically speaking, it inhibits NF-κB leading to prevention of Abeta-induced cell death in a human neuroblastoma cell line that has been considered as the therapeutic strategy for Alzheimer’s disease. It also inhibits fibril and oligomer formation, inhibit Egr-1, Abeta-induced cell death, and activation of transcription factors that is further strengthening the role of curcumin in AD treatment.
Piperine, an active alkaloid in Piper nigrum, has also shown efficacy against AD. Researchers found that the compound improved the memory impairment much in the rat model. It also improved neurodegenration in the hippocampus.
Aged garlic extract (AGE) has also showed antiamyloidogenic properties. Technically speaking, AGE suppressed the development of reactive oxygen species (ROS) that are found to be involved in the apoptotic mechanism of Abeta-mediated neurotoxicity.
Sage
Angelica sinensis
Angelica gigas
Morin
Ginger
Cinnamon
(All of these compounds from 4 to 9 are found to protect the neuronal cells from Abeta-induced neurotoxicity)

Ursolic acid
Linalool
(These compounds in 10 and 11 act through the inhibition of acetylcholinesterase)

Reference:

Kannappan, R., Gupta, S., Kim, J., Reuter, S., & Aggarwal, B. (2011). Neuroprotection by Spice-Derived Nutraceuticals: You Are What You Eat! Molecular Neurobiology, 44 (2), 142-159 DOI: 10.1007/s12035-011-8168-2... Read more »

Kannappan, R., Gupta, S., Kim, J., Reuter, S., & Aggarwal, B. (2011) Neuroprotection by Spice-Derived Nutraceuticals: You Are What You Eat!. Molecular Neurobiology, 44(2), 142-159. DOI: 10.1007/s12035-011-8168-2

April 3, 2013
10:53 AM
133 views

Risky Business: Ape Style

by Miss Behavior in The Scorpion and the Frog

The decisions of this chimpanzee living in the Tchimpounga Chimpanzee Sanctuary are affected by his social situation. Photo by Alex Rosati.If you have a choice between a prize that is awesome half the time and totally lame the other half of the time or a mediocre prize that is a sure-thing, which would you choose? Your choice probably depends on your personality somewhat. It may also depend on your needs and your mood. And it can depend on social contexts, like if you’re competing with someone or if you’re being watched by your boss or someone you have a crush on.All animals have to make choices. Some choices are obvious: Choose the thing that is known to be of high quality over the thing that is known to be of low quality. But usually, the qualities of some options are uncertain and choosing them can be risky. As with us, the likelihood of some primates, birds, and insects to choose riskier options over safer ones can be affected by outside influences. And we aren’t the only species to have our risk-taking choices influenced by social context. Anthropologists Alex Rosati and Brian Hare at Duke University tested two ape species, chimpanzees and bonobos, in their willingness to choose the riskier option in different social situations. They tested chimpanzees living in the Tchimpounga Chimpanzee Sanctuary and bonobos in the Lola ya Bonobo Sanctuary, both in the Democratic Republic of Congo. Most of the apes living in these sanctuaries are confiscated from poachers that captured them from the wild for the pet trade and for bushmeat. In these sanctuaries the animals live in social groups, generally spending their days roaming large tracts of tropical forest and their nights in indoor dormitories. This lifestyle rehabilitates their bodies and minds, resulting in psychologically healthy sanctuary inhabitants.It is in these familiar dormitories that Alex and Brian tested the apes’ propensity for making risky choices. For their experimental set-up, an experimenter sat across a table from an ape and offered them two options: an overturned bowl that always covered a treat that the apes kinda like (peanuts) versus an overturned bowl that covered either an awesome treat (banana or apple) or a lousy treat (cucumber or lettuce). In this paradigm, the peanut-bowl represents the safe choice because whenever the ape chooses it, they know they’re getting peanuts. But the other bowl is the risky choice, because half the time they get fruit (yum!), but the other half of the time they get greens (bummer).This figure from Rosati and Hare's 2012 Animal Behavour paper shows Alex demonstrating the steps they would go through before the ape chose one of the two options.After spending some time training the apes to be sure they understood the game, the researchers tested their choices in different social situations. In each test session, the ape was allowed to choose between the two bowls (and eat the reward) multiple times (each choice was called a trial). But before the test session began and in between choice trials, another experimenter sat with the ape for two minutes and did one of three things: In one group, the experimenter sat at the table and silently looked down (they called this the “neutral condition”). In another group, the experimenter repeatedly offered the ape a large piece of food, pulling it away and grunting whenever the ape reached for it (they called this the “competitive condition”). In a third group, the experimenter tickled and played with the ape (they called this the “play condition”).Alex and Brian found out that whereas bonobos chose the safe option and the risky option about equally, the chimpanzees were significantly more likely to choose the risky option. But despite this species difference, both species chose the risky option more often in the “competitive condition”. Neither species increased their risk-taking in the “play condition”.The graph on the left shows that wheras bonobos chose the safe option and the risky option each about 50% of the time (where the dashed line is), the chimpanzees chose the risky option much more often. The graph on the right shows that both species chose the risky option more often in the "competition condition" than they did in the "neutral condition". Figure from Rosati and Hare's 2012 Animal Behavour paper.These are interesting findings, especially when you consider the natural behaviors and lifestyles of these closely related species. Bonobos can be thought of as the hippies of the ape world, happily sharing and using sex to settle disputes and strengthen relationships. In comparison, chimpanzees are more like gangsters, aggressively fighting over resources and dominance ranks. So in general, the more competitive species is more likely to take risks. But when the social environment becomes more competitive, both species up the ante. This effect doesn’t seem to be simply the result of being in a social situation, because the apes didn’t increase their risk-taking in the presence of a playful experimenter. This still leaves us with some questions to ponder though. Are apes more likely to take risks when an experimenter is offering food and taking it away because of a heightened sense of competition, or is this the result of frustration? And would we see the same effect if the “competitor” were another ape of the same species, rather than a human experimenter? How would their behavior change if they were hungry? These questions are harder to get at, but this research does demonstrate that like in humans, the decision-making process in chimpanzees and bonobos is dependent on social context. Want to know more? Check this out:Rosati, A., & Hare, B. (2012). Decision making across social contexts: competition increases preferences for risk in chimpanzees and bonobos Animal Behaviour, 84 (4), 869-879 DOI: 10.1016/j.anbehav.2012.07.010 ... Read more »

Rosati, A., & Hare, B. (2012) Decision making across social contexts: competition increases preferences for risk in chimpanzees and bonobos. Animal Behaviour, 84(4), 869-879. DOI: 10.1016/j.anbehav.2012.07.010

April 2, 2013
07:52 PM
167 views

Antidepressant epigenetic action of a common fitness supplement

by Shelly Fan in Neurorexia

A short note on the history of antidepressant research: From MAOIs/SSRIs to ketamine and BDNF Traditional antidepressants, like Prozac, don’t work too well. Back in the 50s, researchers thought that depression was caused by a depletion of a group of neurotransmitters in the brain known chemically as the monoamines (i.e. serotonin, noradrenaline, dopamine). Hence, the [...]... Read more »

Nasca C, Xenos D, Barone Y, Caruso A, Scaccianoce S, Matrisciano F, Battaglia G, Mathé AA, Pittaluga A, Lionetto L.... (2013) L-acetylcarnitine causes rapid antidepressant effects through the epigenetic induction of mGlu2 receptors. Proceedings of the National Academy of Sciences of the United States of America, 110(12), 4804-9. PMID: 23382250

April 2, 2013
11:48 AM
119 views

Vitamin P as a potential molecule for motor neuron diseases

by Usman Paracha in SayPeople

Main Point:

Researchers have found that vitamin-P could help us in the treatment of damaged motor neurons. It can help us in potentiating the new therapeutic strategies for diseases such as Amyotrophic Lateral Sclerosis (ALS).

Journal:

Molecular and Cellular Neuroscience

Study Further:

Vitamin P is also called as 7,8-Dihydroxyflavone. Motor neurons are involved in the control of movements.

Researchers from Ruhr-Universität Bochum have found that vitamin P works by sending the signals through another path than the molecule Brain Derived Neurotrophic Factor (BDNF) that was previously considered as important for the treatment of motor neuron disorders or after spinal cord damage.

"The Brain Derived Neurotrophic Factor only had a limited effect when tested on humans, and even had partially negative consequences", Prof. Dr. Stefan Wiese from the RUB Work Group for Molecular Cell Biology, said in a statement. "Therefore we are looking for alternative ways to find new approaches for the treatment of neurodegenerative diseases such as Amyotrophic Lateral Sclerosis."

BDNF stimulates two signaling pathways, the so-called MAP kinase and PI3K/AKT signal paths while researchers found that Vitamin P makes use only of the latter.

Researchers are of the opinion that vitamin P could have less negative effects than BDNF as vitamin P showed only positive effects on the motor neurons in less concentration range.

"These results show how important an accurate determination of dose and effect is", said Prof. Wiese. "It is easier to use, because vitamin P, in contrast to BDNF, can pass the blood-brain barrier and therefore does not have to be introduced into the cerebrospinal fluid using pumps like BDNF," Wiese added.

Source:

Eurekalert

Reference:

Tsai, T., Klausmeyer, A., Conrad, R., Gottschling, C., Leo, M., Faissner, A., & Wiese, S. (2013). 7,8-Dihydroxyflavone leads to survival of cultured embryonic motoneurons by activating intracellular signaling pathways Molecular and Cellular Neuroscience, 56, 18-28 DOI: 10.1016/j.mcn.2013.02.007... Read more »

Tsai, T., Klausmeyer, A., Conrad, R., Gottschling, C., Leo, M., Faissner, A., & Wiese, S. (2013) 7,8-Dihydroxyflavone leads to survival of cultured embryonic motoneurons by activating intracellular signaling pathways. Molecular and Cellular Neuroscience, 18-28. DOI: 10.1016/j.mcn.2013.02.007

April 2, 2013
03:04 AM
170 views

Steven Pinker: "People in music hate this theory"

by Henkjan Honing in Music Matters

Steven Pinker explains again why music is not an adaptation but should be seen as a kind of 'supernormal stimulus'...... Read more »

Honing, H. (2011) Muziek is geen luxe.. maar wat dan wel?. Academische Boekengids. info:/

Collier, D., Honing, H., & Oliver, R. (2012) REVIEWS. Journal of Music, Technology and Education, 5(1), 109-121. DOI: 10.1386/jmte.5.1.109_5

April 1, 2013
05:31 PM
112 views

Excuse me, that's my hand! (... but is it really?)

by Isabel Torres in Science in the clouds

About 15 years ago, a one-page Nature study shook the scientific community. Researchers from the University of Pittsburg showed with a simple experiment that people could feel that a fake rubber hand was in fact their own- they called it the ‘rubber hand illusion’. It goes like this: place a fake hand on a table in front of you and your own hand just next to it. Then block your hand from your view, stare at the fake hand, and get someone to stroke both hands in the same way for a few minutes. Now close your eyes and point at your hand. Most people will point at the fake hand, and so should you. Credit: melodi2/everystockphotoSince this intriguing discovery, neuroscientists have been trying to understand how the brain combines visual, touch and position information to create the feeling of body ownership, or in another words, the awareness that our body parts belong to ourselves. A new study led by Anna Berti’s team at the University of Turin now shows that the embodiment of an alien limb, like someone else’s hand, can be so deeply rooted in our neural circuits that it affects motor control.When we try to perform a different motor task with each hand at the same time, let's say drawing a circle with one hand and a straight line with the other, ... Read more »

Garbarini Francesca, Pia Lorenzo, Piedimonte Alessandro, Rabuffetti Marco, Gindri Patrizia, & Berti Anna. (2013) Embodiment of an alien hand interferes with intact-hand movements. Current Biology, 23(2). DOI: 10.1016/j.cub.2012.12.003

April 1, 2013
05:00 PM
154 views

Can a Sea Lion keep the beat too?

by Henkjan Honing in Music Matters

Yesterday another piece of evidence was published in the Journal of Comparative Psychology showing a sea lion (Zalophus californianus) being able to learned to entrain to the beat of the music.... Read more »

Cook, P., Rouse, A., Wilson, M., & Reichmuth, C. (2013) A California Sea Lion (Zalophus californianus) Can Keep the Beat: Motor Entrainment to Rhythmic Auditory Stimuli in a Non Vocal Mimic. Journal of Comparative Psychology. DOI: 10.1037/a0032345

March 31, 2013
06:56 PM
167 views

Are Cognitive Factors Related to Criminal Reoffending?

by The Neurocritic in The Neurocritic

Image from Graphic SociologyCan Brain Activity Predict Criminal Reoffending? The previous post discussed a functional MRI study suggesting that the level of error-related activation in the anterior cingulate cortex (ACC) might have value in predicting whether a recently released prisoner will be rearrested within 4 years (Aharoni et al. 2013):The odds that an offender with relatively low anterior cingulate activity would be rearrested were approximately double that of an offender with high activity in this region, holding constant other observed risk factors. These results suggest a potential neurocognitive biomarker for persistent antisocial behavior.However, using ACC activity as a dichotomous variable misclassified 40% of low ACC participants who did not reoffend and 46% of high ACC participants who did commit crimes after release, not exactly the odds you'd want for making parole decisions. Even the senior author was doubtful that an fMRI test would ever be useful for risk assessment purposes on a case by case basis.Since Aharoni and colleagues made their individual subject data available as supplementary material (Download Dataset_S01, XLSX), I was interested in how some of the demographic and performance variables might be related to recidivism, since these are obviously cheaper and easier to collect from incarcerated prisoners than MRI scans.The cognitive task performed during the fMRI experiment required responding to a frequent stimulus presented 84% of the time ("X") and inhibiting responses to a rare stimulus ("K").Fig. S4. (Aharoni et al., 2013). Go/No-Go task.The study compared brain activity on incorrect responses to "K" (commission errors) and correct responses to "X" (hits) in a region of interest in the dorsal ACC, which has been implicated in error processing (Simons, 2010), among many other things. The authors framed the results largely in the context of impulse control, but other explanations are possible (as we'll see later).Are any of the task performance variables related to recidivism? Starting with some very simple-minded t-tests, the rate of commission errors in the group of participants arrested for nonviolent offenses1 (n=40) did not differ significantly from what was seen in those not arrested again (n=56).2Data from (Aharoni et al., 2013). Commission errors in the Go/NoGo task (% incorrect responses on NoGo trials) and omission errors (% missed responses on Go trials) for inmates that went on to commit nonviolent offenses within 4 years after release (Nonviolent) and those that did not (None). The trend for the reoffenders to commit more errors was not significant (p=.09) even without correcting for multiple comparisons.Although there were data from a large control group of nonoffenders (n=102) used to set the ACC ROI, we don't have their behavioral results. I consulted an earlier fMRI paper by Kiehl et al. (2000) that used a very similar Go/NoGo task in 14 control participants. Commission errors occurred on 23.7% of NoGo Trials and omission errors on 3% of Go Trials, which is similar to what was seen in the offenders (overall means of 25.04% and 3.44%, respectively).Reaction times (RTs) did not differ between the two offender groups either, suggesting there wasn't a differential speed-accuracy tradeoff (e.g., if the reoffenders were slower yet making marginally more errors).Data from (Aharoni et al., 2013). RTs in milliseconds for commission errors (incorrect responses on NoGo trials) and hits (correct responses on Go trials) for inmates that went on to commit nonviolent offenses within 4 years after release (Nonviolent) and those that did not (None). There were no group differences.Surprisingly, RTs were slower on commission errors (358 ms) than on hits (346 ms), a small but highly significant difference (p=.0005). This is the opposite of what you'd expect if the errors were due to impulsive responses. If the participants were becoming careless and not fully evaluating the NoGo stimulus, they'd be faster on error trials. This is why I'm not convinced the ACC activations are entirely related to behavioral impulsivity. In EEG studies of error processing, the degree of ACC activity3 is related to the emphasis placed on accuracy (Gehring et al., 1993), so if the reoffenders didn't care as much about accuracy, this could account for their low ACC status. One interesting bit of data for the authors to examine would be RT and accuracy on responses following an error, which indicates the amount of behavioral adjustment after making a mistake. Did the reoffenders show a lower propensity to slow down and become more careful? If so, this might reflect a lack of concern about the consequences of their actions.However, the most puzzling thing to me were scores on Factor 2 of the Psychopathy Checklist-Revised (PCL-R) (Hare, 2003). Factor 2 is thought to reflect impulsivity, stimulation seeking, and irresponsibility (Ermer et al., 2012). The rearrested and not-rearrested groups were significantly different as expected, but in the opposite direction (unless I'm missing something here) — scores were lower in the group that was rearrested, in comparison to those who were not (p=.001).Data from (Aharoni et a... Read more »

Aharoni, E., Vincent, G., Harenski, C., Calhoun, V., Sinnott-Armstrong, W., Gazzaniga, M., & Kiehl, K. (2013) Neuroprediction of future rearrest. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1219302110

Kiehl, K., Liddle, P., & Hopfinger, J. (2000) Error processing and the rostral anterior cingulate: An event-related fMRI study. Psychophysiology, 37(2), 216-223. DOI: 10.1111/1469-8986.3720216

March 29, 2013
11:26 AM
161 views

Blast-related Traumatic Brain Injury and fMRI

by William Yates, M.D. in Brain Posts

Blast-related traumatic brain injury (TBI) is an important research topic. Over 100,000 armed services personnel experienced a significant traumatic brain event in the last decade. A majority of these were explosion or blast-related in nature.However, standard brain imaging techniques (computed tomographay, structural MRI) typically fail to demonstrate changes following blast TBI. New imaging strategies are needed to assess severity and progression.Graner and colleagues from Walter Reed National Medical Center recently published a summary of promising functional MRI techniques in blast-related TBI. They noted promising fMRI approaches to the assessment of blast-related TBI focus on functional deficits common to the injury: working memory deficits, attention deficits and deficits in emotional processing:Working memory: Functional brain MRI carried out while carrying out a working memory task activates multiple brain regions including the prefrontal cortex, temporal cortex, parietal cortex, cerebellum and white matter connectivity. The N-Back Task and Delayed Recall Task engage brain working memory regions. There have been very few studies of working memory fMRI in TBI but initial studies suggest demonstrable changes including increased activation of the prefrontal cortex.Selective attention: Attention requires activation of multiple neural networks including the prefrontal cortex, anterior cingulate cortex, the striatum and parietal cortex. Non-blast TBI subjects completing the Stroop attention task show increased brain activation compared to controls. The level of hyper-activation correlates with post concussion symptoms.Emotional response: Blast-related TBI commonly occurs in the context of depression and post-traumatic stress disorder (PTSD). Emotional response tasks activate the brain limbic network including the amygdala and hippocampus. Few studies of fMRI using emotional response in blast-related TBI have been completed.The authors highlight an additional promising approach, resting state fMRI. Resting state fMRI is a relative straight-forward approach that does not require completion of a specific task. Resting state fMRI abnormalities in the default mode network have been demonstrated in a variety of neurological and mental disorders. However, only a few TBI subjects have completed resting state fMRI but initial studies show normalization of networks with recovery.The authors note one key research challenge in blast-related TBI is identifying and controlling for the common comorbidities, i.e. major depressive disorder and PTSD. Measurement of depression and PTSD symptoms is needed to tease out specific brain changes linked to blast-related TBI.Despite the challenges, functional MRI appears to be a promising strategy in studying blast-related TBI. This strategy might lead to better treatment and rehabilitation approaches to this common neuropsychiatric disorder.Readers with more interest in this topic can access the free full-text manuscript by clicking on the PMID link below.Photo of sunset over Sanibel Island is from the author's files.Graner J, Oakes TR, French LM, & Riedy G (2013). Functional MRI in the investigation of blast-related traumatic brain injury. Frontiers in neurology, 4 PMID: 23460082... Read more »

Graner J, Oakes TR, French LM, & Riedy G. (2013) Functional MRI in the investigation of blast-related traumatic brain injury. Frontiers in neurology, 16. PMID: 23460082

March 28, 2013
06:57 PM
125 views

Throw another dog in the (data) pool

by Cobb & Hecht in Do You Believe In Dog?

Hello Julie,My, oh my! What an exciting time it was last week, witnessing Dog Spies' migration to the Scientific American Blog Network. Such a great day for dogs, for science and for YOU! Yah! for this recognition of your fabulous writing achievements, communicating the field of canine science to a broader audience. WELL DONE!As for your question about writing and how I do it, I have to admit I'm 'between systems' currently. By this, I mean that I sometimes map out ideas and plan my writing on paper before hitting the laptop; other times I just let rip straight onto the keyboard. I don't know if I'll ever migrate to a completely paperless system, but I feel that I'm moving in that direction. I still take most of my notes in meetings on paper, which is ridiculous as my handwriting is barely legible, even to me!Thanks also for the link to that piece by Clive Wynne about academic writing - I really enjoyed reading it.META-ANALYSIS You said it. I'm neck-deep in meta-analysis goodness right now and I'd love to tell you more about it. The meta-analysis data set I'm currently involved in compiling is about canine salivary cortisol (that just means cortisol found in dog spit). Cortisol is a hormone (more detail here) regularly used in research concerning animal stress and welfare. I've been interested in canine salivary cortisol for a while now. That's partly because I collected a lot of it (dog spit, that is) from dogs living in home environments and working dog kennels as part of my PhD research; and partly because its really interesting! But my data alone is just one piece of a bigger puzzle. While it's really valuable information (of course it's valuable, it's part of my PhD!), it only offers insight into around 75 dogs from one population of purpose-bred dogs in one geographic area during one two-year period. How do the results of these dogs in my study compare to 'normal' dogs?Well, you see - that's the thing. What is the normal range for salivary cortisol in dogs? We don't really know. What is it?Meta-analysis is a way of evaluating and interpreting the results from research about a particular topic. It adds together the data from different studies, then looks at the compiled data pool to see what patterns and relationships might emerge in the larger body of available information created by the many research projects.Throw another dog in the (data) pool! (source)Why use it?The patterns and groups we might look at within a meta-analysis of salivary cortisol (often used as an indicator of stress/welfare in dog research) are things like: Effects of different environments (do all the results from dogs housed in 'unfamiliar kennel environments' or 'familiar home environments' clump together at different or similar points within the range of values as a whole?); Effects of breed/age (is the range for labradors the same as that for german shepherds? Are all the young dogs in the same place as the old dogs?); Methodological aspects (such as what collection media was used: cotton swabs / synthetic rope / swabs with a saliva stimulant, etc. - does this effect where the cortisol results lie within the whole range?) All this information (and much more!) can be investigated and the information will help to provide further context for the existing studies, while also informing the design and interpretation of future studies. ... Read more »

Liberati Alessandro, Altman Douglas G., Tetzlaff Jennifer, Mulrow Cynthia, Gøtzsche Peter C., Ioannidis John P.A., Clarke Mike, Devereaux P.J., Kleijnen Jos, & Moher David. (2009) The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. Journal of Clinical Epidemiology, 62(10). DOI: 10.1016/j.jclinepi.2009.06.006

Dorey Nicole R., Udell Monique A.R., & Wynne Clive D.L. (2009) Breed differences in dogs sensitivity to human points: A meta-analysis. Behavioural Processes, 81(3), 409-415. DOI: 10.1016/j.beproc.2009.03.011

Fratkin Jamie L, Sinn David L, Patall Erika A, & Gosling Samuel D. (2013) Personality consistency in dogs: a meta-analysis. PloS one. PMID: 23372787

Nimer Janelle, & Lundahl Brad. (2007) Animal-Assisted Therapy: A Meta-Analysis. Anthrozoos: A Multidisciplinary Journal of The Interactions of People , 20(3), 225-238. DOI: 10.2752/089279307X224773

March 28, 2013
05:36 PM
155 views

The biological basis of orchestra seating

by Richard Kunert in Brain's Idea

Many cultural conventions appear like the result of historical accidents. The QUERTY – keyboard is a typical example: the technical requirements of early typewriters still determine the computer keyboard that I write this text on, even though by now technical advances would allow for a far more efficient design. Some culturally accepted oddities, however, appear [...]... Read more »

Deutsch, D. (1999) Grouping Mechanisms in Music. The Psychology of Music, Second Edition, 299-348. DOI: 10.1016/B978-012213564-4/50010-X

Schneider P, Sluming V, Roberts N, Bleeck S, & Rupp A. (2005) Structural, functional, and perceptual differences in Heschl's gyrus and musical instrument preference. Annals of the New York Academy of Sciences, 387-94. PMID: 16597790

March 28, 2013
04:13 PM
151 views

Can Brain Activity Predict Criminal Reoffending?

by The Neurocritic in The Neurocritic

Is it possible for a brain scan to predict whether a recently paroled inmate will commit another crime within 4 years? A new study by Aharoni et al. (2013) suggests that the level of activity within the anterior cingulate cortex might provide a clue to whether a given offender will be rearrested.Dress this up a bit and combine with a miniaturized brain-computer interface that continuously uploads EEG activity to the data center at a maximum security prison. There, machine learning algorithms determine with high accuracy whether a given pattern of neural oscillations signals the imminent intent to reoffend that will trigger deep brain stimulation in customized regions of prefrontal cortex, and you have the plot for a 1990s cyberpunk novel.But we're getting way ahead of ourselves here...Dr. Kent Kiehl outside the mobile scanner his group uses to look at the brains of inmates at New Mexico prisons. Credit: Nature News.The actual study in question used functional MRI to scan the brains of 96 male inmates at two New Mexico state correctional facilities while they performed a cognitive task (Aharoni et al., 2013). The task required responding to a frequent stimulus presented 84% of the time ("X") and inhibiting responses to the rare stimulus ("K").Fig. S4. (Aharoni et al., 2013). Go/No-Go task.The major comparison examined brain activity on incorrect responses to "K" (commission errors) vs. correct responses to "X" (hits). This contrast was restricted to a region of interest (ROI) in the dorsal anterior cingulate cortex (dACC), which has been associated with a wide array of cognitive and emotional control functions (Posner et al., 2007).Results from a separate group of 102 age-matched control participants (mean = 33.9 yrs) from Hartford, CT1 determined the a priori ROI, with the peak voxel located at coordinates x = −3, y = 24, z = 33 in the center of a 14 mm sphere. One control ROI was chosen in a more ventral and anterior region of medial prefrontal cortex (mPFC) at 0, 51, −6.The most strongly activated voxel in the offender group for the error vs. hit contrast was remarkably close to the one determined from the independent sample and fell well within the a priori ROI (see blue crosshairs in figure below).Fig. 2 (modified from Aharoni et al., 2013). (B) Mean hemodynamic response change in offender sample (n = 96) during commission errors vs. correct hits from sagittal (Upper Left), coronal (Right), and axial (Lower Left) orientations. Peak activation located at x = 3, y = 24, z = 33 within the anterior cingulate cortex region of interest (P < 0.00001, FWE).The dACC has been strongly implicated in error processing (Simons, 2010), and that was no different in the offenders as a group. Other regions significantly activated by commission errors included bilateral inferior frontal cortex/insula, fusiform gyrus, and cerebellum but these were not discussed.Of greatest interest is whether this dACC activity can predict recidivism. For this the authors did a survival analysis:First, a Kaplan–Meier survival function was computed to describe the proportion of participants surviving any felony rearrest over the 4-y follow-up period, ignoring the influence of any particular risk factor (Fig. S1). Cox proportional hazards regression was then used to examine (i) the zero-order effects of ACC activity on months to rearrest for any crime, (ii) the shared and unique influence of the ACC and other potential risk factors on months to rearrest for any crime, (iii) for nonviolent crimes, and (iv) the shared and unique influence of the medial prefrontal cortex (mPFC) control region and other potential risk factors on months to rearrest for any crime. ...... A significant association was found whereby, for every one unit increase in ACC activity, there was a 1.39 (i.e., 1/exp[B]) decrease in the probability of rearrest....Meaning that the participants with greater ACC activity were less likely to reoffend. The mPFC ROI did not show this association. Then a median split divided the offender sample into high ACC and low ACC groups (survival function shown below).Fig. 1 (Aharoni et al., 2013). Cox survival function showing proportional rearrest survival rates of high (solid green) vs. low (dashed red) ACC response groups for any crime over a 4-y period. Results of this median split analysis were equivalent to that of the parametric model: bootstrapped B = 0.96; SE = 0.40; P < 0.01; 95% CI, 0.29–1.84. The mean survival times to rearrest for the low and high ACC activity groups were 25.27 (2.80) mo and 32.42 (2.73) mo, respectively. The overall probabilities of rearrest were 60% for the low ACC group and 46% for the high ACC group.So for all felonies (both violent and nonviolent), a substantial percentage of participants were likely to be rearrested within 4 years. The ACC classification scheme would wrongly condemn the 40% of low ACC parolees who did not reoffend, and would miss the 46% of high ACC parolees who did commit crimes after release. When you look at it that way, it's not all that impressive and completely inadmissable as evidence for decision-making purposes. For nonviolent felonies only, the probability of rearrest for high ACC offenders was 31%, compared to 52% for low ACC offenders.A number of other variables were considered in the regression models (and singly as predictors), including age at release, drug and alcohol use, scores on the Psychopathy Checkli... Read more »

Aharoni, E., Vincent, G., Harenski, C., Calhoun, V., Sinnott-Armstrong, W., Gazzaniga, M., & Kiehl, K. (2013) Neuroprediction of future rearrest. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1219302110

March 28, 2013
12:09 PM
145 views

Football and the Blood Brain Barrier

by William Yates, M.D. in Brain Posts

A variety of research tools are being utilized to study the effect of trauma on the brain. In a previous post, I summarized some of the research using diffusion brain imaging or DTI.A recent study looked at the function of the blood-brain barrier (BBB) in a group of football players. The BBB is an important brain protective mechanism. A variety of blood proteins and other compounds have the potential to cause inflammation and other damage to neurons and other brain cells.Marchi and colleagues recruited a series of 67 college football players for a prospective study during the football season.This study focused on study of a marker of BBB disruption, the compound astrocyte protein S100B. When the BBB is disrupted, brain astrocyte protein S100B leaks out from the brain and is found in the blood stream. Normally, an intact BBB prevents this brain protein from entering the blood. Higher levels of astrocyte protein S100B in the blood reflects greater BBB damage.The key findings in the Marchi et al study included the following findings:None of the football players in the study experienced a concussionHowever, a subset of players with sub-concussive head hits showed elevated blood astrocyte protein S100B levelsThe level of blood astrocyte protein S100B correlated with the number of sub-concussive head hits during playThe level of blood astrocyte protein S100B correlated with abnormalities in brain diffusion tensor imaging and cognitive impairmentThe authors conclude that leakage of astrocyte protein S100B with sub-concussive head hits in football players may play a key role in brain injury. Astrocyte protein S100B is known to induce a autoimmune response. This autoimmune response may produce brain inflammation, brain structural changes and impairment in cognition.This study also is worrisome because the BBB disruption occur in players without a full concussive episode. Significant BBB disruption appears to occur with less severe head hits that may be clinically ignored. The number and severity of these sub-concussive head hits appear to directly correlate with BBB disruption and brain inflammation.This study also suggests that blood levels of astrocyte protein S100B after a game may be a potential marker of BBB in football players. Additionally, measures of autoimmune response to astrocyte protein S100B may provide a clue to the level of BBB disruption and brain inflammation.Additional research tools to measure brain changes in football players and others with traumatic brain injury are needed. This study supports further research of the BBB as a key mechanism in brain injury.Readers with more interest in this topic can access the free full-text of the manuscript by clicking on the PMID link below.Photo of osprey with largemouth bass is from the author's files.Marchi N, Bazarian JJ, Puvenna V, Janigro M, Ghosh C, Zhong J, Zhu T, Blackman E, Stewart D, Ellis J, Butler R, & Janigro D (2013). Consequences of repeated blood-brain barrier disruption in football players. PloS one, 8 (3) PMID: 23483891... Read more »

Marchi N, Bazarian JJ, Puvenna V, Janigro M, Ghosh C, Zhong J, Zhu T, Blackman E, Stewart D, Ellis J.... (2013) Consequences of repeated blood-brain barrier disruption in football players. PloS one, 8(3). PMID: 23483891

March 26, 2013
06:42 PM
181 views

Advice vs Victim-blaming: a proposed study on #safetytipsforladies

by TheCellularScale in The Cellular Scale

So there has been a lot of noise about whether giving women 'safety tips' to avoid being raped is a form of 'victim blaming'.Don't get Raped (source)This culminated in a great hashtag (as many things do). Follow #safetytipsforladies to see some lovely tips for avoiding rape.For example:Don't be anywhere. 100% of rapes happen in places and locations. #safetytipsforladies— Conna Stevenson (@1000DaysOfRain) March 25, 2013Others suggest simply not being a woman, not ever drinking anything, not ever wearing anything (but not being naked either), not ever leaving the house (or since many rapes happen inside the house, not ever being home). And so forth.The main point is that it's absurd to tell women to not get raped. Rape by definition is NOT under the victim's control.Yet people still tend to blame the victim in rape cases. An interesting study was published in 2011 showing that people were more likely to blame the victim in a rape case than in a robbery case. The authors gave people short vignettes describing either a rape or a robbery, and had these participants fill out a perpetrator blame scale and a victim blame scale.Bienek and Krahe 2011 Figure 4 Interestingly, but maybe not surprisingly, rape always had more victim blame and less perpetrator blame than robbery and this difference increased with how close the victim and perpetrator were to each other (stranger, acquaintance, ex-partner). Now some people say 'hey, I'm just trying to keep women safe by telling them to avoid dark places, and not take drinks from strangers.' But here's the thing, maybe the mere suggestion that women can do something to avoid being raped is enough to subtly nudge one's opinion toward thinking that if a woman got raped, she should have done something to avoid it and is therefore somewhat to blame.So I propose the following study:Have one group of people read a short article on tips for women to avoid being raped (a serious and well meaning one), and one group of people read some unrelated article. Then have both groups read rape vignettes similar to the ones described in the Bienek and Krahe study and fill out the victim and perpetrator blame scales. They would also fill out a scale for how much punishment the perpetrator should get in a court of law. I hypothesize that simply reading a list of well meant tips for how women can avoid being raped would increase victim blame and would make people more lenient in their prescribed punishment for the perpetrator.Somebody please do this experiment!© TheCellularScale Bieneck S, & Krahé B (2011). Blaming the victim and exonerating the perpetrator in cases of rape and robbery: is there a double standard? Journal of interpersonal violence, 26 (9), 1785-97 PMID: 20587449... Read more »

Bieneck S, & Krahé B. (2011) Blaming the victim and exonerating the perpetrator in cases of rape and robbery: is there a double standard?. Journal of interpersonal violence, 26(9), 1785-97. PMID: 20587449

March 26, 2013
03:36 PM
133 views

Brain Activation: Does 2 2 = 4?

by Neuroskeptic in Neuroskeptic_Discover

An interesting Journal of Neuroscience paper just out argues that Spontaneous and Task-Evoked Brain Activity Negatively Interact. If true, this could be explosive, because a lot of neuroscience is built on the assumption that those two things don’t interact. So what’s going on? We know that the brain is active all of the time. Even [...]... Read more »

He BJ. (2013) Spontaneous and task-evoked brain activity negatively interact. The Journal of neuroscience : the official journal of the Society for Neuroscience, 33(11), 4672-82. PMID: 23486941

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