255 posts · 133,666 views
Comments on neurobiology, neuroimaging, and psychiatry from a skeptical neuroscientist.
Have you read this sentence before? Perhaps it feels strangely familiar? The experience of déjà vu is a common one, but in rare cases, it can become a disorder. In a fascinating new Cortex paper, French psychologists Julie Bertrand and colleagues discuss the phenomenon of pathological déjà vu.
Bertrand et al. present an English translation of what is probably the first description of the condition, published in 1896 in French by the psychiatrist Francois-Léon Arnaud (1858-1927).
Ar... Read more »
Bertrand JM, Martinon LM, Souchay C, & Moulin CJ. (2016) History repeating itself: Arnaud's case of pathological déjà vu. Cortex; a journal devoted to the study of the nervous system and behavior. PMID: 27188828
Migraines are a very unpleasant variety of headaches, often associated with other symptoms such as nausea, vomiting, photophobia (aversion to light) and visual disturbances. Hundreds of millions of people around the world suffer regular migraines, but their brain basis remains largely unclear.
Now a new paper reports that the origin of migraines may have been pinpointed - in the brain of one sufferer, at least. German neuroscientists Laura H. Schulte and Arne May used fMRI to record brain... Read more »
Schulte LH, & May A. (2016) The migraine generator revisited: continuous scanning of the migraine cycle over 30 days and three spontaneous attacks. Brain : a journal of neurology. PMID: 27190019
A new PNAS paper casts doubt on an influential theory of memory.
The reconsolidation hypothesis holds that when a memory is recalled, its molecular trace in the brain becomes plastic, meaning that the memory has to be consolidated or ‘saved’ all over again in order for it to persist. In other words, remembering makes a memory vulnerable to being modified or erased. Reconsolidation has generated lots of research interest and even speculation that blocking reconsolidation could be used as a t........ Read more »
Hardwicke TE, Taqi M, & Shanks DR. (2016) Postretrieval new learning does not reliably induce human memory updating via reconsolidation. Proceedings of the National Academy of Sciences of the United States of America, 113(19), 5206-11. PMID: 27114514
Getting warm has a dramatic antidepressant effect, according to a new report published in the prestigious journal JAMA Psychiatry. But is it hot science or a hot mess?
The researchers, led by Clemens Janssen of the University of Wisconsin-Madison, studied 29 people with depression who were not receiving any other treatments. Half were randomized to receive whole-body hyperthermia (WBH), using a setup which raised their core body temperature to 38.5 degrees (37 degrees is normal).
The o... Read more »
Janssen CW, Lowry CA, Mehl MR, Allen JJ, Kelly KL, Gartner DE, Medrano A, Begay TK, Rentscher K, White JJ.... (2016) Whole-Body Hyperthermia for the Treatment of Major Depressive Disorder: A Randomized Clinical Trial. JAMA psychiatry. PMID: 27172277
A remarkable case report describes the brain activity in a man at the moment that he underwent a revelatory experience.
According to the authors, Israeli researchers Arzy and Schurr, the man was 46 years old. He was Jewish, but he had never been especially religious. His supernatural experience occured in hospital where he was undergoing tests to help treat his right temporal lobe epilepsy (TLE), a condition which he had suffered from for forty years. As part of the testing procedure, the pat... Read more »
Arzy S, & Schurr R. (2016) "God has sent me to you": Right temporal epilepsy, left prefrontal psychosis. Epilepsy , 7-10. PMID: 27176877
The air in a cinema contains a chemical cocktail emitted by the audience - and the emotional tone of the movie influences the molecular composition of the cloud.
That's according to a striking set of results from researchers Johnathan Williams and colleagues who took air samples from two 230-seater screens of a cinema in Germany over a period of two weeks.
Here's an example of the chemical trace associated with shows of the movie "The Hunger Games 2: Catching Fire", featuring three... Read more »
Williams J, Stönner C, Wicker J, Krauter N, Derstroff B, Bourtsoukidis E, Klüpfel T, & Kramer S. (2016) Cinema audiences reproducibly vary the chemical composition of air during films, by broadcasting scene specific emissions on breath. Scientific reports, 25464. PMID: 27160439
In recent years there has been great research interest in ketamine as an antidepressant. Ketamine, a drug better-known for its use as an anaesthetic (and a recreational drug in lower doses) is claimed to have powerful, rapid-acting antidepressant effects, even in depressed patients who have not responded to more conventional drugs. However, its mechanism of action remains unclear.
Now, in a major new Nature paper, Baltimore researchers Panos Zanos and colleagues say that ketamine itself is ... Read more »
Zanos P, Moaddel R, Morris PJ, Georgiou P, Fischell J, Elmer GI, Alkondon M, Yuan P, Pribut HJ, Singh NS.... (2016) NMDAR inhibition-independent antidepressant actions of ketamine metabolites. Nature. PMID: 27144355
Over the past few years I've covered (1,2,3) the work of Anders Eklund, a Swedish researcher who has discovered a potentially serious flaw in software commonly used to analyse fMRI data.
Eklund has shown that popular parametric statistical analysis tools for fMRI are prone to false positives - they often 'find' brain activation even where it doesn't exist. The issue affects the leading software packages such as FSL and SPM.
The main root of the problem is spatial autocorrelation - the ... Read more »
Kriegeskorte, N., Bodurka, J., & Bandettini, P. (2008) Artifactual time-course correlations in echo-planar fMRI with implications for studies of brain function. International Journal of Imaging Systems and Technology, 18(5-6), 345-349. DOI: 10.1002/ima.20166
Psychiatric drugs come in many kinds: there are antidepressants, antipsychotics, anti-anxiety medications, and more. But what all of these categories have in common is that they're anti- something. This is how we classify these drugs - by what they treat.
Except there's a problem - very few psychiatric drugs are only used to treat one thing. Take "antipsychotics". They're used in psychosis, but they're also a key tool in the treatment of mania, a different disorder entirely. Many of these dru... Read more »
Zohar J, Stahl S, Moller HJ, Blier P, Kupfer D, Yamawaki S, Uchida H, Spedding M, Goodwin GM, & Nutt D. (2015) A review of the current nomenclature for psychotropic agents and an introduction to the Neuroscience-based Nomenclature. European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 25(12), 2318-25. PMID: 26527055
In a new Nature paper, Berkely neuroscientists Alexander G. Huth and colleagues present a 'semantic atlas' of the human brain. Huth et al. have mapped which brain areas respond to words, according to the semantics (meanings) of each word. It turns out that these maps are highly similar across individuals - which could have implications for 'mind reading' technology.
Huth et al. recorded brain activity with fMRI while seven volunteers listened to over two hours of audio narrative (taken fr... Read more »
Huth AG, de Heer WA, Griffiths TL, Theunissen FE, & Gallant JL. (2016) Natural speech reveals the semantic maps that tile human cerebral cortex. Nature, 532(7600), 453-8. PMID: 27121839
Back in 2013, I wondered if we would ever discover the neural basis of spontaneous thoughts. Why, I asked, do certain ideas just "pop" into our minds at particular times? Now a new paper published in Neuroimage, Canadian neuroscientists Melissa Ellamil and colleagues reports on the neural basis of spontaneous thoughts.
Ellamil et al. recruited a group of 18 volunteers, all of whom were highly experienced practitioners of mindfulness meditation. These individuals were selected, the authors... Read more »
Ellamil M, Fox KC, Dixon ML, Pritchard S, Todd RM, Thompson E, & Christoff K. (2016) Dynamics of neural recruitment surrounding the spontaneous arising of thoughts in experienced mindfulness practitioners. NeuroImage. PMID: 27114056
Does the thought of money make people more selfish? Last year, I blogged about the theory of 'money priming', the idea that mere reminders of money can influence people’s attitudes and behaviors. The occasion for that post was a study showing no evidence of the claimed money priming phenomenon, published by psychologists Rohrer, Pashler, and Harris. Rohrer et al.'s paper was accompanied by a rebuttal from Kathleen Vohs, who argued that 10 years of research and 165 studies establish that mone........ Read more »
Vadillo MA, Hardwicke TE, & Shanks DR. (2016) Selection bias, vote counting, and money-priming effects: A comment on Rohrer, Pashler, and Harris (2015) and Vohs (2015). Journal of Experimental Psychology. General, 145(5), 655-63. PMID: 27077759
In a new paper called Molecular fMRI, MIT researchers Benjamin B. Bartelle, Ali Barandov, and Alan Jasanoff discuss technological advances that could provide neuroscientists with new tools for mapping the brain.
Currently, one of the leading methods of measuring brain activity is functional MRI (fMRI). However, as Bartelle et al. note, it has its limitations:
Because brain activity mapping with fMRI depends on neurovascular coupling, resolution at the level of single cells is out of reach.... Read more »
Does ice cream cause drownings? Let's think about this statistically. Consider that, in any given city, daily sales of ice cream are, most likely, positively correlated with daily rates of drownings.
Now, no matter how strong this correlation is, it doesn't really mean that ice cream is dangerous. Rather, the association exists because of a 'confound' variable. In this case it's temperature: on sunny days, people tend to eat more ice cream and they also tend to go swimming more often, thu... Read more »
Westfall J, & Yarkoni T. (2016) Statistically Controlling for Confounding Constructs Is Harder than You Think. PloS one, 11(3). PMID: 27031707
A group of Indian psychiatrists have raised concern over suspicious similarities between three papers published in the Indian Journal of Psychological Medicine (IJPM). Their allegations have just been published, also in the same journal.
The authors, Girish Banwari and colleagues, focus on a 2015 paper about the use of the drug modafinil in treating schizophrenia. Banwari et al. say that this article
Contains no data at all and that only one reference was cited in the bibliography. A l... Read more »
Banwari G, Karia S, Avudaiappan S, Tharayil HM, & Andrade C. (2016) Modafinil Augmentation of Atypical Antipsychotic Agents: Duplicate Publication, Self-plagiarism, Salami Publication, and Other Matters. Indian journal of psychological medicine, 38(1), 86-7. PMID: 27011415
Do you haet typos? If you spot a grammo (a grammatical error), does your blood boil?
Some people are more offended by these kinds of linguistic errors than others, but why? Ann Arbor psychologists Julie E. Boland and Robin Queen examine this in a new PLOS ONE paper called If You’re House Is Still Available, Send Me an Email: Personality Influences Reactions to Written Errors in Email Messages
The authors recruited 83 volunteers (on MTurk) and asked them to imagine that they'd placed an... Read more »
Boland JE, & Queen R. (2016) If You're House Is Still Available, Send Me an Email: Personality Influences Reactions to Written Errors in Email Messages. PloS one, 11(3). PMID: 26959823
The 'file drawer problem' refers to the fact that in science, many results remain unpublished - especially negative ones. This is a problem because it produces publication bias.
Now, a group of Belgian psychology researchers have decided to make a stand. In a bold move against publication bias, they've thrown open their own file drawer. In the new paper, Anthony Lane and colleagues of Leuven say that they've realized that over the years, "our publication portfolio has become less and less... Read more »
Anthony Lane, Olivier Luminet, Gideon Nave and Moïra Mikolajczak. (2016) Is there a publication bias in behavioral intranasal oxytocin research on humans? Opening the file drawer of one lab. Journal of Neuroendocrinology. info:/
In July last year I asked, Could Traveling Waves Upset Cognitive Neuroscience? This was a post about a paper from David Alexander et al. arguing that neuroscience was overlooking the importance of how neural activity moves or travels through the brain.
Now Alexander et al. are back with a new PLoS ONE paper in which they describe traveling waves in human brain activity, as measured with magnetoencephalography (MEG). The authors scanned 20 volunteers during a visual and auditory task.
A... Read more »
Alexander DM, Nikolaev AR, Jurica P, Zvyagintsev M, Mathiak K, & van Leeuwen C. (2016) Global Neuromagnetic Cortical Fields Have Non-Zero Velocity. PloS one, 11(3). PMID: 26953886
Last October, Michael R. Blatt, editor in chief of the journal Plant Physiology, ruffled many feathers with an editorial, Vigilante Scientists. In this piece, Blatt argued that anonymous online comments were bad for science, pointing to PubPeer as an especially problematic site.
I wasn't convinced by Blatt's arguments. True, I have used the term "vigilante science" (in 2013) myself, in reference to PubPeer, but I meant it as a compliment.
Now Blatt has re-entered the debate over anonym... Read more »
According to a spectacularly misleading article in the Telegraph: Scientists discover how to 'upload knowledge to your brain'
Feeding knowledge directly into your brain, just like in sci-fi classic The Matrix, could soon take as much effort as falling asleep, scientists believe. Researchers claim to have developed a simulator which can feed information directly into a person’s brain and teach them new skills in a shorter amount of time...
Researchers from HRL Laboratories, based in Cali... Read more »
Choe J, Coffman BA, Bergstedt DT, Ziegler MD, & Phillips ME. (2016) Transcranial Direct Current Stimulation Modulates Neuronal Activity and Learning in Pilot Training. Frontiers in human neuroscience, 34. PMID: 26903841
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