I’ve just received word (along with dozens of others, it appears) that I’ve been selected as an SFN Neuroblogger for the 2009 conference next weekend (10/17-10/21)!  I’m extremely excited and honored to have this opportunity and look forward to sharing my thoughts on this year’s meeting with you all.  For those interested, I’ll also be tweeting, from @M_ostlyHarmless and hashtag #sfnthemef (and possibly #sfnthemeh, which is incidentally the worst hashtag ever).  If there’s anything in particular you’d like me to check out, especially for those not attending the meeting, feel free to let me know and I’ll do my best to cover it.

I look forward to seeing everyone (including the RIKEN 2009 Summer Program alums) in Chicago next weekend.  Until then, I’ll be locked away finishing my poster for the meeting (presentation 94.6, 1-5 pm on Sat at EE56).  If you’re around and interested in short duration perception, drop by.

Being exposed to popular media and fiction about science, we’ve all heard the term ‘brain waves’, loosely related to the frequencies of electrical oscillations in the brain detected at the scalp using EEG.  These signals are extremely vague spatially (you may be able to differentiate left/right or front/back, but you won’t isolate the insula or cuneus), but carry a lot of temporal information (on the order of milliseconds).  Per the modern dogma of neuroscience, most every aspect of human behavior or conscious experience can be reduced to a discrete set of electrochemical processes in the brain.  This includes, obviously, visual perception.  There is an enormous body of research concerning what happens differently in your brain in response to different variations of a stimulus, but not quite as much work has looked at the opposite arrow of causality – that is, what’s going on in your brain that causes you to see the same stimulus in different ways?

For example, let’s say there is a single neuron responsible for perceiving a circular disc. When a disc is flashed, this neuron fires, and you have a vivid perception of a circle (well, as vivid as a circle can be).  Without this neuron, you would not perceive a circular disc, even if it were sitting blatantly in front of your eyes, which were accurately transmitting information to your visual brain.  This is a fairly straightforward, though grossly simplified account of how we often think about vision (but instead of single neurons, we usually consider enormous, brain-wide networks of neurons working in teams; but see Quiroga et al, 2005 for an observation which may suggest otherwise).  But what if we presented this circle in a way that made it difficult to see – say, it is flashed very dimly – so that you sometimes see the circle like normal and sometimes miss it completely.  What is that neuron up to in the time before we show the circle that causes it to be more or less likely to fire, thus leading to your perception of the circle?

A recent study published in the 3/4/09 issue of the Journal of Neuroscience by Matthewson and colleagues used EEG to test this idea – what is different about the global electrical activity in the brain when a hard-to-see flash is perceived compared to when it is not perceived?  To test this, the research group used a phenomenon called metacontrast masking, in which a short initial flash is rendered undetected by a surrounding flash that follows (here, the researchers used a circular disc, flashed for 12 ms, followed by a ring around the disc presented ~50 ms later for 24 ms).  Subjects (whose brain activity was being recorded with a spidery EEG cap) reported whether or not they detected the first ‘target’ circle (there were ‘catch’ trails in which no target was presented to make sure subjects were paying attention).  This type of stimulus allowed the researchers to gather EEG data over a roughly equal number of trials in which the target was detected and undetected.

The main finding was that a certain band of ‘brain waves’ (cortical oscillations) before the target was flashed were able to differentiate between trials in which the target was detected and undetected.  These oscillations, in the alpha band (a frequency range centered at 10 Hz, typically associated with decreased vigilance and alertness), when measured locked to onset of a fixation cross that came onscreen before the target, were found to have different phases for detected and undetected trials.  Since the alpha rhythm is rather slow, which often suggests a greater number of neurons firing in synchrony, the authors suggest that this phase difference reflects a different cortical susceptibility to visual stimulation.  When the target was presented at one peak of the oscillation, subjects were much more likely to report perceiving it – at different times of the rhythm, the visual cortex was more receptive of input.

Personally, I find this result quite fascinating.  I’ve been working to see if there’s a critical error in the methods used or analysis performed, but it seems like the authors were very careful in their work – this finding appears, by my best understanding, to be legit and important.  Though I’ve mentioned throughout this post the possibility of using brain state to predict perceptual state before the stimulus is shown, I want to be clear that this is not what the authors of this study did.  All this analysis and classification of alpha states was done after subjects were long-gone.

Now, what I’d really like to see is a group perform the predictive version of this experiment – keep a running monitor of alpha power and present hard-to-see stimuli at different phases of the alpha oscillations.  If this finding is robust, and computational power is plentiful enough, this experiment should be feasible and yield a positive result.  I’m really excited to see developments like this study, along with several others from the past year, concerning what’s happening neurally in the period before a stimulus is presented or a motor act is performed.  In our efforts to piece together an explanation of human behavior (both subjective experience and objective action) in terms of neural events, this kind of work is just as important as understanding the effects of these behaviors (perception and action) on the brain.

What do you think?  If you’re experienced with EEG experiments/analysis, I’d love to hear a more in-depth evaluation of the methods used in this paper.  Leave a comment, or email me at neurotechnica on gmail.

I was browsing Digg today when I happened upon this Cracked article which talks about different illusions in neuroscience and does a pretty decent job explaining them in a humorous, mostly-accurate way.  I found their description of change blindness to be particularly funny.

I only had one bone to pick with their post (and it’s only a technical note): they discuss (what must be) Changizi et al (2008)‘s predictive model of visual illusions as though it is the established understanding of how these illusions operate.  Additionally, the assertion that scientists, by dunking electrodes in your brain, “could tell you–with 100% accuracy–what decision you’ll make a few seconds from now” is obviously still too sci-fi for my liking.  But that’s just nit-picking – I think this is a great article, and that it has the potential to generate at least a tiny bit of interest in neuroscience to some of the people who will read it.  Any time a scientific topic can be cast in a way so as to garner attention it wouldn’t otherwise receive is a great opportunity to capture the interest of a new population.  Bill Nye is fantastic in this regard – much of my current interest in science goes back to when I used to watch is show every day after school at my grandparents’ house.  Before him, Carl Sagan was a hero to hundreds, if not thousands, of young soon-to-be scientists.  As I’ve mentioned before, Robert Krulwich and Jad Abumrad also do a great job with their work on Radio Lab in reaching to a more mainstream (well, public radio) audience.

After looking around a little further, I found this other post they did a short while back about the psychology of advertising, providing lots of good, colorful examples throughout.

Do you have any other favorite science posts/articles/shows/podcasts that reach in creative ways?  Leave a comment, or email me at neurotechnica on gmail.

This evening I came across an interesting article in the New York Times about the neurological risks of a vitamin B12 deficiency.  A number of recent studies seem to link a B12 deficiency with different neurological ailments, like Alzheimer’s disease and dementia.  The article mentions a recent study that found brain shrinkage in older adults with low levels of B12, an interesting finding given our rapidly-aging population.

Though I’m certainly interested in the health consequences of B12 shortages, I’ve for some time also been curious as to how B12 supplements may positively affect the body in individuals with normal B12 levels (like myself).  Since high school, I’ve used a B12-based energy drink called ZipFizz to give me an extra boost when I need to get up early or study late at night.  ZipFizz is rather similar to the infomercial-tastic Five Hour Energy, but contains more B12 and a number of other supplements.  To be clear, these kind of drinks still usually contain caffeine (100mg for ZipFizz).  But my experience of drinking ZipFizz is qualitatively rather different than guzzling down a pot of coffee.  When on B12, I don’t feel jittery or hyper, just calm, concentrated and alert.  Also, something I’ve found really useful about ZipFizz is that after the initial 100mg caffeine burst wears off (~1.5hrs, it seems like), you can easily go to sleep if you like.  Coffee-drinkers know that this would be impossible after several cups of coffee.  I’m sure at least some of the effects of these drinks can be attributed to the placebo effect, but after using ZipFizz for almost 3 years now, I really do think it works well as a vitamin-based energy supplement.

To my knowledge, not much work has been done on the possible health benefits of these B12 supplements, and I’d be curious to see if B12 can be found to act as a mild cognitive enhancer.  If anyone knows of any articles addressing this topic, leave them in the comments – I’d love to learn more about this.

Having been a huge fan of the first Houston exhibition, I was excited to learn that Body Worlds would be returning this year.  This time, it’s called “Body Worlds 2 & The Brain, Our Three-Pound Gem” (which naturally had me excited).

To start off with, this exhibit is extremely expensive for a museum showing.  My (student!) ticket came out to be $21, and standard adult admission is $25.  There’s definitely not enough to this exhibit to warrant that kind of ticket price (though I’d still suggest attending if you somehow missed the first Body Worlds showing).

Also, for those of you with a strong interest in neuroscience (like myself), Body Worlds 2 is definitely targeted towards a general audience.  There isn’t anything that isn’t taught in PSYC 101 or an intro neuroscience course, but it’s pretty cool that it’s presented in a very readable and exciting way.  The “three-pound gem” part seems to be an afterthought, though, as very little of the exhibit itself is geared towards the brain.  There are lots of wall hangings that briefly introduce different aspects of modern neuroscience (like development, personality, emotion, creativity, memory, consciousness, disease, etc).  These amount to little more than you’d find in a Time or New York Times article, and some even contradict each other.  One (I don’t remember which) attributed long term memory to  “the back of the brain”, and also defined “instantaneous memory” to be the type of memory used to remember a phone number (this is the classic example for working memory).  But, in general, these provide an interesting & broad overview of the more interesting parts of neuroscience.

So what brain-related plastination specimens are shown?  Like before, there are plastinated coronal, saggital, and axial slices of adult brains, as well as several specimens from stroke victims (slices & whole brains).  There are at least 2 examples of the entire nervous system (brain, spinal cord, and large peripheral nerves), which are very impressive and interesting to see, as well as one specimen from an Alzheimer’s disease victim.  The coolest brain-related specimen, I thought, was a cast of the cerebral blood vessels.  The structure is absolutely beautiful.  Also, several of the full-body plastinations placed a great deal of emphasis on the brain, like “The Ponderer“, which is a man seated comfortably in a contemplative pose w/ much of his brain exposed.

As far as the full-body plastinations go, there are some very creative examples on display.  It won’t do anyone much good for me to try and describe them, but there are at least 3 or 4 that I was very impressed with.  Gunther von Hagens is truly an artist.  The full-body specimens are much more artistic this time than they were in the previous exhibit, so perhaps those alone could be worth the price of admission.

It surprises me that they’re marketing this exhibit as focusing on the brain.  Aside from the wall hangings, there isn’t really any additional brain-related content this time around.  There is, however, a large and very interesting display of human development, from conception to birth.  This part of the exhibit should certainly be the main attraction, but for whatever reason (probably support from the Mischer Neuroscience Institute), the brain was this year’s focus.

Overall, I was a little disappointed in Body Worlds 2.  I guess I was expecting to be as impressed as I was the first time, which I unfortunatley wasn’t.  Don’t get me wrong, Body Worlds is a wonderful opportunity to see real human bodies and what happens to them as we age & suffer disease.  The full-body plastinations are as impressive as ever, if not moreso, and the neuroscience blurbs on the wall will hopefully further promote awareness of neuroscience as an important discipline.  But if you’re expecting something new and brain-centered, Body Worlds 2 isn’t quite there.

What: Body Worlds 2 & The Brain, Our Three-Pound Gem

Where: Houston Museum of Natural Science

When: until Feb 22

How (much): $21 for college students, $25 for adults, $17 for members (buy here)

Worth it? Depends on who you are.  Definitely check it out if you missed the first Houston showing, but otherwise, there’s not much new to see here.

You’ve been falsely accused of a crime – a crime for which you could receive a life sentence if convicted.  The hard evidence is shaky at best.  The prosecution comes to you with a new idea: attach 32 electrodes to your scalp and listen to a series of sentences while the electrical fields caused by brain activity are recorded and analyzed.  The scientists claim that your pattern of brain activity will be different depending on whether you were there (thus, it will reflect ‘experiential memories’) or if you have only heard about the event.

This is the scenario reflected in a recent International Herald Tribune article sent to me by a friend.  Indian courts are now accepting results from the Brain Electrical Oscillations Signature test (BEOS) as evidence in criminal trials.  A young woman accused of murdering her husband was convicted to life in prison based in part on results from a BEOS test.  The woman, Aditi Sharma, insists she is innocent.

The IHT article reports that the judge wrote a 9-page defense of BEOS in his decision on the case, though there is no scientific consensus as to the accuracy of this test.  It has not been reported in any peer-reviewed scientific journals and has not been carefully evaluated by the neuroscientific community as a whole.  The article, though, is unclear as to whether the BEOS evidence was the deciding factor in the case or if it was solely corroborating evidence that supported the prosecution’s argument.  The 9-page defense makes it seem as though the BEOS test was an important part of this conviction.

In a comment on a relevant post on the Neuroethics and Law Blog, Dr. Lawrence Farwell is quick to distance this technology with his own work on ‘brain fingerprinting‘ – a peer-reviewed and highly-tested alternative that is allowed as scientific evidence in US courts.

The prospect of neuroimaging-based lie detection technologies is nothing new and has been featured in The New Yorker, Time, Newsweek, and The New Atlantis as a possible alternative to the modern polygraph machine.  There is certainly an appealing quality to looking inside a person’s skull, where surely the truth must be hiding in a pattern of bloodflow, synchronous neural firing, or synapse formation.  Maybe one day a criminal won’t even need to be asked any questions at all – we would only need to attach some electrodes and slide him/her inside a magnet and do some complicated physics and statistics to compare his brain to an enormous database of all kinds of criminals and non-criminals.  This is just one way we may be able to decide guilt or innocence in a completely objective way.

Am I not the only person absolutely terrified by this prospect?  The worst part is, it’s not that unfeasible.  It will certainly take a while for this latter scenario to become realized, but a slew of recent developments suggests this may someday be possible.  A group out of UC Berkeley has recently reported on a striking ability to identify which of a large pool of images a person is looking at using fMRI and a sophisticated receptive field model (Nature article), and a different group from Carnegie Mellon University is using image classifiers gathered from other subjects to accurately decide which image a given subject is viewing (PLoS One article).  The popular press reported on these findings as “mind reading” and brought up the obvious possibility of neuroimaging-based lie detection.

Right now, though, as long as scientists are appropriately conservative about the application of these technologies beyond the realms for which they are ready, we have nothing to worry about.  I think this quote from the IHT article sums things up pretty nicely:

“I find this both interesting and disturbing,” Henry Greely, a bioethicist at Stanford Law School, said of the Indian verdict. “We keep looking for a magic, technological solution to lie detection. Maybe we’ll have it someday, but we need to demand the highest standards of proof before we ruin people’s lives based on its application.”

If you’re interested in this topic (neuroscience and law), be sure to check out the conference videos from Baylor College of Medicine’s Initiative on Neuroscience and Law first annual conference.  This topic, among many others, were addressed by experts in the field, including lawyers, forensic psychologists, neuroscientists, and geneticists.

I apologize for the long stretch without updates, but I should be back to normal posting now.  I’ll try to work out a schedule to keep (e.g., Friday linkposts, Tuesday journal reviews, etc), and I’ll post it when I’ve come up with something I’m confident I can keep up with.  But, for today, I’ll just post a few interesting articles, podcasts, and blogs I’ve come across the past several weeks.

A New State of Mind – a very interesting and informative article on neuroeconomics research currently underway at Baylor College of Medicine‘s Human Neuroimaging Lab in Houston, TX.  It’s also a good profile of Read Montague, the director of the HNL.  He’s done some fascinating work on the role of reward in cognition.  For more, check out his book, Your Brain is (Almost) Perfect: How We Make Decisions.

On the technology side of things, Texas senator John Culberson is doing some interesting things with social media (such as Twitter and Qik) and government.  Check out this Houston Chronicle article about his new ideas – is this really the direction politics should be headed?  Barack Obama is one of the (if not the) most followed users on Twitter.  I  like the idea of governmental transparency, but I’m not sure if a 140-character message is the right way to  do it.  Anyway, I admire his innovation (if not his politics).

Teach the Controversy – these are some fantastic science t-shirts.  Can’t remember where I first saw them, though I’m sure either Digg or Reddit is to blame.

NeuroSpeculation – I finally found another undergraduate neuroscience blogger.  It looks like this is more of a research blog,  but still some very interesting and throrough discussions.  Hopefully we’ll be able to find some others and maybe create some kind of undergraduate science blogging community.

This Week In Science – a very entertaining and informative general science news podcast.  I find it especially helpful for keeping up-to-date with science policy news, an aspect of science I’m becoming more and more interested in.  If you know of any other good sources of science policy news, or any other comment/suggestsions/ideas, shoot me an email at neurotechnica shifttwo gmail dot com or drop a comment below.

I had to share this excerpt from a NYTimes article on boredom I read this morning:

While attending lectures on dementia, the doctors, Kenneth Rockwood, David B. Hogan and Christopher J. Patterson, kept track of the number of attendees who nodded off during the talks. They found that in an hourlong lecture attended by about 100 doctors, an average of 16 audience members nodded off. “We chose this method because counting is scientific,” the authors wrote in their seminal 2004 article in The Canadian Medical Association Journal. (emphasis added)

I feel like I should try to slip that sentence into every scientific paper I write from now on.

The article itself is fairly interesting, though it doesn’t discuss much in the way of the actual science of boredom – it just recounts some older findings from the psychology literature that creative thought seems to come when you’re bored, and it cites Dr. Mintum at Washington University in St. Louis concerning the neuroimaging of boredom.  The article claims that the brain consumes 5% less energy during a resting state than during routine tasks, which actually surprises me – that seems like a huge number.  Though the article doesn’t state which imaging methodology was used here (I’d guess it would have to be PET), 5% would be an enormous signal change for fMRI – the numbers I typically see reported are in tenths or hundedths of a percentage point.  I couldn’t find the original article, but I’ll add an update if I come across it.

When checking my ScienceBlogs Brain & Behavior feed this eveninig I came across an interesting post on Neurophilosophy about a new form of synesthesia.

For the uninitiated, Synesthesia is a harmless perceptual condition which causes automatic, uncontrollable associations between different types of perception.  For example, in grapheme-color synesthesia, a color is automatically and uncontrollably associated with a number or letter.

The general story here is that the authors are reporting on a new type of synesthesia they call “hearing-motion” synesthesia in which visual stimuli such as short flashes or moving dot patterns automatically generate an auditory percept (such as beeping or tapping).  If you’re interested in how the authors (Melissa Saenz and Cristof Koch of CalTech) tested this, I recommend checking out the Neurophilosophy post linked to above, or the (very short) research article in Current Biology.

However, what really intrigues me about this finding is the post-experiment reports that some of my subjects have given.  My behavioral experiments generally consist of showing brief (~50-100ms) flashes and asking subjects to compare their durations.  I’d say that 10-25% of people I test mention something about using “beeps” or sounds to help them make these judgments.  Were these subjects hearing-motion synesthetes?

Not necessarily.  There’s a different report from several years ago which argues that the auditory system (the system responsible for much of sound perception) encodes temporal information, while the visual system is more concerned with spatial information.  The authors used an interference paradigm to test whether irrelevant auditory or visual information interfered with performance on a rhythm discrimination task.  Not surprisingly, they found that extra auditory information impaired performance, but not extra visual information.

So if we use an auditory code to represent temporal information, why don’t we all hear beeps in response to flashes?  We know very little about the synesthetes in Saenz & Koch’s experiment.  Since the report mentions that this condition has existed for the entire life of each subject, it seems as though musical training can be ruled out as a possible explanation (though out of curiosity I’d still be interested to know each subject’s musical background).

Though I don’t have (m)any readers yet, I’d like to hear if you by chance have hearing-motion synesthesia, or any other thoughts, ideas, or criticisms.  Email me (neurotechnica <atsymbol> gmail dot com) or leave a comment here.

Update!

Upon looking around some today, I found a few other blogs discussing this finding:

Frontal Blogotomy (disclaimer: I occaisionally contribute to this blog)

The Quantum Pontiff (check out the comments – someone found out they have hearing-motion synesthesia)

Also, a big thanks to NeuroPhilosophy for including NeuroTechnica in a recent roundup of new neuroscience blogs!

2nd Update: Some text of this post was changed after publication.  I apologize for any inconvenience this may cause.

Check out this demo of the new Wii Motion Plus add-on, which Nintendo promises will add true one-to-one motion control to the Wii remote.  Upon first hearing about this at E3 this year, I was very skeptical – especially since the demos, and much of Nintendo’s press conference in general, were pretty lousy.  But this demo by AiLive does a great job at showing off what can be done with this new technology.  There’s even a not-quite-subtle lightsaber-like demo about halfway through the video.  Once can only hope that the Wii Motion Plus will be required for the upcoming Wii Lightsaber Duel game, set to be released later this year.

Also, this kind of technology could be very useful for physical rehabilitation – there’s no reason the Wii remote has to be held in your hand, it could be attached to a patient’s leg, foot, arm, etc.  This may even be a powerful tool for training amputees to effectively use their new prostheses (at least while we’re waiting for true brain-computer interfaces).