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Comment: Re:less money yes, less time no (Score 1) 41

by mandginguero (#47239459) Attached to: Open-Source Hardware For Neuroscience

you can use published results to validate your new equipment. if you can find the same trend in the data, same, and at least similar order of magnitude, then you are on the right path.

hahaha remember this is neuroscience we're talking about.

i am a neuroscientist who does electrophysiological recordings. i perform validation tests every time i get a hold of a new piece of equipment.

Comment: Re:less money yes, less time no (Score 4, Interesting) 41

by mandginguero (#47227953) Attached to: Open-Source Hardware For Neuroscience

True, but imagine how bringing the cost down can lower the entry barrier for things such as teaching labs. My best course by far in undergrad was an electrophysiology course where we recorded action potentials in earthworms with just a couple electrodes and a differential amplifier hooked up to an old macintosh. Getting these technologies lower in cost may not alleviate quality concerns for high throughput research (which is what some of the quoted established company reps are saying in the article). But imagine how cheap the next iteration of these could be? An order of magnitude lower for the openBCI 8 channel EEG system And with scalp potentials and a 512 hz sample rate you can measure muscle potentials too, not just brain. If you could find a way to increase the sample rate you could do things like galvanic skin response too.

Comment: interaction between game designers and soundtrack (Score 2) 66

by mandginguero (#46268517) Attached to: Ask "The Fat Man" George Sanger About Music and Computer Games

Greetings George, thanks for taking the time to do this. Video games were some of my earliest exposure to types of music that my parents never played and has stayed a consistent influence on the music I create now some 20-30 years later.

I'm curious how much of a back and forth process it is to design music for games. At what stage are you often approached about creating music? Is it when there is a finished product for you to see, or during the early stages are you brought on board to share some sounds to inspire coders? Is there a standard timeline for bringing together visuals and gameplay and sounds, or does it vary from project to project? And if it does vary, has there been a general shift over time in the interaction between gameplay design and music design?

Comment: comparing different brain images (Score 3, Informative) 195

by mandginguero (#45044869) Attached to: Probe of Einstein's Brain Reveals Clues To His Genius

Hmm, so we're comparing photographs of a fixed/preserved and sliced brain with those acquired by an MRI. Does anyone know what kind of variance or error these different imaging techniques introduce? There is enough variability in brain size and location of features that normal comparisons of one person's brain via MRI with another person's brain are rather meaningless. The standard procedure is to warp MRI brain scans to a common brain, and then run the comparisons of warped/normalized images....

Comment: scientists on the cheap (Score 1) 192

Imagine if the US were to reinvigorate its sciences. Double the current research budget - drop in the box if they passed a tax measure - invest in their trained talent, and pick up some Russians too. Some country would be smart to pick them up before they jump ship to other professions.

Comment: Re:Excellent! There pre-reading tests for dyslexia (Score 4, Informative) 105

by mandginguero (#44571447) Attached to: Dyslexia Seen In Brain Scans of Pre-School Children

If you check out the actual reporting from the authors (here for abstract you can see that they tested three predictors for dyslexia on children who had not yet received reading lessons. Without making any claims of observing dyslexia, they noted that the size of the arcurate fasciculus is positively correlated with scores of 'phonological awareness' and no correlation with 'rapid naming' or 'letter knowledge.' Perhaps a linguist or clinician could help elucidate what those tests are actually measuring.

It could be that dyslexia is a grouping of somewhat different brain/processing abnormalities that have similar behaviors. If that is the case, then brain imaging of the size of arcurate fasciculus could predict whether treatment aimed at increasing phonological awareness would have any effect. If you haven't had an intro neuropsych course you may not have heard that the arcurate fasciculus is a primary connection between auditory cortex and motor representations - thought to translate hearing into replying. Folk who have damage to this fiber tract are typically unable to repeat back to you what they just heard. The auditory and visual conduits run in parallel in this part of the brain, so it may have bearing on sequencing of writing, not just spoken words.

Comment: science is noisy (Score 2) 564

by mandginguero (#44109867) Attached to: Why Engineering Freshmen Should Take Humanities Courses

Many recorded signals and data are filled with noise making it difficult to tell what you are looking at. I guess it depends what level of science education you deal with, but when I teach, students look at the figures and graphs presented in the literature. Some of the effects are easy to see, others are very subtle. A basic understanding of statistics is critical for describing how we come to measure phenomena. From statistical mechanics, to understanding co-morbid disease, or computer vision, probability distributions show just how variable most things in the world actually are. If you tried to stop a stopwatch at the 1 second mark many times in a row, very rarely do you actually hit the goal, but if you plot your responses they will cluster around a mean of more or less 1 second. A large part of forming a scientist is knowing how to play in these distributions of samples.

What about the process of science? Framing a good question is hard. Is the question testable? 'What does the universe look like' is an ill posed question for a scientist. What form could the answer possibly take? If you can whittle it down, say 'what does the universe look like in the infrared spectrum.' Ok, this we can start collecting data to address, but can you still say what the answer might look like? The more specific the question, the better. If you can't clearly say what form the answer will take, then how can you expect to find it in the data?

How long have we been searching through SETI data? How will you know what evidence of communication from an extraplanetary source looks like? Is it more likely that we will find false positives, or let actual alien missives go undetected?

I think with regards to what the humanities can contribute to science education, philosophy and framing of questions is huge. Ultimately the scientist and philosopher are starting the from same place - wanting to answer a question, the difference is in how they go about finding the answer. Communication skills can never hurt scientists either - how many of you have tried to pick up a journal article expecting it to make sense on the first read? Anything that can help frame and communicate uncertainty would benefit scholars of science, but I think it naive to imply that these skills and foci are not already taught in science curricula.

Comment: I'm an electrophysiologist (Score 5, Interesting) 68

by mandginguero (#44018223) Attached to: Ask Slashdot: Neurofeedback At Home, Is It Possible?

hard call to make - use mod points, or participate. I'm doing my dissertation work in an EEG lab at UCSD, and while I don't actively research neurofeedback training (NFT from hereon out), my adviser and other lab members do. The OP gets it wrong - there is no cure for these psychiatric conditions. NFT may alleviate some of the symptoms, but it is likely the underlying etiology of ADHD, PTSD and Autism (which we investigate) is different enough from individual to individual that this may not be therapeutic for everyone.

A quick crash course in EEG. Neurons in the brain communicate between themselves via chemical signals. Some of these neurotransmitters cause quick voltage changes in their target neurons (either excite with inflow of positive ions like Na+, or inhibit with inflow of negative ions like Cl-). When you have large regions of neurons communicating with others, you'll see synchronized activity - say when someone touches your arm, the part of your parietal cortex that represents that arm will have a large amount of neurons suddenly get excited. When they get excited, they draw in positive charges, and there is a net negative charge left outside of the neurons. You can detect these fluctuations in more or less real time from outside of the head - but there are limitations. Where an electrode sits on the scalp will not give you a good idea of where in the brain the signal comes from. Between the neurons and the sensor on the scalp there are several different protective layers of tissue, some fluid filled with electrolytes, bone, and skin. These electrical signals are more likely to traverse laterally underneath the skull, than to penetrate out. What you record on the outside is a noisy, noisy combination of all the signals from all over your brain, plus some muscle activity (think eye muscles and jaw). In fact, the muscle electricity is a couple orders of magnitude stronger at your scalp electrode than brain electricity. It is mathematically impossible to determine exactly where a signal recorded on the scalp originated in the brain - there are some fancy algorithms to approximate solutions, but that is another thread. Without knowing where the signals come from, one way to try to figure out what brain regions are talking to each other is by decomposing the complex signal into its component frequencies using something like a fourier transform.

Psychiatric therapy directed NFT is supposed to work by identifying different brain frequencies (from hereon out called brain rhythms) at specific locations on the scalp that differ from the general population. There is a database of the general population's brainwaves for this process called QEEG (quantitative EEG, however this is a little misleading because all EEG since digital sampling/recording is quantitative....) and you can take someone with say ADHD and compare their 10 Hz brain rhythm at the site right over the center of their head to the 10 Hz rhythm of the general population. If there is less power (power = amplitude squared) at this electrode site than the general population, a clinician might devise an NFT program to focus on the 10 hz signal at that sensor location.

p00kiethebear describes a very similar protocol for what my lab employs. For instance, we have children with a diagnosis of autism come in and watch videos or play simple games, and when the 10 Hz signal is above the threshold determined by their QEEG diagnosis, the frames will advance. It is in essence a form of guided meditation. The control that a user develops is qualitatively different from person to person. There are no clear instructions you can give someone to help them figure out how to engage a specific brain rhythm. One kid described it as imaging a hand coming out of his head. Another described peeling oranges. I seem to have a stronger 10 Hz rhythm when I imagine kung fu forms. Go figure.

Conceptually, to do this sort of training at home shouldn't be too difficult. If you have the technical savy to follow the open EEG project you'll have the minimum amount of hardware needed. Definitely read up on signal processing to figure out how to best isolate a brain rhythm of interest, and minimize muscle contamination. You may honestly have more fun reading up on some of the other brain computer interface work - like learning how to control cursors on a computer screen than just trying to increase brain rhythms in a meditative like practice. Keep in mind that to gain control of more than one dimension of commands, you'll likely need multiple electrodes and stronger signal processing skills in time x frequency space. For instance with one active electrode (at minimum you also need a second reference electrode for your differential amplifier, I recommend on the earlobe, or on the maastoid bone right behind the ear - both are electrically neutral tissue), you could learn to move a cursor up or down, but not up/down & left/right, unless you are a master of multiple brain rhythms.

Comment: learning to control BCI not misleading (Score 3, Informative) 37

by mandginguero (#43986095) Attached to: Brain-Computer Interface Makes Learning As Simple As Waving

Compared to other BCI's, this does sound like the easiest to learn to control. Some of the other fastest versions rely on what are called steady state visual evoked potentials (SSVEPs) which rely on entraining your visual cortex to the same frequency as a flashing light on a computer screen. Once entrained, deviations by looking at other parts of the screen can be detected. This however leaves you with fairly few options for different commands on the screen at a given time. Another one of the faster acquisition BCIs is based on the P300 brainwave. These work typically for selecting a character from a grid of letters/numbers on a computer screen. The computer will cycle through all the characters, flashing each one for a brief moment. The user's task is to focus on the character they'd want, and when it comes up flashing, the brain has a slightly stronger response about 300 milleseconds afterwards. While both the SSVEPs and P300 systems only take about 10-15 minutes to figure out how to use (compared to 6-8 hours for learning to control a brain rhythm like the mu wave), they leave very few options in terms of commands you could execute.

On to the practical side of controlling artificial limbs by thinking about them, this is missing a crucial piece of the puzzle - feedback! How well could you close your cyborg hand around a fragile plastic cup without dropping it or smashing it if you can't 'feel' the surface and the flexibility of your object in hand? Executing the movement is indeed fancy, but to do it well you'll need to implant some more electrodes in the parietal cortex where you map body sensations, which connect reciprocally with the motor representations of the same body parts. Also, this would likely only work for someone who becomes paralyzed or loses a limb. Those with congenital problems, unless turned into a cyborg during infancy, would never develop the proper representations of limbs they don't own/can't use.

Comment: how many types of neurons? (Score 5, Informative) 393

by mandginguero (#43735819) Attached to: Why We Should Build a Supercomputer Replica of the Human Brain

As a neuroscientist, this seems absurd. Not all neurons perform the same functions, some are very different in terms of structure and connections (pyramidal cell vs interneuron for example). We don't have a good sense for all the multitude of ways they can connect (via axon projections, or through retrograde signals at a given synapse). And we're just starting to appreciate the role that non neuron brain cells play in cellular communication - astrocytes release signaling molecules that modulate neuronal function (caffeine interferes with these) and they also regulate the amount of ions around neurons - in essence they enable neurons to change states.

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