Primers

  • EEG Primer - Part 4

    EEG EQUIPMENT

    To fully understand what people think, you need to look inside their heads. EEG (electroencephalography) is the tool for doing that job; it gives immediate information into the role of the brain, by detecting the small amounts of electrical activity produced by the brain.

    EEG has been used by academics and neuro marketers along with other researchers for a very long time.

    The opportunities it provides are matchless – no other piece of hardware is able to track the function of the brain so quickly, and with such flexibility, as EEG

    EEG equipment has been used over 100 years of history. Today, there is high demand of superior high quality EEG devices. Many companies are trying to cater to this high demand and specific needs of each EEG user. There is a unique value proposition with every device including price! The advanced devices have a high pricing range. While on the low range are devices that take longer to analyze and examine the data. Below are a few EEG devices with specific qualities and price ranges along so that you can find one perfect to your needs.

    Low price range EEG equipment ($100- $1000)

    The lower the price the lower will be the amount of electrodes. The EEG devices of MUSE and NEUROSKY offer improved sleep and meditation. The device Emotiv, offers 5 and 15 electrodes and enhance understanding of the patients mental state. These devices are also wireless, and allow the respondent to move.

    Middle price range( $1000-$24000)

    As the price increases so does the number of electrodes. All of these devices are used for research purposes, the nature of your work will determine which is device is suitable for you. Many companies like ABM, Neuro, Wearable sensing etc offer wireless devices, which allows the recording to occur while the person moves, also increased mobility means increased comfort. These devices also allow the data to be collected at a lesser time span.

    There are a broad variety of choices at this price range, with up to 64 channels presented, fixed units, flexible systems, and head caps.

    The amount of information necessary, flexibility, and comfort of the patient are all elements that can be answered by these headsets, but your needs will determine which device to choose.

    HIGH PRICE RANGE ($25000 and above)

    A huge variety of devices can be found around this price range, with electrodes ranging from 32-256 channels. The more the electrodes the higher the quality of brain signals. These devices allow an extremely high resolution when detecting brain activity.

    ANT Neuro provides wireless devices with up to 64 channels, and can work without conductive gel up to 256 electrodes. At such a high density, the electrode number can be divided, which will allow up to four mobile systems with 256 channels.  The purpose of your research may or may not require such equipment.

    If you aren’t sure of which one to get, it is always advised to speak with colleagues in the field, or other experts, or the manufacturers themselves so that you get the full picture about what exactly their systems offer.

  • EEG Primer - Part 3

    Risks

    The EEG test is completely safe and painless. The patient does not feel any sort of discomfort and there are no risks associated with an EEG.

    Some EEG’s do not have any stimuli which may be useful in detecting abnormalities. Stimuli like flashing light may be added so that abnormalities become apparent.

    If the patient is suffering from epilepsy or has some other sort of seizure disorder, the stimuli presented, such as a flashing light or some sort of sound, may result in a seizure. The technician must be trained to manage such situations before performing the EEG.

    Preparation

    Following steps must be taken to ensure that EEG gives accurate results

    1. Make sure that you hair is clean on the day the EEG is performed. There is no product in your hair like sprays or gels.
    2. In case your doctor has advised not to take any prescribed medicine before the test, make sure that you haven’t. Also, a list of medications that your take should be given to the technician as well that is performing the test.
    3. Do not eat and drink food that contains caffeine for a minimum of 8 hours prior to the test.
    4. As you might have to sleep and relax during the test, the doctor will advise you to sleep as little as possible before the night of the test. During the test you might also be given sedatives so that you relax.
    5. After the test is over, you can carry on with your regular routine. If a sedative was given to you in might take a while for it to get out of your system. So you will have to bring someone along who will take you home after the procedure. Make sure you rest till the effect of the medication wears off.

    Procedure

    The test only takes about 30-60 minutes. The procedure starts with you lying on the table or the bed, the technician will mark the places where the electrodes will be placed, the area will be scrubbed with a special liquid so that high quality recording is done. 20 small sensors are attached to your scalp by the technician. Brain activity is picked up by these sensors also known as electrodes, and is then sent to the machine by the neurons. They are either displayed on the monitor screen of the computer or are recorded as patterns of lines on moving paper. The electrical activity passing between your skin and the electrodes is very low, so your skin will not feel any sort of discomfort.

    The technician will ask you to relax with your eyes open at first, and closed after. You will have to breathe deeply and might have to react to a stimulus, for example a flashing light; this will result in a different brain pattern. He might ask you to close or open your eyes or look at specific thing, like an object or a picture. All of this will produce different patterns, It is rare to have a seizure during the test but people suffering from epilepsy might have one when reacting to the stimulus, but the chances of this happening are low.

    A test called polysomnography will be done if you are sleeping during the test; this is done to check bodily functions like the pulse or your breathing.

    For capturing seizure activity of patient suffering from epilepsy, the patient might undergo a test of 24 hours. The EEG uses video for recording seizure activity. Any abnormalities that didn’t occur during the test become apparent during the EEG. These abnormalities are limited to seizure-related.

    After

    After the test is performed, the electrodes will be removed by the technician. Any residue left from the glue that was holding the electrodes in place can be removed by a nail polish remover at home. It is advised to have someone along when going for an EEG test as you might be given sedatives or if a patient is actively suffering from seizures, so that they can accompany you home. The prescribed medications which were stopped by the doctor before the test can be started to be taken again. The doctor, neurologist will look at the recordings of the brain activity. He will inform if there is any unusual activity that might suggest a problem with your brain. He may schedule an appointment to go over the results. If the brain activity is normal then it means you have no brain disorder.

    It is advised to discuss the results of the test with your neurologist. You should also write down any questions that you have in mind prior to the reviewing of the test. Make sure that you speak up and get the doctor to ask any queries regarding your results that you might be having difficulty understanding. Don’t leave any doubt.

  • tDCS Placements 10/20 Guide

    I’ve been noticing a growing number of announcements of clinical trials investigating the efficacy of transcranial Direct Current Stimulation (tDCS). Eventually, they were getting hard to ignore. So I got to wondering whether this was just me or whether there was genuinely an identifiable increase.

    A lot of the trials are announced on clinicaltrials.gov, so that’s the first place I looked. Here’s a graph of the number of trials that were announced each year since the inception of the site in February 2000.

    So it certainly does seem that there has been a huge increase in the number of clinical tDCS trials being undertaken. These are not all medical in nature. Many published trials involve investigation of the effects of tDCS on healthy participants.

    The vast majority of the clinical trials have not published results yet, but we at foc.us greatly welcome these. The scientific studies conducted in universities tend to have smaller sample sizes and, as we know, meta-analyses of these have had mixed outcome.

    Clinical trials tend to have larger samples sizes so they can throw valuable light on just how effective tDCS interventions are. We’ll be following and reporting on the results as best we can.

  • Achieve Sporting Prowess with Foc.us Brain Stimulation

    Sporting excellence is achieved through years of dedicated practice. Whether you're trying to increase the curve on your free kicks or perfect your golfing swing, you will spend hours repeating the actions over and over again until you can execute them with the precision you need. But we all know that it's not just your body that you need to train. You also have to train your mind. It's your mind that controls your bodily actions. And training your mind involves fine-tuning all the pathways in your brain that control those actions.

    The perfect golf swing requires carefully coordinated movement

    Every time you practice your swing, your brain gets feedback on how well it turned out. That feedback let's your brain make tiny adjustments in the strength of connections between brain cells that in turn make tweaks to the way you execute that swing. This means you are strengthening the pathways that led to success and weakening the ones that didn't.

    It's when you're making these tiny adjustments that brain stimulation can help. Stimulating your brain isn't going to let you suddenly bend it like Beckham or wallop it like Bale. You're not going to suddenly hit a hole-in-one when you've only just started playing golf a couple of weeks ago. Don't believe anyone who tells you something like that. But the evidence so far suggests that it can help you make those small changes that have big effects.

    The way brain stimulation does this is by increasing what neuroscientists call the plasticity of the connections between brain cells. Which – translated into language you and I can understand – means your brain's ability to do things slightly differently to the way it's done things so far; or in other words, it's ability to shift out of ingrained, habitual, behaviour. As the tiny charges enter the brain they come to rest on brain cells, including on the cells’ axons that transmit messages. This alters the amounts of charge that naturally resides on the axons and makes it either easier or more difficult (depending on the type of charge applied) for the brain cell to transmit messages along those axons. It also makes it easier or more difficult for the brain cell to pick up a messages from other cells connected to it. The volume of messages a brain cell sends out along its axons to other brain cells, and how many of those messages are actually picked up, dictates how strong the connections between brain cells become. The more the messages the stronger the connections, the fewer the messages, the weaker they become.

    One way to think of this is that the added current randomly fuzzes up the established connections between brain cells. Kind of like giving your brain cells a bit of a shake. When you do this, they are more easily able to fall in (and out) of a preferred pattern of connection. And when your brain is primed like this, you are primed and ready to tweak and fine-tune your performance. Which is exactly the state you want to be in when you want to practice those sporting moves!

    So that's enough of the background. How do we do it?

    The Things you'll need

    A brain stimulation device

    You're not going to get far without one of these! If you're not in the market for research grade equipment (which could set you back thousands of dollars), the next best thing is the Foc.us V2. It's packed with features and supports both transcranial Direct Current Stimulation (tDCS) and transcranial Alternating Current Stimulation (tACS), as well as less known protocols such as random noise stimulation (tRNS).

    If the Foc.us V2 is still too much for you, you can buy the Foc.us Go Flow. This shares a lot of the circuity of the V2 but is limited to Direct Current Stimulation. So it can actually do everything that Halo headphones can do – except play music, of course. For that, you'll need your Dr Dres – or whatever brand you prefer.

    You may want to start with the basics of the Go Flow and when you're a more advanced user, ready for a fine-tuned approach to brain stimulation (look for our future posts on that), you might consider upgrading to the V2. In any case, for the purposes of the techniques we're about to discuss, you only need Direct Current Stimulation. So the Go Flow would do just fine.

    Electrodes and Head Fixture

    There are plenty of choices here. The Foc.us stimulator will work with different types of electrodes, and Foc.us offers it's own versions. You can choose sponge electrodes or sticky electrodes. The sponge ones generally work better and unless you are going to place your electrodes super accurately, you are better off sticking with a Foc.us head band or cap. Regarding accuracy of placement, bear in mind that the stimulation electrodes tend to be quite large. So obsessing over millimetres isn't worth it. I'm not saying that accurate placement isn't important, it is. But the truth is that no one really knows exactly the arch of the current as it enters your brain. Scientists are still working it out. We have some models, but their veracity is yet to be proved. What's more, ideal positioning will vary slightly from person to person. So the best thing is to carefully explore what's best for you.

    The Foc.us cap is by no means as accurate as a research-grade cap (Foc.us are trying to improve that), but used carefully it will help place electrodes accurately enough for the beginner.

    The other alternative is the Foc.us headband. This can be oriented in different ways to get the electrodes in the right position. For some montages, it works very well. For others it doesn't. And for what we're describing here, you're really better off with a Foc.us cap orsomething completely different like the many headstraps offered by other manufacturers or even something you might make at home.

    Highly accurate electrode placement becomes more important when you are applying advanced protocols such as HD-tDCS (more on that in future posts) where the electrodes and currents themselves are much smaller exactly because the aim is to produce more controlled and targeted effects.

    How to Stimulate Your Brain

    We're going to describe a two stage process which uses only transcranial Direct Current Stimulation (tDCS). In the training phase, you will prime your motor cortex to learn and fine tune the actions involved in your chosen sport, whether that's taking a penalty or putting a golf ball. Then in the competition stage you will suppress your brain's explicit conscious analysis so that you can more instinctively perform the actions you learnt in the training phase. This will involve two different brain stimulation protocols.

    Preparation - Preparing your electrode before a stimulation session.

    Carefully prepare your electrodes. Add about 9 grams of salt to about 100ml of water and shake thoroughly until completely dissolved. Soak the sponges in the solution. It's important to not over soak them. If solution is dripping off the electrodes, then you've added too much. Current flows through the saline solution, so if it leaks off, the current will flow through a broader area than intended. Conversely, do not under soak the sponges. You don't want the sponges to dry out or have any dry patches; these may lead to skin burns. You want to add as much water as the sponges will bear without excessive dripping. Some dripping is inevitable if the sponges are squeezed. But they shouldn't drip under mild pressure as you attach them to your head.

    Training – Electrode placement, current and duration

    The anodal (+ve) electrode should be placed over the motor region of the brain. The motor cortex is a thin band of neocortex that runs over the top of your head, approximately from ear to ear.

    If you're using a Foc.us head band or cap it should be fairly easy to place your anode in the right position – make sure that it sits above your left ear and slightly toward the back your head. The image below shows the motor strip in red.

    If you want to train your left-handed or left-footed swing or kick, this should be the other way around (over right motor cortex). You place your electrode on the opposite side because the right-hand side of the body is controlled by the left motor cortex and vice versa.

    Position the cathode on the shoulder opposite the anode. So if you want to train right-hand or right-foot actions and your anode is over left motor cortex, your cathode would go on your right shoulder; and if you want to train left-hand or left-foot actions and your anode is over right motor cortex, the cathode would go over your left shoulder.

    Set your current to 1mA and stimulate for 20mins. It's important not to go over time or over current. More is not necessarily better. Research suggests that higher currents or longer durations can in some cases have the reverse effect.

    When to stimulate and how often

    These are still early days in brain stimulation, so stimulation protocols used in research vary. Some will stimulate just before training and some during. Which one of these two you choose might have an impact, but it is still unclear to what degree and the differences are likely to be small. So you'll be fine if you choose a protocol on practical grounds.

    In any case, you should try to leave as little time as possible between stimulation and doing your training. The neural priming that results from applying current to the brain lasts for some time, but will slowly dissipate at a rate that is dependent on your environment and activity, as well as the duration of the stimulation. Hence the need to take advantage of the priming as quickly as possible after stimulation.

    If you're practising your golf putting, you could probably wear the headset during practice. On the other hand, if you're engaging in a contact sport, such as rugby or football, you might risk dislodging the headset and interrupting the stimulation session. Interruption of the stimulation session should be avoided. Don't fret about a few seconds here and there, but it is important to get the right dose, as we've said.

    The training phase of stimulation can be repeated every few days. Some studies have stimulated daily but it's still unknown what's optimal (or safe) and it may vary person to person or on the desired goal. We would recommend it's best to leave 48 hours between stimulation sessions for a good safety margin. This gives your brain a chance to recover in just the same way as your body does after training.

    For those of you who want to read a little from the source science, here's a very recent paper that uses this approach and here's a slightly older review of several studies.

    Competing – Electrode placement, current and duration

    When you are about to compete, all your learning is done and you just want to get into that zone. You want suppress all distracting thoughts, including those that monitor how well you're doing, and focus on putting all your training into practice. With motor actions this involves quietening your conscious chatter. Here's how you do it.

    Place the cathode (-ve) over the left dorsolateral prefrontol cortex (DLPFC) and the anode (+ve) over the right supraorbital region. Under the 10-20 labelling system these positions are referred to as F3 (cathode) and FP2 (anode). If you have a Foc.us 10-20 cap, the positions will be marked. FP2 is on your forehead above your right eye, but some distance from it. Don't put the electrode too close to your eyes or you may experience some small white flashes called phosphenes. These aren't particularly dangerous but can be uncomfortable and alarming. If you place the electrode in the middle of the line from the centre of your eyebrow to your hairline, it should be about right.

    Finding F3 is a little harder without the cap. It is situated over your left temple slightly into the hairline and about an inch towards the top of your head. Check here if you're in doubt and watch the positions being marked.

    Left-handers should do the same because, unlike motor functions, the primary region that consciously monitors the self and causes conscious chatter is not dependent on handedness.

    Stimulation should be at 1.5mA for 15 minutes just before you compete. Again, you should try to leave as short an interval as possible between stimulation and competing.

    Now, just because your conscious self-monitoring is turned down a little, doesn't mean you can't learn. As we all know, competing is one of the best ways to improve! And in a similar way, some research has shown that we can acquire and improve implicit learning when we are in this state. If you're interested in reading more, you can read this study.

    tDCS Saftey

    Transcranial Direct Current Stimulation is generally well tolerated by the majority of people and despite hundreds of thousands of trials, very few cases of adverse effects have been reported. But it's important to remember that these trials were generally performed well within conventional safety parameters and this caution may be the underlying reason for so few cases of deleterious effects.

    Hence it's important to always follow good safety protocols. Don't combine brain stimulation with any other drugs including alcohol. Avoid strong painkillers and don't have too much coffee. If you're particularly tired or likely to be in an unfamiliar situation, administer it with caution. If you feel any discomfort or disorientation at any time, discontinue the stimulation immediately - don't tough it out to the end! It just doesn't work like that.

    However, never suddenly pull off the electrodes. Depending on your equipment, this can cause a sudden current spike. The correct thing to do is to hit the safety switch on your stimulation device. With a V2, you can just shake it. With the Go Flow, you can press the main rocker button at any time during a stimulation session and it will ramp down and shut off. If you're using another manufacturer, check the instructions for a termination switch. If it doesn't have this feature, I would recommend that you use another brand.

    Foc.us products all come with a list of warnings which err on the side of caution.just

    If you're thinking of trying tDCS, you should at the very least read these warning from scientists. If you read that and think it sounds pretty uncategorical, you'd be right. The truth is, as we've said, these are early days and no body is completely sure about what tDCS does and how exactly it works. There's a lot that scientist know, but there's a lot they don't and there is a great deal of controversy within science itself. Watch out for future post where I will try to make sense of what we really know and what don't.

    In the meantime, it's worth remembering that people respond very differently to tDCS. Some feel dramatic changes and some feel nothing at all. Your mood, environment and even your level of caffeination can change how you experience it. Always go slow and be safe.

  • EEG Primer - Part 1

    As you think, see, sense, dream, or try to solve a crossword puzzle or start to learn how to drive, the brain is constantly active, engrossing all the information it is presented with, compressing and re-connecting the existing data, and integrating all of it into an experience for you. Everything you see, understand, learn is all shaped by the brain. Based on thoughts, emotions and previous experiences the brain creates its own narratives and it is what ultimately drives your behavior

    EEG stands for Electroencephalogram. It is the continuous recording of electrical brain activity. The brain is made up of 100’s of billion of brain cells called neurons. These neurons have axons that release neurotransmitters and then dendrites that receive them. When the dendrites of the neurons receive the neurotransmitters from the axons of other neurons it causes an electrical polarity change inside of the neuron. This polarity change is what the EEG recording. It is the post-synaptic dendritic currents from cortical pyramidial cells. The activity from one single neuron is way too small to be detected with EEG equipment. But when thousands of neurons work together, they generate an electrical field which is strong enough to spread through bone and skull that is recorded on the head surface by the EEG. It is like how a single subtle earthquake might not be noticeable, but if a number of of them occur at the same time and location, it will be with much more impact and will definitely be noticeable.

    The EEG, Electroencephalography, is a way of recording electrical activity that is produced by the brain. To ensure that the data is collected from similar scalp positions across all respondents, electrodes are accumulated in elastic caps.

    Even though the name of EEG (Electroencephalogram) might intimidate people and seem like somewhat daunting, the biophysics behind EEG is surprisingly simple. The EEG calculates the electrical activity produced by the neurons, hence allowing you to analyze which areas of the brain are active at a specific time.

    Small voltage fluctuations measured at the electrodes are digitized after recording and then sent to an amplifier. The data amplified allows it to be displayed as a series of voltage values.

    The number of electrodes and the quality of the amplifier and the digitization along with the quantity of snapshots the device can take adds up to the price difference between EEG equipments.

    100 years ago EEG time course was plotted on a piece of paper. Now the technology has advanced to the extent that EEG is one the fastest and quickest imaging techniques available allowing taking thousands of snaps per second.

    Follow us on facebook or twitter to read the next part of this EEG primer.

  • A quick biofeedback primer

    NEUROFEEDBACK

    Neuro-feedback is a way to train brain activity. It is a non-invasive method of direct brain function training. It is helpful for people that have brain imbalances. Basically it is a kind of biofeedback, which teaches self-control of brain functions to subjects by measuring brain waves and providing a feedback signal. Brain waves tells us about how you feel and perform functions your it deals with stress levels, mood and overall brain function.

    Neurofeedback is also called EEG biofeedback it offers the treatments for persons that are suffering from some disorders like eating disorders and mood disorders. It stabilizes the brain to reduce anxiety and depression and early recovery from eating disorders mood disorders or other addictions.

    Some biofeedback provides audio, video, positive and negative feedback for desirable or undesirable activities.

    Here electrodes are used (which act like tiny microphones). These are placed on the patient scalp to record and amplify the EEG, or brainwaves and control auditory, visual, and/or tactile feedback which allows learning to take place. This operant learning initiates self-regulation and enhances relaxation, both necessary components of good brain function.

    Example A girl had trouble in sleeping and was unable to concentrate on objectives. From our diagnosis we concluded that she is suffering from anxiety disorder. Anxiety was utilizing most of the brain resources so she was unable to concentrate. We made the neurofeedback training program. We asked her to watch her favorite movie and we measured her brain activity when there was a loving scene there was a positive feedback and she was in non-anxious state and when there was some stressed scene she was in anxious state .With practice her skills improved and now she has no trouble in sleeping and she can concentrate well.

    How it works

    Our brain has the whole control of our body and is a complex system of chemical and electrical activities with about 100 billion neurons. Brain is designed to adapt to changes in the body and our environment and function well at all times. However, due to some genetics and environment condition brain does not function as well as it is able. The brain then becomes "dys-regulated".

    Simply put, a dysregulated brain tends to be over-stimulated when it is supposed to be calm and under-stimulated when it is supposed to be attentive. Sometimes, the brain self-corrects. When it doesn't, this dys-regulation becomes “the new normal”. So it makes sense that we should be able to re-train the brain to function optimally, the way it was designed. In neurofeedback training, we work in conjunction with other treatments. When your brain is better regulated, it allows you to change behavioirs and thoughts.

    Clinical applications It is used in some disorders like Attention deficit hyperactivity disorder Stroke Concussion Anxiety Enhancement of performance by surgeon’s athletes and artists Drug addiction PTSD Sleeping disorder Schizophrenia Insomnia Dyslexia Autistic spectrum disorder Epilepsy Depression

    ADVERSE EFFECTS

    There are some adverse effects of neurofeedback These includes Mental fatigue Return of old feeling in dreams Dizziness nausea and light sensitivity

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