tDCS revisited

It was five years ago that I experimented with tDCS and at that time the protocols were very sketchy.
This represents a risk with tDCS as you may enhance one skillset but accidentally negate another.

So at the time I decided to use safe & proven CES as a neuro enhancer instead and made a machine which I have used for the last 5 years.

But there has been such vast progress with tDCS that I will now revisit this technology beginning with a delve into current protocol knowledge.

Following that I will examine all research using tDCS pertinent to cognitive enhancement.

Finally I will perform some experimentation once again.

Transcranial random noise stimulation (TRNS) - A new kind of Brain Stimulation

Its been many months now since I experimented with TDCs. I noticed a mild cognitive improvement in my alertness after certain protocols but no substantial improvement in memory or mathematical ability occurred.

There is now a new form of electrostimulation called Transcranial random noise stimulation (TRNS).

This has superior results with actual mathematical calculations. There is a direct link between mental calculation & working memory. TDCs protocols exist to enhance working memory.

So here we see an area of training which can benefit from both stimulation methods.

Mental Calculation.

Here are some excerpts regarding TRNS:


Applying high-frequency electrical noise to the brain can boost maths skills up to six months later, say Oxford University researchers.

A small study in Current Biology suggests the brain stimulation technique makes neurons function more efficiently.

It could help those suffering with neurodegenerative illness, stroke or learning difficulties.

An expert said the technique could have "real, applied impact."

Transcranial random noise stimulation (TRNS) involves applying random electrical noise to targeted areas of the brain by placing electrodes on the surface of the scalp.

It is a relatively new method of brain stimulation which is painless and non-invasive.

Our neuro-imaging results suggested that TRNS increases the efficiency with which stimulated brain areas use their supplies of oxygen and nutrients.”

Dr Roi Cohen Kadosh
University of Oxford
Fifty-one students from the University of Oxford, split into two groups, were asked to perform two arithmetic tasks over a five-day period. Only one group received TRNS while performing the tasks each day.

The tasks tested participants' abilities for calculation (eg 32-17+5=20) and rote learning (committing times tables such as 4x8=32 to memory).

Dr Roi Cohen Kadosh, study author from the department of experimental psychology at the University of Oxford, said the noise stimulation group showed improvements in cognitive and brain functions compared with the control group.

"Performance on both the calculation and rote learning tasks improved over the five days, and the former improvements were maintained until six months after training.

"Our neuro-imaging results suggested that TRNS increases the efficiency with which stimulated brain areas use their supplies of oxygen and nutrients."

There were no significant differences in performance between the groups at the start of the study yet TRNS was found to improve the speed of learning for both calculation and rote learning tasks.

Six months later, when participants were contacted again and asked to solve calculations, researchers found that the group which had received five days of transcranial random noise stimulation showed "superior long-term performance, compared to sham controls".

Potential
Cohen Kadosh and his colleagues had previously shown that another form of brain stimulation could make people better at learning and processing new numbers.

But he said transcranial random noise stimulation could help more people because it had the potential to improve the ability to add, subtract or multiply a string of numbers in your head - not just new number learning.

"Mental arithmetic is a more complex and challenging task, which more than 20% of people struggle with," the study said.

A learning disorder, called dyscalculia, which is characterised by struggles with arithmetic is thought to affect around 5%-7% of the population. Similar problems affect people suffering from neurodegenerative disease or stroke.

Cohen Kadosh added that it was important to identify any downsides of this and other similar forms of transcranial electrical stimulation to ensure that boosting one cognitive ability did not lead to damage in another.

Looking ahead, he said he hoped these stimulation techniques would one day be used in the clinic, the classroom and even at home.

Dr Michael Proulx, senior lecturer in psychology at Bath University, said the study findings were important and exciting.

"This study reinforces the idea that brain stimulation enhances cognitive training. It is not some panacea that just makes the brain work better overall, but it helps boost a learner's effort.

"The results also clarify that stimulation does not only improve specific learning, where practice might make perfect, but also generalised learning, where practising one skill can transfer to new situations."

He added: "These two findings suggest that this technique could have real, applied impact."

TDCs for Calculus exam

I have deliberately taken a break from TDCs for over a month - I dont want to become dependent upon it or do any harm.

I have a calculus exam coming up November the 3rd however so will do 2-3 math protocol sessions prior to the exam.

Heck I may even do one the morning of the exam before I leave home - why not.

Wish me luck.

Mental Imagery reinforcement with TDCS

I decided to pass up tinnitus self treatment with TDCS due to individual variability in the type and parameters of the tinnitus.

Mental imagery is far too valuable a skill to pass up. I will undertake my own in depth research on the psychophysiology of mental imagery & experiment with the protocols and neuroplasticity training required to develop an excellent imagination & sensory memory.

At present my  minds eye has moments of lucidity, some of wild streaming rapidity but generally a fog and clouded swirling mist.

I want my imagination & eidetic memory to be a lucid on demand tool at my command.

Some people achieve this rapidly with hypnosis, some slowly with meditation. A lucky few with artistic training.

I will document my research & experimentation here.

Further Working Memory training today

Its now over a month since my initial TDCs session. I have been distracted by academic studies. Today I will do the working memory protocol again and tomorrow the Math protocol. I still have not built the new device but would like to get that done next week.

I would also like to make a suitable DC bio current monitor. Many years ago there was a gentleman selling a German DC bio current monitor. It was perhaps 15 years ago & I have forgotten the brand name. It should be a relatively easy device to construct but I would like to code a JAVA PC interface also.

In the flow on working memory training today

Today I did another working memory N-Back training session. Definitely more in the flow than normal. Making less conscious effort to recall selections. Did have an issue with humidity & sweat causing an electrode to fall off at first.

Combining TDCs with fNIRS Hemoencephalography for Working Memory

Hemoencephalography is a form of biofeedback that employs fNIRS infra red LEDs to project light through the skull into the brain. The light is then reflected back to detectors & reveals the blood flow to the brain surface.

This is most commonly used on the prefrontal cortex where working memory is localized. Research reveals that the strength of links between the prefrontal cortex and other brain structures are an indicator of intelligence http://news.wustl.edu/news/Pages/24068.aspx

Control of thought and behavior is fundamental to human intelligence. Evidence suggests a frontoparietal brain network implements such cognitive control across diverse contexts. We identify a mechanism—global connectivity—by which components of this network might coordinate control of other networks. A lateral prefrontal cortex (LPFC) region's activity was found to predict performance in a high control demand working memory task and also to exhibit high global connectivity. Critically, global connectivity in this LPFC region, involving connections both within and outside the frontoparietal network, showed a highly selective relationship with individual differences in fluid intelligence. These findings suggest LPFC is a global hub with a brainwide influence that facilitates the ability to implement control processes central to human intelligence.

As HEG is non electrical and even less invasive than TDCs there is no interference between the two modalities if used at the same time.

By combining HEG biofeedback and TDCs one should be able to generate a more significant progression with working memory training. Both Working Memory and prefrontal cortex biofeedback are linked to cognitive enhancement and increases in IQ.

HEG devices are very easy to construct simply consisting of an array of infra red LEDs with the correct bandwidth to be responsive to blood cells. The software is more challenging for non programmers but I am a JAVA developer & electronics engineer so I am comfortable with the project.

From the image above you can see the fNIRS device consists of an array of several LEDs and sensors.
The data is processed and interfaced with biofeedback software.

Software sources are listed here: http://www.fnirs.org/software.html

Last year I researched fNIRS and found a site showing how to make a device in some detail especially how to make the head set from silicone, sensors & LED's. Unfortunately a search of my HDD has failed to come up with the link. Really such a device is easy to construct with optical fibres running to the the signal processing box .http://felixchenier.com/lib/exe/fetch.php?media=research:pdf:a_new_brain_imaging_device_based_on_fnirs.pdf Discusses some of the hardware.

As a final observation if we look at the Drexel page outling areas of fNIRS research http://www.biomed.drexel.edu/fnir/CONQUER/fNIR_Research.html we can see that there is a strong overlap with TDCs research of most interest math ability and general cognitive enhancement.

Principles of Memory & Neuroplasticity

1.  "Interest" – In order to remember something thoroughly, you must be interested in it. You must
have a reason to learn it. Seek ways to make it personal.

2. "Intent to Remember"  – has much to do with whether or not you remember something. A
key factor to remembering is having a positive attitude that you will remember. Take notes.
Predict test questions. Use a concentration checklist; every time your mind wanders, put a check
on this sheet. Eventually, you will program your mind to pay attention.

3. "Basic Background"( – Your understanding of new material depends, to a great degree, on
how much you already know about the subject. The more you increase your basic knowledge, the
easier it is to build new knowledge on this background. Before reading an assignment, preview it.
Try to recall what you already know.

4. "Selectivity"– You must determine what is most important, and select those parts to study and
learn. You cannot remember everything about everything. Look for verbal and non-verbal clues
during lecture. Make flashcards. Devise sample tests.

5. "Meaningful Organization" – You can learn and remember better if you group ideas into
meaningful categories. Search for ways to organize information into categories that are
meaningful to you. Alphabetize a list. Use a variety of mnemonic devices.

6. "Recitation" – Saying ideas aloud in your own words is one of the most powerful tools you
have to transfer information from short-term to long-term memory. When you finish reading a
paragraph/section in a textbook, stop and recite.

7. "Mental Visualization" – Another powerful memory principle is making a mental picture of
what needs to be remembered. By visualizing, you use an entirely different part of the brain than
you do when reading or listening.


8. "Association" – Memory is increased when facts to be learned are associated with something
familiar to you. By recalling something you already know and making a link to the "brain file"
that contains that information, you should be able to remember new information more efficiently.

9. "Consolidation" – Your brain must have time for new information to soak in. Take notes and
review them. Ask questions. Make flashcards. Make practice tests.

10."Distributed Practise"– A series of shorter study sessions distributed over several days is
preferable to fewer, but longer study sessions. After each hour of study, take a 10-minute break.
Have a scheduled time to study each subject. Make use of daylight hours and time you usually
waste. Study immediately before and after class. Review. Review. Review!

"Don't forget the curve of forgetting"

12 more principles of memory:

Selectivity
Association
Visualization
Elaboration
Concentration
Recitation
Intention
Big & Little pictures
Feedback
Organization
Time on Task
Ongoing Review

Four More:

Practice Retrieval
Process Material Actively
Use Distributed Practise
Use Metamemory

Specifics: Eidetics, Mnemonics, Chunking, Linking, Synaesthesia


Neuroplasticity

• Synaptic connections are continually being modified (re-organisation of
circuitry)
– In response to demand – learning, memory, disuse
– After damage to the CNS
– LTP: alteration of the structure of the synapse

• Cellular level
– Increased sensitivity to neural transmitters
– Increase number and branches of dendrites
– Increase and strengthening of synaptic connections (Hebbe)
– Axon sprouting


Cortical maps – ‘use it or lose it’

"CONSTRAINT & REINFORCEMENT"

By constraining an appropriate behaviour and reinforcing another the underlying brain structure will modify its neural function to perform the reinforced task & not the constrained one.

i. The Effect of Use on Neural Substrates 

The first principle of neuroplasticity is that if a neural substrate is not biologically active, it will degrade in function.

ii. Usage Improves Function

This principle, an extension of the first, states that with increased biological activity, future functioning can be enhanced.

iii. Plasticity is Experience Specific

This principle suggests that changes in neural function with practice may be limited to the specific function being trained.

iv. Repetition of Training

This principle states that changes in neural substrates will occur only as a result of extensive and prolonged practice and that neural changes may not become consolidated until later in the training process.

v. Intensity of Training

The principle that training must be continuous over long periods to induce neural change.

vi. The Time of Training Onset

This principle states that different forms of neural plasticity may occur at various times in response to treatment.

vii. Salience of Training

The principle that training must be sufficiently salient to induce plasticity may be of considerable importance to speech. That is, simple repetitive movements or strength training may not enhance skilled movement and may have less potential for inducing changes in neural function underlying voice and speech production for communication. 

viii. Age Effects on Training

Although neural plasticity can occur over the entire lifespan, it is well recognized that training and environmentally induced plasticity occur more readily in younger than in older nervous systems.
(See Ergogenics below)

ix. Transference

The principle of transference states that plasticity following training in one function may enhance related behaviors and has been studied both in animals and human rehabilitation.

x. Interference

The interference principle is that plasticity can cause changes in neural function, which may interfere with behaviors or skills.

Neuroplasticity Ergogenics:

Hormonal factors NGF, IGF

TDCs

Amino Acids

Personal Observation: Somnabulistic Hypnosis & dreaming prove that neuroplasticity can in fact be practically instantaneous. Age related factors are largely determined by alterable physiological parameters such as growth factors, circulation & neurotransmitter levels.

TDCs Visualization Training

I have had a break from TDCs for a few days. My next protocol to try will be for the visual system - in particular visualisation in the minds eye & eidetic memory. I am an artist and have very vivid visual imagery if uncontrolled quite often. I also have flashes of eidetic memory.


Eidetic memory is not some genetic gift of savants as the western media portrays it. In Japan children are trained in Eidetic memorisation methods at special schools. 


In Germany advanced Autogenic Therapy trains the minds eye to visualise with extreme precision & clarity. Most of the schools of meditation also train visualisation. Deep trance Hypnosis can induce vivid sensory experiences in a post trance.


What's more every night you enter the realm of an inner perceptual environment when dreaming.


So essentially we have been trained "not" to have an imagination, which is kind of like being trained not to walk. Human culture is an odd thing.


In France in the last century there was a famous art teacher Horace Lecoq de Boisbaudran, he trained Rodin and dozens of famous French artists.


His method was based upon drawing, and painting from memory. All pupils were forbidden from using direct vision or any physical likeness to reproduce a subject. After the initial visual familiarisation it had to be done entirely from memory.


The interesting point is that all of his pupils developed Eidetic Memory within six month of gruelling training. Not just memory but a vivid imagination also.


Now today this is largely neglected by the lazy masses thanks to TV & camera's. So without the proper mental stimulation we lose our inner world.


Neuroscientists have discovered that the principle behind the phenomena is neuroplasticity. The very basis of TDCs. 


De Boisbaudran, by forbidding the use of physical props or scenes was "constraining" that part of the nervous system. The brain adapted by reinforcing the neurons and brain centres that are the basis of visualisation. After a period of intense training the students brains adapted to the extent that they had Eidetic Memory & a fully functioning imagination.


Eventually I would like to train my self to do the same. In a day or two I will try TDCs to stimulate visual memory and imagery.

Effective TDCs Tinnitus Protocols Undefined

I am still researching appropriate electrode placements for tinnitus treatment. I am not going to risk placing them in the wrong area so this may take some time. 


Both hemispheres of the Dorso Lateral Prefrontal Cortex are commonly treated but this is a relatively large surface area. 


From:http://www.tinnitusresearch.org/en/patients/newintinnitusresearch_en.php

Many different functional and structural imaging techniques have been used to identify structures in the central nervous system which are believed to play an important role in the pathophysiology of many forms of tinnitus.

The neuroimaging methods functional magnetic resonance (fMRI) and positron emission tomography (PET) enable to measure regional changes of cerebral blood flow, which in turn is an indirect measurement of neuronal activity. Electro- (EEG) and Magnetoencephalography (MEG) measure neuronal activity directly. Alterations in the central auditory pathways in tinnitus patients have been shown already 15 years ago. However it has been only very recently that neuroimaging studies have systematically been used to differentiate the different forms of tinnitus (unilateral versus bilateral, pure tone versus noise like, with more and less distress, with shorter and longer duration) (Schecklmann et al. 2011;Vanneste, Van de Heyning, & De Ridder 2011a;Vanneste, Van de Heyning, & De Ridder 2011b). It has been demonstrated that all these forms differ in their brain activity pattern, especially in non-auditory brain areas. Also for the first time brain activity changes related to acute tinnitus after noise trauma have been studied (Ortmann et al. 2011) and it has been found that these differ substantially from those in chronic tinnitus.EEG and MEG have revealed consistent results across many studies in the sense that in tinnitus the normal activity pattern in the auditory cortex is changed. In the auditory cortex of tinnitus patients alpha activity is reduced, whereas delta and gamma activity is increased. Successful treatment reverses these abnormalities, indicating that they represent the neuronal correlate of tinnitus loudness. Syst Neurosci. 2012;6:15. Epub 2012 Apr 9. Neuroimaging and neuromodulation: complementary approaches for identifying the neuronal correlates of tinnitus. "...In conclusion, these preliminary studies indicate that both anodal stimulation of the left auditory cortex and bifrontal tDCS with the cathode left and the anode right can have beneficial effects on tinnitus in some individuals. The interindividual variability of treatment effects is high in all studies, suggesting that there may be pathophysiologically distinct forms of tinnitus that respond particularly well to different tDCS protocols (Vanneste et al.,

2011c).
In order to unravel the mechanism by which tDCS suppresses tinnitus EEG
measurements were performed before and after single sessions of bifrontal tDCS
in 12 patients who responded to tDCS. Reduction of tinnitus intensity and
tinnitus-related distress was related to modulation of neuronal activity in
pregenual anterior cingulate cortex, parahippocampal area, and right primary
auditory cortex regions (Vanneste et al., 2011a). These findings are comparable
to those obtained in healthy controls after a similar tDCS intervention (anode
positioned over the left DLPFC and the cathode over the right supraorbital
region), that revealed a tDCS induced modulation of regional electrical activity
in the left subgenual prefrontal cortex, the anterior cingulate cortex and the
left parahippocampus (Keeser et al., 2011b) and significant changes of regional
brain connectivity both for the default mode network and the fronto-parietal
network (Keeser et al., 2011a)."

Neuroanatomical correlates of tinnitus revealed by cortical thickness analysis and 
diffusion tensor imaging.

Abstract

INTRODUCTION: Tinnitus is a poorly understood auditory perception of sound in
the absence of external stimuli. Convergent evidence proposes that tinnitus
perception involves brain structural alterations as part of its pathophysiology.
The aim of this study is to investigate the structural brain changes that might
be associated with tinnitus-related stress and negative emotions.


METHODS: Using high-resolution magnetic resonance imaging and diffusion tensor
imaging, we investigated grey matter and white matter (WM) alterations by
estimating cortical thickness measures, fractional anisotropy and mean
diffusivity in 14 tinnitus subjects and 14 age- and sex-matched non-tinnitus
subjects.

RESULTS: Significant cortical thickness reductions were found in the prefrontal
cortex (PFC), temporal lobe and limbic system in tinnitus subjects compared to
non-tinnitus subjects. Tinnitus sufferers were found to have disrupted WM
integrity in tracts involving connectivity of the PFC, temporal lobe, thalamus
and limbic system.

CONCLUSION: Our results suggest that such neural changes may represent neural
origins for tinnitus or consequences of tinnitus and its associations.

Neuroanatomical correlates of tinnitus revealed by cortical thickness analysis
and diffusion tensor imaging.
Abstract
INTRODUCTION: Tinnitus is a poorly understood auditory perception of sound in
the absence of external stimuli. Convergent evidence proposes that tinnitus
perception involves brain structural alterations as part of its pathophysiology.
The aim of this study is to investigate the structural brain changes that might
be associated with tinnitus-related stress and negative emotions.
METHODS: Using high-resolution magnetic resonance imaging and diffusion tensor
imaging, we investigated grey matter and white matter (WM) alterations by
estimating cortical thickness measures, fractional anisotropy and mean
diffusivity in 14 tinnitus subjects and 14 age- and sex-matched non-tinnitus
subjects.
RESULTS: Significant cortical thickness reductions were found in the prefrontal
cortex (PFC), temporal lobe and limbic system in tinnitus subjects compared to
non-tinnitus subjects. Tinnitus sufferers were found to have disrupted WM
integrity in tracts involving connectivity of the PFC, temporal lobe, thalamus
and limbic system.
CONCLUSION: Our results suggest that such neural changes may represent neural
origins for tinnitus or consequences of tinnitus and its associations.

http://www.springerlink.com/content/d67t81vx500870l2/

Some research:http://proceedings.ebea2011.org/modules/request205f.pdf?module=oc_program&action=view.php&id=5178


Bifrontal transcranial direct current stimulation (tDCS), with the anodal electrode overlying the right and the cathodal electrode overlying the left dorsolateral prefrontal cortex, has been shown to suppress tinnitus significantly in 30% of patients.



So there are various types of tinnitus with different neurological correlates. On top of this there are individual brain structures and neural layouts. At present the research is ongoing and a partial reduction of symptoms in 30% of subjects is not sufficient for me to undertake TDCs for Tinnitus as of this time.

Kewl new TDCs device plans

I have the most basic device - 2 resistors, a regulator & a battery. But http://www.diytdcs.com/ has discovered a nice little circuit with ramping (via a potentiometer) and an analog meter.


I would prefer auto ramping with on/off and a digital meter but for now I will build this new circuit.

I will build this as an intermediate device until I design a proper digital one with a micro controller.

Anti Humour - Killed by a 9 volt Battery

From: http://www.darwinawards.com/darwin/darwin1999-50.html

Resistance is Futile

(1999) A US Navy safety publication describes injuries incurred while doing don't's. One page described the fate of a sailor playing with a multimeter in an unauthorized manner. He was curious about the resistance level of the human body. He had a Simpson 260 multimeter, a small unit powered by a 9-volt battery. That may not seem powerful enough to be dangerous… but it can be deadly in the wrong hands.

The sailor took a probe in each hand to measure his bodily resistance from thumb to thumb. But the probes had sharp tips, and in his excitement he pressed his thumbs hard enough against the probes to break the skin. Once the salty conducting fluid known as blood was available, the current from the multimeter travelled right across the sailor's heart, disrupting the electrical regulation of his heartbeat. He died before he could record his Ohms.

The lesson? The Navy issues very few objects which are designed to be stuck into the human body.

August 2000 Dan Wilson elaborates:

I'm a former Navy petty officer, enlisted for six years as an electrician aboard a US Submarine. I got a lot of training. This story was used frequently during my training in the US Navy as an example of what can happen when procedures and safety measures are not followed. I considered the story an urban legend until I found the incident report referenced in the official Navy electrical safety guidelines. I now know it is true.

The actual event is slightly different than described above, and even more deserving of a Darwin award. This sailor stuck the sharpened ends of the probes through his thumbs intentionally. You see, he had just taken a course that taught a critical concept called "internal resistance."

Internal resistance is resistance to electrical power flow that exists inside any power source. It causes the terminal voltage to drop when load (current) increases. You can demonstrate this concept, if you're careful, by monitoring your car battery's terminal voltage, while someone starts up the engine. The reading will be ~13 volts while the engine is off, but during the period where the starter is cranking it will drop to 8-9 volts. The voltage drop is due to the internal resistance of the battery.

This sailor, like all other electricians in training, had already been through a safety class in which one of the excercises is to measure your body's resistance by simply holding the probes between your fingertips. (Most people read 500Kohms to 2Mohms.) Evidently, adding information from the internal resistance class, this sailor wanted to determine his own body's "internal resistance.". So he intentionally pushed the sharpened probe tips through the skin to elimate the rather high skin resistance and get only the "internal resistance". This, of course, caused his death.

How, you might ask, with only a 9V battery? Easy. One of the "rules of thumb" that the Navy teaches is the 1-10-100 rule of current. This rule states that 1mA of current through the human body can be felt, 10mA of current is sufficient to make muscles contract to the point where you cannot let go of a power source, and 100mA is sufficient to stop the heart. Let's look at Ohm's law. Ohm's law (for DC systems - I will not discuss AC here) is written as E=IR, where E is voltage in volts, I is current in Amps, and R is resistance in Ohms.

When we did the experiment in the electrical safety class to determine our body's resistance, we found a resistance of 500K Ohms. Using 9V and 500K Ohms in the equation, we come up with a current of 18 microAmps, below the "feel" threshold of 1mA. However, removing the insulation of skin from our curious sailor here, the resistance through the very good conducting electrolytes of the body is sharply lower. Around 100 ohms, in fact, resulting in a current of 90mA - sufficient to stop our sailor's heart and kill him.

As my electrical safety instructor said, "The reason we now have to teach the electrical safety course to all electricians at least twice per year is because some joe was bright enough to be the one person in the world who could figure out how to kill himself with a 9V battery."

Day 7 TDCs Maths Protocol

I just finished the 7th day math reinforcement. So this was my 3rd math training hooked to the electrodes. The session went well with no electrode problems or sensitivity.

I will do the tinnitus session in a day or two.

Cautious Opinion on TDCs

I do not wish to be seen to be encouraging people with no scientific background to perform unsafe experimentation so I am including a link to a cautious blog post below. Despite this many FDA approved CES devices are available to the general public. 


So while this post is clearly discouraging I am including it as a matter of caution rather than vitriol. Personally I think TDCs is safe enough to do at home. But you must have some back ground knowledge.


http://blog.zocdoc.com/can-electrical-stimulation-tdcs-enhance-your-brain-performance-fact-vs-myth/

 While the acute effects of tDCS only last about 75 percent of the time of application (e.g. If you stimulate for 20 minutes, the effects will last only about 15 minutes after the current is removed), any enhanced learning that is achieved during the session could potentially last months, just as learning a task without stimulation would. The difference is that you can potentially acquire that new task (i.e. learn) faster, and better.

For this reason, the task you choose is just as important as the tDCS current. Without a learning task, little is likely to be achieved with electrical stimulation. Similarly, the stimulation has to be in the area of the brain that is performing the task. Stimulation in the wrong part of the brain would have no effect or could potentially impair the task, if you happen to stimulate in an area that negatively regulates the area being used.

Safety is another concern. Most of the studies to date have suggested that tDCS is safe at least in a laboratory setting and for short-term use. The few reported side effects such as itching and headache appear to be mild. However, the safety has not been assessed very rigorously, and the results of long-term and repeated use are unknown. Though the effective voltage used in most of the studies is only around two milliamps, caution must be used to ensure that higher voltages are not accidentally applied.

Needless to say, tDCS should never be tried at home because of these potential risks. Scientists using tDCS in a laboratory setting have the expertise and high-quality equipment to assure the safety of their participants. They also have equipment like EEG and MRI that can help them localize the appropriate brain region for stimulation, as well as the training to understand how and when tDCS could be safe and effective. If you’re curious about tDCS your best bet is to find a local university that studies tDCS and volunteer for an experiment.

I don't encourage Joe Blogg's to read my blog and stick a battery onto his drunk mates head. 

I know enough about Electronics & Neuroscience to do this experiment. I would not ever experiment with neuro magnetics. At 1-2mA I feel its reasonably safe taking the large amount of research data into account. I am also limiting my exposure to the procedure to only four initial sessions per protocol. If I feel its worth it at the end of my foray I may do more sessions.

The good news is this - You are regulating an electrical parameter of your nervous system, the current between certain parts of the brain. So the same protocols can be used for BIOFEEDBACK.

Biofeedback eliminates any risk from the application of electricity. By studying and experimenting with TDCs for some time I hope to progress to using a suitably amplified & isolated Ammeter to regulate the protocols by a more natural & safe means. I certainly do not intend to do TDCs for an extended period of time.


So let me spell it out : I have studied Electronics & Neuroscience for many years - that is why I feel comfortable performing these experiments at home. Also my ultimate objective is to develop biofeedback protocols that are more effective & less invasive than TDCs.


I do not intend to use TDCs for an extended period of time. Maybe for a few months at the most.


Also clearly there are various cognitive trainings that can be taken advantage of while applying TDCs, such as speed reading & photo reading, eidetic training, mental calculation, artistic visualisation and so on. I am interested to see the improvement that TDCs offers in these area's.


I also want to add with respect to the post excerpt above from the other persons blog. 


The objective with TDCs - as with working memory training is "Cognitive Enhancement". 
This does not refer to the short term affect during or immediately after the training. It refers to the training of actual cognitive neurological patterns. 


These patterns are reinforced during TDCs and are long term or permanent. The learning of these patterns does not wear off in 20 minutes. This is why I am using the "curve of forgetting". Neurological patterns can be reinforced permanently or with infrequent retraining if it is done correctly. This is also why Biofeedback is probably a superior approach once an intitial familarization has been established with TDCs.

Session 5 - Further electrode problems above right eye

This was my seventh day reinforcement of the "working memory" protocol. Again I had an issue with the electrode above my right eye. This nerve is sensitive because of a dental abscess in my right upper molar.

Again I could feel a mild but sharp pain in the nerve and see a white flash in my right eye. I removed the electrode and placed a new one slightly to the left by a few mm which resolved the problem.

This time it also happened immediately when I started the device which strongly suggests I need to build a better circuit with current ramping to avoid any micro trauma to the nerves involved.

I will look into that.

So this was an initial distraction. Apart from that the session seemed to go OK. I have seemed to notice an improvement in my cognition over all during the last couple of days but perhaps it is placebo.

Here are photos of the electrode placement...