A Treasure Trove of Stimulating Information!

universityNMJust found this in iTunesU. Wow! You’ll recognize many of these names if you’re reading the tDCS literature. I’ve only watched the Michael Weisend talks (whom we met earlier on the blog) so far. I have a much better understanding of the difficulty of running a tDCS trial now. There’s a lot that can go wrong. If your protocols aren’t set up just right, your information might be useless. Here’s the web link iTunes Link from which you can download in iTunes. Downloads are quite slow.

Introduction to Neurosystems Engineering, Spring 2011 (ECE 595)                   Neurosystems Engineering is an emerging field at the intersection of Neuroscience, Psychology, and Engineering, and the University of New Mexico is its epicenter.

Course Intro   Dr. Gerold Yonas
Course Syllabus   Dr. Gerold Yonas
Tools and Techniques in Neuronal Stimulation  Dr. Edl Schamiloglu
Basic Principles of Feedback and Control   Prof. Chaouki T. Abdallah
Discussing the Course General Approach and Direction  Dr. Gerold Yonas
Effects of Direct Current, Non-Invasive Brain Stimulation on Learning  Michael Weisend
In the Laboratory Transcranial Direct Current Stimulation (tDCS)   Michael Weisend
Posttraumatic Stress Disorder: Roles for Treatment & Prevention (Part I) Dr. Pilar M Sanjuan
Posttraumatic Stress Disorder Roles for Treatment & Prevention (Part II) Dr. Pilar M Sanjuan
Tour of the Mind Research Network   Dr. Vince D. Calhoun
Neuroimaging of Intelligence and Creativity (Part I)    Dr. Rex E. Jung
Neuroimaging of Intelligence and Creativity (Part II)   Dr. Rex E. Jung
Memories and Migraines: Application of tDCS  Laura Matzen
Neurochemistry Application in NonInvasive Brain Stimulation  Dr. Charles Gasparovic
Non-Invasive Brain Stimulation    1:03:47   Lucas C. Parra
Epilepsy, Autism, and Novel Treatment Strategies   Dr. Jeffrey David Lewine
The Emerging Field of Sleep Disorders Medicine  Dr. Barry Krakow
Presentation of Class Projects   Student

Another DIY tDCS Video

Hard to imagine how he’d have learned enough about tDCS to build a device, but have gotten the (typical) montage so wrong. Placing the cathode over left DLPFC and anode over right orbital is exactly the opposite of what you’ll find in most studies related to both depression and working memory. He doesn’t go into how he’s constructed his electrodes at all. Anecdotally, it is interesting that the reverse montage made him feel angry and depressed.


Weekend tDCS Insights – Chi & Snyder, SpeakWisdom, Carlo Miniussi

Some very excellent tDCS-related documents came to my attention over the weekend. I’m pretty sure I’d looked for at least one of them before, but that it was behind a paywall. I’ll provide links to the pdfs here, but suggest that (as has happened elsewhere on the blog) pdf links frequently go bad so ‘get em while they’re hot’.

Brain stimulation enables the solution of an inherently difficult problem (pdf)
This is the paper by Alan Snyder and Richard Chi that is frequently referenced in ‘unlock your inner savant’ articles on various pop-sci sites. (See also) Spoiler alert! Gives the answer to the ‘9 dot’ problem and once you’ve seen it it will be impossible to discover how ‘savant-like’ you are (at least according to this test).

ninedot …we applied cathodal tDCS (1.6mA) at the left anterior temporal lobe (ATL) together with anodal tDCS at the right ATL for approximately 10 min… None of the 22 participants in the main experiment solved the nine-dot problem before stimulation. But with 10 min of right lat- eralizing transcranial direct current stimulation (tDCS), we found that more than 40% of participants could do so.

speakWisdomTakeapartDr. Brent Williams, at his SpeakWisdom blog, published another excellent tDCS post updating his DIY device, and adding a .doc that outlines his recommended (For Discussion) protocols for depression, ‘Savant Learning’, memorization, and chronic pain.
His protocol describes directions for use with either his ‘User-Built tDCS Research Device’, or the ActivaDose II.

Transcranial Magnetic and Electric Stimulation in Perception and Cognition Research (pdf)
This is a fascinating paper (Carlo Miniussi et al) that brings us up to date (2012) on applications of tDCS, TMS tACS (transcranial alternating current), and tRNS (transcranial random noise stimulation), especially in relation to cognition and learning. What really caught my eye was this entry about tRNS…

 tRNS consists of the application of a random electrical oscillation spectrum over the cortex. tRNS can be applied at different frequency band ranges over the entire spectrum from 0.1 to 640 Hz…They applied tRNS to the visual cortices of healthy subjects and observed a significant improvement in the performance of healthy subjects in a visual perceptual learning task. This improvement was significantly higher than the improvement obtained with anodal tDCS…

And that folks, is how a weekend disappears down the rabbit hole!

Marom Bikson of Soterix Medical and CUNY – DIY tDCS Podcast Episode #3

Marom Bikson is CEO of Soterix Medical and Associate Professor at City College of New York in the Department of Biomedical Engineering. Marom is a distinguished tDCS scientist and prominent in the development of HD-tDCS. Download the interview here (zipped mp3). (Firefox users- there is an audio player here, but it’s displaying intermittently. Trying to track down the issue. In the meantime you can download the episode or open the page in another browser).

Marom Bikson

Marom Bikson

(We got a good forty minutes of interview in before the Skype gremlins caught up with us. I had to cobble an ending together.)

Show Notes:
Post-Doc, Neurophysiology Unit, University of Birmingham Medical School, U.K., 2003
Ph.D., Biomedical Engineering, Case Western Reserve University Cleveland, OH, 2000
B.S., Biomedical Engineering (EE Concentration), Johns Hopkins University, Baltimore, MD, 1995
Introduction to Transcranial Direct Current Stimulation (tDCS) in Neuropsychiatric Research
5th International Conference on Non-invasive Brain Stimulation 2013

Instrumentation – making medical gizmos, process.
IRB- Institutional Review Board
IRB at the FDA
Small Business Technology Transfer STTR grant.

Soterix partners
Abhishek Datta CTO,
Lucas Parra
Bootstrapped at this point.

Difficulty in engineering medical devices is in designing for the anomalous cases- how that 1 in 999 times situation could go wrong.

Clinical trials. Depression, (Colleen Loo, Blackdog Institute), pain, stroke, epilepsy clinical trials ongoing.

Customizing technologies to match needs of particular clinical situations.

Soterix developed software designed for clinicians.
Modeling current flow through the head.

Perhaps depression studies are closest to FDA qualification for tDCS?
(Prediction is very hard, especially about the future – Yogi Berra.)

A device (NorDoc Smartstim) that can go to 4mA is being used in a smoking cessation trial? (Trial info indicates 2mA current dose.)

FDA tDCS approval would be device-specific at first.  But would open the door to ‘me too’ mechanism, FDA 510(k)

HD tDCS can have multiple cathodes and or multiple anodes. An array of 4 small anodes splitting 2mA, for example (.5 mA each electrode), can function as an anodal ‘virtual pad’. Assumes cathode somewhere else on the body).

Image By Richard McKinley USAF

Image By Richard McKinley USAF

Tolerability is how tolerable in terms of side effects a medication is.

Transcutaneous Spinal Direct Current Stimulation Example tsDCS paper.

A Theory of tDCS (“Gross oversimplification”) As positive current flows into the cortex it passes neurons.
Because of the nature of neurons, this positive current depolarizes somas (cell’s body), increasing excitability, thereby increasing the functionality & plasticity of that region (hypothesis… “We really don’t know.”). Under the cathode, somas (cells) are being hyper-polarized – excitabilty decreases.

A synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another cell.
Pyramidal neuron

Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte.

TES Transcranial Electric Stimulation
“transcranial electrical stimulation” Merton and Morton 1980

“Priming the network in conjunction with applying tDCS makes a lot of sense, as a way to make the tDCS to do what you want.” (Co-priming – The idea that one would initiate an activity first, and THEN add tDCS.)

DARPA supported accelerated learning.

Memory consolidation.
Lisa Marshall

H. Branch Coslett, MD

DIY tDCS community and building medical devices. Redundancy.
tDCS implies proven, vetted protocols, that have been used in clinical trials.

Thanks Marom!

Recent tDCS Papers of Interest

  1. Acute working memory improvement after tDCS in antidepressant-free patients with Major Depressive Disorder. All effect sizes were large. In other words, one session of tDCS acutely enhanced WM in depressed subjects…(Paywall)
  2. Neurobiological Effects of Transcranial Direct Current Stimulation: A Review The purpose of this systematic review is to summarize the current knowledge regarding the neurobiological mechanisms involved in the effects of tDCS. (pdf)
  3. Modulating Human Procedural Learning by Cerebellar Transcranial Direct Current Stimulation. Our finding that anodal cerebellar tDCS improves an implicit learning type essential to the development of several motor skills or cognitive activity suggests that the cerebellum has a critical role in procedural learning. (Paywall)
  4. Neuroenhancement of the aging brain: Restoring skill acquisition in old subjectsThese results suggest noninvasive brain stimulation as a promising and safe tool to potentially assist functional independence of aged individuals in daily life. (Paywall)
  5. Examining transcranial direct-current stimulation (tDCS) as a treatment for hallucinations in schizophrenia. Although this study is limited by the small sample size, the results show promise for treating refractory auditory verbal hallucinations and other selected manifestations of schizophrenia. (Paywall)
  6. Modulation of training by single-session transcranial direct current stimulation to the intact motor cortex enhances motor skill acquisition of the paretic hand.These results indicate that tDCS is a promising tool to improve not only motor behavior, but also procedural learning. (Paywall)
  7. Interactions between transcranial direct current stimulation (tDCS) and pharmacological interventions in the Major Depressive Episode: Findings from a naturalistic study. tDCS over the DLPFC acutely improved depressive symptoms. Besides the inherent limitations of our naturalistic design, our results suggest that tDCS effects might vary according to prior pharmacological treatment… (Paywall)
  8. Amelioration of Cognitive Control in Depression by Transcranial Direct Current StimulationDeficient cognitive control over emotional distraction is a central characteristic of major depressive disorder (MDD). The present study demonstrates that anodal tDCS applied to the left dlPFC improves deficient cognitive control in MDD. (Paywall)
  9. Comparing immediate transient tinnitus suppression using tACS and tDCS: a placebo-controlled study. Our main result was that bifrontal tDCS modulates tinnitus annoyance and tinnitus loudness… (Paywall)
  10. Review of transcranial direct current stimulation in poststroke recovery. In this review, we summarize characteristics of tDCS (method of stimulation, safety profile, and mechanism) and its application in the treatment of various stroke-related deficits… (Paywall)
  11. Enhancing vigilance in operators with prefrontal cortex transcranial direct current stimulation (tDCS)These findings indicate that tDCS may be well-suited to mitigate performance degradation in work settings requiring sustained attention or as a possible treatment for neurological or psychiatric disorders involving sustained attention. (Paywall)