HD tACS to Synchronize Medial Frontal Cortex & Lateral Prefrontal Cortex Leads to Improved Executive Function

You may have noticed that I’ve not been posting as much to the blog lately. The blog is already so full of useful content for anyone looking into tDCS that I’m inclined to only post significant information that would move our current understanding of tDCS and neurostimulation forward. This article/paper describing a new technique using ‘HD tACS’ to synchronize (brainwaves) parts of the brain definitely looks intriguing and has implications for anyone paying attention to DIY neurostimulation. Very early, but very interesting.

Prof Rob Reinhart. Photo by Cydney Scott for Boston University Photography

Full story:  “Turbo Charge” for Your Brain? by By Barbara Moran

“These (medial frontal cortex & lateral prefrontal cortex) are maybe the two most fundamental brain areas involved with executive function and self-control,” says Reinhart, who used a new technique called high-definition transcranial alternating current stimulation (HD-tACS) to stimulate these two regions with electrodes placed on a participant’s scalp. Using this new technology, he found that improving the synchronization of brain waves, or oscillations, between these two regions enhanced their communication with each other, allowing participants to perform better on laboratory tasks related to learning and self-control. Conversely, de-synchronizing or disrupting the timing of the brain waves in these regions impaired participants’ ability to learn and control their behavior, an effect that Reinhart could quickly fix by changing how he delivered the electrical stimulation. The work, published October 9, 2017, in the journal Proceedings of the National Academy of Sciences (PNAS), suggests that electrical stimulation can quickly—and reversibly—increase or decrease executive function in healthy people and change their behavior.

Here’s the paper (paywall): Disruption and rescue of interareal theta phase coupling and adaptive behavior. The supplemental pdf. describes the equipment used in the experiment.
High definition transcranial alternating current stimulation ( HD- tACS ). The alternating current stimulation was administered noninvasively using an MxN9-3 channel high definition transcranial electrical current stimulator from Soterix Medical (New York, NY). Eight sintered Ag/AgCl electrodes were attached to high-definition plastic holders, filled with conductive gel, and embedded in the Biosemi EEG cap. HD-tACS electrode placement was guided by current-flow modeling using HD- Explore and HD-Targets (Soterix Medical), with the goal of targeting the MFC and lPFC to facilitate the synchronization of neural activity between these regions (the in phase protocol ) or disrupt the signals being conveyed between the MFC and lPFC (the antiphase protocol ).

Listen to Bob McDonald discuss HD tACS with Prof Rob Reinhart on the always interesting Quirks and Quarks.

Focus announces EEG Dev Kit

Update 2/2/17. Focus just announced functional Near-InfraRed Spectroscopy (fNIRS) capabilities for their EEG Dev kit!

This was announced a few days ago and to be honest, I wasn’t sure what to make of it… a battery-looking EEG thing. Certainly I’m not a ‘Dev’ and so I left it to those who are to parse the details, still…  Ah, yes, further details arrived today via email I’m happy to share with you (below). I do get the feeling this will make EEG devs excited.

Update 1/19/17 The focus site now has a photo of their new dry EEG electrode.

Thanks for all your feedback and questions about the focus EEG. A common question has been what exactly is included (see below) and is it everything required (yes).

Included in EEG Dev Kit

  • foc.us EEG 24-bit 8-channel EEG with tES & Wi-Fi
  • 8 active dry electrodes for EEG, plus bias & reference electrodes
  • 2 active bio-potential electrodes for ECG, EOG, EMG or EKG
  • 2 wet tES electrodes for tDCS, tACS, tPCS or tRNS
  • 10-20 placement cap
  • Mains power adapter for recharging
  • Raw data access

Next week we will provide more details on the software and SDK for EEG processing.

Sincerely,
team focus

P.S. The first 100 66 are available at only $999 $499 – half price!

What I’m excited about is the Focus EEG headset, but a recent tweet exchange indicates we’re a good year away from release.