“Older people’s memory got better up to the level that we could no longer tell them apart from younger people,” said lead investigator Joel Voss, associate professor at Northwestern University Feinberg School of Medicine. “They got substantially better.”
Not related directly with the research, but interesting to note in the video where Canadian researcher Jed Meltzer, a scientist at Baycrest Hospital’s Rotman Research Institute in Toronto is shown demonstrating an ActivaDose device and an unusual montage.
Not tDCS, but TMS -Transcranial Magnetic Stimulation, another form of TES – Transcranial Electric Stimulation, that is being used both clinically (FDA approved for the treatment of depression) and as a research tool. Unlike tDCS, TMS can be of sufficient power to cause neurons to fire– imagine a finger twitching in response the the activation of the TMS device.
The video describes an experiment where researchers are attempting to improve the quality of memory encoding using TMS. The point of sharing it with you on the blog is to point out how difficult this is in fact to do. tDCS for cognitive enhancement was what initially inspired this blog, and now these six years later, I’m not sure we’re any closer to having a useful tool for cognitive enhancement of any kind, though I am reasonably confident in stating that tDCS for the treatment of depression is at least worth trying. (Other areas of research I’m more optimistic about are tDCS and Aphasia, tDCS and Parkinson’s, and tDCS for the enhancement of physical training. But in all of these the jury is still out, as there is conflicting research results.)
Note as well in the video the elaborate set up for measuring the effect of TMS in the memory study. These are often standardized tests used throughout psychology research. Unfortunately they are often costly and complicated to use. Point being that any sort of DIY cognitive enhancement experiments need to consider how effects will be measured.
Though TMS not tDCS, it would be interesting to see the original paper (Targeted enhancement of cortical-hippocampal brain networks and associative memory – paywall). My understanding is that the hippocampus is a difficult target for tDCS. But perhaps insights from this study could lead to ideas for a ‘memory enhancing’ tDCS montage.
To test this, Voss and his team of researchers had 16 healthy adults between the ages of 21 and 40 undergo MRIs so the researchers could learn the participants’ brain structures. Then, the participants took a memory test which consisted of random associations between words and images that they were asked to remember. Then, the participants underwent brain stimulation with TMS for 20 minutes a day for five days in a row. TMS uses magnetic pulses to stimulate areas of the brain. It doesn’t typically hurt, and has been described by some as a light knocking sensation. The researchers stimulated the regions of the brain involved in the memory network.
Throughout the five days, the participants were tested on recall after the stimulation and underwent more MRIs. The participants also underwent a faked placebo procedure. The results showed that after about three days, the stimulation resulted in improved memory, and they got about 30% more associations right with stimulation than without. Not only that, but the MRIs showed that the brain regions became more synchronized by the TMS.