The Mirror declares, ‘Scientists develop Matrix-style technique of ‘feeding’ information directly into your brain.’ Discovery News went with, “Novices ‘Download’ Pilots’ Brainwaves, Learn To Fly.” Most other outlets spoke of ‘uploading’ information to the brain, and learning in seconds.

The one thing I was certain of from reading these headlines is that this was not what was happening. Brain-machine interface technology is progressing rapidly, but we are a long way away from downloading information from or uploading information to the human brain.

The news outlets reported that electrical activity was recorded from pilots and then used to stimulate the subject. They also reported that this enhanced learning by 33%.

What actually happened

Here is the actual study: “Transcranial Direct Current Stimulation Modulates Neuronal Activity and Learning in Pilot Training.”

There were 31 subjects in the study, divided into four groups. One group had transcranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex (DLPFC), while a second had sham stimulation of this area. Sham stimulation creates the sensation of being stimulated but does not reach the brain. A third group had tDCS to the primary motor cortex (M1) and a fourth group had sham stimulation of M1.

Stimulation of DLPFC has been associated with increasing working memory in prior studies. While this finding is still somewhat controversial, the studies so far are promising. The introduction to the new study gives a thorough review of this research if you want to delve into the details.

Stimulation of M1 is meant to enhance acquiring motor skills, although this finding is less well established with prior research. The 31 subjects were trained on a flight simulator and their performance tracked. The question for the study was whether or not either type of stimulation would aid in learning of this new and fairly complex task.

Here is the main result for DLPFC stimulation:

Neither the initial nor the final behavioral performance were significantly different between DLPFC stimulation and sham groups (Supplementary Table S1). The average trial duration to reach 2-/3-back was not significantly different between stimulation and sham groups. In addition, the average number of trials to reach 2-/3- back and the average 2-/3- back streak durations were not statistically different between groups. Significant differences in online, offline, and combined learning rates were not observed between stimulation and sham groups (see Supplementary Table S1, Figure 4E).

What they did observe is that the variance for the stimulation groups was 33% less than the sham group. So there was less variability in performance, even though overall average performance was no different.

The results for the M1 group were the same – no statistically significant difference in overall learning, and this time no difference in variance either.

The researchers also took many measures of brain activity looking for differences in the stimulation and sham groups, and there were some difference, but these do not directly relate to actual learning.

Journalism failure #1: Turning a negative into a positive

Overall this was a negative study. Stimulation of either brain region did not improve learning in the subjects. The only effect was to reduce the variability in learning in the DLPFC stimulation but not M1 stimulation.

Given the small size of this study and the number of variables they observed it is not a surprise that there would be a few statistically significant outcomes. These could easily be chance outcomes, and should not be considered reliable until they are replicated in larger studies.

More interesting than the outcome of the study itself is how absolutely wrong the mainstream reporting was. There was never any ‘downloading’ or in fact any kind of recording made from pilots. There are no pilots in this study. Further, the brain stimulation was standard, not based at all on activity recorded from pilots.

Finally – the study was essentially negative. There was no improvement in learning in the stimulation group compared to the sham group. The 33% ‘improvement’ reported was not an improvement, but just a decrease in variability.

Journalism failure #2: Stopping at the press release

This is one of the most complete journalistic fails reporting a science news item I have seen in a while. However, in this case it is the press release from HRL Laboratories that is largely to blame (not to suggest that the journalists are off the hook). The press release reports:

Dr. Matthew Phillips and his team of investigators from HRL’s Information & System Sciences Laboratory used transcranial direct current stimulation (tDCS) in order to improve learning and skill retention. ‘We measured the brain activity patterns of six commercial and military pilots, and then transmitted these patterns into novice subjects as they learned to pilot an airplane in a realistic flight simulator,’ he says.

I found that nowhere in the paper itself. It seems that the quote is taken out of context, but it’s hard to imagine the context since it seems to have no relationship to this study.

The press release also states:

The study, published in the February 2016 issue of the journal Frontiers in Human Neuroscience, found that subjects who received brain stimulation via electrode-embedded head caps improved their piloting abilities.

This is true – but then so did the controls. They did not improve their skills more than the controls. Elsewhere the release says that stimulation ‘modulates’ learning (not ‘improves’). It modulated learning only in the decrease in variance. However, then the press release states it outright:

While previous research has demonstrated that tDCS can both help patients more quickly recover from a stroke and boost a healthy person’s creativity, HRL’s study is one of the first to show that tDCS is effective in accelerating practical learning.

But learning was not accelerated.

Conclusion: A press release is not a study

Using tDCS to alter brain function is an interesting area of research. This type of treatment may eventually play a role in recovery from stroke or other brain injury, but it is still too early to tell.

The current study is small, with 31 subjects spread across four groups, and the researchers looked at many variables. This is clearly a preliminary study (one might say a ‘pilot’ study, but not in the way the news reporting indicated), which is useful for guiding further research but lacking the power and specificity to draw any firm conclusions.

What the reporting of this study shows is the massive problem that exists in reporting science news items to the public. The press release and the reporting that flowed from that press release seem to have almost no correlation with the findings of the study itself.


Posted by Steven Novella

Founder and currently Executive Editor of Science-Based Medicine Steven Novella, MD is an academic clinical neurologist at the Yale University School of Medicine. He is also the host and producer of the popular weekly science podcast, The Skeptics’ Guide to the Universe, and the author of the NeuroLogicaBlog, a daily blog that covers news and issues in neuroscience, but also general science, scientific skepticism, philosophy of science, critical thinking, and the intersection of science with the media and society. Dr. Novella also has produced two courses with The Great Courses, and published a book on critical thinking - also called The Skeptics Guide to the Universe.