Oct 29 2010

Digital Mind Reading

We are making progress, very slowly, in “reading” human brain activity. This is an exciting area of research, but reporting about it consistently falls prey to one typical formula of science reporting – lead with the most speculative and fantastical potential application of the technology.

In this case just about every news story I read about the latest study involving reading brain activity leads with the idea that this technology can be used for either mind reading or dream recording. It would be better for such far future extrapolation to be buried deep within the article, after some more balanced discussion about where the science actually is.

I know this is a frequent quibble of mine, but it does affect the public perception of science. The public is constantly hearing about how one tiny advance in our understanding of some aspect of biology might lead to a cure for some horrible disease. Wasn’t the genome project supposed to lead to countless cures and medical advances? Where are all the invisibility cloaks we were promised, and why can’t I watch my own dreams like a high definition movie?

After a few years of these bold promises not coming to fruition, the media begins to write stories about how the original advances were overhyped and maybe now they are not going to provide us with anything. It is an iatrogenic news cycle of the media.

Admittedly, naive scientists play into this phenomenon as well. It’s easy to get goaded into saying irresponsible things, especially when your research is getting media attention.

It is with all this in mind that I read the latest news reports about a dream-recording technology. Sure – one day we may have Matrix-type technology where we can translate brain activity into a virtual reality, and vice-versa. But the current research is very far away from this.

What we have now is another research group conducting research that basically looks for neuronal correlates of specific ideas and images. We already know that often an idea can be recorded in a single neuron in the brain. This is an important concept, and certainly lends itself to brain mapping. If the same neuron fires every time I think about Wink Martindale, that certainly creates the potential for interpreting the meaning of brain activity.

What Dr. Cerf and colleagues have done is test subjects that already have electrodes implanted deep within their brain for the purpose of studying their epilepsy. His research team was able to record the firing of specific neurons and correlate them to specific concepts or people. They demonstrated that this firing was consistent.

This is great, although nothing really new. There are also many limitations. This level of precision requires implanted electrodes. This is not a minor hurdle but a major limitation of any practical application. Sure – one day we may all have supercomputers implanted in our skulls with millions of connections to our gray matter. Or we may develop scanning technology with single-neuron precision, but not anytime soon.

Also – the proof of concept here is that we can map individuals to find out which of their neurons correlates with certain concepts. An individual has to be mapped before they can later be read. You cannot apply any generic map to a person. This is probably not a significant limitation – but means that any software that reads neurological activity will have to go through a calibration period where the subject will be exposed to standardized stimuli while their brain is recorded.

The question is – how elaborate and time-consuming will such a calibration phase need to be before any useful complexity is achieved? How many millions of concepts are stored in our brain, and how useful will mapping a few thousand of them be? I suspect that mere advances in raw computing power will greatly help such tasks, so this might ultimately not be a limiting factor.

However, there remains an important proof of concept limitation. So far researchers have mapped visual information and individual items or people. But what about a complex narrative – the complex interplay of language, vision, sound, abstract concepts, and emotions with people and things?  Reading or creating a full virtual experience may be orders of magnitude more complex than reading individual components.

My concern is that this complexity will follow the rules of chaos theory, and we will no more be able to map full experience than we can predict the weather a month from now. This goes beyond high-fidelity recording. We may be able to record someone’s mental activity and play it back for them – so you could re-experience anything recorded in the past, maybe even your own dreams. This process would involve recording and playback only – not interpretation. The same recording may be gibberish to any other person, and could not be played on a video for anyone to watch.

My question is about the ultimate limits of interpreting brain activity. I’m not sure what the answer is. I follow the research to see if we are making any progress in this regard. We are  – but it is still so preliminary we cannot yet answer this question.

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