No, I’m talking about actually reconstructing pictures of what a person is ‘seeing’ in their head. The House episode took a few liberties, but actually, the reality of the technology is not all that different - take a look at the video embedded on this page:
ETA: OK, I think it was actually reproducing something they were seeing, rather than just thinking about.
Yeah it’s the same thing, they just go more in depth than I did. Note lines like:
“As yet, the technology can only reconstruct movie clips people have already viewed.”
or
“Finally, the 100 clips that the computer program decided were most similar to the clip that the subject had probably seen were merged to produce a blurry yet continuous reconstruction of the original movie.”
I remember House showing it much higher resolution but with reduced color variations.
Actually, it’s a bit weird - I think there must be some essential detail missing from the write-up, because it sounds like they:
Built and trained a system for correlating brain scan data to specific movie clips from a small library, allowing them to:
Determine which clip is being watched, and having done so:
Construct a shitty interpolated computer rendering of the known clip.
Unless I’m missing something, the visually striking output from step 3 is not actually a rendering of anything inside the head, just a re-rendering of a known piece of footage. It can’t be that lame can it?
No, it’s pretty cool. They can predict your perception based upon brain activity. They cannot read your mind. But many hours were spent measuring brain activity with fMRI ($500-$1000 per hour).
Spider Robinson wrote a book based on this idea, and the “My life flashed before my eyes” meme.
Distant future descendants had perfected this technology, and time travel, and were trying to save/recover their ancestors. When it appeared you were about to die, the system scanned you into memory. if you survived, your memories of the process were the “white light” and “life recap” of the near-death experience.
Robert Sawyer wrote a trilogy around a parallel Earth where Neandertals became the successful hominid. They had a form of this technology where an implanted unit recorded a low-res scan of your life, with data dumps to a secure repository (and other functions - think of a modern smartphone, plus). You could access your record at will - “Where did I leave my coat?” - or the police could access it either with your explicit permission - “Who assaulted me?” - or by court order - “Where were you on the night of …”. These last two had a beneficial effect on the crime rate. :dubious:
Close but not quite.
In other words, they are finding videos that induce a similar response in a specific individual, and then trying to pick out what visual features the similarities correspond to by blurring those videos together.
From comparing the reconstructions to the originals, you can see that certain things can be picked out pretty reliably one you know an individual’s activity patterns. In particular, the responses to images of people are reliably similar to that for other images of people in similar poses, and text brings up other text in similar positions (people and text are probably the two most readily identifiable things, since there are specific brain regions largely dedicated to face recognition, and text activates language areas, so once you know the individual person’s activity map those signals are fairly distinctive).
Beyond that, simple patterns with strong contrast (the horizontal lines and central blobs) bring up other similar patterns, etc. So if we could record from someone without the giant machine, we could probably tell if they are looking at a person, or at text, or something with a strong horizontal/vertical/diagonal/center-surround structure, etc., but so far we are nowhere near being able to tell exactly what the person is looking at, and of course the algorithm needs to be trained on a large amount of data where the activity is matched to known visual input.
Chemical reactions are electrical reactions. Well, electromagnetic reactions, since you can’t have one without the other (electricity and magnetism).
As the name suggests, the electron is the basic unit of electricity. Chemical reactions involve the transfer of electrons in various ways to alter the relative locations of molecules.
For example, the system that makes cells function runs on transfers of electrons via adenosine tryphosphate. Gatorade and your gardening adviser aren’t lying about the importance of potassium for healthy growth and maintenance of your body and plants.
In the psychological world, researchers analyze the time course of changes in the electrical status of various parts of the brain to link them to the responses to stimuli (called “event-related potentials” or “ERPs”). These are generally referred to with a polarity and a time, so the P300 ERP is a positive electrical spike that occurs about 300ms after the exposure to a stimulus that was unexpected for the context.
Yes, fMRI voxels are better, but ERPs are so much cheaper. And a bit more ecologically valid.
OK, fine, nuclear reactions are chemical reactions that are not primarily electromagnetic in nature. However, nuclear reactions induce powerful electromagnetic activity in chemicals. This is because they involve smashing bits of matter together in a way that causes a whole bunch of electrons to go crazy, regardless of whether that smashing results in fission or fusion.
But the point remains: human neurons, like all things composed of matter that undergo changes, do so using electrons as the foundational mechanism. No voltage change, no chemical reaction.