mind over matter

Whoa. Scientists, probing around in a man’s deep brain tissue, unexpectedly triggered a sense of déjà vu and a super-vivid personal memory. You can read the article here.

While they were identifying potential appetite suppressant sites in the hypothalamus by stimulating electrode contacts that had been implanted there, the patient suddenly experienced a feeling of ‘déjà vu.’ He reported the perception of being in a park with friends from when he was around 20 years old and as the intensity of the stimulation was increased, the details became more vivid.

Ahh! Does anyone else find this freaking bizarre?! Especially since I understood the sensation of déjà vu to be misclassification by the brain of something unfamiliar as familiar. Last year, ScienceDaily did an article on chronic déjà vu-sufferers. The researchers in the story called déjà vu “not a delusion, but a dysfunction of memory.”

So how could the mind-probers of the original article conjur the eerie sensation while evoking a (supposedly) genuine memory? It’s even stranger to me that the stronger they stimulated the spot, the more vivid the memory became. What if evil scientists found a way to root out your most tortured, repressed, humiliating memories? And then they stuck in their probe and turned the voltage higher and higher as means of torture until you just couldn’t take it? (”Did you ever see that Twilight Zone where the guy signed a contract and they cut out his tongue and put it in a jar and it wouldn’t die, it just grew and pulsated and gave birth to baby tongues? Pretty cool, huh?”)

But here’s the part of the article that excites me most:

“[Researchers] tested the patient’s memory during and without stimulation and found that after three weeks of continuous hypothalamic stimulation he showed significant improvements in two learning tests. In addition, the patient was much more likely to remember unrelated paired objects when stimulation was on than when it was off. They conclude that “just as DBS can influence motor and limbic circuits, it may be possible to apply electrical stimulation to modulate memory function and, in so doing, gain a better understanding of the neural substrates of memory.”

Obviously we don’t want to run around sticking probe into all sorts of forgetful people’s brains, but I’ll be interested to hear if there’s a clinical application here, however far off.