Decapitated worms regrow their heads with old memories intact

Decapitated worms regrow their heads with old memories intact: to embed a specific memory, the researchers spent 10 days teaching the flatworms that food could be found at the center of a petri dish with a light shining on it...

Then their heads were chopped off...

Once their heads and brains grew back, the scientists threw them back into the petri dish. But the memory wasn’t there right away. And in fact, the biologists had to give the worms a refresher course on the matter of finding food — but one quick lesson was all it took; the lesson basically allowed the worms to refresh their memories. Subsequent trials showed that the previously decapitated worms reached the food significantly faster than those (previously undecapitated) worms who were also given the benefit of one training session.