"Every perception is to some degree an act of creation, and every act of memory is to some degree an act of imagination."

-- Gerald Edelman, Second Nature: Brain Science and Human Knowledge
Distributed practice2 Distributed practiceDistributed practicePart II: Personal Memory Systems More BroadlyAugmenting Long-term Memory2020-09-24JournalThat is, memories decay. This isn't news! But the great German psychologist Hermann Ebbinghaus had the good idea of studying memory decay systematically and quantitatively\\ Hermann Ebbinghaus, Memory: A Contribution to Experimental Psychology (1885). A recent replication of Ebbinghaus's results may be found in: Jaap M. J. Murre and Joeri Dros, Replication and Analysis of Ebbinghaus' Forgetting Curve (2015).. In particular, he was interested in how quickly memories decay, and what causes the decay. To study this, Ebbinghaus memorized strings of nonsense syllables – things like “fim“ and “pes” – and later tested himself, recording how well he retained those syllables after different time intervals.