Hermann Ebbinghaus
He conducted key studies on forgetting and memory. He started out with 3 letter syllabus and studied how long if took him to learn the words on the first versus second day. He also discovered, in regard to forgetting, that there is a rapid loss of information learned and then is gradually levels off. He is credit with the Forgetting Curve/Ebbinghaus Curve.
George Sperling
He did research about sensory memory. He flashed a grid of 9 letters for 1/20th of a second and tested recall.
George Miller
Proposed the idea that everyone have 7 +/- 2 M-Spaces in our short term memory.
Elizabeth Loftus
She studies repressed memories and false memories and showed how easily memories could be changed and falsely created by techniques such as leading questions and illustrating the inaccuracy in eyewitness testimony. She established the concept of the misinformation effect.