a strength is the case study of HM and Clive wearing
episodic memory was severely impaired due to brain damage
But their semantic memories were relatively unaffected
They still understood the meaning of words, and their procedural memories were still in tact
This evidence supports tulvings view that there are different memory stores in long-term memory
however, studies on brain injuries lack control variables. researchers have no way of controlling what happened to the patients memory before or during the injury, or know what their memory was like before