The memory consolidation theory was proposed nearly a century ago Although the research was presented a number of years ago it still provides the framework for modern research There has been evidence that that new memories strengthen over time and in stages Evidence also showed that cerebral trauma showed a loss of memory to potentially provide an explanation for retrograde amnesia The theory was ignored for 50 years but was considered again in 1949 when electroconvulsive shock produced amnesia in rodents The research done by Hebb and Gerard indicates that there are at least two stages of memory thus protein synthesis is required for long term memory consolidation It was also shown that stimulant drugs that were administered within minutes or hours after training enhances memory consolidation 2 The consolidation theory is still able to guide research today 3 Most research on memory consolidation indicate that memory has a time window of hours after learning However recent evidence has shown that memory may continue for weeks months or years and that they are stages of learning The various stages of consolidation rely on cellular mechanisms and brain systems Such as lesions on the hippocampus impair recently learned information This means that the hippocampus does play a role in consolidating and storing McGaugh s work shows that memories are not created immediately in a lengthy indefinite manner Instead immediately after learning an event the memory is impressionable