If the memory was created from before his lobectomy, he still had the ability to retrieve it and remember. However, he was able to learn some new skills. He was the first well-documented case of severe anterograde amnesia, and was studied until his death in 2008.A similar case involved Clive Wearing, an accomplished musicologist who contracted a cold sore virus that attacked his brain, causing herpes simplex encephalitis. As a result, Wearing developed both anterograde and retrograde amnesia, so he has little memory of what happened before the virus struck him in 1985, and cannot learn new declarative knowledge after the virus struck him either. As a result of anterograde amnesia, Wearing repeatedly "wakes up" every day usually in 30-second intervals. He has a history of repeatedly recording these moments of waking up in his journal (e.g., On Sept 2, 2013, I woke up, etc. etc.) and crossing out prior entries, as if the other moments of waking up were not real. His episodic memory is nonfunctional (so he does not consciously recall having woken up 30 seconds prior). Clive is often elated to see his wife, as if he has not seen her for a while. Despite this, however, Wearing maintained his ability to play the piano and conduct choirs. This case is significant because it demonstrates declarative and procedural memory are separate.
When alcohol is consumed at a rapid rate, the point at which most healthy peoples long-term memory creation starts to fail usually occurs at approximately 0.20% BAC, but can be reached as low as 0.14% BAC for infrequent drinkers. The exact duration of these blackout periods is hard to determine, because most people fall asleep before they end. Upon reaching sobriety, usually after waking, long-term memory creation is completely restored.Chronic alcoholism often leads to a thiamine (vitamin B1) deficiency in the brain, causing Korsakoffs syndrome, a neurological disorder which is generally preceded by an acute neurological condition known as Wernickes encephalopathy (WE). The memory impairment that is pathognomonic to Korsakoffs syndrome predominantly affects the declarative memory, leaving non-declarative memory that is often procedural in nature relatively intact. The disproportionate severity in anterograde episodic memory processes in contrast to other cognitive processes is what differentiates Korsakoff syndrome from other conditions such as alcohol-related dementia. Evidence for the preservation of certain memory processes in the presence of severe anterograde episodic memory serve as experimental paradigm to investigate the components of human memory. Pathophysiology
The pathophysiology of anterograde amnesic syndromes varies with the extent of damage and the regions of the brain that were damaged. The most well-described regions indicated in this disorder are the medial temporal lobe (MTL), basal forebrain, and fornix. Beyond the details described below, the precise process of how we remember – on a micro scale – remains a mystery.