Blackouts seen in a new light.

• Author: Sweeney, Donald F.
• Position: Law & Justice - health and social aspects of alcoholism

IN THE MID 1980s, I was giving a lecture on alcoholism at the University of California, Santa Barbara, when a young man stood up and asked, "What's a blackout?" I had heard of them, of course. Hasn't everyone? Alcohol blackouts are the subject of as many jokes as traveling salesmen, but this was a serious question, and I suddenly realized I did not know the answer. It was something I had overlooked. I gave some lame response, I am sure, and promised myself to seek a better one. I quickly discovered that references to blackouts in the medical literature were sparse and mostly inadequate. Usually, they were called a form of amnesia, but what was there about alcohol and the human body that caused the amnesia'? The research cited most often was performed in the 1960s. It established that blackouts occur, but little as to cause.

Clearly, one of the most common neurological dysfunctions--blacking out and not remembering while consuming a common and legal substance--had fallen through the cracks of medicine, or maybe it was swept under the rug because no one knew the answer. Thus, my search began and continues 20 years later. It has taken me far a field into neurology, neuroscience, psychiatry, psychology, pharmacology, and anesthesiology, along with forays into the law, forensics, public health, emergency medicine, and other places doctors of internal medicine usually do not enter.

In the end, the answer came from neuroscientists using the latest techniques to study the human memory and brain function. They had no interest in blackouts, but I did. At last, we had a pretty good idea what happens to cause an alcohol blackout. The answer is complex. We still do not know all the details but, eliminating the technical jargon, it is known that, under certain circumstances, alcohol in sufficient quantities blocks new memory formation in the brain. We so take our memory for granted that it is extremely difficult even to imagine what life would be like without it. Minus new memory formation, thoughts or observations last for mere seconds, no more than a minute or two. Blacked-out persons do not know where they are, what they are doing, even what time it is. They cannot learn, plan, or think. They have no idea what their actions are, let alone their consequences. Blacked out people suddenly are living in the exact present, with no idea what happened a minute ago. They have no clue as to what to do next or any possibility of carrying it out. They have no control of their future.

Yet, their preblackout memory, coupled with procedural or how-to memory, remains intact, enabling them to function. They remember everything up to the moment of blackout, family and friends, all their schooling, everything they previously learned, all the procedures they know. These long-term memories enable them to walk, talk, drive, go to work, travel, write checks, have sex, appear reasonably normal--only they never will remember any of it. If they wake up in a bed with a stranger, deplete their checking account, or perhaps become angry, get into a fight, pick up a knife or gun, they will not remember that, either--or be able to stop themselves from using it. They are in what amounts to an unconscious state.

Alarmingly, the...