When an individual experiences an alcohol induced blackout, his consciousness remains throughout the period but will be unable to have complete recollection of what happened during that time. It is as if events are never imprinted on the brain for recall. It's amnesia in a way, but it's caused by alcohol abuse and not a traumatic event or physical injury.

There are two types of alcohol induced blackouts commonly studied:

1. Fragmentary or partial blackouts.

These tend to occur when lower levels of alcohol are taken. You might forget names or what you were talking about in the middle of a conversation. These partially interfere with memory formation during intoxication. People can sometimes remember the missing pieces if they are prompted or reminded of the context of conversation or situation.

2. Complete or en bloc, blackouts

When a person has a complete alcohol blackout, he is still physically and mentally able to perform actions although he may seem not like his usual self. In this type of blackout, an individual is still conscious - but will be unable to retain any memory of what happened during his blackout, what so ever. Prompting or reminders will not lead to recall the events. It appears that the ability to transfer and imprint memory from the present and short term to long term storage is blocked.

How alcohols and drugs can cause blackouts:

In most cases, blackouts are a result of binge drinking, that is, consuming an excessive quantity of liquor in a brief period of time. This has been confirmed by a research conducted for the National Institute on Alcohol Abuse and Alcoholism which reports how large and especially rapid consumption of alcohol (such as 'doing shots'), can produce partial or complete blackouts.

One researcher states "If recreational drugs were tools, alcohol would be a sledgehammer ...alcohol produces detectable memory impairments beginning after just one or two drinks. As the dose increases, so does the magnitude of the memory impairments."

Other things you should know about blackouts:

Age is a determining factor in how much alcohol you can safely consume, and women are more susceptible. A womans' tendency to black out more easily probably results from differences in how men and women metabolize alcohol. Females also may be more susceptible than males to milder forms of alcohol-induced memory impairments, even when men and women consume comparable amounts of alcohol.

The dangers of experiencing blackouts:

Surveys have discovered that college students who had experienced blackouts found out later on they had participated in various high-risk activities like engaging in sex without protection, driving under the influence of alcohol, or committing vandalism and other similar offenses.

People who experience blackouts may at that time have an impaired ability to decide and judge and possess minimal or no control at all over their impulses.

Tips for safe drinking and preventing and managing blackouts:

The only sure-fire method for not having a blackout or memory problems is to not drink. One puzzling aspect of blackouts is that the occurrence and consequences cannot be predicted.