Today I want to take another look at alcohol’s effect on cognitive functioning, specifically learning and memory. I have already touched upon learning theory in earlier posts, especially the role played by this in the development of alcohol problems. Here I also want to explore memory.
My interest in memory dates back to when I did a neuropsychology placement at Western General Hospital in Edinburgh during my clinical training. I undertook a research project comparing memory problems (and insight into the problems) of patients who had chronic degenerative conditions (such as Multiple Sclerosis and Parkinson’s Disease) with those who had acute conditions such as strokes and head injuries. I learnt a lot about memory and its assessment, but I won’t go into the details here (probably because I have forgotten most of it!).
To remember something you first have to attend to that something. If nothing goes in then nothing is going to come out. Once attended to, the information has to be encoded and stored. We have our short-term memory system which holds small amounts of information for up to 30 seconds or so and our long-term memory system which holds loads of info for months and years. The former is used for tasks such as remembering a phone number to be able to dial it straightaway or to go into the next room to get something. The hippocampus (part of the brain’s limbic system we met in an earlier post) plays an important role in encoding and transferring information from short-term to long-term storage. There is an intermediary process known as working memory. This has to function well if we are to solve problems and make decisions – it allows us to manipulate information in our short-term memory and also has links with long term memory. There are also different types of memory – facts and figures, how to do things, how to find our way around, faces, people and so on. There is also a specific category known as autobiographical memory – the story of our lives. Memory problems can occur at different stages – failure to attend, failure to encode properly leading to it not being stored, and difficulties with retrieval – the information is somewhere, but you just can’t find it. How often do you try to recall something without success, and then later it pops into your mind?
Hopefully the above has set the scene. Memory is something we take for granted and probably only appreciate its importance to our lives when it starts to malfunction. I imagine we all know people who have struggled with memory loss, most profoundly in dementia or following a severe head injury. It is memory that has made us who we are today – it is a vital part of our sense of identity, the continuity of self, what connects the present to the past. To quote Rabbi Jonathan Sacks…
Without memory there is no identity, and without identity we are cast adrift into a sea of chance without compass, map or destination.
One of the most serious memory disorders found in severe alcoholism is known as Korsakoff’s Syndrome. It is characterised by memory loss and an inability to learn new information. While the exact causes are not fully understood, it is widely accepted that it is related to a deficiency in thiamine (vitamin B-1). It is likely that the deficiency is caused by a combination of poor diet and impaired absorption of the vitamin. It is standard practice to give injections of high-dose vitamin B-complex to patients undergoing alcohol detoxification. An interesting facet of Korsakoff’s Syndrome is confabulation. This is where sufferers make up stories to fill the gaps in their memory. They are not lying, they are just trying to make sense of things.
There is another severe condition that often precedes the onset of Korsakoff’s Syndrome, known as Wernicke’s encephalopathy. This is characterised by confusion, poor coordination, loss of balance and abnormal eye movements. While alcohol is usually the prime cause of these conditions, other diseases where there is a deficiency of thiamine can also be a cause.
Alcohol consumption can impair both the storage and retrieval of memories in laboratory studies. A condition that is quite serious but not so dangerous in itself as Korsakoff’s Syndrome is alcoholic blackout. This occurs when a lot of alcohol has been consumed over a short period of time. There are people who engage in what is known as high intensity drinking, which is particularly risky. There are two types of blackout – fragmentary and en block. In the former, there are little islands of memory about what happened during and after the drinking session. In the latter, there is a complete absence of memory, as if nothing ever happened. Blackouts are not the same as passing out because of drinking too much.
Oh, I’ve gone on quite a bit about memory without talking about learning. There is just one phenomenon that I wanted to mention and that is State Dependent Learning. This is the theory that if you learn something new in one condition then you are more likely to remember it best when you are in that condition again. There is a lot of research evidence to show that alcohol can produce State Dependent Learning – get drunk, learn something new, and remember it best when you are drunk again, This is my description of the phenomenon – it is not advice. Could this explain why heavy drinkers suddenly remember where they hid their bottle the night before when they are drunk again?
Another quite heavy post, so let’s end on a lighter note. A quote from US comedian Steven Wright…
Whenever I think of the past, it brings back so many memories.
Remember to drop by again tomorrow. Only a few more days left! Meanwhile, keep safe and well.
Alcohol Trivia Quiz
Yesterday’s answers:
1. Sir Walter Scott.
2. Buckfast Tonic Wine. [Originally from Buckfast Abbey in Devon, made by monks and gained notoriety among young drinkers, especially in Scotland]
3. Italy.
Today’s questions:
1. In what radio programme would you hear “A pint of Shires please”?
2. Who drank to “make other people more interesting”?
3. Who had a hit with “Cigarettes and Alcohol”?
Understand Yourself Better 