Last week we discussed about the brain and memory. As we promised last week, today we are going to discuss more interesting facts about memory.

Memory is a wonderful place. It helps to continue our work very well. But, if I would ask that what is the main issue regarding your memory? Definitely you will say that forgetting issue is the most annoying issue of all. Sometimes you are fed up forgetting what you have studied.

Do we all have that situation? Yes; everyone forgets. It is a common barrier, we face  in our lives.

Why do we forget? There are two simple answers to this question. Firstly, the memory has disappeared – it is no longer available. Second, the memory is still stored in the memory system but, for some reason, it cannot be retrieved. These two answers summarise the main theories of forgetting developed by psychologists. The first answer is more likely to be applied to forgetting in Short-Term Memory (STM), the second to forgetting in Long Term Memory (LTM). Forgetting information STM can be explained using the theories of trace decay and displacement.

Forgetting from LTM can be explained using the theories of interference and lack of consolidation.

This explanation of forgetting in short-term memory assumes that memories leave a trace in the brain. A trace is some form of physical and/or chemical change in the nervous system. Trace decay theory states that forgetting occurs as a result of the automatic decay or fading of the memory trace. Trace decay theory focuses on time and the limited duration of short-term memory. This theory suggests short-term memory can only hold information for between 15 and 30 seconds unless it is rehearsed. After this time the information/trace decays and fades away.

No one disputes the fact that memory tends to get worse the longer the delay between learning and recall, but there is disagreement about the explanation for this effect. According to the trace decay theory of forgetting, the events between learning and recall have no effect whatsoever on recall.  It is the length of time the information has to be retained that is important. The longer the time, the more the memory trace decays and as a consequence more information is forgotten.

If you had asked psychologists during the 1930s, 1940s, or 1950s what caused forgetting you would probably have received the answer “Interference”. It was assumed that memory can be disrupted or interfered with by what we have previously learned or by what we will learn in the future.

This idea suggests that information in long-term memory may become confused or combined with other information during encoding thus distorting or disrupting memories. Interference theory states that forgetting occurs because memories interfere with and disrupts one another, in other words forgetting occur because of interference from other memories.

When we take in new information, a certain amount of time is necessary for changes to the nervous system to take place – the consolidation process – so that it is properly recorded. During this period information is moved from short-term memory to the more permanent long-term memory.

There is evidence that the consolidation process is impaired if there is damage to the hippocampus (a region of the brain). In 1953, HM had brain surgery to treat his epilepsy, which had become extremely severe. The surgery removed parts of his brain and destroyed the hippocampus, and although it relieved his epilepsy, it left him with a range of memory problems. Although his STM functioned well, he was unable to process information into LTM.

Forgetting can be happen because of these things. As students we suffer with this problem many times.

Don’t forget to read more about memory next week!

Everyone forgets (1)