Understanding Memory Decay: Definition and Causes
Forgetting can be frustrating, even embarrassing. But forgetting is important and necessary for everyday functionality. Without it, we might struggle to distinguish between past and present experiences.
Memory decay refers to the fading of memories over time. It explains how our ability to recall information diminishes if we don't use or reinforce those memories. Several factors contribute to this decay, impacting both short-term and long-term memory.
Transience: The Gradual Fading of Memory
Transience refers to the general deterioration of a specific memory over time. It is more evident in short-term memory, which declines with age, leading to difficulties in recall and recognition. It is easier to remember recent events than those further in the past, and the more we repeat or use information, the more likely it is to enter into long-term memory. However, without use, or with the addition of new memories, old memories can decay.
Memory Interference: When Memories Collide
Memory interference occurs when old and new memories impact how well we can recall a memory. This is known as proactive and retroactive interference.
- Proactive interference occurs when old memories hinder the ability to make new memories.
- Retroactive interference occurs when old memories are changed by new ones, sometimes so much that the original memory is forgotten.
Absentmindedness: The Role of Attention
If you’ve ever put down your keys when you entered your house and then couldn’t find them later, you have experienced absentmindedness. Attention and memory are closely related, and absentmindedness involves problems at the point where attention and memory interface. Common errors of this type include misplacing objects or forgetting appointments.
Blocking: The Tip-of-the-Tongue Phenomenon
Occasionally, a person will experience a specific type of retrieval failure called blocking. Blocking is when the brain tries to retrieve or encode information, but another memory interferes with it. Blocking is a primary cause of the tip-of-the-tongue phenomenon. This is the failure to retrieve a word from memory, combined with partial recall and the feeling that retrieval is imminent. People who experience this can often recall one or more features of the target word, such as the first letter, words that sound similar, or words that have a similar meaning.
False Memories: When Memory Distorts Reality
Memory retrieval can also be inaccurate and often leads to false memory. This occurs when people remember events differently from the way they happened or, in the most dramatic case, remember events that never happened at all. False memories can be very vivid and held with high confidence, and it can be difficult to convince someone that the memory in question is wrong.
Physiological Diseases: Impact on Memory Storage
Memory can also be lost due to physiological diseases that interfere with the memory storage system in the body. Dementia is a disorder which causes injury to the brain and can lead to a decrease in mental processes. Alzheimer’s disease is commonly associated with those over the age of 65 and is a deterioration in the memory capacity of an individual in forgetting recent events.
Trace Decay Theory
The trace decay theory of forgetting states that all memories fade automatically as a function of time. Under this theory, you need to follow a certain pathway, or trace, to recall a memory. If this pathway goes unused for some amount of time, the memory decays, which leads to difficulty recalling, or the inability to recall, the memory. Rehearsal, or mentally going over a memory, can slow this process. But disuse of a trace will lead to memory decay, which will ultimately cause retrieval failure.
Amnesia
There are two main forms of amnesia: retrograde and anterograde.
| Type of Amnesia | Description |
|---|---|
| Retrograde Amnesia | Inability to recall past memories. |
| Anterograde Amnesia | Inability to form new memories. |