Memory

Your mind keeps things you learn.

This helps you know your friends. It helps you know yourself.

First, your senses catch things. You see an image or hear a sound. This stays in your mind for a split second.

Next, you use short-term memory. This holds a few things for a little while. You can group things to help you remember.

Then, you use long-term memory. This can store facts for your whole life. It helps you remember your birthday.

Sometimes, it is hard to remember. Pain or damage to the brain can help. We use our minds to learn every day.

Your mind keeps information so you can use it later.

This helps you learn skills and know your friends. Memory works in a few different ways.

First, your senses catch information. This is called sensory memory. It only lasts for a split second. You might have iconic memory, which stores a quick image. You might have echoic memory, which stores a quick sound.

Next, you use short-term memory. This holds a few items for a few seconds. You can use a way called chunking to help. Chunking means grouping items into small sets. For example, you can group digits in a phone number.

Finally, you use long-term memory. This can store many things for a long time. You can remember facts or special events. This is called episodic memory.

Sometimes, memory can be hard to use. Physical pain can make it difficult. Damage to the brain can also change how you remember. The hippocampus is a part of the brain that helps. It helps move things into long-term memory.

Memory is the amazing way our minds keep information. It lets us save data to use for future actions. Without it, we could not use language or build relationships. We would also lose our personal identity.

Memory works like a system that processes information. It has different parts that handle different jobs. These parts include a sensory processor and working memory. It also uses long-term memory to store things for a long time.

Information moves through several steps to be saved. First, sensory memory catches things from the outside world. This happens in less than one second after you see or hear something. For example, iconic memory holds a quick visual image. Echoic memory holds a quick sound.

Next, working memory helps us encode or use that information. It can also pull information from things we already know. Finally, long-term memory stores information using different systems. Some of this is conscious, like remembering a specific fact.

Scientists have studied how these steps work for many years. In 1956, George A. Miller studied short-term memory at Bell Laboratories. He found it could hold about seven items. This led to his famous paper called "The Magical Number 7±2."

George Sperling also did important work in 1963. He used a "partial report paradigm" to study sensory memory. He showed that sensory memory holds about 12 items. However, he found that this memory fades very quickly.

There are many specific ways we remember things. Declarative memory is when we consciously recall data. This includes semantic memory for meanings and episodic memory for events. Episodic memory helps you remember a wedding or a birthday.

There is also implicit memory, which is unconscious. Procedural memory is a type of implicit memory for learning skills. You might learn a skill slowly without even thinking about it. Memory can also be affected by physical things like pain. Damage to the hippocampus can also make it hard to store new memories.

You can use special tricks to help your memory work better. One way is called chunking. This means grouping items into meaningful sets. You can chunk a ten-digit phone number into three smaller groups. This makes the number much easier to remember.

Another way is to think about the deep meaning of something. Thinking about meaning creates a much richer memory trace. It also helps to study in the same place where you take a test. This is called context dependence, and it makes recalling facts easier.

Memory is the mental faculty used to encode, store, and retrieve information. This process allows us to retain data over time to influence our future actions. Without memory, humans could not develop language, maintain relationships, or form a personal identity. Scientists often view memory as an information processing system. This system relies on different stages: a sensory processor, working memory, and long-term memory.

The process begins with the sensory processor. This stage receives chemical and physical stimuli from the outside world. It allows us to attend to information with varying levels of focus. Following this, working memory acts as an encoding and retrieval processor. It takes stimuli and encodes them into either explicit or implicit functions. Working memory also pulls information from previously stored material to help us process the present. Finally, long-term memory functions to store this information through various categorical systems.

Memory is divided into two main types: declarative and non-declarative. Declarative memory, also called explicit memory, involves the conscious storage and recollection of data. This includes semantic memory, which encodes specific meanings, and episodic memory, which records information on a spatial and temporal plane. In contrast, non-declarative or implicit memory involves unconscious storage and recollection. Examples include procedural memory, which is the slow, gradual learning of skills without conscious attention. Another example is priming, where specific responses are subliminally aroused from memory.

Sensory memory is the very first stage of this system. It holds information from the senses for less than one second after perception. This process is an automatic response and is outside of cognitive control. There are three specific types of sensory memory. Iconic memory is a fast-decaying store of visual information. Echoic memory is a fast-decaying store of auditory information. Haptic memory serves as a database for touch stimuli.

Researchers have used experiments to define the limits of these stages. In 1963, George Sperling used a "partial report paradigm" to study sensory memory. He presented subjects with a grid of 12 letters in three rows. He found that while sensory memory capacity was approximately 12 items, it degraded within a few hundred milliseconds. Regarding short-term memory, George A. Miller conducted research at Bell Laboratories in 1956. He famously identified the capacity of short-term memory as 7±2 items. Modern perspectives suggest the limit may actually be lower, around 4 to 5 items.

We can influence how well we remember things through specific methods. One method is chunking, which increases short-term memory capacity. This involves grouping items into meaningful sets, such as breaking a ten-digit phone number into three smaller groups. Another method involves the level of processing. "Deep" encoding, which focuses on meaning, creates richer and more connected memories than "shallow" encoding. Context dependence also plays a role. This principle suggests that remembering is easier when the environment during testing matches the environment during study.

Memory is not a perfect system and can be corrupted by several factors. Physical pain has been identified as a condition that impairs memory in both humans and animals. Additionally, the amount of attention given to new stimuli can reduce how much information is encoded. Physical damage to brain regions like the hippocampus can also corrupt the storage process. Finally, the retrieval of information can be disrupted by decay within long-term memory. Accuracy and capacity are constantly affected by normal functioning, decay, and brain damage.

At a molecular level, long-term memory is a complex biological process. It requires gene transcription activation and the synthesis of new proteins. Research shows that long-term memory depends on activating memory-promoting genes while inhibiting memory-suppressor genes. This dual regulation is achieved through a major mechanism called DNA methylation. In rats, strong long-term memory was linked to the modified expression of 9.17% of the hippocampal genome. This shows that memory is deeply tied to the very instructions within our cells.