Memory is the cognitive process that allows the brain to encode, store, and retrieve information. Although I hope you already think so and I'll tell you anyway, memory is essential for learning and adapting to new situations, and it plays a critical role in daily life. There are several different models of memory, each of which describes a different aspect of the memory process. One influential model, known as the Atkinson-Shiffrin model, proposes models for the ways that memory works. It can be divided into three stages; encoding, storage, and retrieval. 

Encoding is the process of converting sensory information into a form that can be stored in memory. It involves paying attention to the information and transforming it into a meaningful representation.  

• Sensory memory (SM) is the initial stage of memory in which information from the senses is briefly held before it is either forgotten or transferred to short-term memory. The different types of sensory memory are iconic, echoic, haptic, olfactory, and gustatory. 

1. Echoic memory is responsible for holding onto auditory information. For example, if you hear a song and then it stops playing, you may still be able to “hear” the song in your mind for a short period afterward.
2. Iconic memory is the visual counterpart of echoic memory, which is responsible for holding onto visual information. For example, if you are quickly glancing at a photograph, iconic memory allows you to briefly “see” the photograph in your mind even after you’ve looked away.
3. Haptic memory is responsible for holding onto information related to touch and movement. For example, if you were to close your eyes and run your fingers over a rough surface, you would be able to remember the sensation of the rough surface on your fingers even after you stop touching it
4. Olfactory memory is responsible for holding onto information related to smells. For example, if you smell a particular scent, such as the smell of baking cookies, you may be able to remember that smell even after it is no longer present.
5. Gustatory memory is responsible for holding onto information related to taste. For example, if you taste a particularly strong or distinct flavor, such as the taste of a particularly spicy dish, you may be able to remember that taste even after you’ve finished eating.

The second stage, storage, is the process of your brain deciding to hold onto or throw out sensory information you have just received from your environment. The processes involved in storage are short-term memory, working memory, and long-term memory. 

• Short-term memory (STM), is the stage of memory in which information is held for a limited time, about 30 seconds before it is either forgotten or transferred to long-term memory. It has limited capacity and is involved in tasks such as problem-solving, decision-making, and comprehension. Examples of short-term memory include, following a set of instructions, mental arithmetic, and remembering a phone number. Included in short-term memory is working memory, which is responsible for for manipulating information in the mind. Working memory is what you use to accomplish immediate tasks and solve problems.

• Long-term memory (LTM) is the stage of memory in which information is stored for an extended period. Long-term memory has a vast capacity and holds knowledge, skills, personal experiences, and facts accumulated over your lifetime. Long-term memory can be further divided into two main types:

• • Explicit Memory involves conscious recollection and the ability to explicitly retrieve and describe information. It includes episodic memory (personal experiences) and semantic memory (general knowledge and facts). It is also known as declarative memory.
  • Implicit Memory is unconscious and does not require conscious effort for retrieval. It includes procedural memory (skills and routines) and priming (previous exposure influencing behavior without awareness).

Retrieval is the process by which your brain brings stored information back from the subconscious to active use. Retrieval will be talked about in another section of this textbook. 

In addition to these models, there are several different theories of memory, which propose different mechanisms for how memory works. These theories include connectionist models, which propose that memory is based on the strengthening of connections between neurons, and cognitive models, which propose that memory is based on the mental manipulation of information.

Overall, memory is a complex cognitive process that is essential for learning and adapting to new situations. While there are many different models and theories of memory, research in the field continues to provide new insights into how memory works and how it can be improved.