Memory is the cognitive process through which experiences, information, and skills are encoded, stored, and retrieved over time. It allows us to learn from past experiences and use that knowledge to adapt to our environment.
The ways we classify memory have typically been linked to two functions: long-term and short-term. But cognitive psychologists and neuroscientists have worked together to identify and define a wider range of ways in which we gather, store, and recall memories.
Below are 25 of those forms of memory that have been identified through scientific research.
Types of Memory
1. Sensory Memory
Sensory memory is the shortest-lived type of memory. It is the memory that directly relates to our senses: hearing, seeing, touching, tasting, and smelling (Winkler & Cowan, 2005).
The purpose of sensory memory is to retain impressions of sensory information after the original stimulus has ceased. It acts as a kind of buffer for stimuli received through the senses.
A key feature of sensory memory is its short duration. It lasts for a fleeting moment before disappearing, unless attended to (Nicholas, 2008).
This kind of memory is responsible for our ability to remember things like the softness of a puppy’s fur or the aroma of fresh baked bread, even years later.
See Also: Sensory Memory Examples
2. Short-term Memory
Short-term memory refers to memories that last from a few seconds to about a minute. This type of memory facilitates the execution of tasks at hand, like reading a paragraph or performing a calculation (Chai et al., 2018).
Short-term memory keeps information in our minds for a brief period, making it available for quick recall.
This crucial function enables us to process information, whether in work or social environments (Chai et al., 2018; Nicholas, 2008).
However, its capacity is limited. For most people, only about seven items can be held in short-term memory at a time.
See Also: Short-Term Memory Examples
3. Long-term Memory
Long-term memory refers to the system in our brain that stores information for extended periods, from hours to a lifetime (Baddeley, Eysenck & Anderson, 2009; Norris, 2017).
Long-term memory serves as our personal database, storing facts, experiences, and skills we’ve acquired over our lifetimes.
The information held in long-term memory ranges from what we’ve learned at school to the skills we’ve gained through experience, like knitting or playing an instrument.
Long-term memory can be divided into many types, as shown in the following graph:
Unlike short-term memory, there appears to be no limit to how much information can be stored in our long-term memory database, although our ability to recall such memories can fade with age or time (Revlin, 2012).
This longevity and versatility of long-term memory contribute to its essential nature in our cognitive function.
See Also: Long-Term Memory Examples
4. Implicit Memory
Implicit Memory is also known as nondeclarative memory. This type of memory involves recollection that does not require conscious thought. It allows you to perform tasks by rote (Dew & Cabeza, 2011; Glisky, 2017).
Implicit memory, as the name suggests, relates to memories we don’t actively recollect. This type of memory is formed and used unconsciously and can affect thoughts and behaviors.
A subset of long-term memory, this might include learned motor skills, habits, or conditioned associations. Procedural memory, as explained before, is a part of implicit memory (Glisky, 2017).
While implicit memory might not take centre stage in conscious cognition, it significantly influences our daily routines and behaviors.
See Also: Implicit Memory Examples
5. Explicit Memory
Explicit memory involves the conscious recollection of factual information, previous experiences, and concepts. This memory system processes information that you are making a conscious effort to remember (Dew & Cabeza, 2011).
Explicit memory encapsulates the conscious, intentional recollection of factual information, previous experiences, and concepts. In essence, when you ‘try’ to remember something, you’re tapping into explicit memory.
It has two forms- episodic and semantic memory. With explicit memory at work, you can recall that exciting cross-country trip or solve a challenging puzzle.
So, despite its subtle operations, explicit memory plays a foundational role in our cognitive experience.
See Also: Explicit Memory Examples
6. Episodic Memory
Episodic memory refers to the memory of specific events or experiences, remembered along with related details. It allows us to travel back in time to recall these events (Herlitz & Rehnman, 2008; Levy, 2013).
Episodic memory plays a key role in building our unique life stories. It helps us recall that unforgettable vacation or a special birthday party. It places you as a chief character in your narrative, recalling the time, place, and emotional context of these memories (Levy, 2013).
It is a sub-type of both declarative memory and long-term memory (see graph above). It also happens to be similar to flashbulb memory, explained later.
See Also: Episodic Memory Examples
7. Semantic Memory
Semantic memory refers to the capacity to remember facts and general knowledge about the world that we’ve amassed throughout our lives. It takes up the task of storing learned knowledge (Kearns & Lee, 2015; Levy, 2013).
Semantic memory constitutes the ‘fact bank’ in your brain. It provides the information that enables you to answer factual questions, like the capital of France or solving mathematical problems.
It is less about personal experience than episodic memory, but no less important. Working together, each memory type contributes to your overall cognitive function and shapes your unique identity (Kearns & Lee, 2015; Levy, 2013).
Like episodic memory, semantic memory is a sub-type of both declarative memory and long-term memory.
See Also: Semantic Memory Examples
8. Procedural Memory
Procedural memory is a type of long-term memory involving how to perform different actions and skills. Essentially, it’s the “how-to” part of your memory (Votaw, 2020).
Proficiency in a range of activities is possible thanks to procedural memory. From tying shoelaces to playing the guitar to driving, these are all tasks well-managed by your procedural memory subsystem.
Regardless of complexity, what characterizes all procedural memories is their automatic nature. Once a task becomes procedural, carrying it out generally requires very little conscious effort.
Subsequently, procedural memory impinges heavily on areas like talent and skill development, offering a significant cognitive and practical advantage.
See Also: Procedural Memory Examples
9. Declarative Memory
Declarative memory refers to a subtype of long-term memory. It’s the type of memory that we refer to when we consciously recall facts or events (Riedel & Blokland, 2015).
Declarative memory specializes in storing facts about the world and personal experiences. This aids in forming your worldview and supports your understanding.
Importantly, declarative memory has two subcategories: episodic and semantic memory, both mentioned previously in this article.
Consequently, declarative memory forms a crucial part of our memory system and cognitive abilities.
See Also: Declarative Memory Examples
10. Working Memory
Working memory refers to the system that actively holds multiple pieces of transitory information in the mind and manipulates them. It’s where new information is temporarily held (Nicholas, 2008; Spielman, Jenkins & Lovett, 2020).
For example, mental calculations need working memory. Without it, you wouldn’t be able to remember what numbers you’re adding or subtracting.
Just like short-term memory, the capacity for working memory is limited. Nevertheless, it’s instrumental in guiding decision-making and behavior (Nicholas, 2008).
Furthermore, working memory assists in other cognitive functions like learning and reasoning, cementing its crucial role in our cognition.
See Also: Working Memory Examples
11. Autobiographical Memory
Autobiographical memory is a memory system consisting of episodes recollected from a person’s life. It’s not just remembering time, place, and emotion, but also understanding the deeper context (Conway & Rubin, 2019).
Autobiographical memory focuses on personal events and knowledge about one’s self. It combines elements of episodic and semantic memory to create contextualized memories.
The vividness and intensity of autobiographical memories often depend on the emotional significance and personal importance of the events (Conway & Rubin, 2019). Recalling the first day at your job or the birth of your child would count as autobiographical memories.
12. Prospective Memory
Prospective memory involves remembering to perform future intentions and actions at the correct time or in the right context. It’s the art of remembering to remember (Kliegel et al., 2016; Smith, Hunt & Murray, 2017).
Remembering to take your medication, meeting a friend, or even small things like buying groceries on your way back qualifies as prospective memory.
Interestingly, prospective memory is more about remembering to do something rather than recalling something from the past (Kliegel et al., 2016).
It’s a critical aspect of daily life that lets us plan and complete intended actions in the future.
13. Retrospective Memory
Retrospective memory refers to the ability to remember past events, information, and activities. It’s looking back and remembering what happened (Chopik & Edelstein, 2019).
Retrospective memory is the counterpart to prospective memory. It’s about recalling past events rather than thinking ahead.
This memory type contains all memories of the past, such as what you ate for breakfast, your family’s birthdays, historical events, and learned facts. It involves both episodic and semantic memory.
14. Echoic Memory
Echoic memory is a subtype of sensory memory that stores audio information. It deals with auditory stimuli that we either ignore or attend to and process further (Wingfield, 2016).
Echoic memory captures the sounds and words we hear and keeps them fresh in our memories just long enough for us to pay attention and process them.
It’s the reason why you can say “‘Pardon?'”, then answer the question even without anyone repeating it (Wingfield, 2016). The echo of the question remains in your mind for a few seconds – just long enough for you to realize what was asked.
The duration of this type of memory is typically up to a few seconds, allowing us an extra moment to pay attention or recall recent auditory information.
15. Iconic Memory
Iconic memory is a type of sensory memory that pertains to visual information. In other words, it’s how the brain remembers an image after briefly seeing it (Quilty‐Dunn, 2020).
Iconic memory handles the brief ‘snapshot’ of what you’re seeing at any moment. It’s why, after seeing an image for just a fraction of a second, we can still visualize it even after it’s gone (Quilty‐Dunn, 2020).
This fleeting memory helps create a sense of continuity in the visual world. Even though our eyes dart to various points of interest, iconic memory assists us in maintaining a stable and continuous perspective.
16. Spatial Memory
Spatial memory is a cognitive process that allows us to remember different locations and relate objects to those locations. It’s your mind’s internal GPS (Olton, 2018).
Spatial memory allows us to recall where we’ve left our keys or parked our car. When you navigate your way through familiar surroundings, whether mundane like your house or complex like your city, that’s spatial memory at work.
Spatial memory provides not just a mental snapshot of our surroundings but also a dynamic model that we continually update as we move and experience changes in our environment (Olton, 2018).
17. Associative Memory
Associative memory is a type of memory that connects various pieces of information together. It’s about linking different bits of information, creating a web of associations.
Associative memory aids your mind in making connections between seemingly unrelated items. For example, hearing a particular song might remind you of a specific moment in your past because your mind has associated the two.
This type of memory plays an essential role in learning and enables us to understand and interpret complicated concepts by relating them to something familiar.
18. Muscle Memory
Muscle memory, more formally known as motor learning, is a form of procedural memory that helps our bodies to remember how to perform specific tasks, like riding a bike or typing on a keyboard (Sharples & Turner, 2023).
Muscle memory is responsible for the ease with which you can get back into the rhythm of activities even after years of disuse (Sharples & Turner, 2023). It maintains learned motor skills and allows you to perform them without conscious effort.
Once actions become part of muscle memory, they’re ingrained in our minds at such a level that they seem instinctive and natural instead of acquired or learned, making this an essential tool for both general functioning and specific skill acquisition.
19. Tactile Memory
Tactile memory involves how your brain retains and recalls information about touch sensations, including texture, size, and temperature. It’s remembering what something feels like (Gallace & Spence, 2020).
If you’ve ever identified an object just by touch, you have your tactile memory to thank. It’s this memory system that allows you to remember how soft your favorite blanket is or the feel of a cat’s fur under your fingertips.
Tactile memory provides essential context to our interaction with the world, as it helps us understand and recall the way things feel, contributing depth and detail to our memories.
20. Olfactory Memory
Olfactory memory is the recollection of odors (Sullivan et al., 2015). Humans can remember smells with 65% accuracy after a year, making it a particularly potent form of memory.
In practice, certain odors can trigger vivid memories. For example, the smell of fresh-baked cookies might bring back memories of baking with your grandmother during your childhood (Sullivan et al., 2015).
This distinct form of memory is strongly tied to emotions and emotional memory, largely because the olfactory system is connected to the limbic system, an area of the brain heavily involved in experiencing emotions.
21. Flashbulb Memory
A flashbulb memory is a highly detailed snapshot of a moment or circumstance in which particularly surprising or emotionally arousing news was heard. It’s the memory that freezes a moment in time in great detail (Brown & Kulik, 1977; Hirst & Phelps, 2016).
Flashbulb memories encapsulate moments of high emotional impact or significance. They are vivid and detailed, almost as if the mind took a high-resolution snapshot of a moment (Hirst & Phelps, 2016).
Interestingly, despite their vividness, flashbulb memories aren’t infallible and can be influenced and distorted over time, just like any other memories.
See Also: Flashbulb Memory Examples
22. Recognition Memory
Recognition memory is the ability to identify information that you encountered previously. It’s your ability to recognize something you’ve experienced before.
Recognition memory allows you to judge whether you’ve seen a particular face, object, word, or picture before. It’s what allows you to identify a friend in a crowd or notice an unusual object in your normal surroundings.
Recognition memory is a vital part of human cognition, underpinning other functions like learning and episodic memory.
23. Recall Memory
Recall memory is the mental process of retrieval of information from the past. Unlike recognition memory, which involves identifying previously learned information, recall involves reproducing the information without any specific cues.
Recalling details about an event you attended last week, retrieving scientific facts for a test, or remembering the name of an actor in your favorite movie are all examples of recall memory in action.
Recall is a fundamental component of cognition and is involved in tasks from basic navigation through spatial environments to complex problem-solving and planning.
24. Source Memory
Source memory is a specific form of memory that relates to recalling the origin or source of a remembered fact, concept or event. It’s remembering where or when you learned something.
For example, you might remember a fact about dolphins (semantic memory), but also remember that you learned it during a visit to the aquarium (source memory).
Source memory is what allows you to discriminate between real experiences and information you’ve thought, heard, or inferred. It provides context to your memories, making them richer and more detailed.
25. Priming Memory
Priming memory, or just ‘priming‘, is an unconscious form of memory that aids in identifying objects or words based on previous exposure to similar stimuli. It’s your brain predisposing you to choose or recognize a certain object or word.
Priming is not conscious, meaning you can be primed to think about something due to your environment without even realizing it.
For example, if you saw the word ‘yellow’, you would be slightly quicker to recognize the word ‘banana’ in a subsequent test. This happens because ‘yellow’ and ‘banana’ are closely associated in your memory.
Priming memory demonstrates how our neural connections can be ‘prepared’ to react in particular ways based on prior encounters, allowing for quicker information processing.
References
Baddeley, A., Eysenck, M. W., & Anderson, A. C. (2009). Memory. New York, NY: Psychology Press.
Brown, R., & Kulik, J. (1977). Flashbulb memories. Cognition, 5(1), 73-99.
Chai, W. J., Abd Hamid, A. I., & Abdullah, J. M. (2018). Working memory from the psychological and neurosciences perspectives: a review. Frontiers in psychology, 9, 401.
Chopik, W. J., & Edelstein, R. S. (2019). Retrospective memories of parental care and health from mid-to late life. Health Psychology, 38(1), 84.
Conway, M. A., & Rubin, D. C. (2019). The structure of autobiographical memory. In Theories of memory (pp. 103-137). Psychology Press.
Dew, I. T. Z., & Cabeza, R. (2011). The porous boundaries between explicit and implicit memory: behavioral and neural evidence. Annals of the New York Academy of Sciences, 1224(1), 174–190. https://doi.org/10.1111/j.1749-6632.2010.05946.x
Gallace, A., & Spence, C. (2020). A memory for touch: The cognitive psychology of tactile memory. In Touch in Museums (pp. 163-186). Routledge.
Glisky, E.L. (2017). Implicit Memory. In: Kreutzer, J., DeLuca, J., Caplan, B. (Eds) Encyclopedia of Clinical Neuropsychology. Springer, Cham. https://doi.org/10.1007/978-3-319-56782-2_1129-3
Herlitz, A., & Rehnman, J. (2008). Differences in episodic memory. Current Directions in Psychological Science, 17(1), 52–56.
Hirst, W., & Phelps, E. A. (2016). Flashbulb memories. Current Directions in Psychological Science, 25(1), 36–41. https://doi.org/10.1177/0963721415622487
Kearns, T., & Lee, D. (2015). General psychology: an introduction. Georgia: University System of Georgia.
Kliegel, M., Ballhausen, N., Hering, A., Ihle, A., Schnitzspahn, K. M., & Zuber, S. (2016). Prospective memory in older adults: Where we are now and what is next. Gerontology, 62(4), 459-466.
Levy, J. (2013). Psychology: The Science of Human Potential. British Columbia: University of British Columbia.
Nicholas, L. (2008). Introduction to Psychology. Cape Town: UCT Press.
Norris, D. (2017). Short-term memory and long-term memory are still different. Psychological Bulletin, 143(9), 992.
Olton, D. S. (2018). Characteristics of spatial memory. In Cognitive processes in animal behavior (pp. 341-373). Routledge.
Quilty‐Dunn, J. (2020). Is iconic memory iconic?. Philosophy and Phenomenological Research, 101(3), 660-682.
Revlin, R. (2012). Cognition: Theory and practice. New York: Macmillan.
Riedel, W. J., & Blokland, A. (2015). Declarative memory. Cognitive Enhancement, 215-236.
Sharples, A. P., & Turner, D. C. (2023). Skeletal muscle memory. American Journal of Physiology-Cell Physiology, 324(6), C1274-C1294.
Smith, R. E., Hunt, R. R., & Murray, A. E. (2017). Prospective memory in context: Moving through a familiar space. Journal of Experimental Psychology: Learning, Memory, and Cognition, 43(2), 189.
Spielman, R. M., Jenkins, W., & Lovett, M. (2020). Psychology 2e. Texas: RICE University.
Sullivan, R. M., Wilson, D. A., Ravel, N., & Mouly, A. M. (2015). Olfactory memory networks: from emotional learning to social behaviors. Frontiers in behavioral neuroscience, 9, 36.
Votaw, K. (2020). General Psychology for Honors Students. California: UC Davis.
Wingfield, A. (2016). Evolution of models of working memory and cognitive resources. Ear and hearing, 37, 35S-43S.
Winkler, I., & Cowan, N. (2005). From sensory to long-term memory: evidence from auditory memory reactivation studies. Experimental Psychology, 52(1), 3-20.
Appendix
Description Of Long-Term Memory Image
Top Level Heading: Long-term Memory
Sub-Category 1: Explicit Memory (conscious effort)
Types of Explicit Memory: Semantic Memory (facts and general knowledge) and Episodic Memory (events and experiences)
Sub-Category 2: Implicit Memory (without conscious effort)
Types of Implicit Memory: Procedural Memory (motor skills) and Priming (enhanced activation)
Dr. Chris Drew is the founder of the Helpful Professor. He holds a PhD in education and has published over 20 articles in scholarly journals. He is the former editor of the Journal of Learning Development in Higher Education. [Image Descriptor: Photo of Chris]