Persistence of Memory, Salvador Dali, 1931

‍‍‍‍Basics of Memory‍‍‍‍

Memory is the ability to encode, store, and retrieve information.
Encoding - perceiving information and transforming the data so that it may be stored in long term memory.
Storage - Creating a record of information.
Retrieval - Recalling information that has been stored in memory.

Types of Memory

‍‍‍‍Sensory memory - very short term memory that registers that are specific to individual senses. Lasts roughly 2 seconds‍‍‍‍.
Short term memory - Limited capacity memory store that is used as a work station for processing information. Lasts roughly 30 seconds.
Long term memory - Unlimited capacity memory storage that helps process new memories and retrieve old mei reamories.

‍‍‍‍What Develops?‍‍‍‍
Memory development over the lifespan increases through efficiency. The infant brain begins by having far too many neurons and virtually unlimited paths for memory development. The process of removing these unused or unneeded neurons is called ‍‍‍‍pruning‍‍‍‍. ‍‍‍‍In physiological studies of the human brain infants have been shown to have 41% more neurons that the adult brain ‍‍‍‍(Abitz et al. 2007).
‍‍‍As the child learns to make connections to things or people in their environment they develop easier ways to remember what they have experienced. As the human learns to categorize information the process becomes much quicker. When new stimuli is experienced in the environment, it can be more easily stored if it is comparable to something that has already been experienced. The new stimuli can be added to the repertoire of memories‍‍‍.

As the child grows and learns how to develop new memories, new simple pathways are created. Long term potentiation is a term that describes building new pathways to form new future memories. Just as pruning reduces the overall possible connections, long term potentiation creates a simplified path for new specific memories. For example if a new visual memory of seeing a bird fly fits reminds you of seeing something else fly in a similar way, your brain will take a similar path to creating the new memory that is reminiscent of the original memory.

The shortcuts mentioned above are just a few ways that memory has been shown to develop and become more efficient. Memory is a vast and complicated cognitive process that is still quite mysterious to many researchers. Pruning for instance was merely conceptual until 2007 where research showed that the infant brain actually contained a much larger amount of neurons in the brain than adults. New physiological studies have advanced the field of memory substantially over the past few decades and will no doubt continue to do so.

Pruning - Overall reduction of neurons during early childhood.
Long Term Potentiation - new pathways or shortcuts are created to form new memories.

‍‍‍Models of Memory‍‍‍

  • Atkinson-Shiffrin Memory Model
    • ‍‍‍‍Multi-store model that breaks memory into all forms.
    • Breaks down memory into a time frame sequence
    • Depicts how forgetting occurs
    • Explains how short-term memory is transferred to long term memory through a process called rehearsal.‍‍‍‍

  • Baddeley's Model of Working Memory Model
    • Model of short term memory
    • Made of three components:
      • ‍‍‍Central Executive‍‍‍: system that controls the flow of information
      • Phonological loop: information gathered through language or auditory processes
      • Visuo-spatial Sketchpad: Information gathered through visual-spatial processes
    • The model is widely utilized and studied which indicates it's relevance to memory development as well as its validity and reliability.
  • ‍‍‍Memory Prediction Framework‍‍‍
    • Sensory information is stored in memory through patterns.
    • Predicts how information will be processed in the future.
    • Created through the observation of brain similarities and structures.
    • Focuses on the cortex, hippocampus, and thalamus in the process of memory retention and retrieval.


When studying individuals with differing demographic variables (i.e. socioeconomic status, gender) within the United States, all significant differences in working memory (within these three articles) were attributed the differences in socialization and motivation. The influence of socialization was further explored in Wang et al.’s study where she found that socialization and culture influenced children’s accounts of past events and description of self.

Cultural backgrounds and heritages influence what each individual remembers about situations, other people and oneself. In one study conducted by Wang in 2004, American and Chinese children were asked to describe themselves and their last birthday. ‍‍American children were significantly more likely to focus on self and give highly positive descriptions of self. Chinese children were significantly more likely to focus on self as a part of the group and give neutral descriptions of self. ‍‍One possible flaw in this article is the differences in socially desirable behavior may have influenced the children's verbal description of themselves and their birthday.


Colley et al. asked males and females to recall a list of items that were to be purchased. The list of items were identical, but half the participants were told the items were to be purchased at a grocery store and the other half of the participants were told the items would be purchased at a hardware store. The participants were then asked to recall what items had been on the list. Males significantly outperformed females on the hardware list while females significantly outperformed males on the grocery list. The authors speculated that the difference was due to motivation and an individual’s personal expectation for recalling more items or fewer items.

Socioeconomic Status
Six and seven year old children were matched in age, gender and non-verbal ability; half of the children had a lower socioeconomic status and half had a higher socioeconomic status. While significant differences existed in verbal communication and vocabulary, no significant differences existed in working memory.


Empiricism (17th-19th century‍)

Empiricism is “the view that sensory experiences are the only ultimate source of knowledge and truths about the world” (Bower, 2000). Empiricism stated that one’s impression of objects within the world was merely a collection of sensory experiences (sight, sound, smell, texture) called ‍constellations‍. For example, one would gain an impression of a cup based on its color, shape, size, weight, and texture. For the empiricist, the study of memory was the study of the formation of these constellations. Prominent empiricist philosophers such as ‍John Locke, John Stuart Mill and Thomas Brown‍ theorized that the association by contiguity was the process by which constellations were learned. Association by contiguity stated that constellations and memories were formed by grouping sensations that were experienced concurrently. So, the constellation off the cup would be formed by viewing the cup’s size, shape and color while feeling its weight and texture and tasting the liquid/substance within the cup. Locke, Mill and Brown recognized that some associations were stronger than others due to specific factors associated with the original experience of the object such as the duration of experience, interest of the individual with the object and whether the individual had repeated contact with the object.

Behavioralism (Early 20th century)
As Behavioralism became more prevalent, the Empiricist theories of Association by Contiguity were adopted by Behavioralists as they began studying behavioral changes due to
Hermann Ebbinghaus
stimuli in the environment. Ivan Pavlov and Edward Thorndike were two of the earliest Behavioralists to study learning and memory while researching conditioned responses and “trial-and-error” learning, or stimulus learning.

Ebbinghaus and Rote Learning (Late 19th century- Early 20th century)
Ebbinghaus fused the Association by Contiguity and Behavioralist perspectives. Ebbinghaus greatly influenced the study of learning and memory. In 1885, he published Memory: A Contribution to Experimental Psychology where he discussed his studies on difficulty of learning and forgetting. He created the forgetting curve, the amount of time it takes an individual to forget, and the learning curve, the amount of time it takes to
Ebbinghaus' Learning Curve

learn information. Ebbinghaus’s revolutionary ideas jump-started the study of memory, as very little had been published on learning and memory.

Rote Learning is composed of serial learning, paired-association learning and skill learning. Serial learning is the process of learning to place letter, numbers or other objects in a correct sequence. Paired-association learning is the process of linking two units together. For example, a child may learn that a cow says “moo.” The child has paired two distinct units or items together. Skill learning is composed of perceptual-motor skill learning (learning basketball, how to type or play music instruments) and cognitive skill learning (learning to play chess, edit a paper or prove a geometry theorem).

Cognitive Psychology (Beginning in the 1950s)
Cognitive theories of learning and memory, such as the Information Processing Theory and Computer-Based theories, such as Connectionism, began to emerge. For more information on the Information Processing Theory and Connectionsim, please visit their wiki pages.

Implications & Relevant Developmental Outcomes
  • Memory development is critical to an individuals functioning related to their outside world. Without the development of memory or memory processes, individuals would not have the capacity to maintain/understand language, utilize motor functioning or remember factual information. Due to this, memory development has been a large component of psychological research because it pertains to all individuals.
  • Memory development is constant. Memories are retained everyday regarding information that is both meaningful, and non-meaningful. Information such as colors of clothing or specific individuals habits can be retained depending on what individuals attend to.
  • Memory retention and the development of exception memory is a booming industry, and has become a large money making strategy, targeting parents of young, school aged children.

  • Advertisements both on screen and on the radio are utilized to make individuals remember their product when they are in the stores. Items like Dr. Pepper and their current add, often trigger distinct memories and facilitate reactions.


‍‍‍‍Outcomes of performance (Memory Disorders)‍‍‍‍

  • **Alzheimers**: degenerative disorder of the brain which causes dementia. Dementia, when progressed to a certain state results in memory loss and confusion. Individuals with this disorder often have loss of abstract thinking, disorientation, lack of initiative, and language problems. Individuals in the early onset of Alzheimer's disease often find themselves misplacing items, having rapid mood swings and severe personality changes, which can often result in poor judgment.
  • Corticobasal Degeneration: Rare disease that occurs neurologically which results in a swift brain degeneration. Individuals often loose brain tissue in the frontal cortex, which is active in decision making processes. Early signs of corticobasal degeneration is loss of balance, short term memory problems, difficulty controlling muscles and eventual speech difficulties.
  • Creutzfeldt-Jakob Disease: rare fatal brain disorder, caused by an infection. Early stages of this disorder can be seen as mental health concerns such as depression, insomnia and behavioral/personality changes.
  • Amnesia: Memory loss that is stemmed from psychological or physiological reasons. There are two types of amnesia, Antereograde (inability to form new memories) and Retrograde (inability to remember old memories).

Strengths and Weaknesses

There is a lot of consistent research (including current research) on the development of memory as related to different aspects of the human conditions (attachment, gender, and early childhood experiences)
Memory can easily be altered or fabricated which makes accurate memory analysis difficult, especially when conducting studies regarding memories/events that have occurred in the distant past.
Types of Memory
Different types of memory (i.e. episodic memory, short term memory and long term memory) are thoroughly explained and researched.
There is still not definitive understanding of specific memory faults, such as infantile amnesia (the inability to remember information prior to a specific age, normally prior to the ages of 5 or 6).
Memory Models
The working memory model, depicted below, is widely used and common in the study of memory and cognition. It accurately depicts the relationship between visual and auditory information and its relationship to the brain's central functioning.
There is no one specific memory model that depicts all the different aspects of memory, including the ability for memory to be altered or fabricated. Most models either facilitate brief instances of memory retention, such as the working memory model, or understanding memory retention in those with memory deficits (i.e. amnesia). The same memory models are also depicted in a lot of different ways which can reduce reliability and validity.
Memory research can be easily related to all individuals. Although memories are different between cultures, generations, and individuals alike. Memory allows individuals to progress, by understanding their past, while giving them the ability to function in their present. Without memory individuals would have difficulty remembering language, motor skills and critical information.
Memory acuteness can vary between individuals and can be difficult to assess. There are various individual differences on what individuals pay attention to, ergo it is plausible that two people watching the same event can remember two completely different scenarios.

Additional Articles

Forbes et al. conducted a meta-analysis of 187 different studies on individuals with Schizophrenia and working memory (2009). They found that individuals diagnosed with Schizophrenia were significantly more likely to have poorer phonological, visuospatial and central executive working memory than individuals who were not diagnosed with Schizophrenia.

Lyons et al. found that as age increased, the participants became significantly more likely to have backward causal-inference errors (2010). In other words, as age increased, participants were far more likely to report remembering having viewed the cause of an effect when the participants did not view the cause.

D‍‍‍‍amme et al. provided a combined approach of cognitive theory and neuropsychology to the study of false memory (2009).‍‍‍‍ Damme et al.’s results indicated there was no significant deficit in encoding in participants with amnestic disorders. Rather, their results indicated the participants with amnestic disorders were significantly more likely to have a lessened capacity to retrieve memories.

Howe et al. conducted a series of studies on the relationship of age with true and false memories (2009). They found that both true and false memories increased with age, and a decrease in false memories was correlated with an increase in backward associative strength.


Abitz, Damgaard et al. (2007) Excess of neurons in the human newborn mediodorsal thalamus compared with that of the adult, Oxford, Oxford Journals