L4: Better phrasing for an essay Flashcards
defining memory
Memory is the ability to store and retrieve information over time, forming the foundation of our learning, decision-making, and personal identity. Despite its importance, memory is also remarkably fragile, susceptible to distortion, interference, and decay.
At the core of understanding human memory are several fundamental concepts, including the structure of memory, the processes of remembering, forgetting, and the strategies involved in memorisation.
multistore memory model
The Modal Model of Memory, proposed by Atkinson and Shiffrin in 1968, is one of the most influential frameworks for understanding how information is processed and stored in the human mind. It outlines a linear flow of information through three distinct memory stores: sensory memory, short-term memory (STM), and long-term memory (LTM).
The process begins with sensory input — information we receive from the environment through our senses (e.g., hearing a lecturer speak, seeing slides during a presentation). This information first enters the sensory memory, which is a very brief store that holds raw, unprocessed sensory information for a fraction of a second. Only the information that receives attention moves forward in the system. Information that is not attended to is quickly lost and does not proceed to the next stage.
Once attended to, information passes into short-term memory, which acts as a temporary workspace where information can be held and manipulated for a short period of time. Short-term memory has limited capacity and duration. If the information is not actively rehearsed, it is likely to be forgotten. However, through rehearsal or meaningful processing, the information can be encoded and transferred into long-term memory.
Long-term memory serves as a more permanent store with a theoretically unlimited capacity. Some information in long-term memory can be retrieved back into short-term memory when needed. However, it’s important to note that even within long-term memory, some information may be lost over time, either through decay, interference, or retrieval failure.
sensory memory
Sensory memory is the first stage of the memory process, responsible for briefly holding incoming sensory information from the environment. This type of memory acts as a buffer that retains raw sensory data just long enough for the brain to process and determine whether it should receive further attention.
A landmark experiment that explored visual sensory memory was conducted by George Sperling (1960). In his Iconic Memory Test, participants were briefly shown a grid of letters for just 1/20th of a second and then asked to recall them. On average, participants were only able to report about half of the letters shown.
Sperling proposed two hypotheses to explain this partial recall:
Insufficient encoding time – participants did not have enough time to process all the letters before the display disappeared.
Rapid forgetting – participants did manage to encode the full display, but the information faded too quickly to be recalled.
To test this, Sperling introduced a selective retrieval technique using auditory tones. After the letter grid was displayed, a high-, medium-, or low-pitched tone indicated which row of the grid participants should recall (top, middle, or bottom respectively). When the tone was presented immediately after the display, participants were able to recall nearly all of the letters in the cued row — suggesting that they had encoded the entire visual array, but the information quickly decayed before they could access all of it.
This supported the second hypothesis: iconic memory, or visual sensory memory, holds a complete image of the visual input for a brief moment before it fades, usually within less than a second. In contrast, echoic memory — the auditory form of sensory memory — can last a bit longer, typically around five seconds.
Sperling’s study demonstrated that sensory memory has a large capacity but an extremely short duration, and that selective retrieval mechanisms (like cueing with tones) can help access information before it vanishes.
stm
Short-term memory (STM) is the stage of memory where information is held temporarily for processing. While it allows us to actively manipulate and use information, it is also highly fragile—easily lost unless deliberately rehearsed. This aspect of STM was demonstrated in a classic experiment by Peterson and Peterson (1959).
In their study, participants were presented with three-letter nonsense strings (e.g., “DBX” or “HLM”) and instructed to memorise them. Immediately after seeing each string, they were given a distractor task—counting backwards from 100 in steps of three—for varying amounts of time (e.g., 3, 6, 9, 12, 15 seconds). This task was used to prevent rehearsal of the letters.
The results showed a rapid decline in recall accuracy as the delay increased. After just 18 seconds, participants remembered very few of the letter strings. This finding provided strong evidence that short-term memory, when not rehearsed, decays quickly—typically within 15 to 30 seconds.
Quick Notes Version
Short-term memory (STM) = temporary storage; info is lost if not rehearsed
Peterson & Peterson (1959):
Participants memorised 3-letter trigrams (e.g., DBX)
Then counted backwards from 100 by 3s (distractor task)
Delays varied (3, 6, 9…18 sec)
Result: recall decreased rapidly as delay increased
STM duration ≈ 15–30 sec without rehearsal
One important process that helps retain information in short-term memory (STM) is rehearsal—the mental repetition of information to keep it active and prevent it from fading. Without rehearsal, items in STM tend to be forgotten within a short period.
Research by George Miller (1956) famously proposed that the average capacity of STM is about seven meaningful items, a concept known as the “magical number 7, plus or minus 2.” This means that most people can hold between 5 and 9 chunks of information at once. However, this doesn’t necessarily mean 7 individual letters or numbers—through a strategy called chunking, people can group individual bits of information into larger, meaningful units (e.g., turning “1 9 4 5” into the year “1945”).
Although chunking can significantly enhance memory efficiency, the total number of chunks a person can hold at one time still appears to be limited to around seven, showing that STM has both a capacity and duration limit.
wmm
Working memory (Baddeley and Hitch, 1974; Baddeley, 2000) refers to the system that manipulates and maintains information in short-term storage. It’s an attentional system responsible for coordinating and controlling the different types of information being processed.
Central Executive: This is the attentional system that coordinates and controls plans of action and output. It decides what tasks to focus on, allocates attention, and switches between tasks. Its effectiveness is determined by the attentional span, which affects how well the system manages coordination and prioritization of tasks.
Visuospatial Sketchpad: This system briefly stores visual and spatial information, allowing you to manipulate and visualize things like shapes, locations, and spatial arrangements. It handles tasks related to “seeing” and moving objects mentally.
Phonological Loop: This part lets you repeat information to yourself (articulatory rehearsal). It stores verbal and auditory information and helps you rehearse and maintain it in working memory, like when you repeat a phone number to remember it.
Episodic Buffer: This serves as a temporary storage space where information from long-term memory can be integrated into working memory. It allows the combination of different types of information (visual, verbal, spatial) to create a coherent experience or understanding of events.
Separation evidence comes from dual-task interference studies. These studies show that when two tasks are performed at the same time, they can interfere with each other. If there’s interference, we’ll see a drop in performance on at least one of the tasks.
For example, in an experiment, participants might be asked to trace a route on a map while performing a secondary visuospatial task, like drawing a circle with the other hand. The second task (the circle drawing) would disrupt the main task (tracing the route), showing that the visuospatial system has limited resources and can only handle so much at once.
This evidence suggests that different components of working memory (like the visuospatial sketchpad) are separate systems because they can be disrupted independently by different tasks.
ltm
Long-term memory is distinct from short-term memory in two important ways: duration and capacity
Long-term memory can last for lifetime and has no known capacity limits
Henry Gustav Molaison, aka H.M.
His hippocampus and some surrounding regions are removed
Can converse normally but can’t form new memory after the operation
Encoding: the process whereby information pass from short-term memory into long-term memory to be remembered
The case of HM (Henry Molaison) provides evidence for the distinction between short-term and long-term memory systems. HM’s case shows that these memory systems can function separately, where one system can be intact while the other is non-functional.
HM had a short-term memory span, meaning he could remember information for a brief period, but his encoding process was disrupted. This meant that although he could hold information in his short-term memory for a short time, he couldn’t encode it into long-term memory. His ability to transfer information from short-term memory to long-term memory was impaired, even though his short-term memory itself was intact.
This suggests that short-term memory and long-term memory rely on different systems in the brain, and damage to one system (in HM’s case, his hippocampus) can leave the other functional.
memory formation
Memory formation involves three fundamental processes: encoding, storage, and retrieval. Encoding refers to the process by which we transform experiences—what we perceive, think, or feel—into an enduring memory trace. One classic study illustrating encoding was conducted by Bartlett (1932). In this experiment, participants were asked to read a Native American folktale called The War of the Ghosts and then recall it later. While the general gist of the story was often retained, participants tended to fill in missing details with what seemed logical or familiar to them—information that matched their own cultural schemas and worldview. This showed how memory is reconstructive and not a perfect record of experience.
Once encoded, information must go through storage, the process of maintaining memory over time. Lastly, retrieval is the act of bringing stored information back into conscious awareness. These three processes vary in difficulty depending on the type of memory. Some memories are easy to encode and retrieve, while others may be more fragile or harder to access. Understanding the interaction between these stages helps explain why we remember some things vividly and forget others entirely.
schemas
Schemas are mental models or frameworks we use to organize and interpret information about the world. They contain knowledge and expectations that help us encode new information by placing it into a meaningful context. For example, our cultural background can influence how we interpret information. In a study where Native American stories were told, people from a Western context often misinterpreted the stories because their own schemas (based on Western culture) shaped their understanding, leading to distortions in memory.
Schemas can distort memory because they encourage us to fit new information into existing mental frameworks. This means that when we try to remember something, we might modify or “fill in” details to make the new information align with what we already know or expect, even if those details weren’t actually part of the original experience.
In essence, memory is constructed, not simply recorded. We combine old information (our existing knowledge) with new information (what we experience) to form our memories. This process of blending and interpretation means that memories are not perfect, and they can be shaped by our prior knowledge and expectations
elaborative encoding
Elaborative encoding refers to the process of actively linking new information to knowledge already stored in memory. This technique enhances long-term memory by integrating new material with meaningful context. A foundational study exploring this concept was conducted by Craik and Tulving (1975), who proposed the Levels-of-Processing (LOP) theory. According to this theory, the depth at which information is processed affects how well it is remembered.
In their study, participants were given words like hat and asked to process them in one of three ways. The deepest level of processing involved semantic judgment, where participants decided whether a word belonged to a certain category (e.g., “Is a hat a type of clothing?”). This task required accessing prior knowledge, thus involving more meaningful cognitive effort.
A second group engaged in rhyme judgment—a shallower form of processing. For example, they were asked, “Does hat rhyme with cat?” This required less prior knowledge and weaker semantic associations. Finally, the shallowest level involved visual judgment, such as determining whether a word was written in uppercase or lowercase letters. This type of encoding required minimal cognitive processing and no semantic understanding.
Craik and Tulving found that memory performance increased with the depth of processing. Words processed semantically were recalled most accurately, followed by rhyme-based processing, and then visual processing. This supports the idea that deeper, more meaningful engagement with information leads to better memory retention.
visual imagery encoding
Visual imagery encoding is a memory process in which new information is stored by converting it into mental images. This technique enhances memory by leveraging the brain’s strong visual and spatial capabilities. By turning abstract information into vivid images, we are more likely to retain and recall it.
A key study in this area was conducted by Wollen, Weber, and Lowry (1972). They found that creating mental images where objects interacted significantly improved memory retention—even when the images were strange or unrealistic. For example, participants remembered a cigar smoking a piano (an image both bizarre and interactive) just as well as a cigar resting on a piano (interactive but not bizarre). Interestingly, bizarreness alone was not enough to enhance memory; it was the interaction between objects that made the difference. Non-interacting images, even if bizarre (e.g., a piano peeling open with a cigar nearby), were less effective for memory.
One popular technique that builds on this idea is the Method of Loci. This is a memory aid (mnemonic) that involves associating pieces of information with specific locations in a familiar setting—such as rooms in your house or landmarks along a street. During recall, a person takes a “mental walk” through these familiar locations, retrieving the associated information.
The Method of Loci is effective for several reasons:
It combines old knowledge (familiar places) with new information, creating stronger mental associations.
It engages multiple modalities—visual, spatial, and sometimes emotional—making the memory richer and more retrievable.
It supports elaborative encoding, where deeper cognitive processing improves memory.
For example, to remember to buy milk, you might imagine your house flooded with milk. The striking image, paired with a familiar place, strengthens your ability to recall the information later.
Overall, visual imagery encoding—especially when combined with interaction or spatial strategies like the Method of Loci—serves as a powerful tool for boosting memory and recall.
organisational encoding
Organisational encoding is the process of improving memory by categorising information based on the relationships between items. This technique allows people to store and recall information more efficiently by structuring it in a meaningful and logical way.
A study by Stevens (1988) demonstrated organisational encoding in a real-world setting. Researchers observed how waiters and waitresses remembered customer orders without writing them down. The participants were asked to think out loud while taking and processing orders. The findings revealed that as soon as the servers left the table, they mentally grouped orders into categories such as hot drinks, cold drinks, hot food, and cold food. They also structured the sequence of these items to match the layout of the kitchen—placing drink orders first, followed by hot food, then cold food. This strategic categorisation helped them remember the orders more accurately and deliver them more efficiently.
A common tool that uses organisational encoding is a mnemonic device. Mnemonics help structure and simplify complex or unrelated information into memorable patterns, such as acronyms, rhymes, or visual images. One popular example is the mnemonic:
“Richard Of York Gave Battle In Vain”,
which represents the colours of the rainbow:
Red, Orange, Yellow, Green, Blue, Indigo, Violet.
Mnemonics make information more meaningful and easier to recall by leveraging structure, imagery, and association, all of which are central to the process of organisational encoding.
survival
Charles Darwin proposed that memory should be particularly good at preserving information that is relevant for survival, as this would be essential for adapting to the environment.
In a study by Nairne et al. (2007), they compared three types of encoding tasks:
Survival encoding: How relevant each item would be for survival.
Moving encoding: How useful each item might be for setting up a new home.
Pleasantness encoding: How pleasant each word seemed.
The results showed that survival encoding led to the highest recall performance, meaning that people remembered survival-related information better than the other types of information.
Further analysis indicated that the superior memory performance for survival encoding was not due to differences in relevance or response time—meaning that survival-related items weren’t necessarily more relevant or quicker to respond to than the others.
However, the study also found that, across all three conditions (survival, moving, pleasantness), there was a trend of better recall for survival-related items, though not always in the same exact pattern or circular way across all participants. This suggests that survival-related information might have a special advantage in memory, regardless of other factors.
retrieval
Recognition: the capacity to correctly match information presented with the contents of memory
E.g., have you seen ‘method of Loci’ in this lecture?
Recall: the capacity to spontaneously retrieve information from memory
E.g., what was the method about using the locations of mental imageries?
Retrieval cues: external information that is associated with stored information and help brings to mind
Encoding specificity principle: a retrieval cue can serve as an effective reminder when it helps re-create the specific way in which information was initially encoded (Tulving & Thomson, 1973)
State-dependant retrieval: the tendency for information to be better recalled when the person is in the same state during encoding and retrieval
Godden and Baddeley (1975): divers’ memory test
Recalling the list of words in the same state as encoding increase the memory performance (e.g., encode underwater – recall underwater)
Persons physiological state and and psychological state and time of encoding associated with info being encoded
State itself can serve as memory cues.
TAP
Transfer-appropriate processing (TAP) suggests that memory is more likely to transfer successfully from one situation to another when we process information in a way that matches the retrieval cues that will be available later. In other words, how we encode the information (e.g., by thinking about its meaning, its sound, etc.) should align with the type of question or cue we will use to retrieve it later. Studies like Morris et al. (1977) and Roediger et al. (1989) support this idea.
Regarding the brain as an organ: If you ask someone, “Does it rhyme with ‘train’?” and then later ask them, “What word related to the body rhymes with ‘train’?”, they might recall the word “brain” more easily. This is because the encoding question (“Does it rhyme with ‘train’?”) was similar to the recall question (“What word of an organ rhymes with ‘train’?”).
If the encoding and retrieval questions match, it can make recall easier, which ties into the idea that using consistent encoding and recall strategies can boost performance, even when the level of processing (deep or shallow) differs. In simpler terms, if the way you study something is similar to the way you’ll be tested on it, you’ll perform better. For example, if you study by thinking about how something sounds (shallow processing) and are later tested by hearing similar sounds, your recall will be improved
