Sensory Memory

Sensory Memory is the initial memory stage briefly storing sensory information, characterized by its brief duration, large capacity, and automatic processing. It comprises Iconic (visual) and Echoic (auditory) Memory categories. While advantageous for rapid perception and understanding, it faces challenges of information transience and selective attention. Its implications include information filtering and perceptual learning, with practical applications in UX and marketing.

Introduction to Sensory Memory

Sensory memory is the gateway to the complex processes of human memory. It involves the initial reception and retention of sensory information from the environment. This information is collected through our senses, including sight (visual), hearing (auditory), touch (tactile), taste (gustatory), and smell (olfactory). Sensory memory acts as a buffer that briefly holds incoming sensory input before deciding whether it should be further processed or discarded.

Key principles of sensory memory include:

  1. Automatic Processing: Sensory memory operates automatically and involuntarily. It does not require conscious effort or attention to function.
  2. Duration: Sensory memory has a very brief duration, typically lasting for a fraction of a second to a few seconds. It provides a momentary snapshot of the sensory environment.
  3. High Capacity: Sensory memory has a high capacity to store a vast amount of sensory information simultaneously. It serves as a temporary storage system that can handle a significant amount of data.
  4. Selective Attention: Not all sensory information is processed equally. Selective attention helps filter and prioritize specific sensory inputs for further processing, allowing us to focus on what is most relevant or salient.

Types of Sensory Memory

Sensory memory can be categorized into different types based on the sensory modality involved:

  1. Iconic Memory (Visual): Iconic memory refers to the sensory memory associated with visual information. It stores visual stimuli for a very brief duration, typically less than a second. Iconic memory is responsible for our ability to perceive motion in movies and animations, as it retains a series of still images briefly before they merge into fluid motion.
  2. Echoic Memory (Auditory): Echoic memory pertains to auditory sensory memory. It stores auditory information, such as spoken words or sounds, for a slightly longer duration compared to iconic memory, typically a few seconds. This allows us to process and make sense of continuous speech.
  3. Haptic Memory (Tactile): Haptic memory is related to the sense of touch. It briefly retains tactile sensations, such as the feeling of an object or texture, for a few seconds. Haptic memory is crucial for our ability to navigate and interact with the physical world.

Duration of Sensory Memory

The duration of sensory memory is extremely brief but varies among sensory modalities:

  1. Iconic Memory Duration: Iconic memory lasts for a fraction of a second, typically around 200-300 milliseconds. This duration is just long enough to provide continuity in our visual perception of the world.
  2. Echoic Memory Duration: Echoic memory has a slightly longer duration compared to iconic memory, lasting for several seconds, typically around 3-4 seconds. This brief retention period allows us to comprehend spoken language and process auditory information in real-time.
  3. Haptic Memory Duration: Haptic memory also has a short duration, typically lasting for a few seconds to less than a minute. It enables us to interact with and explore the physical environment effectively.

The Role of Sensory Memory in Information Processing

Sensory memory serves several crucial functions in the broader context of information processing and memory formation:

  1. Immediate Sensory Input: Sensory memory captures and retains sensory input from the environment as it occurs. This allows individuals to perceive and make sense of their surroundings in real-time.
  2. Sensory Integration: It helps integrate and combine sensory information from various modalities. For example, when we watch a movie, sensory memory integrates visual and auditory information to create a coherent and immersive experience.
  3. Selective Attention: Sensory memory plays a role in selective attention by briefly storing sensory input, allowing the brain to decide which information to prioritize for further processing. This filtering process helps individuals focus on relevant stimuli and ignore distractions.
  4. Continuity in Perception: Iconic memory provides the continuity needed for visual perception. It ensures that our visual experience appears seamless, even though it is constructed from a series of discrete snapshots.
  5. Language Processing: Echoic memory is essential for language comprehension. It enables individuals to process spoken words and sentences in real-time, allowing for effective communication.

Significance of Sensory Memory

Sensory memory holds significant importance for several reasons:

  1. Perceptual Experience: It is responsible for our immediate perceptual experience of the world. Without sensory memory, our perception would be fragmented and disjointed.
  2. Selective Attention: Sensory memory helps us selectively attend to relevant information while filtering out irrelevant or less important sensory input. This plays a vital role in our ability to focus and make sense of our surroundings.
  3. Memory Continuity: Iconic memory ensures that we perceive the visual world as continuous and fluid, enhancing our ability to track moving objects and engage with visual media.
  4. Language Processing: Echoic memory is indispensable for language comprehension and effective communication. It allows us to process spoken language and respond appropriately in conversations.
  5. Information Processing: Sensory memory is the initial stage in the process of encoding information into long-term memory. It provides a brief window of opportunity for relevant information to be transferred to short-term memory for further processing and potential storage in long-term memory.

Experiments and Studies

Numerous experiments and studies have been conducted to investigate the characteristics and properties of sensory memory. Some notable ones include:

  1. Sperling’s Iconic Memory Experiment: In the 1960s, George Sperling conducted experiments to study the capacity and duration of iconic memory. Participants were briefly shown a matrix of letters and then asked to recall them. Sperling found that participants could recall more letters from a specific row when cued, demonstrating the existence of a brief but high-capacity iconic memory.
  2. Echoic Memory Studies: Research on echoic memory has explored the ability to recall and recognize auditory information. Studies have shown that individuals can retain and recognize spoken words and sounds for a few seconds after they are presented.
  3. Haptic Memory Research: Haptic memory studies have investigated how individuals remember tactile sensations and textures. Research in this area has implications for fields such as product design and human-computer interaction.


Sensory memory is the initial stage of memory processing that provides the brain with a brief and immediate snapshot of the sensory environment. It operates automatically and has a high capacity for storing sensory information. Sensory memory is crucial for our perceptual experience, selective attention, language processing, and the continuity of our visual and auditory perception. While sensory memory has a very brief duration, it plays a pivotal role in the larger process of information processing, where relevant sensory input is transferred to short-term and eventually long-term memory for storage and retrieval. Understanding the characteristics and significance of sensory memory contributes to our broader knowledge of memory processes and human cognition.

Case Studies

Examples of Sensory Memory:

1. Vision:

  • Iconic Memory in Reading: When reading a book, each word you see is briefly stored in your Iconic Memory. This allows you to recognize and process words as part of sentences, even though each word is presented for only a fraction of a second.
  • Visual Illusions: Optical illusions, such as the persistence of vision seen in movies, exploit the brief duration of Iconic Memory to create the illusion of continuous motion from a sequence of still images.

2. Auditory Perception:

  • Echoic Memory in Conversation: In a conversation, when someone speaks, you remember the words they said for a few seconds. This enables you to understand the meaning of a sentence even if you didn’t process each word as it was spoken.
  • Auditory Experiments: In psychology experiments, researchers use Echoic Memory to study auditory perception. For example, participants might be asked to recall a series of tones they heard a few seconds ago.

3. Visual Arts:

  • Paintings and Art: Artists use the principles of Iconic Memory to create visual artworks that convey a sense of motion, continuity, or harmony. Techniques like pointillism or impressionism rely on the viewer’s ability to blend and remember colors and shapes.
  • Photography: In photography, capturing a moment relies on the viewer’s Iconic Memory to understand the content of a photograph instantly, despite the brief exposure to the image.

4. Music and Sound Design:

  • Musical Compositions: Composers create melodies, harmonies, and rhythms that take advantage of Echoic Memory. Musical phrases are crafted to linger in the listener’s mind, allowing them to appreciate the structure and emotional impact of a piece.
  • Sound Branding: Companies use short audio jingles or logos in their advertisements to make use of Echoic Memory. These memorable sounds become associated with the brand and can trigger recognition even after a brief exposure.

5. User Interface Design:

  • App Icons: App designers rely on Iconic Memory to create recognizable and memorable icons. Users can quickly identify and tap on these icons to open apps without reading labels.
  • Auditory Feedback: Mobile devices use auditory feedback, such as the sound of a keyboard click when typing or a notification alert, to provide immediate user feedback, capitalizing on Echoic Memory for user recognition.

6. Educational Tools:

  • Flashcards: Flashcards are a study tool that leverages the principles of Sensory Memory. Briefly displaying a term or concept on one side and its explanation on the other helps learners reinforce their memory through quick recall.
  • Language Learning Apps: Language learning apps often incorporate auditory cues and visual images to enhance memory retention. Users briefly see and hear new words or phrases to aid learning.

Key Highlights of Sensory Memory:

  • Ultra-Brief Duration: Sensory Memory represents the earliest stage of memory processing and has an ultra-brief duration, lasting only milliseconds to a few seconds. It serves as a buffer that temporarily holds incoming sensory information.
  • Visual and Auditory Components: Sensory Memory is divided into two primary components—Iconic Memory for visual information and Echoic Memory for auditory information. Iconic Memory deals with visual stimuli, while Echoic Memory deals with sounds and auditory stimuli.
  • Immediate Perception: Sensory Memory allows for the immediate perception and recognition of sensory input. It provides a snapshot of the world as we perceive it, allowing us to process and make sense of our surroundings.
  • Preventing Sensory Overload: It acts as a filter to prevent sensory overload. Not all sensory information is transferred to higher memory systems; only select information deemed important or relevant is passed on for further processing in short-term and long-term memory.
  • Role in Cognitive Processing: Sensory Memory plays a crucial role in various cognitive processes, including reading comprehension, visual recognition, understanding spoken language, and appreciating art. It enables continuity and coherence in our perception of the world.
  • Influence on Design: Designers and creators in various fields, such as user interface design, art, music, and advertising, leverage the principles of Sensory Memory to create visually and auditorily appealing experiences. Iconic and Echoic Memory influence how users interact with products and media.
  • Educational Implications: Sensory Memory is essential in education and learning. Techniques like flashcards, quick recall of information, and multimedia learning tools make use of the ultra-brief retention capabilities of Sensory Memory to aid in the retention and comprehension of new concepts.
  • Temporal Characteristics: The duration of Sensory Memory is extremely short-lived, typically lasting less than a second. This characteristic distinguishes it from short-term and long-term memory systems, which have longer storage durations.
  • Transient Nature: Information in Sensory Memory quickly fades if not transferred to short-term or long-term memory. This transient nature underscores the importance of selective attention and cognitive processing.
  • Continuous Processing: Sensory Memory works seamlessly with other memory systems, such as short-term and long-term memory, to support the flow of information from perception to comprehension and storage. It is an integral part of the broader memory process.

Connected Thinking Frameworks

Convergent vs. Divergent Thinking

Convergent thinking occurs when the solution to a problem can be found by applying established rules and logical reasoning. Whereas divergent thinking is an unstructured problem-solving method where participants are encouraged to develop many innovative ideas or solutions to a given problem. Where convergent thinking might work for larger, mature organizations where divergent thinking is more suited for startups and innovative companies.

Critical Thinking

Critical thinking involves analyzing observations, facts, evidence, and arguments to form a judgment about what someone reads, hears, says, or writes.


The concept of cognitive biases was introduced and popularized by the work of Amos Tversky and Daniel Kahneman in 1972. Biases are seen as systematic errors and flaws that make humans deviate from the standards of rationality, thus making us inept at making good decisions under uncertainty.

Second-Order Thinking

Second-order thinking is a means of assessing the implications of our decisions by considering future consequences. Second-order thinking is a mental model that considers all future possibilities. It encourages individuals to think outside of the box so that they can prepare for every and eventuality. It also discourages the tendency for individuals to default to the most obvious choice.

Lateral Thinking

Lateral thinking is a business strategy that involves approaching a problem from a different direction. The strategy attempts to remove traditionally formulaic and routine approaches to problem-solving by advocating creative thinking, therefore finding unconventional ways to solve a known problem. This sort of non-linear approach to problem-solving, can at times, create a big impact.

Bounded Rationality

Bounded rationality is a concept attributed to Herbert Simon, an economist and political scientist interested in decision-making and how we make decisions in the real world. In fact, he believed that rather than optimizing (which was the mainstream view in the past decades) humans follow what he called satisficing.

Dunning-Kruger Effect

The Dunning-Kruger effect describes a cognitive bias where people with low ability in a task overestimate their ability to perform that task well. Consumers or businesses that do not possess the requisite knowledge make bad decisions. What’s more, knowledge gaps prevent the person or business from seeing their mistakes.

Occam’s Razor

Occam’s Razor states that one should not increase (beyond reason) the number of entities required to explain anything. All things being equal, the simplest solution is often the best one. The principle is attributed to 14th-century English theologian William of Ockham.

Lindy Effect

The Lindy Effect is a theory about the ageing of non-perishable things, like technology or ideas. Popularized by author Nicholas Nassim Taleb, the Lindy Effect states that non-perishable things like technology age – linearly – in reverse. Therefore, the older an idea or a technology, the same will be its life expectancy.


Antifragility was first coined as a term by author, and options trader Nassim Nicholas Taleb. Antifragility is a characteristic of systems that thrive as a result of stressors, volatility, and randomness. Therefore, Antifragile is the opposite of fragile. Where a fragile thing breaks up to volatility; a robust thing resists volatility. An antifragile thing gets stronger from volatility (provided the level of stressors and randomness doesn’t pass a certain threshold).

Systems Thinking

Systems thinking is a holistic means of investigating the factors and interactions that could contribute to a potential outcome. It is about thinking non-linearly, and understanding the second-order consequences of actions and input into the system.

Vertical Thinking

Vertical thinking, on the other hand, is a problem-solving approach that favors a selective, analytical, structured, and sequential mindset. The focus of vertical thinking is to arrive at a reasoned, defined solution.

Maslow’s Hammer

Maslow’s Hammer, otherwise known as the law of the instrument or the Einstellung effect, is a cognitive bias causing an over-reliance on a familiar tool. This can be expressed as the tendency to overuse a known tool (perhaps a hammer) to solve issues that might require a different tool. This problem is persistent in the business world where perhaps known tools or frameworks might be used in the wrong context (like business plans used as planning tools instead of only investors’ pitches).

Peter Principle

The Peter Principle was first described by Canadian sociologist Lawrence J. Peter in his 1969 book The Peter Principle. The Peter Principle states that people are continually promoted within an organization until they reach their level of incompetence.

Straw Man Fallacy

The straw man fallacy describes an argument that misrepresents an opponent’s stance to make rebuttal more convenient. The straw man fallacy is a type of informal logical fallacy, defined as a flaw in the structure of an argument that renders it invalid.

Streisand Effect

The Streisand Effect is a paradoxical phenomenon where the act of suppressing information to reduce visibility causes it to become more visible. In 2003, Streisand attempted to suppress aerial photographs of her Californian home by suing photographer Kenneth Adelman for an invasion of privacy. Adelman, who Streisand assumed was paparazzi, was instead taking photographs to document and study coastal erosion. In her quest for more privacy, Streisand’s efforts had the opposite effect.


As highlighted by German psychologist Gerd Gigerenzer in the paper “Heuristic Decision Making,” the term heuristic is of Greek origin, meaning “serving to find out or discover.” More precisely, a heuristic is a fast and accurate way to make decisions in the real world, which is driven by uncertainty.

Recognition Heuristic

The recognition heuristic is a psychological model of judgment and decision making. It is part of a suite of simple and economical heuristics proposed by psychologists Daniel Goldstein and Gerd Gigerenzer. The recognition heuristic argues that inferences are made about an object based on whether it is recognized or not.

Representativeness Heuristic

The representativeness heuristic was first described by psychologists Daniel Kahneman and Amos Tversky. The representativeness heuristic judges the probability of an event according to the degree to which that event resembles a broader class. When queried, most will choose the first option because the description of John matches the stereotype we may hold for an archaeologist.

Take-The-Best Heuristic

The take-the-best heuristic is a decision-making shortcut that helps an individual choose between several alternatives. The take-the-best (TTB) heuristic decides between two or more alternatives based on a single good attribute, otherwise known as a cue. In the process, less desirable attributes are ignored.

Bundling Bias

The bundling bias is a cognitive bias in e-commerce where a consumer tends not to use all of the products bought as a group, or bundle. Bundling occurs when individual products or services are sold together as a bundle. Common examples are tickets and experiences. The bundling bias dictates that consumers are less likely to use each item in the bundle. This means that the value of the bundle and indeed the value of each item in the bundle is decreased.

Barnum Effect

The Barnum Effect is a cognitive bias where individuals believe that generic information – which applies to most people – is specifically tailored for themselves.

First-Principles Thinking

First-principles thinking – sometimes called reasoning from first principles – is used to reverse-engineer complex problems and encourage creativity. It involves breaking down problems into basic elements and reassembling them from the ground up. Elon Musk is among the strongest proponents of this way of thinking.

Ladder Of Inference

The ladder of inference is a conscious or subconscious thinking process where an individual moves from a fact to a decision or action. The ladder of inference was created by academic Chris Argyris to illustrate how people form and then use mental models to make decisions.

Goodhart’s Law

Goodhart’s Law is named after British monetary policy theorist and economist Charles Goodhart. Speaking at a conference in Sydney in 1975, Goodhart said that “any observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes.” Goodhart’s Law states that when a measure becomes a target, it ceases to be a good measure.

Six Thinking Hats Model

The Six Thinking Hats model was created by psychologist Edward de Bono in 1986, who noted that personality type was a key driver of how people approached problem-solving. For example, optimists view situations differently from pessimists. Analytical individuals may generate ideas that a more emotional person would not, and vice versa.

Mandela Effect

The Mandela effect is a phenomenon where a large group of people remembers an event differently from how it occurred. The Mandela effect was first described in relation to Fiona Broome, who believed that former South African President Nelson Mandela died in prison during the 1980s. While Mandela was released from prison in 1990 and died 23 years later, Broome remembered news coverage of his death in prison and even a speech from his widow. Of course, neither event occurred in reality. But Broome was later to discover that she was not the only one with the same recollection of events.

Crowding-Out Effect

The crowding-out effect occurs when public sector spending reduces spending in the private sector.

Bandwagon Effect

The bandwagon effect tells us that the more a belief or idea has been adopted by more people within a group, the more the individual adoption of that idea might increase within the same group. This is the psychological effect that leads to herd mentality. What in marketing can be associated with social proof.

Moore’s Law

Moore’s law states that the number of transistors on a microchip doubles approximately every two years. This observation was made by Intel co-founder Gordon Moore in 1965 and it become a guiding principle for the semiconductor industry and has had far-reaching implications for technology as a whole.

Disruptive Innovation

Disruptive innovation as a term was first described by Clayton M. Christensen, an American academic and business consultant whom The Economist called “the most influential management thinker of his time.” Disruptive innovation describes the process by which a product or service takes hold at the bottom of a market and eventually displaces established competitors, products, firms, or alliances.

Value Migration

Value migration was first described by author Adrian Slywotzky in his 1996 book Value Migration – How to Think Several Moves Ahead of the Competition. Value migration is the transferal of value-creating forces from outdated business models to something better able to satisfy consumer demands.

Bye-Now Effect

The bye-now effect describes the tendency for consumers to think of the word “buy” when they read the word “bye”. In a study that tracked diners at a name-your-own-price restaurant, each diner was asked to read one of two phrases before ordering their meal. The first phrase, “so long”, resulted in diners paying an average of $32 per meal. But when diners recited the phrase “bye bye” before ordering, the average price per meal rose to $45.


Groupthink occurs when well-intentioned individuals make non-optimal or irrational decisions based on a belief that dissent is impossible or on a motivation to conform. Groupthink occurs when members of a group reach a consensus without critical reasoning or evaluation of the alternatives and their consequences.


A stereotype is a fixed and over-generalized belief about a particular group or class of people. These beliefs are based on the false assumption that certain characteristics are common to every individual residing in that group. Many stereotypes have a long and sometimes controversial history and are a direct consequence of various political, social, or economic events. Stereotyping is the process of making assumptions about a person or group of people based on various attributes, including gender, race, religion, or physical traits.

Murphy’s Law

Murphy’s Law states that if anything can go wrong, it will go wrong. Murphy’s Law was named after aerospace engineer Edward A. Murphy. During his time working at Edwards Air Force Base in 1949, Murphy cursed a technician who had improperly wired an electrical component and said, “If there is any way to do it wrong, he’ll find it.”

Law of Unintended Consequences

The law of unintended consequences was first mentioned by British philosopher John Locke when writing to parliament about the unintended effects of interest rate rises. However, it was popularized in 1936 by American sociologist Robert K. Merton who looked at unexpected, unanticipated, and unintended consequences and their impact on society.

Fundamental Attribution Error

Fundamental attribution error is a bias people display when judging the behavior of others. The tendency is to over-emphasize personal characteristics and under-emphasize environmental and situational factors.

Outcome Bias

Outcome bias describes a tendency to evaluate a decision based on its outcome and not on the process by which the decision was reached. In other words, the quality of a decision is only determined once the outcome is known. Outcome bias occurs when a decision is based on the outcome of previous events without regard for how those events developed.

Hindsight Bias

Hindsight bias is the tendency for people to perceive past events as more predictable than they actually were. The result of a presidential election, for example, seems more obvious when the winner is announced. The same can also be said for the avid sports fan who predicted the correct outcome of a match regardless of whether their team won or lost. Hindsight bias, therefore, is the tendency for an individual to convince themselves that they accurately predicted an event before it happened.

Read Next: BiasesBounded RationalityMandela EffectDunning-Kruger EffectLindy EffectCrowding Out EffectBandwagon Effect.

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