An engram, a concept in neuroscience, signifies the physical or biochemical changes in the brain responsible for memory storage. It encompasses characteristics like memory encoding and neural pathways. Theories, including Hebbian learning, and experimental evidence involving the hippocampus, shed light on its complexity. Engrams have applications in memory enhancement and neurological disorders, but controversies persist regarding their localization and empirical proof, fueling philosophical inquiries into memory and identity.

Introduction to Engram

The term “engram” was first introduced by the renowned German neuroscientist Richard Semon in the early 20th century. He coined the word to describe the physical trace or neural pathway that represents a specific memory in the brain. Semon’s engram concept proposed that memories are not stored as isolated units but as physical changes or imprints in the neural tissue.

The idea of the engram implies that memories are not just abstract constructs but have a concrete, physiological basis within the brain. This concept has been pivotal in shaping research on memory and cognition, leading scientists to explore the neurobiological underpinnings of memory formation, consolidation, and retrieval.

Historical Background of the Engram

The concept of the engram can be traced back to ancient philosophical and psychological inquiries into the nature of memory. However, it was Richard Semon’s work in the early 20th century that formalized and popularized the term. Semon proposed that experiences leave a lasting trace in the brain, which he referred to as the engram.

One of the most famous early experiments related to engrams was conducted by the Russian physiologist Ivan Pavlov. Pavlov’s research on classical conditioning with dogs suggested that memories are associated with specific patterns of neural activity. His work laid the foundation for understanding how experiences could lead to lasting neural changes.

The engram concept gained further prominence in the mid-20th century with the advent of modern neuroscience techniques. Researchers like Karl Lashley conducted lesion studies in animals to locate the engram within the brain. These studies aimed to identify specific brain regions or structures where memories were stored. However, Lashley’s findings proved inconclusive and raised questions about the distributed nature of memory storage.

Cognitive and Neurobiological Processes Involved

Memory formation and storage are complex processes that involve multiple brain regions, neurotransmitters, and neural pathways. While the precise nature of the engram remains a topic of research and debate, several key cognitive and neurobiological processes are associated with memory:

  1. Encoding: Memories are formed through a process called encoding, where sensory information is transformed into neural signals. This process is influenced by attention, perception, and cognitive processing.
  2. Consolidation: Once encoded, memories undergo consolidation, a process that stabilizes and strengthens the memory trace. It is believed that this process involves changes in synaptic connections and neural networks.
  3. Reconsolidation: Memories are not static but can be modified or updated through reconsolidation. When a memory is retrieved, it becomes temporarily labile and can be modified before being re-stored.
  4. Neurotransmitters: Neurotransmitters, such as acetylcholine and glutamate, play a crucial role in synaptic plasticity, which underlies memory formation and the strengthening of synaptic connections.
  5. Hippocampus: The hippocampus, a region deep within the brain, is heavily involved in the formation of declarative memories, which include facts and events. It is considered a critical structure in the early stages of memory consolidation.
  6. Long-Term Potentiation (LTP): LTP is a phenomenon where repeated synaptic stimulation leads to a long-lasting increase in synaptic strength. It is often cited as a cellular mechanism underlying memory formation.

Contemporary Theories of Engram

Contemporary research on the engram has evolved beyond the idea of a single, localized memory trace. Instead, it suggests that memories are distributed across neural networks and involve multiple brain regions. Several theories and models attempt to explain the engram’s nature:

  1. Synaptic Plasticity: The most widely accepted view is that memories are encoded through changes in synaptic strength and connectivity. This is supported by the phenomenon of long-term potentiation (LTP) and long-term depression (LTD), which are thought to underlie memory storage.
  2. Memory Systems: Different types of memories may involve distinct neural systems. For example, declarative memories are associated with the medial temporal lobe, while procedural memories are linked to the basal ganglia.
  3. Distributed Engram: Memories are believed to be distributed across a network of neurons and synapses rather than localized in a single engram. This distributed representation allows for redundancy and resilience in memory storage.
  4. Pattern Completion: Memories may be retrieved through a process called pattern completion, where partial cues or associations activate the entire memory network. This theory explains how a fragment of a memory can trigger the recall of the entire memory.
  5. Memory Reconsolidation: The reconsolidation theory suggests that memories are not stored as fixed traces but are labile and subject to modification during retrieval and reconsolidation.

Implications of Engram Research

Understanding the engram has profound implications for memory research, neuroscience, and various fields. Some of these implications include:

  1. Neurological Disorders: Research on the engram can shed light on the underlying mechanisms of neurological disorders that affect memory, such as Alzheimer’s disease and amnesia.
  2. Learning and Education: Insights into memory formation and retrieval can inform educational practices, including strategies for effective learning and memory enhancement.
  3. Cognitive Enhancement: The ability to manipulate and enhance memory traces has implications for cognitive enhancement technologies and treatments for memory-related disorders.
  4. Ethical Considerations: As our understanding of memory manipulation advances, ethical questions arise regarding the potential use of such knowledge, especially in the context of memory modification or erasure.
  5. Artificial Intelligence: Understanding how the brain stores and retrieves information can inspire developments in artificial intelligence and neural network models.


The engram, a concept that has intrigued scientists and thinkers for centuries, represents the physical substrate of memory within the brain. While the precise nature and location of the engram continue to be subjects of research and debate, it is clear that memories involve complex cognitive and neurobiological processes. Contemporary theories suggest that memories are distributed across neural networks and involve various brain regions, challenging the notion of a single, localized engram. The study of the engram has far-reaching implications for understanding memory-related disorders, enhancing learning and education, and exploring the boundaries of memory manipulation and ethical considerations. As research on the engram continues to advance, it promises to unveil new insights into the mechanisms of memory and cognition, enriching our understanding of the human mind.

Case Studies

  • Learning to Ride a Bicycle: When someone learns to ride a bicycle, the physical and procedural memory associated with this skill is stored in the brain as an engram. The specific movements, balance adjustments, and coordination become encoded in neural pathways.
  • Episodic Memory of a Vacation: Imagine going on a memorable vacation. The sights, sounds, and experiences are encoded as engrams in your brain. When you recall the details of that vacation, you are accessing the engram associated with that specific episode.
  • Remembering a Childhood Friend: Memories of childhood friends are stored as engrams. The neural connections formed during those friendships are part of the engram that allows you to recall their names, faces, and shared experiences.
  • Muscle Memory in Sports: Athletes develop muscle memory through repetitive training. The engrams associated with specific movements, such as a tennis serve or a golf swing, enable precise execution of these actions without conscious thought.
  • Language Acquisition: Learning a new language involves forming engrams for vocabulary, grammar rules, and pronunciation. These engrams allow individuals to speak and understand the language fluently.

Key Highlights

  • Memory Encoding: Engrams represent the physical traces of memories in the brain. They are formed through the process of memory encoding, where specific neural pathways are strengthened as a result of learning and experiences.
  • Neural Pathways: Engrams are associated with specific neural pathways and connections in the brain. These pathways include both the structure and function of neurons that enable the storage and retrieval of memories.
  • Types of Memories: Engrams can encode various types of memories, including declarative memories (facts and events), procedural memories (skills and habits), and episodic memories (personal experiences).
  • Memory Retrieval: When we recall information or experiences, we are essentially activating the engrams associated with those memories. This retrieval process involves the reactivation of the same neural pathways that were involved in encoding.
  • Spatial Distribution: Engrams are distributed throughout different brain regions. For example, the hippocampus is crucial for the formation of certain types of memories, while other brain regions are involved in storing and retrieving memories.
  • Long-Term Potentiation: The process of strengthening synaptic connections, known as long-term potentiation (LTP), plays a significant role in the formation and maintenance of engrams. It is a cellular mechanism of memory storage.
  • Neuroplasticity: Engrams are a testament to the brain’s remarkable neuroplasticity. The brain can adapt, reorganize, and create new engrams throughout a person’s life, enabling learning and memory.
  • Memory Consolidation: Engrams are involved in memory consolidation, where newly acquired information is stabilized and integrated into long-term memory. This process ensures that memories are retained over time.
  • Role in Learning: Engrams are fundamental to the learning process. They allow individuals to acquire new knowledge, skills, and behaviors by encoding and retrieving information from their experiences.
  • Memory Disorders: Conditions such as Alzheimer’s disease, which affect memory and cognition, involve disruptions in engram formation and retrieval. Understanding engrams is critical for researching and treating memory-related disorders.
  • Scientific Research: The study of engrams has been a focal point in neuroscience and cognitive psychology. Researchers use various techniques, including neuroimaging and electrophysiology, to explore engram formation and function.
  • Future Applications: Advancements in our understanding of engrams may have implications for enhancing memory, treating memory disorders, and developing neuroprosthetic devices that interface with the brain.

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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