Consciousness Dictionary

An American neuroscientist from MIT who is a leading voice in the study of brain waves. While many in the field have traditionally viewed brain waves as a mere byproduct of neural activity—like the exhaust from an engine—Miller has argued that they are, in fact, the brain’s fundamental language of communication. His research demonstrates how different frequency bands (such as gamma, beta, and alpha waves) work together to control cognitive functions like attention and working memory. According to his theory, gamma waves package information while slower beta waves provide a top-down signal, acting as a “director” to gate and prioritize information. His work suggests that a true understanding of cognition requires a deeper appreciation for how these rhythmic oscillations may orchestrate cognition.

An American anesthesiologist and philosopher of science best known for his work with physicist Roger Penrose. Together, they developed the Orchestrated Objective Reduction (Orch-OR) theory of consciousness. The theory proposes that consciousness is not a product of classical computation within neurons but arises from quantum gravity effects within protein structures called microtubules inside neurons. According to Orch-OR, consciousness results from “orchestrated” quantum collapses within these structures, making it a phenomenon that is both non-computational and fundamentally linked to the physical laws of the universe. He is also a prominent figure in the field for his role in organizing and hosting the Science of Consciousness conferences, which have become a major international forum for discussing the nature of conscious experience.

A neuroscientist and entrepreneur known for his research on the cerebellum and its role in consciousness. His work challenges the traditional view that the cerebellum is a simple motor-coordination center, instead arguing that it is essential for the unified, predictive nature of conscious experience. He proposes that the cerebellum, as a massive prediction machine, is constantly making and correcting models of the world, and that this process is integral to the seamless flow of consciousness. His research suggests that our sense of a continuous, subjective present is, in large part, a result of the cerebellum's continuous predictive activity.

Originator of the Ring/Bank theory (Dynamic Frame Theory), which proposes that consciousness arises dimensionally. The most incipient processing of stimuli* is their “when” and “how much;” with increased processing time (added latency), this intensity signal (mic voice) is interpreted into low-dimensional 0-2D manifold ringframes (“where,” “what shape”), and with further processing (latency), the ringframes “scratch-to-reveal” content voxels which can auto-complete to a full 3D experience schema (“what,” meaning). In normal state consciousness, the entire heirarchy usually occurs with little latency, and ongoing context helps the volume of experience stay afloat and seem continuous.

*These stimuli are not the entire swath of inputs hitting primary cortices; they are a filtered, TDMA Mic which changes Voice roughly 1–4 times a second, and seems capable of millisecond, if not microsecond, resolution, and a large bit depth of intensity variation.

A neuroscientist known for his work on how the brain plans and executes movement. His research on the motor cortex of rhesus monkeys during tasks like cyclic hand movements revealed that neural activity evolves in a complex but highly structured way, following a “rotational dynamic.” His work, using techniques such as Principal Component Analysis (PCA), showed that the population of neurons behaves like a dynamical system, generating a predictable neural trajectory that can be visualized as a “ring” in a low-dimensional space. This challenges the older view that individual neurons directly represent muscle commands and instead suggests that movement is generated by an elegant, unified choreography of a large population of neurons. The form of PCA often used by neuroscience could be called FM-PCA (frequency modulation PCA), as it uses the changing frequency of action potentials of single neurons as the axes for PCA consideration. This is in distinction from AM-PCA (amplitude modulation PCA), where variations in amplitude or power of a frequency band are taken as the axes for PCA consideration.

A Spanish neuroscientist and pathologist, he is considered the father of modern neuroscience. He was the first person to identify the neuron as the fundamental unit of the nervous system, a discovery that earned him the Nobel Prize in Physiology or Medicine in 1906. His work established the “Neuron Doctrine,” which states that the nervous system is made up of individual cells, laying the groundwork for all future study of the brain.

A pioneering Canadian neurosurgeon, Penfield's research provided groundbreaking insights into the link between the brain and conscious experience. By stimulating different regions of the brains of awake patients during surgery for epilepsy, he was able to map the sensory and motor cortices, revealing how specific brain areas correspond to physical sensations and body movements. His work showed that memories and emotions could be “re-enacted” by stimulating specific parts of the temporal lobe, suggesting that conscious experiences are localized within the brain.

An American neurophysiologist and cybernetics pioneer, he is best known for his work with Walter Pitts on the computational model of the neuron. He also introduced the concept of “anastomotic processing,” a model of neural networks that contrasts with serial or parallel processing. In this model, information is processed in a tangled, interwoven network where upper layers of the neural net can receive feedback from the lower layers, allowing for the unification of meaning.

A cognitive scientist known for his work on the visual system and a geometric model of consciousness. Lehar proposes that conscious experience is a geometric-topological representation of reality, a kind of internal virtual reality created by the brain. His work attempts to explain phenomena like illusions and the nature of qualia by modeling the brain's internal representations. This approach resonates with other dimensional theories, such as the Ring/Bank theory, as both see consciousness as a process of building a structured, dimensional model of the world, rather than a mere collection of disparate neural signals.

An American computer engineer, known for his work on artificial intelligence and brain theory. His book “A Thousand Brains: A New Theory of Intelligence” introduces the “Thousand Brains Theory,” which proposes that the brain uses a common algorithm to create a model of the world. This model is based on a hierarchical network of cortical columns, each creating its own complete model of an object or concept. These models are then unified through a voting mechanism to produce a single conscious perception.

A German-American neuroscientist known for his work on consciousness and for proposing the Integrated Information Theory (IIT) with Giulio Tononi. He has spent his career seeking the neural correlates of consciousness (NCC), which are the minimal neural mechanisms jointly sufficient for any one specific conscious percept. His work has focused on the claustrum, a thin sheet of neurons deep within the brain, as a potential "seat of consciousness."

A British molecular biologist and neuroscientist, best known for co-discovering the structure of the DNA molecule. In the later part of his career, he turned his attention to neuroscience and consciousness. In his book “The Astonishing Hypothesis: The Scientific Search for the Soul,” he proposed that consciousness can be explained by the physical workings of the brain and that consciousness is a biological problem to be solved.

A neuroscientist and psychiatrist who, along with Christof Koch, proposed the Integrated Information Theory (IIT) of consciousness. IIT postulates that consciousness is a fundamental property of a system that has a high degree of integrated information. It is based on the idea that consciousness corresponds to a system's capacity to integrate information and that it is both “differentiated” (having many states) and “integrated” (the states form a unified whole).

An Australian philosopher and cognitive scientist who coined the term “the hard problem of consciousness.” The "hard problem" is the question of why and how we have subjective, qualitative experiences (qualia), which he argues cannot be explained by purely physical processes. This is contrasted with the "easy problems," such as explaining brain function and cognitive abilities, which he believes can be solved through neuroscience.

An American philosopher and cognitive scientist who has a well-known materialist perspective on consciousness. He argues that there is no "hard problem" of consciousness because there is no non-physical or subjective quality of experience. In his “Multiple Drafts Model,” he proposes that conscious experience is not a single, unified stream but is rather a collection of parallel processes in the brain that create a series of "drafts" of experience.

A Portuguese-American neuroscientist who has focused on the neural basis of emotion and consciousness. He argues that consciousness is not a single, centralized process but is built upon a foundation of basic body sensations and feelings. His work in his book “Descartes’ Error” challenges the traditional mind-body dualism and proposes that emotions and the body's internal state are essential components of conscious experience.

An American neuroscientist who won the Nobel Prize for his work on the structure of antibodies. He later developed a theory of consciousness called “Neural Darwinism” or the “Theory of Neuronal Group Selection” (TNGS). This theory proposes that the brain creates consciousness through a process similar to natural selection, where certain groups of neurons are selected and strengthened based on their ability to respond to and interpret sensory input from the world.

A British mathematical physicist and philosopher of science who has proposed a controversial theory of consciousness based on quantum mechanics. He argues that consciousness is not a product of conventional computation but is instead a result of "orchestrated objective reduction" (Orch-OR), a process that occurs within microtubules inside neurons. This theory suggests that consciousness is non-computable and cannot be fully explained by classical physics.

A cognitive neuroscientist and pioneer of the Global Workspace Theory (GWT) of consciousness. He proposed that consciousness arises from a “global workspace” in the brain, a kind of central processing stage where unconscious, specialized brain processors can broadcast information. This theory suggests that conscious attention acts like a spotlight, making certain information available to the entire system for unified, integrated processing.

A neuroscientist and psychologist known for his Attention Schema Theory (AST). AST proposes that consciousness is a brain-generated model of attention. The brain constructs a simplified schematic of its own state of attention, and this model is what we experience as consciousness. Graziano argues that we are not “aware” in a mystical sense, but rather that the brain is a machine that builds a simplified, useful model of itself to control behavior.

A British neuroscientist who studies consciousness and its neural basis. He is a strong proponent of the predictive processing framework, viewing conscious experience as the brain’s best “predictive guess” about the causes of sensory signals. He argues that we don’t passively perceive the world but actively create a controlled hallucination of it based on our internal predictions and prior beliefs.

A British writer and psychologist known for her work on memes, evolutionary theory, and consciousness. She argues that consciousness is a grand illusion, a compelling fiction created by the brain. She is a strong advocate for the idea that there is no single "conscious self" and that our sense of a unified self is a constructed narrative, not a fundamental property of the mind.

An American philosopher known for his critiques of functionalism and for distinguishing between two types of consciousness. He coined the terms “access consciousness,” which is the ability to use information for reasoning and action, and “phenomenal consciousness,” which is the subjective, experiential aspect of consciousness. He argues that phenomenal consciousness is the true “hard problem.”

An American philosopher known for his “Chinese Room” thought experiment, which is a powerful critique of the idea that artificial intelligence can achieve true understanding. He argues that a computer simply manipulates symbols according to a program without any actual comprehension, a process that is fundamentally different from a conscious human mind that has subjective experiences and genuine intentionality.

A Canadian-American philosopher known as a central figure in eliminative materialism. This view holds that folk psychology, our common-sense understanding of the mind based on concepts like belief and desire, is a flawed theory that will eventually be replaced by a more precise, neuroscientific account. She argues that a complete understanding of consciousness will come from looking at the brain, not by analyzing abstract concepts.

A Canadian philosopher and husband of Patricia Churchland, also a proponent of eliminative materialism. He argues that consciousness is a phenomenon of the brain’s ability to represent the world. He suggests that a better understanding of consciousness will come from a new framework based on neural network models, which can better explain how the brain processes and represents information.

An American philosopher known for his influential paper, “What Is It Like to Be a Bat?” In it, he argues that consciousness has an ineliminable subjective character, and that no amount of objective, physical information about the brain can ever explain what it is like to be a conscious being. His work highlights the “subjective point of view” as the central mystery of consciousness, distinct from physical or functional explanations.

An Austrian-British philosopher of science, known for his theory of falsifiability, which states that for a theory to be scientific, it must be possible to prove it false. While not a neuroscientist, his philosophy has influenced many thinkers on the nature of science and the scientific method. He was a dualist who believed that the mind and body are distinct entities that interact with one another.

An American neuroscientist who is a pioneer in the field of optogenetics, a revolutionary technique that uses light to control the activity of genetically modified neurons. His work allows scientists to precisely activate or inactivate specific circuits in the brains of living animals, providing unprecedented insight into the neural basis of behavior, emotion, and consciousness.

An American linguist, philosopher, and political activist who is a key figure in the field of cognitive science. He argues that language is an innate, biological capacity of the human mind, challenging the behaviorist view that language is learned through imitation and reinforcement. His work on “universal grammar” suggests that the mind has a pre-existing structure that governs how we acquire language, a concept that has influenced theories of brain architecture and consciousness.

A British neuroscientist and computer scientist who made foundational contributions to the computational understanding of vision. His book “Vision” laid out a three-level framework for understanding information processing systems, including the brain. This framework, which includes the computational, algorithmic, and implementational levels, has been highly influential in both cognitive science and artificial intelligence.

A Colombian neuroscientist known for his work on the electrophysiology of neurons and the cerebellum. He developed the theory of “intrinsic oscillations,” which suggests that the brain’s intrinsic electrical activity is the basis for consciousness. He argues that consciousness is a unified sensory experience created by the brain's internal rhythm, not a reaction to external stimuli.

An American philosopher who proposes an enactive and embodied view of consciousness. He argues against the idea that consciousness is a purely internal, brain-based phenomenon. Instead, he believes that conscious experience is a form of “skillful activity” that arises from the dynamic interaction between the brain, body, and the environment. We don't just perceive the world; we “enact” it through our actions and movements.

A Canadian philosopher and cognitive scientist who has worked to integrate phenomenology (the study of subjective experience) with neuroscience. His work is heavily influenced by the enactive approach, arguing that consciousness is not located in the brain but is a property of the living organism as a whole, shaped by its interactions with the environment.

An Indian-American neuroscientist who has made significant contributions to the fields of behavioral neurology and visual psychophysics. He is best known for his work on phantom limb syndrome, synesthesia, and other neurological conditions. His research on the human brain's remarkable plasticity has provided key insights into how our subjective experience of the body and consciousness can be altered and reshaped.

A British neurologist and writer who popularized the field of clinical neurology by writing fascinating case studies of his patients. His books, such as “The Man Who Mistook His Wife for a Hat,” revealed how brain disorders can dramatically alter a person’s perception, memory, and sense of self. His work emphasized the profound link between brain function and conscious experience in a humanistic and accessible way.

An American philosopher and a prominent critic of artificial intelligence. He argued that the human mind cannot be modeled as a formal, symbolic-processing machine. His work, which was influenced by phenomenology, emphasized the importance of embodied knowledge and skills that are not based on explicit rules, suggesting that true consciousness requires more than just formal computation.

A German neuroscientist who conducts research on the neural basis of consciousness and free will. He is famous for his experiments using fMRI to show that the brain’s decision-making process begins several seconds before a person becomes consciously aware of their choice. His work is often cited in debates about whether free will is an illusion and whether conscious decisions are truly free.

An Austrian neurologist, psychiatrist, and Holocaust survivor who developed logotherapy, a school of psychotherapy centered on finding meaning in life. While not a neuroscientist, his work is relevant to the study of consciousness as it explores the highest levels of human experience, including the search for meaning, purpose, and spiritual freedom, even in the face of immense suffering.

A British neurobiologist known for his work on the visual cortex and for pioneering the field of neuroaesthetics. He has shown that different aspects of vision, such as color and form, are processed by separate areas of the brain. He argues that our subjective, conscious experience of vision is created by the brain’s ability to bring these disparate signals together to form a unified image of the world.

An American neuroscientist who conducted groundbreaking experiments on the timing of conscious intention and action. He showed that the brain’s neural activity associated with a voluntary movement (the “readiness potential”) begins before a person consciously decides to move. His work has sparked intense debate on the nature of free will and whether conscious decisions are a cause of action or simply an after-the-fact awareness of a decision already made by the brain.

A French cognitive neuroscientist who is a leading proponent of the Global Neuronal Workspace Theory (GNWT). He uses advanced brain imaging techniques to study how conscious thought differs from unconscious processing. His research suggests that consciousness is not a single location but a specific brain state where information is widely broadcast across a network of cortical neurons, allowing for a flexible and integrated response.