Daniel Böttger describes his experience after brain surgery for cancer removed his right amygdala, resulting in the complete elimination of visceral fear, depression, and most suffering, while also causing some social difficulties and autism-like symptoms. Longer summary

Daniel Böttger, who previously contributed ACX book reviews and consciousness theories, provides an update after his 2024 brain cancer diagnosis and treatment. He underwent multiple neurosurgeries to remove an astrocytoma, with collateral damage including his right amygdala, part of his hippocampus, and temporal cortex. The post details his surprisingly cheerful journey through six surgeries and experimental chemotherapy, during which he noticed he could no longer feel visceral fear or depression. He explores the neurological basis for these changes, focusing on how losing his right amygdala eliminated the fight-or-flight response while leaving abstract risk assessment intact. The latter part discusses both benefits (elimination of fear, depression, and suffering; possible IQ increase) and drawbacks (reduced ability to read facial expressions, difficulty empathizing with others' fears, autism-like symptoms). He advocates for considering amygdalectomy as a treatment for certain psychiatric disorders, noting modern techniques like stereotactic radiosurgery are far safer than historical lobotomies. Shorter summary

Scott explains why he's not interested in participating in the current wave of God debates on Substack, arguing that religious explanations fall into the same category as conspiracy theories by invoking "powerful hidden entities" to explain anomalies. Longer summary

Scott discusses his lack of interest in the resurgent religion debates on Substack, comparing religious explanations to a hypothetical theory that aliens caused Napoleon's rise. He argues that God explanations suffer from the same overfitting problem as conspiracy theories—they invoke powerful hidden entities to explain specific outcomes while being unfalsifiable. The post critiques the "divine simplicity" argument that God is simple because He is "mind without limits," showing this is a sleight-of-hand that confuses removing limits with reducing complexity. Scott also challenges computational dualism, arguing that computation clearly happens in the physical brain based on extensive evidence from neuroscience, which undermines the claim that "mind" exists on an exotic substrate that could support infinite capabilities. Shorter summary

Scott argues the real distinction in psychology isn't between subfields but between settled science (like dopamine, brain localization, heritability) and breaking-news research, defending psychology's solid core against critics who conflate bad recent studies with the entire field. Longer summary

Scott clarifies his previous post on psychology research, explaining that the key distinction isn't between social psychology and other subfields, but between settled science and novel research. He lists ten examples of well-established psychological findings (like dopamine's role in reinforcement learning, brain localization, heritability studies) that are fundamentally different from flashy new studies that often fail to replicate. Drawing on Eliezer Yudkowsky's concept of 'The Beauty of Settled Science,' he argues that psychology's core knowledge is solid and valuable, even if recent clickbait studies are often wrong. He addresses two types of critics: those who genuinely can't distinguish good from bad psychology (to whom he says the distinction is actually obvious), and those deliberately discrediting all psychology for political reasons (which he argues is counterproductive propaganda). Shorter summary

A replication of a 2023 neuroscience study on brain entrainment and learning found that the original effect likely doesn't exist, revealing how the study obscured key issues through statistical averaging and highlighting how AI tools are democratizing scientific scrutiny. Longer summary

Sasha Putilin received an ACX grant to replicate a 2023 study claiming that flickering lights synchronized to individual brain rhythms could boost learning speed threefold. The $32,000 replication with 12 participants (versus 80 in the original) found no such effect. Upon examining the original data more closely, Putilin discovered the apparent effect was driven entirely by a few participants with large negative learning rates (getting worse over time) who happened to all be in one experimental group. The original study had obscured this pattern by presenting averaged data rather than individual results. Putilin argues this exemplifies 'cargo-cult statistics' where researchers mechanically apply statistical rituals without critically examining underlying data. The post concludes by suggesting AI tools are democratizing meta-science, enabling anyone to audit published research that previously required expert-level effort. Shorter summary

Scott argues that dismissing AI as 'just a next-token predictor' is like dismissing humans as 'just reproduction machines' - both confuse the optimization process that shaped an entity with how that entity actually thinks. Longer summary

Scott argues that dismissing AI as 'just a next-token predictor' confuses levels of optimization. He draws an analogy to humans: just as humans were shaped by evolution optimizing for reproduction but don't think about sex when doing math, AIs were shaped by next-token prediction but don't simply predict tokens when thinking. Scott explains that human brains use predictive coding (predicting next sense-data) to build world-models, while AIs use next-token prediction to build their own world-models. Both processes create complex internal representations - like helical manifolds in 6D space for AIs, or toroidal attractors in human hippocampi - that operate far above the level of simple prediction. The post concludes that both humans and AIs perform 'real thought' using structures created by their respective optimization processes. Shorter summary

Scott explains the Buddhist claim that 'life is suffering' through a temperature analogy: just as cold is merely the absence of heat, joy is merely less suffering, with nirvana being 'absolute zero suffering' rather than a neutral state. Longer summary

Scott explores the Buddhist claim that 'life is suffering' by explaining it through an analogy with temperature: just as scientifically there is only heat (with cold being merely the absence of heat), Buddhists claim there is only suffering (with joy being merely less suffering than baseline). The post addresses the common objection that Buddhism seems to reject life's good experiences, explaining that nirvana isn't a gray neutral state but rather 'absolute zero suffering' - more blissful than ordinary happiness, just as absolute zero is colder than room temperature. Scott connects this to previous discussions about jhanas, meditation, and the symmetry theory of valence, where irregularity in brain activity corresponds to suffering. Shorter summary

A review of the synaptic plasticity and memory hypothesis arguing that it is insufficient to explain memory, and proposing a broader cellular processes and memory hypothesis that includes molecular and intracellular mechanisms. Longer summary

The post reviews the synaptic plasticity and memory (SPM) hypothesis, which claims that learning and memory are stored in changes to synaptic weights between neurons. Through several compelling examples, from cannibalism rituals to heart transplant stories and single-cell learning, the author argues that while the SPM hypothesis has been productive, it is incomplete and partially wrong. The post presents evidence that memory can be stored through non-synaptic mechanisms, and proposes an alternative called the cellular processes and memory (CPM) hypothesis, which suggests memory storage involves multiple molecular and intracellular processes beyond just synaptic weights. Shorter summary

A guest post defending the amyloid hypothesis of Alzheimer's disease, explaining why amyloid is likely the root cause despite recent criticism and discussing why early treatments have only been partially effective. Longer summary

David Schneider-Joseph presents a detailed defense of the amyloid hypothesis of Alzheimer's disease, which states that the disease is caused by accumulation of amyloid-β peptide. He explains the ATN model (amyloid → tau → neurodegeneration) and provides extensive evidence from genetics, clinical studies, and animal models. The post addresses various criticisms of the hypothesis, including the recent research fraud controversy and apparent failures of early treatments. The author explains why current treatments have only achieved about 30% efficacy and predicts that future treatments targeting amyloid earlier and more effectively could achieve much better results. Shorter summary

Scott investigates the correlation between intelligence and neuron count, exploring various theories before suggesting that more neurons allow for less polysemantic (overlapping) representations of concepts. Longer summary

Scott explores why intelligence correlates with neuron count across species, humans, and AI models, despite this correlation not being immediately intuitive. He examines various hypotheses about how having more neurons could help with complex pattern-matching tasks like IQ tests. After discussing several possibilities including pattern storage and matching, he settles on polysemanticity as a potential explanation: fewer neurons means each neuron must encode multiple concepts, reducing precision. The post concludes with insights from an expert suggesting that larger neural networks (biological or artificial) can better approximate complex functions and maintain multiple hypotheses simultaneously. Shorter summary

Scott Alexander examines the surprisingly broad effects of GLP-1 drugs like Ozempic, exploring their mechanisms and speculating on why they seem to impact so many different conditions. Longer summary

Scott Alexander explores the wide-ranging effects of GLP-1 receptor agonist medications like Ozempic, which are approved for diabetes and obesity but show promise for many other conditions. He delves into the mechanisms behind their effects on diabetes, weight loss, and addiction, speculating on why these drugs seem to have such broad impacts. The post discusses how GLP-1 drugs work in the brain to reduce hunger and dampen reward systems, potentially explaining their effects on addiction. Scott also touches on their anti-inflammatory properties and potential benefits for neurodegenerative diseases, while cautioning that some reported effects may not replicate. Shorter summary

Daniel Böttger proposes a new theory of consciousness as recursive reflections of neural oscillations, explaining qualia and suggesting experimental tests. Longer summary

This guest post by Daniel Böttger proposes a new theory of consciousness, describing it as recursive reflections of neural oscillations. The theory posits that qualia arise from the internal processing of information within oscillating neural patterns, which can reflect on themselves. The post explains how this theory accounts for various characteristics of qualia and consciousness, and suggests ways to test the theory using EEG source analysis. Shorter summary

The post explores the Far Out Initiative's goal to eliminate suffering through biotechnology, inspired by a pain-free woman and David Pearce's philosophy. Longer summary

This post discusses the Far Out Initiative, a project aimed at eliminating suffering through biotechnology. It begins by introducing Jo Cameron, a woman genetically incapable of feeling pain or anxiety, and explores the philosophical implications of her condition. The post then delves into David Pearce's suffering abolitionism philosophy and his practical approaches to ending suffering. Finally, it describes the Far Out Initiative's current efforts, led by Marcin Kowrygo, to create suffering-free animals through genetic engineering and potentially extend this to humans in the future. Shorter summary

Scott Alexander proposes that political hyperpartisanship might be a form of trauma, comparing PTSD symptoms to behaviors observed in political extremists. Longer summary

Scott Alexander explores the idea that political extremism might be a form of trauma. He compares symptoms of PTSD to behaviors observed in politically hyperpartisan individuals, such as triggers, distorted cognitions, and hypervigilance. The post discusses how trapped priors in the brain might explain both cognitive and emotional aspects of political extremism. Scott also considers the implications of framing political partisanship as trauma, including potential risks of expanding the concept of trauma. Shorter summary

Scott Alexander discusses recent breakthroughs in AI interpretability, explaining how researchers are beginning to understand the internal workings of neural networks. Longer summary

Scott Alexander explores recent advancements in AI interpretability, focusing on Anthropic's 'Towards Monosemanticity' paper. He explains how AI neural networks function, introduces the concept of superposition where fewer neurons represent multiple concepts, and describes how researchers have managed to interpret AI's internal workings by projecting real neurons into simulated neurons. The post discusses the implications of this research for understanding both artificial and biological neural systems, as well as its potential impact on AI safety and alignment. Shorter summary

Scott Alexander investigates the claim that children learn languages faster than adults, finding it partially true but more nuanced than commonly believed. Longer summary

Scott Alexander examines the claim that children learn languages faster than adults, finding it to be partially true but more complex than commonly believed. He explores various aspects of language acquisition, including critical periods for first language learning, age effects on second language learning, and differences in learning rates between children and adults. The post concludes that while children seem to pick up second languages faster than adults, this advantage is not as clear-cut as often thought, and factors like exposure, motivation, and declining learning rates with age play significant roles. Shorter summary

The review of 'The Mind of a Bee' examines the cognitive abilities of bees, raising questions about their intelligence and potential consciousness. Longer summary

This book review of 'The Mind of a Bee' by Lars Chittka explores the complex cognitive abilities of bees, discussing their behaviors, brain structure, and potential for consciousness. The review covers topics such as the waggle dance, honeycomb construction, brain waves, and various experiments demonstrating bees' problem-solving skills. While not definitively answering whether bees are 'smart' or conscious, the review highlights the complexity of bee cognition and the challenges in studying animal intelligence. Shorter summary

A review of 'Why Machines Will Never Rule the World', presenting its arguments against AGI based on complexity and computability, while critically examining its conclusions and relevance. Longer summary

This review examines 'Why Machines Will Never Rule the World' by Jobst Landgrebe and Barry Smith, a book arguing against the possibility of artificial general intelligence (AGI). The reviewer presents the book's main arguments, which center on the complexity of human intelligence and the limitations of computational systems. While acknowledging the book's thorough research and engagement with various fields, the reviewer remains unconvinced by its strong conclusions. The review discusses counterarguments, including the current capabilities of language models and the uncertainty surrounding future AI developments. It concludes by suggesting alternative interpretations of the book's arguments and questioning the practical implications of such theoretical debates. Shorter summary

Scott explores GABA-A receptor subunits, their effects, and how various drugs interact with them, discussing potential for more selective drug development. Longer summary

This post explores GABA-A receptor subunits and their role in psychiatric drugs and supplements. It explains the structure of GABA-A receptors, focusing on the alpha subunits and their associated effects. The post discusses how different drugs like benzodiazepines and zolpidem (Ambien) interact with these subunits, and mentions attempts to create more selective drugs. It also touches on the role of GABA receptors in alcohol's effects and the classification of Z-drugs. The author includes personal experiences with supplements claiming to have selective GABA modulation. Shorter summary

Scott summarizes interesting comments on his 'Rhythms of the Brain' book review, covering various aspects of brain waves and related topics. Longer summary

This post highlights various comments on Scott's review of 'Rhythms of the Brain'. Topics include explanations of brain waves, their importance in AI and neuroscience, criticisms of their perceived significance, interesting facts about brain rhythms, discussions on phi and conduction delay, perspectives on synchrony, and some tangential discussions on other scientific naming conventions and cryptocurrency. Shorter summary

Scott Alexander summarizes comments debating the reality and implications of jhanas, a meditative state of extreme bliss. Longer summary

Scott Alexander reviews and summarizes comments on his previous post about jhanas, a meditative state of extreme bliss. He discusses the debate over whether jhanas are real, how they compare to other pleasures like sex, whether they can substitute for other pleasures, what science says about them, and whether pursuing jhanas is good or bad. The post includes many quotes from commenters sharing their own experiences with jhanas and opinions on the topic. Shorter summary

Scott Alexander examines the Buddhist concept of jhana, a blissful meditative state, through Nick Cammarata's experiences, exploring its implications for understanding pleasure and reinforcement. Longer summary

Scott Alexander discusses the concept of jhana, a state of extreme bliss achieved through meditation in Buddhism. He focuses on Nick Cammarata's experiences with jhana, describing it as incredibly pleasurable yet non-addictive. The post explores the paradox of jhana being more pleasurable than sex but less reinforcing, challenging conventional models of reward and pleasure. Scott also mentions the Qualia Research Institute's approach to understanding these phenomena and poses discussion questions about the nature of pleasure, reinforcement, and decision-making in relation to jhana. Shorter summary

Scott reviews 'Rhythms Of The Brain', exploring the nature and potential significance of brain waves in neuroscience and consciousness. Longer summary

Scott reviews 'Rhythms Of The Brain' by Gyorgy Buzsaki, exploring the nature and potential significance of brain waves. He discusses why brains produce oscillations, the characteristics of these waves, their possible functions, and speculates on their relationship to consciousness and spiritual experiences. The review concludes with thoughts on how the absence of brain-wave equivalents in AI might affect their development of consciousness or selfhood. Shorter summary

Scott Alexander explores various commenters' insights on the neuroscience of reward, happiness, and relationships, expanding on his original post about unpredictable rewards. Longer summary

Scott Alexander discusses highlights from comments on his post 'Unpredictable Reward, Predictable Happiness', covering topics such as neuroscience of reward, dopamine, and relationships. He explores various perspectives on how the brain processes rewards, predictions, and happiness, including insights from neuroscientists, psychologists, and personal anecdotes. The post touches on topics like abusive relationships, polyamory, wealth and happiness, and the cognitive burden of poverty. Shorter summary

Scott Alexander analyzes a study showing Concerta improves ADHD children's attention but not their learning, and speculates on the reasons behind this unexpected result. Longer summary

Scott Alexander discusses a recent study on the effects of Concerta (a long-acting form of Ritalin) on ADHD children's learning in a summer camp setting. The study found that while Concerta improved attention, reduced disruptive behavior, and slightly improved test scores, it didn't significantly enhance learning of the course material. Scott explores potential reasons for this counterintuitive result, drawing parallels to other studies and speculating on the nature of learning and intelligence. He considers factors such as redundancy in teaching, innate intelligence limits, and the possibility of 'difficulty thresholds' for learning. The post ends with a speculative comparison to AI scaling laws, suggesting there might be human equivalents to parameters, training data, and compute in learning. Shorter summary

A review of Stanislas Dehaene's 'Consciousness and the Brain', discussing scientific findings on consciousness and their implications. Longer summary

This review discusses Stanislas Dehaene's book 'Consciousness and the Brain', which explores the scientific understanding of consciousness. The book defines consciousness as the ability to report on a perception, and describes experiments that differentiate conscious from unconscious processing. It explains what the brain can do unconsciously, what requires consciousness, and how consciousness operates in the brain. The review also covers the book's insights on topics like schizophrenia and the 'hard problem' of consciousness. Shorter summary