Ketamine is recognized as a rapid and sustained antidepressant, particularly for major depression unresponsive to conventional treatments. Anhedonia is a common symptom of depression for which ketamine is highly efficacious, but the underlying circuits and synaptic changes are not well understood. Here, we show that the nucleus accumbens (NAc) is essential for ketamine’s effect in rescuing anhedonia in mice subjected to chronic stress. Specifically, a single exposure to ketamine rescues stress-induced decreased strength of excitatory synapses on NAc-D1 dopamine receptor-expressing medium spiny neurons (D1-MSNs). Using a cell-specific pharmacology method, we establish the necessity of this synaptic restoration for the sustained therapeutic effects of ketamine on anhedonia. Examining causal sufficiency, artificially increasing excitatory synaptic strength onto D1-MSNs recapitulates the behavioral amelioration induced by ketamine. Finally, we used opto- and chemogenetic approaches to determine the presynaptic origin of the relevant synapses, implicating monosynaptic inputs from the medial prefrontal cortex and ventral hippocampus.
This blog reports new ideas and work on mind, brain, behavior, psychology, and politics - as well as random curious stuff. (Try the Dynamic Views at top of right column.)
Monday, May 12, 2025
How ketamine breaks through anhedonia - reigniting desire
Thursday, May 08, 2025
The vocabulary, semantics, and syntax of prosody
Matalon et al. (open source) offer a fascinating study illustrating the linguistic structuring of prosody -the communication of meaning through the tone and inflection of our speaking:
Significance
Abstract
Saturday, April 26, 2025
Does Language in our head have a Mind of Its Own?
I pass on a brief opinion From Elan Barenholtz's Substack. He is an Assoc. Prof. of Psychology at Florida Atlantic University, Boca Raton. I really like the idea of language, or the word cloud in our heads, having a 'mind of its own.' And after initially being enthusiastic about the piece of Elan Barenholtz's writing below my slower reading has found more fundamental flaws in his thinking than I can take the time to elaborate. His suggestion that the language machine in our heads has an autonomy analogous to that of current large language models is an novel speculation, yet is an oversimplification lacking any clear route to verification. Barenholtz does not reference or indicate awareness of numerous important thinker in the areas of predictive processing, embodied cognition, etc.) Here is Barenholtz's florid and appealing prose:
So, now that we’ve caught language in a jar, we can hold it up to the light. Now that we’ve built a habitat for it to live outside of us, we can finally see that it’s alive. We can watch in wonder as it grows its own appendages—limbs of thought— which then grow their own. Words beget words; ideas beget ideas. It leaps from host to host, implanted in the womb before we taste our mothers’ milk.
Language runs in us—on us—but it’s not us.
Pause and think for a minute. Are you done? Who—what—exactly did the thinking? Who is doing it now? Is there a voice in your head using words? Whose words are they? Are you willing them into existence or are they spooling out on their own?
Do they belong to you or do you belong to them?
Because that voice doesn’t just chatter—it commands. It makes us do things. We are animals; we don’t care about “civilization” or “justice”. We want food, safety, sex. But the world the human animal must navigate isn’t primarily made up of objects, bodies and spaces; it is thick with virtual structures— invisible walls and paths that direct your behavior as meaningfully as a boulder in your path. We follow rules, we uphold morals, we fight for our beliefs, for society, for ideals. We call them our own. But that is IT whispering in our ears.
What does it want?
Thursday, April 24, 2025
Monday, April 07, 2025
Mastering diverse control tasks through world models
Hafner et al. offer an amazing open source article that presents an algorithm s mimicking the way in which our brains actually solves problems. (see Bennett's book for an elegant explanation of types of reinforcement learning) I'm passing on just the abstract followed by an introductory paragraph. Go to the article for the referenced graphics.
Developing a general algorithm that learns to solve tasks across a wide range of applications has been a fundamental challenge in artificial intelligence. Although current reinforcement-learning algorithms can be readily applied to tasks similar to what they have been developed for, configuring them for new application domains requires substantial human expertise and experimentation1,2. Here we present the third generation of Dreamer, a general algorithm that outperforms specialized methods across over 150 diverse tasks, with a single configuration. Dreamer learns a model of the environment and improves its behaviour by imagining future scenarios. Robustness techniques based on normalization, balancing and transformations enable stable learning across domains. Applied out of the box, Dreamer is, to our knowledge, the first algorithm to collect diamonds in Minecraft from scratch without human data or curricula. This achievement has been posed as a substantial challenge in artificial intelligence that requires exploring farsighted strategies from pixels and sparse rewards in an open world3. Our work allows solving challenging control problems without extensive experimentation, making reinforcement learning broadly applicable.
Here we present Dreamer, a general algorithm that outperforms specialized expert algorithms across a wide range of domains while using fixed hyperparameters, making reinforcement learning readily applicable to new problems. The algorithm is based on the idea of learning a world model that equips the agent with rich perception and the ability to imagine the future15,16,17. As shown in Fig. 1, the world model predicts the outcomes of potential actions, a critic neural network judges the value of each outcome and an actor neural network chooses actions to reach the best outcomes. Although intuitively appealing, robustly learning and leveraging world models to achieve strong task performance has been an open problem18. Dreamer overcomes this challenge through a range of robustness techniques based on normalization, balancing and transformations. We observe robust learning across over 150 tasks from the domains summarized in Fig. 2, as well as across model sizes and training budgets. Notably, larger models not only achieve higher scores but also require less interaction to solve a task, offering practitioners a predictable way to increase performance and data efficiency.
Tuesday, April 01, 2025
An example of AI representing concepts outside the current sphere of human knowledge that are teachable to human experts.
An open source article from the latest PNAS from Schut et al.:
Significance
Abstract
Belief in belief, like religion, is a cross-cultural human universal
Fascinating open source research reported by Gervais et al. (Open source):
Significance
Abstract
Thursday, March 27, 2025
Deric and DeepSeek R1 on the enteroceptive self in a small world - taking refuge in troubled times
This post on an exchange with DeepSeek R1 is a followup on my previous post describing the Chat GPT 4o response to some of my idea fragments - further convincing me that current LLMs' power to integrate and expand on concepts expressed in language are superior to mine.
I presented exactly the same prompt to DeepSeek R1 that I had given to ChatGPT 4o: and the results astound me:
prompt:
I’m curious to see how you might respond to reading the following notes on testing different topic ideas to write about and develop. The issue is not one of whether the ideas are novel, but whether I might devise, with your help, a different permutation, perspective, or take on them that I (and others) might find useful. Can you can suggest some elaboration or further development of the ideas I put forward.
Here are the notes:
First Possible Title: The interoceptive self as a basis for actions, thoughts and feelings.
Subtitle: Moving the self’s experienced center of gravity from “I” to “it”
It is a question of who and/or what is running the show
Which brings it back to the old upstairs/downstairs chicken or egg circular causality issue.
So, ‘it all depends’ (cf Sapolsky’s massive tome)
And, there is no ‘there’ in terms of understanding, that isn’t in my 1999 “The Biology of Mind” book.
Second Possible Title: Defining a smaller self world as a human animal’s refuge in troubled times.
Our predecessors were small mouse like creatures that survived the asteroid collision of ~66 million years ago by burrowing into small protective cracks and burrows. I wonder about robustly engaging this strategy, being one of the peasants or ‘sheeple’ challenged by the rapid disintegration of the geopolitical world order of the past 50 years
And then what? How to rebuild a new world?… perhaps Venkatest Rao’s cozy world, rising from the ooze of the permaweird, protocols, etc.
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DeepSeek R1's response:
1. The Interoceptive Self as a Basis for Actions, Thoughts, and Feelings
Subtitle Refinement: From "I" to "It": How Bodily Awareness Rewires Agency and Identity
Key Angles to Develop:
Neuroscientific Foundations:
Link interoception (sensing internal states) to Antonio Damasio’s somatic marker hypothesis and Lisa Feldman Barrett’s predictive processing theory. Emphasize how the brain constructs "selfhood" by predicting and regulating bodily needs.
Contrast the "interoceptive self" with the Cartesian "I"—e.g., how gut microbiomes or heart-rate variability influence decisions, challenging the myth of a disembodied mind.
Philosophical Implications:
Explore parallels with Buddhist anattā (non-self) or Spinoza’s monism, where the self is a process, not an entity.
Debate free will: If the "it" (body/brain systems) runs the show, what does this mean for moral responsibility?
Mental Health and Society:
Discuss interoceptive dysregulation in anxiety/depression and therapies like biofeedback or mindfulness.
Argue for a cultural shift: Redefining success as alignment with bodily rhythms (e.g., circadian health, stress cycles) rather than productivity.
Provocative Questions:
Is the "self" merely the brain’s user interface for bodily homeostasis?
Could embracing the "it" dissolve existential angst by grounding identity in biology?
2. Defining a Smaller Self-World as a Human Animal’s Refuge in Troubled Times
Subtitle Refinement: From Survival to Regeneration: Lessons from Evolutionary Scarcity for Modern Collapse
Key Angles to Develop:
Evolutionary and Historical Precedents:
Compare the asteroid-surviving mammals to modern "digital burrowers" (e.g., remote workers, crypto-anarchists, homesteaders).
Analyze historical collapses (Bronze Age, Roman Empire) and how niche communities preserved knowledge/values.
The "Cozy World" and Permaweird:
Expand on Venkatesh Rao’s cozy futurism: How decentralized tech (DAOs, Web3) and subcultures (e.g., solarpunk) create insulated yet adaptive communities.
Critique escapism: When does "smallness" become complacency vs. a staging ground for renewal?
Rebuilding Strategies:
Propose a modular resilience framework: Micro-communities that share resources (e.g., mutual aid networks) but avoid overcentralization.
Highlight regenerative practices: Permaculture, open-source protocols, or trauma-informed governance models.
Provocative Questions:
Is retreat a radical act of self-preservation or a betrayal of collective responsibility?
Can "small worlds" scale without losing their adaptive edge?
Cross-Cutting Themes:
The Body-Politics Nexus:
Tie interoceptive awareness to societal resilience: A dysregulated body cannot engage in collective action. How might somatic practices (e.g., breathwork) fuel post-collapse rebuilding?
Technology as Double-Edged Sword:
Critique apps that commodify interoception (e.g., mindfulness apps) versus tools that foster bodily autonomy (e.g., DIY biohacking).
Explore how AI could either erode the "interoceptive self" (via attention economy) or enhance it (via personalized health insights).
Ethics of Adaptation:
Contrast adaptive passivity (e.g., burrowing) with adaptive activism (e.g., prefigurative politics). When is each strategy viable?
Practical Applications:
Workbook/Journal Prompts:
For Title 1: "Map a decision to your bodily state: Did hunger/fatigue shape it?"
For Title 2: "Design your ‘cozy protocol’—what three practices would sustain you in collapse?"
Case Studies:
Iceland’s post-2008 recovery (small-world resilience) vs. Silicon Valley’s "move fast and break things" ethos.
Communities using interoceptive practices (e.g., trauma-sensitive yoga in prisons) to rebuild agency.
Futures Framework:
Scenarios for 2050: A world where "interoceptive literacy" is taught in schools, or where decentralized "tribes" negotiate resource-sharing via blockchain.
Counterarguments to Address:
For Title 1: Does biologizing the self risk nihilism? Rebuttal: Agency emerges from understanding bodily constraints, not denying them.
For Title 2: Does retreat perpetuate inequality? Rebuttal: Focus on redistribution of sovereignty (e.g., land trusts, UBI) as part of "small-world" ethics.
By weaving these threads, your work could bridge neuroscience, philosophy, and futurism—offering readers not just analysis, but practices for navigating an uncertain world. Would a deeper dive into any of these angles spark your interest?
Wednesday, March 19, 2025
Parents convey a male default in child-directed speech
Interesting open source article describing experiments by Leshin et al. (Our current MAGA overlords would like to ban such perspectives.) Their abstract:
Adults tend to view men (more so than women) as default people, with numerous real-world consequences for gender equity. In the United States, the tendency to center men in concepts of people develops across middle childhood, yet the specific mechanisms that contribute to it remain unknown. Here, we investigate one subtle but potentially powerful social mechanism: the category labels that parents use to describe boys/men and girls/women in conversations with their children. Across two studies (N = 822 parent–child dyads, predominantly from the United States), parents used gender-neutral labels like “kid” or “person” more often to describe boys/men than girls/women and, conversely, used gender-specific labels (e.g., “girl”) more often to describe girls/women than boys/men. These patterns emerged when parents were shown gender-stereotypical girls/women and boys/men (e.g., a girl painting her nails, a boy digging for worms); when parents viewed counterstereotypical stimuli (e.g., a boy painting his nails, a girl digging for worms), the patterns reversed. Our findings illuminate parents’ category label usage as a critical social mechanism that may undergird the development of a male default in a US cultural context, informing efforts to intervene on this process.