Changes in human brain organization at age ~83 (as well as ages ~9, 32, and 66)

This open source paper by Mousley et al. caught my eye because at 83 years of age I am at one of the article's 'turning points' in brain organization.   I would urge MindBlog readers to have a scan through its descriptions of infancy to 9 years old, Adolescence (~9-32), Adulthood ~32-66), early aging ~66-83, and late aging (~83 onward)  You don't have to understand the jargon and analytical techniques employed to get the gist of the findings. 

I gave Chat GPT 5.2 the following prompt:  

One of the major topological turning points across the lifespan is around 83 years of age. Based on the contents of this paper, and acting as if you are one of its authors, please explain to an 83 year old (like myself) in what ways a brain older than 83 years will be processing information differently than younger brains.  

Here is  the response. It's descriptions conform to my subjective experience, which I would describe in very similar terms:

How an 83-year-old brain processes information differently

By the early 80s, the brain is not simply a weaker version of a younger brain. It is operating in a different organizational regime. The turning point we identify around this age reflects a shift in how information is routed, prioritized, and stabilized across brain networks.

1. Information flow becomes more selective, not uniformly slower

In younger adulthood, the brain relies heavily on fast, globally integrated communication: information moves quickly across many regions using multiple alternative routes. By the early 80s, the network has shed many weaker, redundant connections. What remains is a smaller set of stronger, more reliable pathways.

Consequence:

• Less “broadcasting” of information across the whole brain

• More reliance on well-established routes

• Processing may feel slower, but it is also less noisy and more deliberate

This is pruning with consequences: flexibility is reduced, but stability increases.

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2. Stronger dependence on core hubs and rich-club pathways

At this age, communication is increasingly routed through a central backbone of highly connected hub regions (the “rich club”). Peripheral regions interact less directly and more through these hubs.

Consequence:

• Thinking depends more on central coordination than on parallel exploration

• Multitasking and rapid task-switching become harder

• Sustained, focused cognition remains comparatively preserved

If a hub is disrupted (fatigue, illness, stress), performance drops more noticeably than in younger brains.

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3. Increased modularity: subsystems operate more independently

Earlier in life, brain modules (vision, language, memory, executive control) are highly integrated. After the early 80s, modules become more segregated again.

Consequence:

• Cross-domain integration (e.g., combining new sensory input with abstract reasoning) requires more effort

• Familiar, well-practiced tasks within a domain are relatively spared

• Novel tasks that require coordination across systems feel disproportionately taxing

This explains why learning entirely new frameworks can be difficult, while deep expertise remains intact.

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4. Reduced exploratory processing, increased reliance on prior models

From a network perspective, the older brain favors prediction over exploration. It relies heavily on established internal models and expectations rather than rapidly updating from incoming data.

Consequence:

• Pattern recognition based on long experience remains strong

• Ambiguous or rapidly changing situations are harder to parse

• “Sense-making” may be excellent, while raw speed and novelty handling decline

This is not cognitive rigidity—it is a rational adaptation to reduced network redundancy.

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5. Global efficiency decreases, but error suppression improves

Global efficiency (shortest paths between all regions) declines after the early 80s. However, this is accompanied by fewer competing pathways and less internal interference.

Consequence:

• Fewer “half-formed” thoughts intrude

• Mental clarity may improve for tasks that benefit from constraint

• Creativity shifts from combinatorial novelty to synthesis and refinement

In other words: fewer ideas per unit time, but a higher signal-to-noise ratio.

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6. The brain becomes less resilient to overload, not less intelligent

The turning point we observe does not indicate a sudden drop in intelligence. It reflects a reduced capacity to absorb simultaneous demands.

Consequence:

• Performance is highly context-dependent

• Quiet, low-interference environments matter more

• Fatigue has a larger cognitive cost

When conditions are right, reasoning quality can match or exceed that of younger adults.

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Summary in plain terms

After about age 83, the brain:

• Communicates through fewer, stronger pathways

• Relies more on core hubs and less on diffuse integration

• Prioritizes stability, prediction, and experience over speed and flexibility

• Performs best when tasks are focused, familiar, and well-paced

This is not “decline” in the simple sense. It is a phase change—from a brain optimized for growth, exploration, and rapid integration to one optimized for coherence, efficiency under constraint, and meaning-making based on a lifetime of stored structure.

From a network standpoint, the older brain is no longer trying to be maximally flexible. It is trying to be maximally reliable.

 

“Core Perception”: Re-imagining Precocious Reasoning as Sophisticated Perceiving

I'm enjoying reading through an interesting article by Bai et al.  that will appear in Behavioral and Brain Science and is now soliciting commentary.  Here is the abstract (motivated readers can obtain a copy of the manuscript PDF from me.):

“Core knowledge” refers to a set of cognitive systems that underwrite early representations of the physical and social world, appear universally across cultures, and likely result from our genetic endowment. Although this framework is canonically considered as a hypothesis about early-emerging conception — how we think and reason about the world — here we present an alternative view: that many such representations are inherently perceptual in nature. This “core perception” view explains an intriguing (and otherwise mysterious) aspect of core-knowledge processes and representations: that they also operate in adults, where they display key empirical signatures of perceptual processing. We first illustrate this overlap using recent work on “core physics”, the domain of core knowledge concerned with physical objects, representing properties such as persistence through time, cohesion, solidity, and causal interactions. We review evidence that adult vision incorporates exactly these representations of core physics, while also displaying empirical signatures of genuinely perceptual mechanisms, such as rapid and automatic operation on the basis of specific sensory inputs, informational encapsulation, and interaction with other perceptual processes. We further argue that the same pattern holds for other areas of core knowledge, including geometrical, numerical, and social domains. In light of this evidence, we conclude that many infant results appealing to precocious reasoning abilities are better explained by sophisticated perceptual mechanisms shared by infants and adults. Our core-perception view elevates the status of perception in accounting for the origins of conceptual knowledge, and generates a range of ready-to-test hypotheses in developmental psychology, vision science, and more...

Dangerous Ideas.......

Deric's MindBlog is almost 20 years old. Its first post appeared on Feb. 8, 2006. The assertions and ideas described in that original post are as fresh and relevant now as they were then, before the appearance of the iPhone, social media, and contracting attention spans.  The Edge.org link that once took you to the essays supporting the 'dangerous ideas' now takes you to their published version on Amazon. The "Reality Club" and John Brockman's "Third Culture" cohort of intellectuals has largely dispersed, although you will note many names still quite prominent today.   Here is the 2006 post:

***************

Edge.org is a website sponsored by the "Reality Club" (i.e. John Brockman, literary agent/impressario/socialite). Brockman has assembled a stable of scientists and other thinkers that he defines as a "third culture" that takes the place of traditional intellectuals in redefining who and what we are.... Each year a question is formulated for all to write on... In 2004 it was "What do you believe is true even though you cannot prove it?" The question for 2005 was "What is your dangerous idea?"

The responses organize themselves into several areas. Here are selected thumbnail summaries most directly relevant to human minds. I've not included cosmology and physics. Go to edge.org to read the essays

I. Nature of the human self or mind (by the way see my "I-Illusion" essay on my website):

Paulos - The self is a conceptual chimera
Shirky - Free will is going away
Nisbett - We are ignorant of our thinking processes
Horgan - We have no souls
Bloom - There are no souls, mind has a material basis.
Provine - This is all there is.
Anderson - Brains cannot become minds without bodies
Metzinger - Is being intellectually honest about the issue of free will compatible with preserving one's mental health?
Clark - Much of our behavior is determined by non-conscious, automatic uptake of cues and information
Turkle - Simulation will replace authenticity as computer simulation becomes fully naturalized.
Dawkins - A faulty person is no different from a faulty car. There is a mechanism determining behavior that needs to be fixed. The idea of responsibility is nonsense.
Smith - What we know may not change us. We will continue to conceive ourselves as centres of experience, self-knowing and free willing agents.

II. Natural explanations of culture

Sperber - Culture is natural.
Taylor - The human brain is a cultural artifact.
Hauser- There is a universal grammar of mental life.
Pinker - People differ genetically in their average talents and temperaments.
Goodwin - Similar coordinating patterns underlie biological and cultural evolution.
Venter - Revealing the genetic basis of personality and behavior will create societal conflicts.


III. Fundamental changes in political, economic, social order

O'donnell - The state will disappear.
Ridley - Government is the problem not the solution.
Shermer - Where goods cross frontiers armies won't.
Harari -Democracy is on its way out.
Csikszentmihalyi- The free market myth is destroying culture.
Goleman - The internet undermines the quality of human interaction.
Harris - Science must destroy religion.
Porco - Confrontation between science and religion might end when role played by science in lives of people is the same played by religion today.
Bering - Science will never silence God
Fisher - Drugs such as antidepressants jeopardize feelings of attachment and love
Iacoboni - Media Violence Induces Imitative Violence - the Problem with Mirrors
Morton - Our planet is not in peril, just humans are.

Enlightenment, Habituation, and Renewal - non-dual awareness as the opiate of the thinking classes.

Enlightenment traditions in Abrahamic, Buddhist, Hindu, or other schools of meditative insight have a common issue. How can the central canon or dogma of the way things are be renewed and kept fresh? The usual practice is to repeat a liturgy set down by gurus or priests of a given tradition. The problem is that with each repetition the message  begins to loose its force. The transforming clarity of the initial enlightenment fades as the habituation and desensitization associated with all repetitive activities begins to set in. Temporary resets can sometimes be found by turning to different vendors of the central message who  deliver their respective theory or practice sessions in sonorous and calming voices, in person or online. Longer lectures from workshops or retreats have yielded audience share to increasingly  brief presentations that accommodate the diminished attention spans of those under 30 who have never known a world without social media. They can prefer to absorb information in transient instances of tik-tok mind, X/twitter mind, or instagram mind seconds to a few minutes in duration.

I have listened to several hundred instructional lectures. As I see the same basic points reframed in many different ways, it is clear that the fundamental axioms of enlightenment that are expressible in language are being repetitively rediscovered throughout history and repeatedly archived.  I feel like their verbal messages are as ingrained in my consciousness as the language of the mathematical and chemical structures I have known most of my life.

My flippant 'non-dual awareness as the opiate of the thinking classes’ phrase in the title of this post is meaning to point to the fact that the market for vendors of enlightenment is a distinctive one. Existential angst, or worrying about value, purpose, and meaning seem most pressing to a relatively small number of highly urbanized and literate humans. I can’t imagine that my two Abyssinian cats, who I sometimes takes to be my best role models, spend a significant fraction of their time worrying about the meaning of it all, or pondering the subtleties of epistemology and ontology. 

So...what beyond words? A space or perspective that doesn’t contain them can only be pointed at by using them in the dualistic linguistic context of a sender and receiver. I can, for example, try to use words to give a crude voice to the mute homeostatic generative visceral organic axes of valence and arousal that underlie and generate everything that I am and experience right now: “Dude, get a grip, I (the visceral one) am the one who is actually running this show, deciding where it goes and whether it works or shuts down. The sooner the “I” you imagine yourself to be realizes this and lets go, the sooner some kind of sane space is attained. All of the surface behaviors acted out for others to see - Deric the family man, the professor, the pianist - are shadow play shimmering on the surface of this basic organic substrate, like water insects skittering around on the surface of a pond. What is writing these words is just another one of the contents of consciousness flitting past. Just turn yourself around to look quickly for the writer…what do you see? What do you see as you imagine being first born into this world? The brief glimpses of expanded naive awareness sometimes elicited by questions such as these have the potential of permitting a scrubbing, refreshing, or renewal of consciousness in a way that permits more choice in selecting which prior individual selves and self habits rise to compose current self conscious life. 

Different iterations of these sentiments, different vendings of the sort mentioned in the first paragraph above, can be found in two previous MindBlog posts. One from Nov. 25, 2022:  

Perhaps an increasing number of people who engage techniques for facilitating non-dual awareness find themselves seeing and experiencing the "I" or self that feels threatened by our anxious times from a more useful perspective - an inclusive expanded awareness that includes the reporting "I" or self as just one of its many contents that include passing thoughts, perceptions, actions, and feelings.  A calm can be found in this expanded awareness that permits a  dis-association of the experienced breathing visceral center of gravity of our animal body from the emotional and linguistic veneer of politics and conflict. This does not remove the necessity of facing various societal dysfunctions, but offers the prospect of doing so without debilitating the organic physiological core from which everything we experience rises.  

And the other from Oct. 26, 2022, , passing on a masterful exposition from James Low that I can not improve on.

If you want stability, if you want real peace, you already have that in the nature of awareness. But if you look to manifestation, to patterning of yourself, to thinking you could establish a stable personalty, to live a life in which you were happy all the time, or in which you were your own person, that way madness lies. To find our original face, to find the ground of our primordial being, we need to release our fixation on the dialogic movement of subject and object, and allow ourselves to be the space within which the movement of experience is occurring. Awareness means being aware that we are present without being something as such. This is a great mystery. When we look at phenomena the world, things exist as something. A car is not a cow, an apple is not an orange, compare and contrast, category allocation. That’s how our cognition, our conceptual elaboration functions to give a seemingly enduring structure to identifications. But awareness can’t be caught. It’s not a thing. You can’t pin a tail on the donkey, there is no donkey there. The mind is not an object for itself, it is self luminous awareness, but you can’t catch it. You can never know your mind but you can be your mind. We are awareness and that’s a very important distinction. 

(The above is an updated,  revised and edited version of my Jan. 2, 2023 post.) 

Value, Purpose, Meaning, Futures

Value, purpose, and meaning vary between  religions and cultures, and are best viewed as emergent properties supporting altruistic behaviors bonding us into groups that have proven to be more successful at sustaining themselves over multiple generations.   I take the value, purpose, and meaning of my life as being to exist as an expanded present centered awareness that encompasses all of this - the space in which thoughts, feelings, selves appear and disappear. 

Our transient Anthropocene era is a brief moment in the vast history of this planet and the cosmos. The disappearance of our human species as we know it is a certainty, a transition either to extinction or to a further evolved trans-human form. Understanding and accepting this can be a source of serenity that enables us to live fully in the present moment as grateful witnesses to what is unfolding.