This UCSF Memory and Aging Center graph shows that our cognitive abilities remain relatively constant until they reach a breakpoint, and then decline at a constant rate. The pace of cognitive decline is the same in our 40’s as in our 80’s. We just notice more accumulated decline as we get older, especially when we cross the threshold of forgetting most of what we try to remember.

(Posit Science used to host this graph, and I needed an online version for my blog on Celebrating the Child-Like Mind, and Childish Scientists.)

At the age of 2 to 3 years old, children have 10x the synapses and 2x the energy burn of an adult brain.

22 responses to “Cognitive Decline by Age”

  1. tifotter Avatar
    tifotter

    Big brain thinking many words now. Soon peak and start go down. Whee!

    But seriously, about the child-like mind. Your blog is interesting. I’m reading a lot of "Creative Systems Theory" right now, by Dr. Charles M. Johnston, and he has a kind of Myers-Briggs (but different) personality typology based on different phases of the creative cycle. "Early" personalities are those most child-like and playful, and they tend to be inventors, artists, creators. "Middle" personalities are the work-horses of the world. Product managers are great middles."Late" personalities are often in sales/presentation and CEOs are typically late personalities. ALL types are needed in a good "system" to take projects from beginning to end. (Earlies are notorious for being great at starting things, not so great at finishing them). Just to the early side of early personalities are schizophrenics, psychotics and other mental disorders.

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  2. Mike_fj40 Avatar
    Mike_fj40

    Say what?

    Reply
  3. biotron Avatar
    biotron

    fascinating stuff, and weirdly reassuring

    Reply
  4. The Rocketeer Avatar
    The Rocketeer

    Why doesn’t it start at 10 and why didn’t the age 50 get used instead of 45? That changes the curve. Also, what was the sample?

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  5. jurvetson Avatar
    jurvetson

    I will try to track down the details. It is frustrating to see a non-linear x-axis. But I don’t think it was to distort the data; rather I think it was an attempt to highlight the inflection point range (30-44 years) in a piecewise linear plot. I presume that the long-term trend is all that one can derive from the data with statistical significance (as opposed to a high order polynomial curve fit).

    In other words, I eyeball the data to say that, on average, we remember 12 words fairly steadily when we are young. Then somewhere around 37 years old (±7 years), we start a steady, linear decline until we die. The “simple to remember” data set that maps to the ranges I see on the graph:

    Age – Words Remembered
    35 – 12
    45 – 11
    55 – 10
    65 – 9
    75 – 8
    85 – 7

    So, on a normal x-axis of ages, I think you would see two linear regions with very different slopes. The early region is roughly flat, and the second region declines by one word per decade.

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  6. The Rocketeer Avatar
    The Rocketeer

    Thanks, Steve.

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  7. Sister72 Avatar
    Sister72

    Your mileage may vary. (Mine did). 😉

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  8. jurvetson Avatar
    jurvetson

    Absolutely! And a mental lube can extend the ride.

    Changing the trajectory of this graph is what motivated UCSF Prof. Merzenich to start Posit Science…

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  9. The Rocketeer Avatar
    The Rocketeer

    I need to go down to the Mental Lube store and get my thinking cap serviced… it’s overdue…

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  10. Erik Charlton Avatar
    Erik Charlton

    I was going to say something but…ummmm…..Darn! Very frustrating.

    Reply
  11. Sister72 Avatar
    Sister72

    …and all this time I’ve been wasting money on oil changes!

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  12. angry shock Avatar
    angry shock

    I think that this graph interpretation seems to be based on the value: "Quantity over Quality". Which is a very modern, capitalist world view. Nature doesn´t work like that in all cases, imo.

    Not for all the people the value "more is better" is true. Quite the contrary sometimes. We minimalists go for the "less is more" actually! =) Good point mentioned above, tifotter about the mental disorders asociated with a highly creative (*) – overconnected and overexcited – brain. I can relate. It is very uncomfortable at times to have a pandora’s box for a brain, fueled by a vast memory. Not as fun as it looks like. [Add reference to "A beautiful Mind" here if you like]. Even children suffer their restlessness and inability to pay attention to one thing at a time.

    Children minds are a Maze to me… (not only they "a-maze" me)… while fascinating and full of possibilities, however, mazes are not the best example of an efficient tool or method to get you anywhere directly, fast and easlily. Can be very disfunctional for some tasks.

    In its reberverations and redundancies lie its virtue and its vice as well.

    This is one of the reasons why I welcome my own aging, as years have helped me manage my mental activity. So, for me, synapse prunning is not that bad. Anybody knows that one main key to success (in anything) is "Focus". Synapse prunning from a positive point of view can mean: "Focus". Whether uncontrolled plasticity may mean "distraction". If there are 5 ways to go from A to B, I´ll most likely succeed in making a decision and start walking until I reach the destination. Now if there are 5000 ways to get there, I´ll possibly never make it.

    Bottom line: Whether lots of synapses is a good or a bad thing much depends on the needs for the task at hand, at the given moment of its process. (again, I agree with tifotter in this)

    Just a point of view..

    —

    (*) To Create [imo] = Ability to recall and shuffle information stored in a brain in unexpected, unstructured ways in order to build up novel information (which will be come subject to further shufflings in the future as well. Many times a creative process regarded as 1, implies in fact large sum of smaller creative processes within, like a chain reaction).

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  13. shawnhoon Avatar
    shawnhoon

    I would be interested to know the result when you segment the population into retirement age/education level etc. I work in a lab with a 80+ year old engineer. He is sharp as a tack and works on, amazingly, nanotechnology.

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  14. angry shock Avatar
    angry shock

    [edit to yesterday’s words]

    I was thinking in bed about this thread. I related cognitive abilitties to synapses’ amount as direct cause the later of the former, for this I interpreted was the connection you made in your caption. But perhaps the ‘decline’ in recalling abilities is not given by synapses number, but by some sort of "buffer" our memory system may have which limits the amount/time of memories that can be recalled to the consciousness? Perhaps this buffer shrinks as we age? Something in the hippocampus? I don´t know about part of the brain’s anatomy/functionality too well…

    I just remembered that microchips -as I know them- beyond their core computational speed, are also limited by a buffer which may limit the amount of data that can enter the microchip for processing…. like bandwidth limits imposed by your ISP condition your Internet use and performance. Or like a bottleneck?

    It doesn´t change the spirit of what I said yesterday, I just wanted to make this revision to it. thx.

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  15. OmMane Avatar
    OmMane

    Can’t remember what I was going to type (age 49).

    Reply
  16. angry shock Avatar
    angry shock

    "Memory is like an orgasm. It’s a lot better if you don’t have to fake it."
    – Seymore, Cray

    Reply
  17. jurvetson Avatar
    jurvetson

    But I like implanted memories!

    Anyhoo, I just came across this nugget from our favorite baboon Professor:

    "ABSTRACT: INVESTIGATIONS about why we reject novelty as we age. The writer, a professor of neuroscience at Stanford University, irritated by his young administrative assistant’s eclectic taste in music, tested whether there any maturational time windows during which we form cultural tastes. He and his research assistants called oldies radio stations, sushi restaurants in the Midwest, and body-piercing parlors and asked the managers when their service was introduced, and how old their average customer was. They found that if you’re more than thirty-five years old when a style of popular music is introduced there’s a greater than ninety-five per cent chance that you will never choose to listen to it. For sushi restaurants, the window of receptivity closed by age thirty-nine; for body-piercing, by twenty-three. The findings were reminiscent of studies that show that creativity declines with age. These studies also indicate that great creative minds not only are less likely to generate something new but are less open to someone else’s novelty. Einstein, in his later years, fought a rear-guard action against quantum mechanics. Psychologist Dean Keith Simonton has shown that the decline in creativity and openness among great minds isn’t predicted by age so much as by how long people have worked in one discipline. Scholars who switch disciplines seem to have their openness rejuvenated. That may be because a new discipline seems fresh and original, or because a high achiever in one discipline is unusually open to novelty in the first place. Or maybe changing disciplines really does stimulate the mind’s youthful openness to novelty. Or it may just be that established generations resist new discoveries because they have the most to lose by them. The explanation is not neurological: in most brain regions there isn’t any dramatic neuron loss as we get older, and there is no such thing as a novelty center in the brain. Given that aging contracts neural networks and makes cognition more repetitive, it would be a humane quirk of evolution if we were reassured by that repetition. There may even be some advantage for social groups if their aging members become protective archivists of their cultural inheritance. But the writer remains dispirited by the impoverishment that comes with this closing of the mind to novelty. If there’s a rich, vibrant world out there, he figures it’s worth putting up a bit of a fight, even it means forgoing Bob Marley’s greatest hits every now and then."
    — Robert M. Sapolsky, Investigations, “Open Season,” The New Yorker, March 30, 1998, p. 57

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  18. biotron Avatar
    biotron

    some of these Cercopithecidaens are really smart, huh?

    as far as taste in music is concerned, it’s interesting to speculate about that 5% who remain open to new styles of "popular" music. their choices may already be fairly narrowly-defined. eclectic taste will assimilate marginal / outsider / experimental ("unpopular"?) music as well as popular styles of all eras.

    having said this, we are fast approaching the point where a huge number of people will not be alive long enough to listen to every second of music in their possession, irrespective of internet / radio streams. the more eclectic one is able to be, the more i reckon one experiences a backlash which narrows and refines one’s tastes.

    almost conversely, as i grow older and choose to actively listen to the general ambience of well-trodden (urban or rural) paths – ie, never ever wearing headphones outside any more – the feeling of excitement increases at "not wanting to miss out" on the sheer variety of sonic permutations and subtleties, in an environment that many might initially dismiss as outwardly predictable / "not prone to novelty".

    a recent rough calculation of how long it would take me to go once completely through my entire music collection left me absolutely flummoxed, subsequently embarking on a mission to whittle through material formats and say goodbye forever in a ruthless manner to many (hypothetically continuous) months of listening. books will have to follow suit.

    i think it was Susan Greenfield who made the remark that the mind is like your favourite room, whose content changes over time – intermittently shedding "excess" that you outgrow, but keeping core "objects" (or variations of these) that define how you identify yourself. constructing some sort of cumulative and consistent matrix upon which to hang your personality is equally useful / necessary for friends and family to feel secure in "knowing" "who" "you" "are".

    certain efforts to achieve "enlightenment" seek to minimise attachment to material bonds and ties. in that sense, i wonder how meditative "insight" gained from empyting the mind or stopping the flow of thought compares with unshackled exposure to unremitting novelty, in terms of preventing cognitive decline?

    good points from GG above that i enjoyed re-reading. all that talk of "focus" relating to good powers of recall and love of novelty prompts me to plagiarise a Flickr member (whose name i conveniently forget…) who said on his profile page : "i have been know to have a very short attention sp

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  19. jurvetson Avatar
    jurvetson

    This just in… Looks like our cognitive function peaks at 22, and shows significant decline by 27 for "reasoning, speed of thought and spatial visualisation. Memory was shown to decline from the average age of 37."

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  20. biotron Avatar
    biotron

    as long as "Daily Mail reading" doesn’t set in at all before death, i’ll be relatively happy…

    Reply
  21. jurvetson Avatar
    jurvetson

    And today’s UCSF study: After ten hours of games from Positscience.com, the older adults showed working memory gains equivalent to a control group with an average age of 24, an improvement of nearly 50 years.

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  22. jurvetson Avatar
    jurvetson

    And from today’s WSJ:

    "A government-funded study published this month found that playing Double Decision can slow and even reverse declines in brain function associated with aging, while playing crossword puzzles cannot."

    This follows "a multi-year, government-funded trial, known as ACTIVE, showed that participants followed for six years had a 50% lower rate of motor-vehicle accidents following cognitive training"

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