What is the brain's timing/clock mechanism?


The Living Force
FOTCM Member
I ran across a person who has been having episodes of time speeding up rapidly, combined with fluctuations in auditory volume levels. -In trying to work out reasons why this might be happening, I've looked at migraine headaches, blood sugar issues, low oxygen (blacking out), and schizophrenia. I could offer some interesting ideas; One fellow offers that high stress events will sometimes cause time-distortion, and whether it speeds up or slows down depends on the sort of focus you are giving the moment...


Interesting, but it offers only pattern observation of WHAT happens, but not WHY it happens. I was interested in the actual mechanics. Through the process of looking at this stuff, I found myself face to face with a question which has been bothering me for a long while now. "How does the brain decide when Now is?"

I found this paper which attempts to summarize the various theories for how the brain keeps track of time. . .


Thus far, the findings in the scientific realm appear to be inconclusive; some interesting ideas, but really, there are no clear answers.

I was wondering if the C's might give some specifics on the mechanics behind how our brains perceive time. They said that our perception of time comes as a result of our DNA, which doesn't necessarily suggest a biological clock, but it might. So specifically, my questions are...

1. How is the "speed" of time established? Does our brain key itself to an external wave and frequency? Assuming yes, what is the source of that wave form?

2. How do our brains choose which frame of reality to focus on? Why is Now, Now and how did we pick it?

3. Is this a collective phenomenon? That is, does everybody on the planet all tick to the same clock, and are they all on the same frame, as it were?



The Living Force
FOTCM Member
These two items stood out and may be connected in some way to this puzzle.

Figured I'd pigeon hole them here to keep the papers together, so to speak!


The mechanism that controls the internal 24-hour clock of all forms of life from human cells to algae has been identified by scientists.

Not only does the research provide important insight into health-related problems linked to individuals with disrupted clocks -- such as pilots and shift workers -- it also indicates that the 24-hour circadian clock found in human cells is the same as that found in algae and dates back millions of years to early life on Earth.

Two new studies in the journal Nature from the Universities of Cambridge and Edinburgh give insight into the circadian clock which controls patterns of daily and seasonal activity, from sleep cycles to butterfly migrations to flower opening.

One study, from the University of Cambridge's Institute of Metabolic Science, has for the first time identified 24-hour rhythms in red blood cells. This is significant because circadian rhythms have always been assumed to be linked to DNA and gene activity, but -- unlike most of the other cells in the body -- red blood cells do not have DNA.

Akhilesh Reddy, from the University of Cambridge and lead author of the study, said: "We know that clocks exist in all our cells; they're hard-wired into the cell. Imagine what we'd be like without a clock to guide us through our days. The cell would be in the same position if it didn't have a clock to coordinate its daily activities.

"The implications of this for health are manifold. We already know that disrupted clocks -- for example, caused by shift-work and jet-lag -- are associated with metabolic disorders such as diabetes, mental health problems and even cancer. By furthering our knowledge of how the 24-hour clock in cells works, we hope that the links to these disorders -- and others -- will be made clearer. This will, in the longer term, lead to new therapies that we couldn't even have thought about a couple of years ago."

For the study, the scientists, funded by the Wellcome Trust, incubated purified red blood cells from healthy volunteers in the dark and at body temperature, and sampled them at regular intervals for several days. They then examined the levels of biochemical markers -- proteins called peroxiredoxins -- that are produced in high levels in blood and found that they underwent a 24-hour cycle. Peroxiredoxins are found in virtually all known organisms.

A further study, by scientists working together at the Universities of Edinburgh and Cambridge, and the Observatoire Oceanologique in Banyuls, France, found a similar 24-hour cycle in marine algae, indicating that internal body clocks have always been important, even for ancient forms of life.

The researchers in this study found the rhythms by sampling the peroxiredoxins in algae at regular intervals over several days. When the algae were kept in darkness, their DNA was no longer active, but the algae kept their circadian clocks ticking without active genes. Scientists had thought that the circadian clock was driven by gene activity, but both the algae and the red blood cells kept time without it.

Andrew Millar of the University of Edinburgh's School of Biological Sciences, who led the study, said: "This groundbreaking research shows that body clocks are ancient mechanisms that have stayed with us through a billion years of evolution. They must be far more important and sophisticated than we previously realised. More work is needed to determine how and why these clocks developed in people -- and most likely all other living things on earth -- and what role they play in controlling our bodies."

Additional funding for the studies was provided by the Biotechnology and Biological Sciences Research Council, the Engineering and Physical Sciences Research Council, the Medical Research Council, the French Agence Nationale de la Recherche, and the National Institute of Health Research.

And. . .


Humans use their senses to help keep track of short intervals of time according to new research, which suggests that our perception of time is not maintained by an internal body clock alone.

Scientists from UCL (University College London) set out to answer the question "Where does our sense of time come from?" Their results show that it comes partly from observing how much the world changes, as we have learnt to expect our sensory inputs to change at a particular 'average' rate. Comparing the change we see to this average value helps us judge how much time has passed, and refines our internal timekeeping.

Dr Maneesh Sahani, from the UCL Gatsby Computational Neuroscience Unit, and an author of the paper said: "There are many proposals for how an internal clock might work, but no one has found a single part of the brain that keeps track of time. It may be that there is no such place, that our perception of time is distributed across the brain and makes use of whatever information is available."

Published online in Current Biology today, the study includes two key experiments. In one experiment 20 participants watched small circles of light appear on a screen twice in a row, and were asked to say which appearance lasted longer. When the circles were accompanied by a mottled pattern programmed to change randomly, but with a regular average rate, participants' judgments were better - suggesting that they used the rate of change in the patterns to judge the passing of time.

In another experiment the authors asked participants to judge how long the mottled patterns themselves lasted, but varied the rates at which those patterns changed. When the patterns changed faster, participants judged them to have lasted longer -- again showing that sensory change shapes our sense of time.

"Our sense of time is affected by outside stimuli, and is therefore highly mutable, which is something that resonates with people's feeling about the passing of time," said Dr Sahani.

"It is possible to bias people's perception of time, which does not fit with the idea of a rigid internal brain clock. The answer to why this happens is that part of our perception of time is based on changing sensory input from the outside world, which we can use to improve our judgments of time in an environment where rate of change is likely to be reliable," added Dr. Misha Ahrens, the first author of the study and a UCL graduate student when the study was conducted.


The Living Force
FOTCM Member
Just adding this article as well. . .


Ever wondered how long a hug lasts? The quick answer is about 3 seconds, according to a new study of the post-competition embraces of Olympic athletes. But the long answer is more profound. A hug lasts about as much time as many other human actions and neurological processes, which supports a hypothesis that we go through life perceiving the present in a series of 3-second windows.

Crosscultural studies dating back to 1911 have shown that people tend to operate in 3-second bursts. Goodbye waves, musical phrases, and infants' bouts of babbling and gesturing all last about 3 seconds. Many basic physiological events, such as relaxed breathing and certain nervous system functions do, too. And several other species of mammals and birds follow the general rule in their body-movement patterns. A 1994 study of giraffes, okapis, roe deer, raccoons, pandas, and kangaroos living in zoos, for example, found that although the duration of the animals' every move, from chewing to defecating, varied considerably, the average was, you guessed it, 3 seconds.

"What we have is very broad research showing that we experience the world in about these 3-second time frames," says developmental psychologist Emese Nagy of the University of Dundee in the United Kingdom.

Hugs also appear to fit the pattern. In 2008, Nagy, a gymnastics fan, was watching the Beijing Summer Olympics on television and noticed a lot of hugging going on. Most of the previous 3-second research had been done on individuals, and she wondered whether the pattern would hold for an experience shared between two people, especially one as intimate and emotionally charged as an embrace.

So Nagy conducted a frame-by-frame analysis of video recordings of the Olympic finals in 21 sports, among them badminton, wrestling, and swimming. She had an independent observer time 188 hugs between athletes from 32 nations and their coaches, teammates, and rivals.

Regardless of the athletes' and their partners' gender or national origin, the hugs lasted about 3 seconds on average, Nagy reports this month in the Journal of Ethology. Not surprisingly, the identity of the partner mattered: athletes hugged their coaches somewhat longer than they did their teammates and hugged their opponents the shortest amount of time.

The results reinforce an idea current among some psychologists that intervals of about 3 seconds are basic temporal units of life that define our perception of the present moment. Put another way, what one psychologist called the "feeling of nowness" tends to last 3 seconds.

That rhythm has fundamentally shaped humans' biological and social evolution, says neuroethologist Geoffrey Gerstner of the University of Michigan, Ann Arbor, who co-authored the 1994 paper on zoo animals. If it were instead much faster, say 10 milliseconds, then we could react much more quickly to incoming stimuli, such as potential threats. "Bullets would be as frightening to us as somebody throwing a ball at us," Gerstner says, "whereas if we lived in 1-minute-duration periods, there's an awful lot of things that could happen in the natural world that we just wouldn't be able to respond to." Either way, there would be big consequences for our survival.

Colwyn Trevarthen, a psychobiologist at the University of Edinburgh in the United Kingdom, agrees that the 3-second pattern is of paramount importance as the foundation of our conscious experience. But he points out that the body has other rhythms, too, including split-second reflexes. All of them make up our natural sense of time, which is hardly a rigid metronome. "We're not talking about something crude and automatic. We're talking about something flexible and highly expressive," Trevarthen says. "It's biological. It's mental. It's spiritual. This is the timing of the human spirit."

The commenters on the front page of this story offer some interesting points.

It's neat; reading a number of these articles causes a sort of barnacle build-up of awareness on the subject. I wonder if continued heating will eventually result in a sort of combustion?


The Living Force
FOTCM Member
Just adding another article which showed up. Bolded possible points of interest.


Even when we're not at work, we're on the clock - our biological clock, that is.

A system of biological clocks controls the daily, or circadian, rhythms of the body. These roughly 24-hour cycles of physical, mental and behavioral changes are found in most organisms, from humans to fruit flies, plants and even tiny microbes. Circadian rhythms determine sleep patterns, contribute to jet lag and are responsible for the groggy feeling you may experience after "springing ahead" for daylight saving time this coming weekend. Research supported by the National Institutes of Health has shown that circadian rhythms also influence hormone production, hunger, cell regeneration and body temperature and are associated with obesity, depression and seasonal affective disorder.

What makes them tick?

Biological clocks aren't made of cogs and wheels, but rather groups of interacting molecules in cells throughout the body. A "master clock" keeps everything in synch. In vertebrates, including people, the master clock is located in the brain. Ours lies within the hypothalamus in a group of nerve cells called the suprachiasmatic nucleus or SCN.

The body's clocks are partially driven by internal factors, including numerous genes and the proteins they produce. In 2006, researchers at the University of California, Irvine, discovered that a protein aptly named CLOCK is an essential component in directing circadian rhythms in humans, fruit flies, mice, fungi and other organisms. Counterbalancing CLOCK is a metabolic protein called SIRT1, which senses energy use in cells.
Upsets in the CLOCK-SIRT1 equilibrium can lead to sleep disruption and increased hunger. If the proteins remain chronically unbalanced, it can contribute to obesity.

Biological clocks are also affected by signals from the environment - primarily light and darkness. The SCN is located just above the optic nerves, which relay information from the eyes to the brain, so it is ideally positioned to receive information about the amount of incoming light. When there is less light, such as after sunset, the SCN directs the brain to produce more melatonin, a hormone that makes you sleepy. In this way, the master clock directs our sleep-wake cycles.

Circadian rhythms are perhaps most famously implicated in jet lag, when passing through multiple time zones offsets your body's clock from that of your wristwatch. "Losing" or "gaining" time during air travel can leave your body feeling disoriented, especially if it is expecting daylight when it is actually dark, or vice versa. Eventually your body is able to adjust its circadian rhythms to the new environment. But return travel will disrupt it again, requiring another reset.

Time for treatment

Understanding circadian rhythms may help lead researchers to improved treatments for sleep disorders, jet lag, depression and even cancer.

For instance, researchers at the University of North Carolina-Chapel Hill measured the activity of DNA repair systems at various times of the day in mice and found that they were most active in the afternoon and evening. Because some cancer drugs target DNA repair systems, the drugs might be more effective if given earlier in the day, when the body is less active in repairing damaged cancer cells.

Also, examining the interaction of metabolic proteins involved in circadian rhythms, such as CLOCK and SIRT1, could lead to the development of drugs aimed at obesity and diabetes.
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