The Truth About Pavlov’s Dogs Is Pretty Disturbing

Pavlov’s dogs made their name in psychology classrooms, but should probably be more famous for their physiology. A Pavlovian response is a physical, not psychological, reaction. And it’s possible that that physical reaction is causing people to overdose on drugs in a very unexpected way.

The Real Story of Pavlov’s Dogs

When did Pavlov’s dogs start salivating? When they heard a bell, you say? Au contraire. Pavlov’s dogs started salivating when they saw lab coats. Workers at a lab that studied digestion noticed that the dogs used in the experiments were drooling for seemingly no reason at all.

It was only Ivan Pavlov, a scientist working at the lab, who made the connection between the lab coats and the drool. The dogs, Pavlov reasoned, knew that they were soon going to be fed whenever they saw a lab coat. What intrigued Pavlov was the fact that a physical response could be produced solely by way of a mental association. The dogs couldn’t drool on command consciously, but they could be trained to do so just the same.

That’s when Pavlov went to work with meat, dogs, and bells, and did the controlled experiment that earned him fame and fortune. He won a Nobel Prize in Medicine and Physiology for his research, but most of us hear about his famous experiment when we study psychology, not medicine. Once the Pavlovian response became a metaphor for an unthinking popular response to stimulus, it was divorced, in the public consciousness, from the physical reality. It shouldn’t have been. The mind, when exposed to certain input, can prime the body into a specific state of physical readiness. This has physical, not just social or psychological, consequences.

Pavlovian Response and Drug Overdose

There are a limited amount of places where one can do drugs. Of those places, drug users select a certain few places where they prefer to do drugs, and then do drugs most often at a select number of places that are convenient. Essentially, a regular drug user will often have a regular place to take their drugs. After they’ve done drugs regularly in the same place, the connection is made. A bathroom, a bedroom, a certain club, will always be associated with drug use. People trying to quit drugs often talk about how they have to avoid their old haunts, because they feel a rush of anticipation. That rush is not just mental.

Scientists learned that putting a dog in a certain injection booth every day and injecting it with adrenaline produced a dog with bradycardia - a dangerously slow heartbeat - when they put the dog in the same booth but only injected it with a placebo. The dog’s body was compensating for the adrenaline it anticipated. It was trying to reduce the dangerous effects of the adrenaline by slowing down the dog’s heartbeat.

A drug user’s body does the same. Over time people build up a tolerance for the drug, not just because the body manages to deal with the drug when it’s in their system, but because the body knows to prepare for the drug before it has been administered. When a person who has built up a tolerance for a drug in a certain place goes somewhere new, the body may not know what’s coming to it, and that tolerance is greatly reduced.

In one experiment, scientists studied rats who had been given regular doses of heroin. Some of the rats were taken to a new area and given a larger dose of heroin. The others were injected with the larger dose, but kept in their regular environment. The mortality rate of the rats injected in a new environment was twice that of the rats injected in the familiar environment. No similar experiment of human drug users would be conscionable, but a survey of the survivors of heroin overdoses found that seven out of ten were in a new place when they overdosed.

Even the most basic functions our bodies perform are marvels of biochemistry. When the dogs salivated, they were releasing chemicals that would help them process their food. The biochemistry involving drugs is more complicated, and more vital, than digestion. When we’re not careful, we can unwittingly train ourselves into Pavlovian responses that are dangerous to ignore.

[Via Pavlovian Conditioning and Drug Overdose: When Tolerance FailsThe Correlation Between Drug Tolerance and the Environment.]

At dusk and dawn: Scientists pinpoint biological clock’s synchronicity

Scientists have uncovered how pacemaker neurons are synchronized at dusk and dawn in order to maintain the proper functioning of their biological clocks. Their findings, which appear in the journal PLOS Biology, enhance our understanding of how sleep-wake cycles are regulated and offer promise for addressing related afflictions.

“We’ve known for some time that the time-keeping of our biological clocks is a complex enterprise,” says New York University’s Justin Blau, a professor of biology and neural science and one of the study’s co-authors. “But our results offer new details on how clock neurons work together to keep each other in check.”

The study, which may be downloaded here, also included researchers from the University of Michigan and the University of Houston.

They examined the biological, or circadian, clocks of Drosophila fruit flies, which are commonly used for research in this area—earlier studies of “clock genes” in fruit flies allowed the identification of similarly functioning genes in humans.

While scientists have a firm understanding of how biological clocks work within individual cells, it is less clear how individual cells tick in time together. Such an understanding is vital so that an organism has one coherent sense of time.

This dynamic was the focus of the PLOS Biology study.

The researchers focused on eight master pacemaker neurons (LNvs) located in the central brain —these neurons set the timing of the daily transitions between sleep and wake in the fly.

Specifically, they examined the signals coming in to these eight LNvs. The researchers found that LNvs need two synchronizing signals: they signal to each other at dawn and receive a signal from a second group of clock neurons at dusk. The LNvs start to desynchronize very quickly in flies lacking either of these synchronizing signals, showing how active and important this process is. And in flies lacking both of these signals, the LNvs show weak clock gene rhythms and disrupted sleep/wake cycles.

The researchers point out their findings shed new light on what occurs at dusk—and the significance of the timing of this signaling.

“Scientists already knew about the signaling at dawn, but we hadn’t previously known about the signaling that occurs in the evening,” explains Blau. “We can see how delicate this process is–and treatments to desynchronize clocks might even allow us to reset our clocks more quickly to a new time zone, which would be invaluable in jetlag.”

huffingtonpost:

This Man With Severe Cerebral Palsy Created Mind-Blowing Art Using Just A Typewriter

Last year, 22-time Emmy award-winning reporter John Stofflet posted this news video he created for KING-TV in 2004, featuring Paul Smith and his artistic talents.

See the full video to see more of Smith’s artworks and to learn more about his inspiring story go here. 

The Psychology of Music

- by University of Florida. 

Art is a discipline that is practiced with passion and science is a passion that is practiced with discipline

Dr. Keith Black (via mediclopedia)
we-are-star-stuff:

Breaking down the ingredient ratios of 23 exquisite espresso-based drinks, this chart is a world tour of the purest form of coffee, from the straight-up varieties like the Doppio and Lungo to frothy drinks like the Cappuccino and Latte to less celebrated (yet no less delicious) concoctions such as the Galao and the Cafe Bombon. Happy Coffee Day!

we-are-star-stuff:

Breaking down the ingredient ratios of 23 exquisite espresso-based drinks, this chart is a world tour of the purest form of coffee, from the straight-up varieties like the Doppio and Lungo to frothy drinks like the Cappuccino and Latte to less celebrated (yet no less delicious) concoctions such as the Galao and the Cafe Bombon. Happy Coffee Day!

Brain Encodes Time And Place Of Taste Memory

Have you ever eaten something totally new and it made you sick? Don’t give up; if you try the same food in a different place, your brain will be more “forgiving” of the new attempt. In a new study conducted by the Sagol Department of Neurobiology at the University of Haifa, researchers found for the first time that there is a link between the areas of the brain responsible for taste memory in a negative context and those areas in the brain responsible for processing the memory of the time and location of the sensory experience. When we experience a new taste without a negative context, this link doesn’t exist.

The area of the brain responsible for storing memories of new tastes is the taste cortex, found in a relatively insulated area of the human brain known as the insular cortex. The area responsible for formulating a memory of the place and time of the experience (the episode) is the hippocampus. Until now, researchers assumed that there was no direct connection between these areas – i.e., the processing of information about a taste is not related to the time or the place one experiences the taste. The accepted thinking was that a negative experience – for example, being exposed to a bad taste – would be negative in the same way anywhere, and the brain would create a memory of the taste itself, divorced from the time or place.

But in this new study, conducted by doctoral student Adaikkan Chinnakkaruppan in the laboratory of Prof. Kobi Rosenblum of the Sagol Department of Neurobiology at the University of Haifa, in cooperation with the Riken Institute, the leading brain research institute in Tokyo, the researchers demonstrate for the first time that there is a functional link between the two brain regions.

In the study the researchers sought to examine the relationship between the taste cortex (which is responsible for taste memory), and three different areas in the hippocampus: CA1, which is responsible for encoding the concept of space (where we are located); DG, the area responsible for encoding the time relationship between events; and CA3, responsible for filling in missing information. To do this the researchers took ordinary mice and mice that were genetically engineered by their Japanese colleagues such that these three areas of the brain functioned normally but were lacking plasticity, which did not allow new memories reliant on them to be created.

“In brain research, the manipulation we do must be very delicate and precise, otherwise the changes can make the entire experiment irrelevant to proving or refuting the research hypothesis,” said Prof. Rosenblum.

The mice were exposed to two new tastes, one that caused stomach pains (to mimic exposure to toxic food) and another that didn’t cause that feeling. By comparing the two groups it emerged that when the new taste was not accompanied by an association with toxic food, there was no difference between the normal mice and those whose various functional areas in the hippocampus didn’t allow plasticity. But when the taste caused a negative feeling, there was clear involvement of the CA1 area, which is responsible for encoding the space.

“The significance of this is that the moment we go back to the same place at which we experienced the taste associated with a bad feeling, subconsciously the negative memory will be much stronger than if we come to taste the same taste in a totally different place,” explained Prof. Rosenblum. Similarly, the DG area, which is responsible for encoding the time between incidents, was involved the more time that passed between the new taste and the stomach discomfort. “This means that even during a simple associative taste, the brain operates the hippocampus to produce an integrated experience that includes general information about the time between events and their location,” he said.

The findings, which were recently published in the Journal of Neuroscience, expose the complexity and richness of the simple sensory experiences that are engraved in our brains and that in most cases we aren’t even aware of. Moreover, the study can help explain behavioral results and the difficulty in producing memories when certain areas of the brain become dysfunctional following and illness or accident. The better we understand the encoding of simple sensory experiences in the brain and the link between the feeling, time and place of the experiences; we will better understand the complex process of creating memories and storing them in our brains.

People don’t realize that now is all there ever is; there is no past or future except as memory or anticipation in your mind.

Eckhart Tolle (via neuromorphogenesis)

Some Things You Can Do In Your Sleep, Literally

For those who find themselves sleeping through work — you may one day find yourself working through sleep.

People who are fast asleep can correctly respond to simple verbal instructions, according to a study by researchers in France. They think this may help explain why you might wake if someone calls your name or why your alarm clock is more likely to rouse you than any other noise.

The connections between sleep, memory and learning aren’t new — but the research is notable for its examination of automatic tasks. The study, published Thursday in Current Biology, first recorded the brain waves of people while they were asked to identify spoken words as either animals or objects while they were awake. After each word, the participant used one hand to push a button for animals, and the other hand to push a button for objects.

The brain map produced by the EEG showed where activity was taking place in the brain and what parts of the brain were being prepped for response. This preparation might include hearing the word elephant and then processing that an elephant is an animal. The participants did this until the task became automatic.

The researchers then lulled the participants to sleep, putting them in a dark room in a reclining chair. Researchers watched them fall into the state between light sleep and the deeper sleep known as rapid eye movement (REM). They were then told a new list of words.

This time, their hands didn’t move, but their brains showed the same sorting activity as before. “In a way, what’s going on is that the rule they learn and practice still is getting applied,” Tristan Bekinschtein, one of the authors of the study, told Shots. The human brain continued, when triggered, to respond even through sleep.

But the researchers weren’t fully satisfied, so they took it a step further. They did it all again, but instead of animals and objects, they used real words and fake words. They also waited until the participants were more fully asleep.

Again, they found that the sleeping participants showed brain activity that indicated they were processing and preparing to move their hands to correctly indicate either real words or fake words were being spoken.

"It’s pretty exciting that it’s happening during sleep when we have no idea," Ken Paller, a cognitive neuroscientist at Northwestern University who is unaffiliated with the study, told Shots. “We knew that words could be processed during sleep.” But, Paller adds, “we didn’t know how much, and so this takes it to, say, the level of preparing an action.”

While this sounds like great news for those who could use a few extra hours in the day for memorizing irregular verbs or cramming for the bar exam, the researchers caution that the neural activity they found may apply only to automated tasks. They hope that future studies may look into whether any similar cognitive task begun in an awake state might continue through early sleep — like crunching calculations.

"It’s a terrible thought, in the modern world," says Bekinschtein, referring to the pride people take in forgoing sleep for work. "I think, in a way, these experiments are going to empower people … that we can do things in sleep that are useful."

The Truth About Pavlov’s Dogs Is Pretty Disturbing

Pavlov’s dogs made their name in psychology classrooms, but should probably be more famous for their physiology. A Pavlovian response is a physical, not psychological, reaction. And it’s possible that that physical reaction is causing people to overdose on drugs in a very unexpected way.

The Real Story of Pavlov’s Dogs

When did Pavlov’s dogs start salivating? When they heard a bell, you say? Au contraire. Pavlov’s dogs started salivating when they saw lab coats. Workers at a lab that studied digestion noticed that the dogs used in the experiments were drooling for seemingly no reason at all.

It was only Ivan Pavlov, a scientist working at the lab, who made the connection between the lab coats and the drool. The dogs, Pavlov reasoned, knew that they were soon going to be fed whenever they saw a lab coat. What intrigued Pavlov was the fact that a physical response could be produced solely by way of a mental association. The dogs couldn’t drool on command consciously, but they could be trained to do so just the same.

That’s when Pavlov went to work with meat, dogs, and bells, and did the controlled experiment that earned him fame and fortune. He won a Nobel Prize in Medicine and Physiology for his research, but most of us hear about his famous experiment when we study psychology, not medicine. Once the Pavlovian response became a metaphor for an unthinking popular response to stimulus, it was divorced, in the public consciousness, from the physical reality. It shouldn’t have been. The mind, when exposed to certain input, can prime the body into a specific state of physical readiness. This has physical, not just social or psychological, consequences.

Pavlovian Response and Drug Overdose

There are a limited amount of places where one can do drugs. Of those places, drug users select a certain few places where they prefer to do drugs, and then do drugs most often at a select number of places that are convenient. Essentially, a regular drug user will often have a regular place to take their drugs. After they’ve done drugs regularly in the same place, the connection is made. A bathroom, a bedroom, a certain club, will always be associated with drug use. People trying to quit drugs often talk about how they have to avoid their old haunts, because they feel a rush of anticipation. That rush is not just mental.

Scientists learned that putting a dog in a certain injection booth every day and injecting it with adrenaline produced a dog with bradycardia - a dangerously slow heartbeat - when they put the dog in the same booth but only injected it with a placebo. The dog’s body was compensating for the adrenaline it anticipated. It was trying to reduce the dangerous effects of the adrenaline by slowing down the dog’s heartbeat.

A drug user’s body does the same. Over time people build up a tolerance for the drug, not just because the body manages to deal with the drug when it’s in their system, but because the body knows to prepare for the drug before it has been administered. When a person who has built up a tolerance for a drug in a certain place goes somewhere new, the body may not know what’s coming to it, and that tolerance is greatly reduced.

In one experiment, scientists studied rats who had been given regular doses of heroin. Some of the rats were taken to a new area and given a larger dose of heroin. The others were injected with the larger dose, but kept in their regular environment. The mortality rate of the rats injected in a new environment was twice that of the rats injected in the familiar environment. No similar experiment of human drug users would be conscionable, but a survey of the survivors of heroin overdoses found that seven out of ten were in a new place when they overdosed.

Even the most basic functions our bodies perform are marvels of biochemistry. When the dogs salivated, they were releasing chemicals that would help them process their food. The biochemistry involving drugs is more complicated, and more vital, than digestion. When we’re not careful, we can unwittingly train ourselves into Pavlovian responses that are dangerous to ignore.

[Via Pavlovian Conditioning and Drug Overdose: When Tolerance FailsThe Correlation Between Drug Tolerance and the Environment.]

Mechanized human hands: System designed to improve hand function lost to nerve damage

Engineers at Oregon State University have developed and successfully demonstrated the value of a simple pulley mechanism to improve hand function after surgery.

The device, tested in cadaver hands, is one of the first instruments ever created that could improve the transmission of mechanical forces and movement while implanted inside the body.

After continued research, technology such as this may offer new options to people who have lost the use of their hands due to nerve trauma, and ultimately be expanded to improve function of a wide range of damaged joints in the human body.

The findings were just reported in Hand, a professional journal, by researchers from OSU and the School of Medicine at the University of Washington. The research was supported by OSU.

“This technology is definitely going to work, and it will merge artificial mechanisms with biological hand function,” said Ravi Balasubramanian, an expert in robotics, biomechanics and human control systems, and assistant professor in the OSU College of Engineering.

“We’ll still need a few years to develop biocompatible materials, coatings to prevent fibrosis, make other needed advances and then test the systems in animals and humans,” Balasubramanian said. “But working at first with hands – and then later with other damaged joints such as knees or ankles – we will help people recover the function they’ve lost due to illness or injury.”

Initially, the OSU research will offer a significant improvement on surgery now used to help restore the gripping capability of hands following nerve damage. That procedure, called tendon-transfer surgery for high median-ulnar palsy, essentially reattaches finger tendons to a muscle that still works. But the hand function remains significantly impaired, requiring a large amount of force, the stretching of tendons, and fingers that all move at the same time, instead of separately as is often needed to grasp an object.

The new mechanism developed at OSU is not really robotic since it has no sensory, electronic or motor capabilities, Balasubramanian said. Rather, it’s a passive technology using a basic pulley that will be implanted within a person’s hand to allow more natural grasping function with less use of muscle energy.

“Many people have lost the functional use of their hands due to nerve damage, sometimes from traumatic injury and at other times from stroke, paralysis or other disorders,” Balasubramanian said. “The impact can be devastating, since grasping is a fundamental aspect of our daily life. The surgery we’re focusing on, for instance, is commonly performed in the military on people who have been injured in combat.”

The new research showed, in cadavers, how the mechanism developed for this problem can produce more natural and adaptive flexion of the fingers in grasping. The needed force to close all four fingers around an object was reduced by 45 percent, and the grasp improvement on an object reduced slippage by 52 percent.

Such progress can be an important step to improve function beyond the existing surgical procedure, by providing an alternative to the suture which has been the previous mainstay. The hand, experts say, is amazingly complex, with 35-38 muscles and 22 joints all working together, innervated by three nerves between the elbow and fingertip.

The long-term potential of such mechanized assistance is profound. In some cases, Balasubramanian said, it may indeed be possible to create joints or limbs that mechanically function as well or better than they did originally.

“There’s a lot we may be able to do,” he said. “Thousands of people now have knee replacements, for instance, but the knee is weaker after surgery. With mechanical assistance we may be able to strengthen and improve that joint.”

Thank you!

Thank you guys for always supporting Neuromorphogenesis. Love you all.

Stay Curious!

biocanvas:

Neurons in a zebrafish embryo
Zebrafish have proven invaluable for understanding what we know about nerves and the brain. Observing brain development and interrogating how growing neurons find their correct targets are possible thanks to the transparent, genetically malleable nature of zebrafish embryos. Recently, scientists have developed a technique called “Brainbow" that individually colors each neuron, allowing researchers to map the start and end points of neural circuits. Applying Brainbow to zebrafish will allow researchers to visualize how neurons connect with one another during development and how different diseases disrupt this process.
Image by Dr. Albert Pan, Harvard University.

biocanvas:

Neurons in a zebrafish embryo

Zebrafish have proven invaluable for understanding what we know about nerves and the brain. Observing brain development and interrogating how growing neurons find their correct targets are possible thanks to the transparent, genetically malleable nature of zebrafish embryos. Recently, scientists have developed a technique called “Brainbow" that individually colors each neuron, allowing researchers to map the start and end points of neural circuits. Applying Brainbow to zebrafish will allow researchers to visualize how neurons connect with one another during development and how different diseases disrupt this process.

Image by Dr. Albert Pan, Harvard University.

journey-to-balance said: Phenomenal Blog - Happy to have found you :)

Thank you!

Why Does Sleeping In Just Make Me More Tired?
We’ve all been there: It’s been a long week at work, so Friday night, you reward yourself by going to bed early and sleeping in. But when you wake up the next morning (or afternoon), light scathes your eyes, and your limbs feel like they’re filled with sand. Your brain is still lying down and you even have faint headache. If too little sleep is a problem, then why is extra sleep a terrible solution?
Oversleeping feels so much like a hangover that scientists call it sleep drunkenness. But, unlike the brute force neurological damage caused by alcohol, your misguided attempt to stock up on rest makes you feel sluggish by confusing the part of your brain that controls your body’s daily cycle.
Your internal rhythms are set by your circadian pacemaker, a group of cells clustered in the hypothalamus, a primitive little part of the brain that also controls hunger, thirst, and sweat. Primarily triggered by light signals from your eye, the pacemaker figures out when it’s morning and sends out chemical messages keeping the rest of the cells in your body on the same clock.
Scientists believe that the pacemaker evolved to tell the cells in our bodies how to regulate their energy on a daily basis. When you sleep too much, you’re throwing off that biological clock, and it starts telling the cells a different story than what they’re actually experiencing, inducing a sense of fatigue. You might be crawling out of bed at 11am, but your cells started using their energy cycle at seven. This is similar to how jet lag works.
But oversleep isn’t just going to ruin your Saturday hike. If you’re oversleeping on the regular, you could be putting yourself at risk for diabetes, heart disease, and obesity. Harvard’s massive Nurses Health Study found that people who slept 9 to 11 hours a night developed memory problems and were more likely to develop heart disease than people who slept a solid eight. (Undersleepers are at an even bigger risk). Other studies have linked oversleep to diabetes, obesity, and even early death.
Oversleep doesn’t just happen as a misguided attempt at rewarding yourself. The Harvard Nurses Study estimated that chronic oversleep affects about 4 percent of the population. These are generally people who work odd hours, have an uncomfortable sleep situation, or a sleeping disorder.
People who work early morning or overnight shifts might be oversleeping to compensate for waking up before the sun rises or going to sleep when it’s light out. Doctors recommend using dark curtains and artificial lights to straighten things out rather than medication or supplements. Apps like the University of Michigan’s Entrain can also help people reset their circadian clock by logging the amount and type of light they get throughout the day.
When you go to bed, your body cycles between different sleep stages. Your muscles, bones, and other tissues do their repair work during deep sleep, before you enter REM. However, if your bed or bedroom is uncomfortable—too hot or cold, messy, or lumpy—your body will spend more time in light, superficial sleep. Craving rest, you’ll sleep longer.
If everything’s just fine with your sleep zone but you still can’t get under the eight hour mark, you might need to go see a doctor. It could be a symptom of narcolepsy, which makes it hard for your body to regulate fatigue and makes you sleep in more. Sleep apnea is a potentially more serious disorder where you stop breathing while you slumber. It’s typically caused by an obstructed airway, which leads to snoring. However, in a small number of sufferers, the brain simply stops telling the muscles to breathe, starving the brain and eventually forcing a gasping response. In addition to all the other terrifying aspects of this disease, it’s not doing your quality of sleep any favors.
No surprise, drugs and alcohol might also be causing you to sleep too much, as does being depressed (In fact, oversleep can contribute to even more depression). But no matter what’s causing it, too much sleep is not good for your long term health. Rather than kicking the can down the road, try getting some equilibrium between your weekend and weekday sleep.

Why Does Sleeping In Just Make Me More Tired?

We’ve all been there: It’s been a long week at work, so Friday night, you reward yourself by going to bed early and sleeping in. But when you wake up the next morning (or afternoon), light scathes your eyes, and your limbs feel like they’re filled with sand. Your brain is still lying down and you even have faint headache. If too little sleep is a problem, then why is extra sleep a terrible solution?

Oversleeping feels so much like a hangover that scientists call it sleep drunkenness. But, unlike the brute force neurological damage caused by alcohol, your misguided attempt to stock up on rest makes you feel sluggish by confusing the part of your brain that controls your body’s daily cycle.

Your internal rhythms are set by your circadian pacemaker, a group of cells clustered in the hypothalamus, a primitive little part of the brain that also controls hunger, thirst, and sweat. Primarily triggered by light signals from your eye, the pacemaker figures out when it’s morning and sends out chemical messages keeping the rest of the cells in your body on the same clock.

Scientists believe that the pacemaker evolved to tell the cells in our bodies how to regulate their energy on a daily basis. When you sleep too much, you’re throwing off that biological clock, and it starts telling the cells a different story than what they’re actually experiencing, inducing a sense of fatigue. You might be crawling out of bed at 11am, but your cells started using their energy cycle at seven. This is similar to how jet lag works.

But oversleep isn’t just going to ruin your Saturday hike. If you’re oversleeping on the regular, you could be putting yourself at risk for diabetes, heart disease, and obesity. Harvard’s massive Nurses Health Study found that people who slept 9 to 11 hours a night developed memory problems and were more likely to develop heart disease than people who slept a solid eight. (Undersleepers are at an even bigger risk). Other studies have linked oversleep to diabetes, obesity, and even early death.

Oversleep doesn’t just happen as a misguided attempt at rewarding yourself. The Harvard Nurses Study estimated that chronic oversleep affects about 4 percent of the population. These are generally people who work odd hours, have an uncomfortable sleep situation, or a sleeping disorder.

People who work early morning or overnight shifts might be oversleeping to compensate for waking up before the sun rises or going to sleep when it’s light out. Doctors recommend using dark curtains and artificial lights to straighten things out rather than medication or supplements. Apps like the University of Michigan’s Entrain can also help people reset their circadian clock by logging the amount and type of light they get throughout the day.

When you go to bed, your body cycles between different sleep stages. Your muscles, bones, and other tissues do their repair work during deep sleep, before you enter REM. However, if your bed or bedroom is uncomfortable—too hot or cold, messy, or lumpy—your body will spend more time in light, superficial sleep. Craving rest, you’ll sleep longer.

If everything’s just fine with your sleep zone but you still can’t get under the eight hour mark, you might need to go see a doctor. It could be a symptom of narcolepsy, which makes it hard for your body to regulate fatigue and makes you sleep in more. Sleep apnea is a potentially more serious disorder where you stop breathing while you slumber. It’s typically caused by an obstructed airway, which leads to snoring. However, in a small number of sufferers, the brain simply stops telling the muscles to breathe, starving the brain and eventually forcing a gasping response. In addition to all the other terrifying aspects of this disease, it’s not doing your quality of sleep any favors.

No surprise, drugs and alcohol might also be causing you to sleep too much, as does being depressed (In fact, oversleep can contribute to even more depression). But no matter what’s causing it, too much sleep is not good for your long term health. Rather than kicking the can down the road, try getting some equilibrium between your weekend and weekday sleep.