Behavioral Effects of Sleep

Behavioral Effects of Sleep

This is an interesting podcast in which we were featured as part of the topic on Behavior Effects of Sleep.   This Behavioral Grooves Podcast is led by well know behavioral scientists, Tim Houlihan and Kurt Nelson:

Click here to view podcast

Will listening to music affect my sleep quality  OR should I learn to play the Didgeridoo?

Will listening to music affect my sleep quality OR should I learn to play the Didgeridoo?

Throughout history, people have spoken of the value of music in helping one get to sleep.  People have used song and soothing music to put babies and young children to sleep.   This would suggest that music may be able to help those with sleep disorders to sleep better.   This blog examines what the research into music and sleep disorders has shown us.


The research into music and sleep has been very heterogeneous with most studies focusing on some sort of measure of sleep quality as characterized by patient reported outcomes of how well they slept or how they felt the next day.   Most of the research has focused on how music can help someone get to sleep.  In other words, these studies examined the effect of music on helping insomnia.   


A relatively recent study from Taiwan (En-Ting Chang et al. 2012) randomized 25 people with insomnia into two groups, one in whom soothing music was played 45 minutes before bedtime, and another without music.  This study was unique in that they also conducted full-scale sleep studies on these patients while they slept.  Interestingly, the people in the music group reported feeling more rested, though the objective analyses of data from sleep studies showed very little difference.    


A similar theme was observed in a meta-analysis study (a study that looks at other research studies and tries to scientifically combine them) of the effect of music on sleep quality from the medical literature (Wang et al. 2013).  What this study found is that some beneficial effects were seen in patient reported outcomes related to restfulness, but there was so much heterogeneity that no definitive conclusions could be made.  Nonetheless, it seems as if music could have some benefit in helping people feel like they had a better night of sleep.


These previous studies all examined sleep from the perspective of insomnia-like symptoms.  What about the larger sleep disorder known as sleep apnea, where sleep is disturbed due to obstruction or partial blockage of the airway (often causing snoring)?   


There have been some studies done in this area, too, but focused on how music, or specifically, playing musical instruments, could potentially reduce or treat sleep apnea.  The idea is that playing certain instruments that exercise the muscles of the mouth, throat, and airway might strengthen muscle tone, to reduce the chance of obstruction during sleep.  


A large survey of orchestral musicians in the US (Brown et al. 2007), to assess their risk of sleep apnea, found no reduction of risk in musicians who played wind instruments where such muscles are used most.   

As a follow up, another survey of musicians published in 2012 (Ward et al.) found that the risk of sleep apnea was slightly lower in a sub-category of these wind instrument players:  those who played double reed instruments like the oboe.


The most interesting study related to this topic was one conducted in Switzerland over 10 years ago, where researchers randomized people with known sleep apnea to learn to play a long Australian pipe-like instrument called the didgeridoo.   Half the people were taught how to play and practiced over 5 days per week.  The other half were put on a waiting list to learn the didgeridoo, but did not actually get to play the instrument during the study.  


The results found that the didgeridoo-playing group had a remarkable improvement in their sleep test scores and were reported by their bed partners to be sleeping better.  While this study has not been repeated, it does provide an interesting alternative therapy for sleep apnea sufferers who are also fans of Australian aboriginal music!


So, soothing music seems to have a mild benefit in improving sleep quality and insomnia.   More importantly, playing specific musical instruments may help to reduce sleep apnea and improve sleep quality for both you and your bed partner… unless, of course, you play the didgeridoo in bed.



Could bad sleep be affecting my behavior?

Could bad sleep be affecting my behavior?

Almost everyone has had the experience of waking up after a bad night of sleep feeling tired and a bit “off”.   Our brain feels sluggish – like it’s not “hitting on all cylinders” – but does this directly affect  our mood or behavior?


The association between sleep disorders and mood disorders has been known for quite some time: it is estimated that 50% of people with sleep apnea also have a higher chance of experiencing episodes of clinical depression and serious anxiety.   


What is less well-understood is the connection between poor sleep and behavior overall.   Some of our best evidence comes from studies in children. Children with poor sleep quality have been found to have greater swings in mood, decreased attention span, and to be overly active, as well as being more anxious and withdrawn.  Sometimes this also manifests as decreased impulse control, or acting without thinking, which is a particular risk in the teenage years due to exposure to other risky activities.   


It has also been found that some children who present with attention deficit hyperactivity disorder (ADHD) may actually be presenting the symptoms of sleep disorders, the treatment of which can potentially resolve the ADHD symptoms.


In adults, a poll by the National Sleep Foundation in 2009 found that lack of sleep could cause irritability and anger, and lessen one’s ability to deal with stress.  NSF termed the “walking tired” as people who will be more irritated when sitting in traffic jams and more likely to pick arguments with others.  Over time, with chronic sleep disorders such as sleep apnea, one’s job and relationships can suffer, potentially creating a vicious cycle of poor mood and behavior leading to events that result in more depression and anxiety.    


Another study in 2009, done by researchers with cadets at the US Military Academy at West Point, found that sleep deprivation hampered information retention and integration, potentially affecting their abilities to react well to new information.  This is a particular problem in higher risk professions such as soldiers, firefighters, and law enforcement, where sleep deprivation is often a problem.


If you find that you are having more conflicts with bosses or friends and are less tolerant of events or circumstances out of your control, consider examining your sleep health.  Similarly, if your children seem to have less attention and more trouble with mood swings, behavior, and learning, the first place to look should be the quality of their restful sleep.

Your Brain Works Faster With Restful Sleep

Your Brain Works Faster With Restful Sleep

Have you ever said to someone, “I’m a little slow today -- I didn’t get enough sleep”?   We all seem to innately know that being deprived of sleep results in changes in how we function mentally.  Most of us describe this as being “slow” likely due to the perceptible delay in how quickly we are able to perform different mental tasks such as reasoning, reaction times, etc.   What is the science behind this phenomenon?


In late 2017, an international group of researchers from Israel, France, and the U.S. (Yuval Nir et al.) published a research paper in the internationally renown scientific journal Nature Medicine.   They studied a group of 12 patients who were quite unique in that they were undergoing potential brain surgery to treat severe seizures that were not responding to normal medical treatment.   In such patients, doctors will place microfiber electrodes in different parts of the brain to try to identify where the seizures are originating from, and determine if this is an area that can be surgically removed without causing significant damage.  In order to make seizures more likely, patients are typically sleep-deprived as that also predisposes to seizure activity.  


These patients agreed to undergo additional testing in both well-rested and in sleep deprived states.  The additional testing consisted of asking patients to look at a series of pictures and identify which ones contained human faces.  This test is similar to the security check we get on some websites where they may ask you to identify pictures containing characteristics, like roads, faces, etc. 


The scientists assessed two major groups of measures.  One was how fast the individuals were able to identify the pictures with faces on them.  The other was measuring electrical conduction from different parts of the brain using the microfibers that were in these patients’ brains.


The findings were not surprising, and yet quite remarkable, at the same time. 


It was not surprising to find that in a number of cases, people who were sleep-deprived were much slower and much more variable in the time they took to identify the correct pictures. 


What was really remarkable was that the brain conduction times were substantially delayed between different regions of the brain in patients who were sleep deprived.  For example, conduction from the visual cortex (the part of the brain that processes visual information from a picture) around the brain to the frontal cortex (the part of the brain that helps control reasoning and judgment) was up to 4x slower after sleep deprivation.   This demonstrates for the first time that there is an actual and measurable slowing of communication in the sleep-deprived brain.


The implications of this study are broad and quite clear.   When we are sleep- deprived we are both figuratively and literally “slower” in our mental function. 


We should be more careful doing higher level thinking activities and even doing activities that require reactions to visual stimuli.  For example, if you are sleep-deprived, reacting to a driver cutting in front of you on the highway may be 4 times slower than your normal reaction time even when you are awake, potentially resulting in an accident.  


Understanding and trying to reduce sleep deprivation is critical to normal brain functioning.  The reality is that your brain works faster with adequate, restful sleep.

Bad night of sleep = bad day at work

Bad night of sleep = bad day at work

With the vast growth in wearables and apps claiming they help determine “sleep quality”, combined with a growing public movement led by celebrities such as Arianna Huffington, sleep is finally being recognized as an major part of our health and wellness.    Beyond just the health implications, we all understand, intuitively, that a bad night of sleep impairs our activities of the following day.


Recent studies have actually tried to quantify how sleep impacts someone’s performance at work.  In other words, how much does a bad night of sleep cost in worker productivity?


An analysis initially presented by Harvard Medical School (“The Price of Fatigue” 2010) and further augmented by work of Optum, a UnitedHealthGroup associated company, (“Fighting the Epidemic of Fatigue: Treating sleep as a critical Part of Health and Wellness” 2015) had a number of interesting findings.

First, the economic cost of moderate and severe obstructive sleep apnea (OSA), the most common sleep disorder, to society ($65-165B in 2010 dollars) is greater than that of asthma, heart failure, stroke and hypertension ($20-80B).   Of this, up to $15B cost is just lost worker productivity.  Employees with untreated sleep apnea were 6x more likely to miss a full day of work and 5x more likely to miss a partial day.  The decrease in productivity leads to 11.3 days of lost work per year.

An additional $20B of cost is related to workplace accidents, independent of medical and traffic accident costs.  Nonetheless, OSA receives very little public attention even though it is on the same scale in cost, for example with accidents, as the costs associated with safety threats like drunk driving.  Optum suggests that employers treat sleep as one of the three pillars of employee health, on an equal footing with nutrition and exercise.


Another recent white paper from the Maxis global benefits network, a partnership of MetLife and AXA, examined the issue of sleep and cost to employers further (“Sleep: A Business Case for Bedtime” 2015).  This analysis reported that upwards of 40% of the US working population is sleep deprived which is a “threat” to a company’s bottom line” in four major ways:

1. Injuries and mistakes at work – pooled data from 27 studies showed that workplace injuries increased by 62% in people with sleep problems

2. Decreased productivity – scientific studies have suggested $63B in lost productivity in the US workforce alone, or $2,280 per worker each year.

3. Increased direct health care costs -  one study estimates that it costs up to $3,200 additional in direct and indirect health care costs for works with sleep disorders (this is particularly prominent in OSA as sleep apnea is often found to worsen many other chronic diseases such as diabetes, obesity, hypertension, heart failure, etc).

4. Increased absenteeism and presenteeism – Sleep disorders are the #1 cause of lost work days due to both being absent from work and from presenteeism (present at work but easily distracted and inattentive to work).  The figure from the Maxis white paper describes this well:

maxisfigureonabsenteeismand sleep copy.jpg


There are a number of possible solutions to improve this issue but all start with awareness of sleep as important to wellness, coupled with the screening for, diagnosis of, and management of sleep disorders in employees.  Not only can it lead to direct cost benefits in worker productivity, but a happier, healthier and safer group of employees.