The Infamous Nap

Good news for you nappers out there: Research shows that a 45-minute nap can greatly improve memory performance. A study was done recently at the University of Saarland, where participants were shown a list of 90 words and 120 word pairs, of which had no previous relation to one another (for example, milk-taxi). Participants who took a 45-60 minute nap compared to the group that watched DVDs were able to recall these words and word pairs as well as they did right after the learning stage, or right after they memorized these words (University Saarland 2015).

During this study, the researchers looked at the hippocampus, which is responsible for turning learned information into long-term memory. The activity of the hippocampus was measured on an electroencephalogram (EEG), where the activity of “sleep spindles” was observed in the napping group. This brain activity is a “burst of rapid oscillations in the EEG” that are suspected consolidate learning memory into the long-term memory storage. The more sleep spindles that the person experiences, the stronger the memory will be. The results of the study were that those who took naps did significantly better when remembering the words and word pairs.

Research on naps is a popular topic; researchers have studied the effects of naps on weight, likelihood of getting disease, productivity and overall health and wellness. The National Sleep Foundation has a whole page on napping benefits and tips, but they do make specifications: a nap under 40 minutes increases alertness and productivity, but longer naps can decrease productivity and make a person more fatigued than before, because they made it to a deeper REM sleep. This can also cause sleep inertia that night. The best thing to do if you are feeling fatigued is to drink caffeine and then take a 20 minute nap- by the time you wake back up, the caffeine will have started to kick in (National Sleep Foundation, n.d.).

Personally, I am a fan of naps. It is very hard to get the recommended 7 or 8 hours of sleep every night while in college due to the amount of work and extracurricular activities most students are involved in, so I typically am fatigued. I have heard that short naps can energize, and getting enough sleep during the night helps the brain process what it has learned, but I was not aware that short naps have the same effect of enhancing learned memory to long term memory. All the more reason to take even a quick nap after that all-night cram session!

References:

Napping. (n.d.). Retrieved April 2, 2015, from http://sleepfoundation.org/sleep-topics/napping?page=0,2

University Saarland. (2015, March 20). Neuropsychology: Power naps produce a significant improvement in memory performance. ScienceDaily. Retrieved April 1, 2015 from www.sciencedaily.com/releases/2015/03/150320091315.htm

The Amazing State of Modern Prosthetics

In honor of the session we had as a class the week of March 23 on Biomedical Engineering, as well as in honor of my own personal major of Biomedical Engineering, I want to use my last long post on this blog to bring attention to my personal favorite topic in the field – prosthetics.  Unlike many who love the topic, I thankfully do not have a personal connection to the subject of prosthesis, but nonetheless it is near and dear to my heart, and some of the ground being broken as we speak is utterly breathtaking.  

Prosthetic limbs have undergone many aesthetic changes throughout history, but until recently the core concept has remained largely unchanged since before the days of pirates, where peg-legs ran amuck on the high seas.  Within the last couple of decades, however, the field has greatly expanded both its knowledge and its flexibility when dealing with practical applications.  The first of this ‘new wave’ of prosthetic limbs came when the real-world forces acting on the body during motion were more thoroughly analyzed and applied to lower limb devices, coming about in the use of advanced springs and padding to simulate the action-reaction motion of force that travels through the legs during activity. The result of this is that the artificial limb pushes back up on the body with a force equivalent to an actual foot and calve, resulting in more fluid and comfortable movement for amputees.  

However, the newest developments taking place in the field though are even more incredible than those prior.  Akin to something strait out of the Star Wars saga, the idea that these limbs can react to natural electrical signals to provide user-created motion is becoming closer and closer to reality.  Two studies out of the Science Translational Medicine are parading a new generation of advanced prostheses that react more naturally to the user’s body thanks to direct-to-bone coupling and two-way implanted electrodes. The study performed in the United States, at Case Western Reserve University in Cleveland, Ohio, used electrodes implanted into prosthetic arms to take in environmental stimuli and transmit the information received up to the nearest natural nerve endings and deposit it.  The results were an ability of the perception of different sensations in different circumstances that lasted for well over a year in the patients acted on.

 

In another part of the country, Dr. Shawn Dirk, alongside colleagues at Sandia National Laboratories, the University of New Mexico and the MD Anderson Cancer Center, has a brilliant concept in the early stages of development.  The hyper-complex nerves that the body houses have been a huge barrier holding reactive prosthetics back, so Dr. Dirk’s proposed solution is to create a synthetic substance that can act as a scaffold for prosthetic limbs and support tissue growth, which would allow for severed nerves to merge with robotic limbs.  One foreseeable application of this technology should the idea work would be to take the next step and implant the electrodes that have been developed in the aforementioned Case Western study in natural positions along the length of the nerves travelling throughout the synthetic limbs.  This would allow for a much greater area of effective data collection as well as sensory output heading the other way from the Central Nervous System.  

The possibilities for this line of approach with prosthesis feels limitless – there are already some incredible ideas being put to the test and some even more incredible results coming out of those tests.  The more the organic structure of the nervous system is understood, and the more the signals involved in it are unlocked and understood, the more prominent the bridge between natural and synthetic will be gapped, right at the source.  

References:

  http://www.medgadget.com/2014/10/breakthrough-prosthetic-arms-with-feeling-of-touch-advanced-integration-video.html

http://www.independent.co.uk/life-style/gadgets-and-tech/news/a-sensational-breakthrough-the-first-bionic-hand-that-can-feel-8498622.html

http://www.wired.com/2012/02/nerve-prosthetics/