Memory Processing

            Memory is one of the most important processes that our brain does. It allows us to make sense of our world and learn from experiences. Without a doubt, memory is one of the hardest subjects to study in neuroscience. One of the reason that memory is so hard to study is the fact that it is not a skill, but a collection of skills. It involves many aspects of consciousness and can be affected by different means. If you were asked to recall an event, say a dinner last week, your brain will use different areas in order to create the image of the event. What you were eating, smelling, experiencing, and feeling at that particular time, combine in order to create the mental picture of the dinner. Not only that, but stuff learned after the dinner could also play a role in how your brain constructs the memory. For example, you might have really enjoyed the dinner right after you left the restaurant, but if all the friends that were with you really hated the food you might begin to think the experience wasn’t as good as you thought. It is for this reason that researchers have come to understand that memories are not rigid, but fluid constructs that depend on multiple levels of reasoning. For this reason, one of the most common tools to improve memory is increasing the associations between the concepts.

 As explained in an article from TIME magazine, one study had its participants draw an object that represented a simple word in the hopes of improving its recall. The word was always something simple, like balloon or stick, and the time that participants spent drawing was controlled for. For example, the participants had to memorize a random lists of words by either looking at each individual word for 10 seconds or drawing the words in the same time. This was done in order to ensure that any benefits in the participant’s recall were due to an actual benefit of the associations instead of simply having more time to think about the object while they were being drawn. The researchers reasoned that having a visual, as well as a mental processing of the concept would lead to increased associations and subsequently better recall of the words. They were correct. No matter how much time the participants spent memorizing the words one thing was consistent: drawing the words led to better recall accuracy.

However, our brains might not even need to be consciously processing associations between concepts in order to see benefits in our memory. As seen in Dr. Vargas’s study, pairing newly learned information with sound cues during REM sleep led to spatial recall advantages. In this study, participants were first taught to associate unique objects to specific locations on a computer monitor. Each object was also paired with a sound cue (for example, kettle was paired with a whistle sound). The participants would then take a nap with an unobtrusive white noise in the background. During the non-REM stage, these participants were cued with some of the characteristic sounds of the objects. After the participants were awaken, they would attempt to place the objects on their corresponding locations in the monitor. The results showed that objects which had received the sound cues during the nap saw better accuracy in their spatial arrangements when compared to objects that had not been paired with their sound cues.

These findings highlight the complexities of memory formation processes in our brain. These studies show how associations formed during the events can be just as important as the actual information being stored. It seems as if our memory is a complex and fluid network; understandably, this network is very difficult to understand or even study. However, studies like these help develop strategies in which we can improve our memory. They also reveal key aspects of memory formation and help find new insights into this process. Since memory is so vital to what makes us human, there will continue to be investigations and research on memory; no matter how daunting or difficult this subject remains.

Bibliography

Kluger, Jeffrey. 2016. "Here's the Memory Trick That Science Says Works." Time, April 22.

<http://time.com/4304589/memory-picture-draw/?iid=sr-link1>

No sleep means No learning

Its finals week and once again you are up to 3 a.m. attempting to cram an entire semesters worth of biochemistry into your head in the next five days. It's hard to remember the last time you got a good night's rest but you think to yourself that all the sleep deprivation in the world may be worth getting an A on that final. But that is where many of us college students actually are wrong because contrary to popular belief depriving yourself of sleep to study is stopping your brain from "consolidating" these newly formed memories.

When we learn new information, it is quite vulnerable and in order for it to actually "stick" in our head it must go through a process called "memory consolidation." This process allows us to retain all this new knowledge by strengthening the connections between our brain cells and other brain regions. (Beth Israel Deaconess Medical Center)

The Science Daily article, Study Shows How Sleep Improves Memory mentions a study conducted on 12 otherwise healthy college aged individuals who were taught a sequence of skilled finger movements. Some of these individuals were subjected to 12 hours of wake while others were allowed to sleep and then tested on how well they were able to recall the finger movements while, an fMRI machine measured the activity of their brain. The results showed that " the cerebellum, which functions as one of the brain's motor centers controlling speed and accuracy was more active when subjects had had a night of sleep. At the same time, the MRI showed reduced activity in the brain's limbic system, the region that controls emotions such as stress and anxiety." 

Sleep not only plays a large role in strengthening our memories but as our speaker Dr. Vargas explained in her findings of Strengthening Individual Memories by Reactivation Them During Sleep it is possible to activate specific memories during sleep when it is paired to a learning context such as a sound. In this study people were taught to associate 50 object images with a location on a computer screen. Every image was also associated with a characteristic sound for example, the image of a cat was associated with a "meow" sound. Subjects were then allowed to take a nap during which only 25 of the objects sounds were played. When they woke up the researchers found that subjects had an easier time placing those images that had been cued vs. those that had not. This shows that information that is rehearsed when we sleep is more accurately remembered when we are awake.

 Therefore, when we decide to not get any sleep we are putting ourselves at a disadvantage. Sleep is needed to get all the new information "stuck" in our heads long enough to recall and use on that very important test day and it helps lower all the stress and anxiety we are most likely feeling. Instead of seeing sleep as wasted precious study hours we should use it as a tool by pairing sounds or other learning contexts with the information we need to learn and play it when we sleep to better consolidate the information. 

Works Cited 

• Beth Israel Deaconess Medical Center. (2005, June 29). Study Shows How Sleep Improves Memory. ScienceDaily. Retrieved May 3, 2017 from www.sciencedaily.com/releases/2005/06/050629070337.htm

• Lundstrum, J. (n.d.). 9 PILLARS OF BRAIN HEALTH – RE-GROW YOUR BRAIN AND MEMORY AT ANY AGE [Image]. Retrieved from https://www.simplesmartscience.com/how-much-sleep-do-i-need-insomnia-and-memory-loss/

• Rudoy, J. D., Voss, J. L., Westerberg, C. E., & Paller, K. A. (2009). Strengthening individual memories by reactivating them during sleep [PDF]. Science, 326(5956), 1079. https://doi.org/10.1126/science.1179013

Natural Robots

Dr. Gregory Dumanian presented his work on targeted muscle reinnervation for enhanced prosthesis function to the Loyola neuroscience community. Dr. Dumanian was focused on studying how to better control the function of prosthetic limbs to create a more effective prosthetic device. Prosthetics of the past were plagued by being very uncomfortable and difficult to use. Usually only consisting of one joint, with most patients describing them as a tool and rarely using them because of impracticality. His findings were based on the premise that residual limbs contain nerves that are still connected to the brain. By surgically repositioning these nerve endings, a prosthetic can be created that is capable of more precise motor control by the brain.

In the case study he presented, a woman was given a new prosthetic device which was capable of greater functionality (the use of more than just one joint) thanks to the targeted muscle reinnervation. This technique uses residual nerves that are a byproduct of amputation but are no longer connected to the limb. Her pectoral nerves, which still receive input from the brain, were reinnervated. Reinnervation consists of severing the already present motor nerve in order to recreate a connection to the sensory nerve junction which is still connected to the brain. This provides electromyogram signals that control the prosthetic. These signals, which originate from the brain, ultimately allow the patient to regain the ability to control hand and arm movements, now through the prosthetic device.
 
In the article “A Prosthetic Hand That Can Feel” by Diane Tsai and Alexandra Sifferlin, we are introduced to the work of researchers at Case Western University. They have created a clinically applicable prosthetic hand that has sensory capabilities. The patient, Igor Spetic, lost his hand in an accident 5 years before obtaining this advanced prosthetic device. This new device allows Spetic to perform more precise tasks such as opening bags and holding a cup with more confidence. What I found most interesting was how Spetic claimed that, ”what I'm excited about is knowing that I can go back from being one-handed to being a two-handed person”. This shows how important the sensory capabilities of a prosthetic device can be. It allows for the person to become one with the device they are using. Hopefully to the point that a device is just as natural as the original hand. The work performed by the team at Case Western uses pressure sensors in the hand to send signals to those amputated nerves which are still connected to the brain. By doing this, the patient is able to feel the sensation of touch which allows for the device to be less of a tool and more of a part of their body.

This article in Time Health connects to the work of Dr. Dumanian because his work with targeted muscle reinnervation also dealt with restoring the sensory capabilities of the hand in his patient’s prosthetic arm. As a result of the surgery, touching certain areas of her chest led to the perception of someone touching her hand. He was able to specifically reorganize the nerves, that once relayed sensory information to certain portions of the hand, to the patient’s pectoral muscles. As a result to control the prosthetic, juts by thinking about which hand muscles to use. I believe the work of researchers at Case Western and Dr. Dumanian are relevant because both are taking the idea of prosthesis to the next level. While Dr. Dumanian focuses on created a more natural and useful prosthetic device with greater control by the patient. While the highly precise hand of the Case Western study, allows a patient to do the same thing while also get feedback in the form of touch. To have better control and function with the prosthetic device to eventually lead to a more natural and normal life.

I think the work at Case Western is important because it uses sensors in the hand to relay pressure as neural messages to the brain using a similar technique that Dr. Dumaian does: by connecting the prosthetic to the brain through nerve endings that are still viable, but not used because of amputation. Dr. Dumanian’s study is more focused on how the brain can better control the device while the hand from Case Western allows for the brain to get feedback from the device as well. I believe that both aspects are needed to create a more advanced and useful prosthetic device for patients, combining the sensory capabilities of the Case Western device allows for the patient to feel as though the prosthetic is their own natural limb, while Dr. Dumanian allows for much better control of the device. Combined can move us closer to a more natural prosthetic.

Todd A Kuiken, Laura A Miller, Robert D Lipschutz, Blair A Lock, Kathy Stubblefield, Paul D Marasco, Ping Zhou, Gregory A Dumanian, Targeted reinnervation for enhanced prosthetic arm function in a woman with a proximal amputation: a case study, The Lancet, Volume 369, Issue 9559, 3–9 February 2007, Pages 371-380, ISSN 0140-6736, https://doi.org/10.1016/S0140-6736(07)60193-7.

http://time.com/4104723/a-prosthetic-hand-that-can-feel/?iid=sr-link1

Reclamation of Touch and Mobility

In his lecture on Targeted Muscle Reinnervation (TMR), Dr. Gregory A Dumanian explained amputees can have their nerves, which are still functioning even after the loss of the limb, and reattach them into larger muscle groups. This is exercised as when a limb is lost, the nerves that are associated with that limb are still functioning and receiving neuronal signals. Because these signals have nowhere to go, the ends of the neurons swell up and cause severe pain to the individual. The expression of these signals account for the phantom limb sensation. The phantom limb sensation are the feelings that an individual experiences in regards to a limb or organ that is not physically part of the body. Fortunately, Dr. Dumanian was able to use TMR to prevent the pains by reinnervating them into muscles, such as the pectoral muscle in the chest. In doing so, patients were able to regain full sensory and mobile abilities when a prosthetic limb was attached in place of the amputated limb. Upon attachment of the prosthetic limb, patients were able to regain their mobility. What is astonishing is that when moving their limb, they were not doing anything special. They simply reported that they imagined their arm moving, and due to TMR, the prosthetic was functioning as though it were the original arm.

As seen with Melissa Loomis from Ohio, who lost her arm when she tried to separate her pets from fighting with a raccoon. The arm that was given to her was advanced high technology. “It designed to integrate with the body and use the brain’s natural neurotransmissions for control.” (Moncrieffe). As seen with the TMR in Dr. Dumanian’s presentation, the stimulation cap processed the electric signals directly from the nerves to the prosthetic. This is what reactivated the pathways that originally were there with her original arm. As these pathways are reawakened, there is minimal, if not any, learning involved with the prosthetic as it is all based on what is there with muscle memory and the nerves telling the prosthetic the action it needs to perform. What is even more interesting here is how Mike McLoughlin, a chief engineer of Research and Exploratory Development Department at APL managed to bring back the sense of touch to Loomis. This involved placement of 100 sensors in the arm to send feedback through the reinnervated nerves, thus allowing Loomis to experience her sense of touch.

In creation of this prosthetic, the main focus for McLoughlin was to ensure to the patient that they were controlling the prosthetic, and not the other way around. Loomis describes how natural it was for her to just motion her making a fist and having witness the prosthetic to the same was amazing. With this innovation, McLoughlin wishes to further ease the process of adding a prosthetic limb to the body through noninvasive techniques. The sole purpose of the prosthetic to begin with it is to bring back mobility and sensory abilities to those who have lost them. Future aims also include cost reductions for patients to afford such high tech prosthetics. 

Works Cited

Chang, James, MD. Hand and Upper Extremity. Third ed. Vol. Six. N.p.: n.p., n.d. Print. Plastic

Surgery.

Moncrieffe, Michelle V. "New prosthetic invention lets users reclaim their sense of touch."

Medical Xpress - medical research advances and health news. Medical Xpress, 24 Mar. 2017. Web. 03 May 2017.

MotherboardTV. "The Mind-Controlled Bionic Arm With a Sense of Touch." YouTube.

YouTube, 18 Aug. 2016. Web. 03 May 2017.

Where Empathy Happens

Empathy is the ability to understand and share the feelings of another. In an fMRI study by Dr. Slyvia Morelli at UCLA, researchers assessed the empathetic responses of 32 participants. In the study, participants were asked to empathize with images of people exhibiting pain, anxiety, and happiness. For the pain condition, participants in the fMRI scanner were presented with an image of someone in a physically painful condition and asked to imagine how much pain that person would be in. For the anxiety and happiness condition, participants were presented with a contextual sentence, followed by six images depicting different people in that situation. The participants were then asked to imagine how each person might feel in either the happy or anxiety-inducing conditions. Finally, participants in the neutral condition were presented with images of people performing everyday tasks, such as ironing or preparing food. (Morelli, Rameson, & Lieberman, 2012).

                                    The results of the study indicate that the empathetic responses occur throughout the brain. The dorsal anterior cingulate cortex (dACC) and the anterior insula (AI), two brain regions associated with negative affect, were activated upon empathizing with people experiencing pain and anxiety. The ventromedial prefrontal cortex (VMPFC), a region associated with positive affect, was active when participants were empathizing with happy people. Additionally, the putative mirror neuron system was more active for context-independent empathizing (empathy with pain) than for context-dependent empathizing (empathy with anxiety and happiness).   Another interesting finding of the study indicated that septal area was active while empathizing with all three emotions in the study: pain, anxiety, and happiness (Morelli et al.). Therefore, this study implicates the dACC, the AI, the VMPFC, and the putative mirror system as important for empathizing with painful, anxiety-inducing, and happy situations.

                                    An article in Science Daily explored a few studies similar to Morelli’s, which aimed to pinpoint the areas of the brain responsible for empathizing and performing altruistic behaviors. In one fMRI study, 20 people watched a video of a hand being poked with a pin, and were then asked to imitate facial expressions from a variety of emotions. The researchers determined that the amygdala, somatosensory cortex, and the anterior insula are associated with experiencing pain and imitating others (ScienceDaily). Another part of the same study had participants playing the “dictator game”, in which participants were given $10 with which they could keep for themselves or share with a stranger. Participants with the most activity in the prefrontal cortex were more likely to be greedy, while participants with more activity in the brain regions associated with empathizing (perceiving pain and emotion) were more likely to give away a greater amount of their money. These findings suggest that people with more activation in the prefrontal cortex (an area of the brain associated with inhibition and regulating behavior) are less likely to perform the altruistic behaviors associated with empathy (ScienceDaily).

                                    These studies conducted by Dr. Sylvia Morelli and other researchers revealed the brain regions most important in experiencing empathy. These areas include the dACC, the AI, the VMPFC, the putative mirror neuron system, the somatosensory cortex and the amygdala. The prefrontal cortex is also important in inhibiting helping behavior, thus it inhibits empathy. This kind of research is important for understanding human nature and the way in which we can relate to each other. It allows gives us a better idea of how to encourage helping behavior.

                  

Sources:

Morelli, S. A., Rameson, L. T., & Lieberman, M. D. (2012). The neural components of empathy: predicting daily prosocial behavior. Social Cognitive and Affective Neuroscience, 9, 39-47. doi:  10.1093/scan/nss088

University of California - Los Angeles. (2016, March 18). Your brain might be hard-wired for altruism: Neuroscience research suggests an avenue for treating the empathically challenged. ScienceDaily. Retrieved May 2, 2017 from www.sciencedaily.com/releases/2016/03/160318102101.htm

Image

http://impakter.com/deconstructing-empathy-in-the-digital-age/