Friday, October 16, 2020

Neuro-genetics and its effects on the Obesity epidemic

 By the year 2025, an estimated 300 million people are expected to be categorized as obese (Bray). This increased intake of calories has caused a plethora of health issues, both physical and mental. Diabetes and obesity are major health issues that must be taken seriously, but too often it is shunted off to the side and condemned as a ‘lack of will’ by those it affects. A change in the perception of the disease, from purely the fault of the person who suffers from it to a “multifactorial disease with distinctive pathologic and pathophysiologic processes”, may help assuage the stigma and shame, and bring to light the health, societal and economic costs (Bray, G A, and J Macdiarmid). Hunger is the impulse to eat caused by falling glycogen levels in the liver. Your brain and your body are in constant communication, and there are 3 main hunger hormones to know; leptin, ghrelin, and neuropeptide Y. Since Obesity is most closely related to the amount of fat on the body, we will be focusing on Leptin. Leptin is secreted by adipose tissue (fat cells) and interacts with the hypothalamus, its main function is to regulate the amount of fat your body has. Leptin insensitivity/ leptin resistance is a defect in this pathway, either by leptin deficiency or an issue with neural receptors. In the study “A Leptin Analog Locally Produced in the Brain Acts via a Conserved Neural Circuit to Modulate Obesity-Linked Behaviors in Drosophila” by researchers Jennifer Beshel, Josh Dubnau, and Yi Zhong, it takes a look at how the genetically dysregulated leptin pathway causes obesity. In a surprising conclusion, it was found that the manipulation of the endogenous ligand for the domeless receptor upd1 causes the obesity phenotype in Drosophila (fruit flies) (Beshel). This dysfunction between the leptin analog in the fruit flies and its receptor leads to behaviors expressed by starved flies, even after feeding, which in turn leads to weight gain. 

Bray, G A, and J Macdiarmid. “The Epidemic of Obesity.” The Western Journal of Medicine, Copyright 2000 BMJ Publishing Group, Feb. 2000, www.ncbi.nlm.nih.gov/pmc/articles/PMC1070754/. 

Gunnars, Kris. “Leptin and Leptin Resistance: Everything You Need to Know.” Healthline, 4 Dec. 2018, www.healthline.com/nutrition/leptin-101. 

Beshel, Jennifer, et al. “A Leptin Analog Locally Produced in the Brain Acts via a Conserved Neural Circuit to Modulate Obesity-Linked Behaviors in Drosophila.” Cell Metabolism, vol. 25, no. 1, 2017, pp. 208–217., DOI:10.1016/j.cmet.2016.12.013. 


The Role of Cerebral Organoids in Neurodevelopmental Research

    The human brain has been known to be one of the most complex organs in the human body and for years, in order to better study it's nearly inaccessible tissue, researchers have used animal models to help us further understand the brain and all it’s complexities. Yet, there is a bit of a disconnect between animal and human research. Although we can dive into molecular and cellular effects in animal brain models, it’s hard to study structural changes in humans, especially in fetal brains. 

    Recently, however, researchers have been using human stem cell models (human organoids) to help fill the gap between animal and human studies, especially considering it provides access to tissues that were once extremely difficult to access in vivo. Human brain organoids are 3D structures that are derived from iPSCs and act just as embryonic stem cells do in vivo, having qualities such as unlimited self-renewal and pluripotency. These models are also as sophisticated as a second trimester fetal brain, which opens the door to research for very young, developing brains. 

    Using brain organoids as a complex model for the fetal brain, Sarah Logan and colleagues wanted to study the apoptotic effects of alcohol on fetal brains, specifically the downstream, toxic effects of alcohol on neural pathways (Logan et al., 2020). They hypothesized that NPAS4 contributes to alcohol-induced developmental brain injury. What they found was that brain organoids can serve as a novel model showing that blood alcohol levels as low as .1 can induce neuroapoptosis in a dose dependent manner, while also affecting the metabolism and ultra structure of these mini brains. They also found that NPAS4 is a key factor in alcohol-induced neuroapoptosis, with it’s down regulation due to alcohol exposure showing severe increase in cell death. This study and it's results would have been extremely difficult to attain had they not had the access to a tissue that is so similar to that of an in vivo human fetal brain. 

    The use of human brain organoids has been a breakthrough in neurological research as an incredibly powerful tool to study not only normal human embryonic development but also, similarly to Logan and colleagues, any neurodevelopment disorders. A great example of this comes from Jessica Mariani and colleagues, who attempted to understand the early development in those with idiopathic Autism spectrum disorder (ASD), which is normally identified though macrocephaly, an increased head/brain size (Mariani et al., 2015). They understood the brilliance behind a brain organoid's ability to capture species-specific developmental timing found in vivo, where they had previously primarily used mice as a model organism.What they found on these organoids was an increase in expression of FOXG1, a transcription factor, which was caused by an increased production of inhibitory neurons. Thanks to the use of organoids, Mariani and colleagues were able to focus on the role of this gene as not only a molecular stamp for idiopathic ASD, but also as a possible target for any future therapies. 


    Although more research must be conducted regarding the downfalls of human brain organoids, it's use has allowed for long standing questions regarding early brain development to be researched beyond the use of animal models and to an extent that was once considered unimaginable, allowing for both better and more effective treatments to be developed as a result. 





References:

Mariani, Jessica, et al. “FOXG1-Dependent Dysregulation of GABA/Glutamate Neuron Differentiation in Autism Spectrum Disorders.” Cell, 16 July 2015, FOXG1-Dependent Dysregulation of GABA/Glutamate Neuron Differentiation in Autism Spectrum Disorders.

Logan, Sarah, et al. “Dynamic Characterization of Structural, Molecular, and Electrophysiological Phenotypes of Human-Induced Pluripotent Stem Cell-Derived Cerebral Organoids, and Comparison with Fetal and Adult Gene Profiles.” Cells, 23 May 2020, pp. 1-22. MDPI, www.mdpi.com/2073-4409/9/5/1301. doi: 10.3390/cells9051301

Feeding the Brain: The Neural Mechanisms of Obesity

Obesity is a public health crisis in America. The Center for Disease Control and Prevention (CDC) reported that 42.4% of American’s (in 2017-2018) were obese (1). Obesity can lead to hypertension, high cholesterol, type II diabetes, coronary artery disease, stroke, and even death (2). Researcher Jennifer Beshel and her team, including Josh Dubnau and Yi Zhong, became interested in what causes obesity. There are many risk factors including environmental, Beshel acknowledges “food deserts” in America, places where there aren’t many grocery stores near individuals. Those in lower socioeconomic brackets as well as those who have less education are also more likely to be obese. Beshel’s team started looking at how they can use the brain to prevent obesogenic behaviors.

In the article, “A Lepin Analog Locally Produced in the Brain Acts via a Conserved Neural Circuit to Modulate Obesity-Linked Behaviors in Drosophila,” Beshel used Drosophila, a fruit fly, to investigate the neural mechanisms behind obesity. The team looked at leptin, which is an adipose/fat hormone, in adipose tissues and in neurons. Leptin upd1 was selected because it is thought to inhibit Drosophila neuropeptide F, which in turn would inhibit the neural circuit, causing increased food attraction. They “knocked down” or did not express the leptin upd1 in both adipose tissues and in neurons to look at the effects. Only in the neurons did they find that when they knocked down upd1, did it increase obesogenic behaviors (the flies had an increased attraction to food and increased in weight). In summary, the inhibition of leptin upd1 in Drosophila neurons led to obesogenic conditions, or increased food attraction and weight gain (3).


Other studies are also being done, similar to Beshel’s work with leptin. In the article, “The Complex Interactions Between Obesity, Metabolism, and the Brain,” by Romina Maria Uranga and Jeffrey Neil Keller, the authors cite that leptin is responsible for regulating body weight homeostasis. Leptin is also key in regulating immune and inflammatory processes, not just metabolic and homeostasis processes. Those with obesity often suffer from pain and inflammation, and increased leptin might be the key to relieving that pain. Lastly, those who suffer from obesity have been linked to mental health disorders, cognitive decline, and at risk for other disorders such as dementia. This article highlights the risk obesity poses in overall health and the lasting health effects. The decrease in leptin, as noted by Beshel, can lead to an increase in inflammation in those with obesity, and obese patients can also have other consequences such as cognitive impairment, diabetes, and other related diseases (4).

Works Cited

1. CDC. (2020, June 29). Adult Obesity Facts. https://www.cdc.gov/obesity/data/adult.html

2. CDC. (2020, September 17). Adult Obesity Causes & Consequences. https://www.cdc.gov/obesity/adult/causes.html

3. Beshel, J., Dubnau, J., & Zhong, Y. (2017). A Leptin Analog Locally Produced in the Brain Acts via a Conserved Neural Circuit to Modulate Obesity-Linked Behaviors in Drosophila. Cell metabolism, 25(1), 208–217. 

4. Uranga, R., & Keller, J. (2019, May 06). The Complex Interactions Between Obesity, Metabolism and the Brain. https://www.frontiersin.org/articles/10.3389/fnins.2019.00513/full

Gestures and Their Role in Mathematical Reasoning

As young children, we are often taught many methods of learning starting from elementary school. These methods may or not work for some students depending on their learning styles. In recent years, the method of using gestures while learning mathematics has been studied. These introductory studies of gesture-based learning may have massive impacts, particularly with the recent online school shift in the COVID-19 pandemic. Understanding how gestures may affect learning may allow teachers to develop newer techniques to ensure that their students are learning what they should be as effective as possible. 

In the article “Learning math by hand: The neural effects of gesture-based instruction in 8-year-old children”, Dr. Elizabeth Wakefield and colleagues study the effects of gesture-based learning on neural activity with specific regard to mathematics. They were able to conduct this study using fMRI equipment, which is able to show changes due to blood flow in the brain. The results of this experiment indicate that children who participated in gesture-based learning had more activated brain regions than the children who did not participate in gesture-based learning. The areas that were activated are generally associated with the motor system, which presents the notion that learning through gestures activates this part of the brain, leading to a more complex neural mechanism. This mechanism shows that there is a lasting impact left of gesture learning on the brain in the form of a neural trace. 

However, they may be some evidence that indicates that personally generated gesture-based learning may only be effective if used at a certain stage in the learning process. In the article “Does restricting hand gestures impair mathematical reasoning?” Dr. Candace Walkington and colleagues study the impact of removing personally generated gestures during mathematical tasks in college students. They use a process called gesture inhibition, in which gestures are physically prevented from occurring to see the effect on the learning and answering process for tasks. The results of this experiment indicate that preventing gestures when solving a mathematical task does not have an effect on their mathematical problem-solving skills. Although this holds true in this particular set of conditions for personally generated gestures, this may not hold for other kinds of gestures. 

The results of both Wakefield et al. and Walkington et al. further demonstrate the need for more research on gesture-based learning across age groups. Although learning with gestures at a young age may be extremely helpful, the same cannot be said for certain for college students. The brain regions indicated by Wakefield et al. may show a possible neural mechanism for learning, but Walkington et al. brings up the difference in the type of gesture and in age. These studies do have a slight difference in gesture type and learning ability, but they both indicate the need for more research in this field to enhance optimal conditions for learning. These prospective findings may then be able to provide a successful approach for not only mathematical learning but perhaps as an approach for all types of learning. 

CITATIONS: 
 
Wakefield, E. M., Congdon, E. L., Novack, M. A., Goldin-Meadow, S., & James, K. H. (2019). Learning math by hand: The neural effects of gesture-based instruction in 8-year-old children. Attention, Perception, & Psychophysics, 81(7), 2343–2353. https://doi.org/10.3758/s13414-019-01755-y 

Walkington, C., Woods, D., Nathan, M. J., Chelule, G., & Wang, M. (2019). Does restricting hand gestures impair mathematical reasoning? Learning and Instruction, 64, 101225. https://doi:10.1016/j.learninstruc.2019.101225

The Benefits of Gesture-Facilitated Learning on Second Language Acquisition

Recently, researchers have begun to explore the benefits of gestures in facilitating learning. There is significant evidence that using gestures in addition to speech can aid in learning and recall, specifically in children. As education and teaching methods are constantly evolving, this research is important as it provides insight as to how learning can be better facilitated amongst the general community. Especially in a world where the nature of education is changing due to limitations enforced by the COVID-19 pandemic, research that can help educators to better understand how their students learn best is essential and extremely relevant.   

 In “Learning math by hand: The neural effects of gesture-based instruction in 8-year-old children” Elizabeth Wakefield et. al examine the effect of gesture learning on neural activity. Using fMRI technique Wakefield and colleagues were able to determine that children who learned through gesture and speech activated more brain regions when using the learned skill than children who learned the same skill through solely speech. The study identified the neural network in which higher activation was observed to include, “ bilateral postcentral gyrus, anterior to the general superior parietal activation shown by all children, extending into the left precentral gyrus and the left inferior gyrus, as well as activation in the right middle temporal gyrus, right insula, and right supramarginal gyrus” (6). These areas are associated with the motor system and indicate that learning through gestures provides a lasting neural trace that is activated when children go to perform the learned skill, even if they do not perform the gesture while using said skill.

In “The effects of observing and producing gestures on Japanese word learning” Naomi Sweller and colleagues provided research that adds to that of Dr. Wakefield. By examining the effects of gesture based learning through both observation and reproduction strategies researchers were able to understand how gestures facilitate recall. The study observed this through testing second language acquisition. Participants were native english speakers, ages 18-35 who had no prior knowledge of the japanese language. They were taught japanese words through videos that utilized speech, speech and gesture observation or speech, gesture observation and gesture reproduction (3). Participants were tested on these words immediately after learning and one week after learning. While the study found that participants in the observation and reproduction conditions had better recall scores than participants that learned through speech alone, there was no significant difference in scores between the observation and reproduction conditions. Further, researchers found no effect of learning method on long term memory; indicating that the "beneficial effect of observing or reproducing gestures over speech only learning does not change with time"(8). This suggests that while gesture is beneficial for learning, it does not need to be reproduced for it to be effective in aiding the learning process. It is implied that the motor system can be activated through observation alone.

The research completed by Dr. Sweller and colleagues helps provide insight into the work  of Dr. Wakefield. Dr. Wakefields research showed how gesture learning engages more of the brain then speech learning alone and identified brain regions involved in this process. Dr. Sweller was able to explain that the increased activation is crucial to facilitating improved learning and recall, however the reproduction of the gesture is not essential for the effects to occur; merely observing the action provides the same benefit. While these studies differ in demographics and academic disciplines, they both provide ample evidence of the benefits of gesture based learning and can help educators to better understand how to approach teaching in order to best serve their students.  


Works Cited: 

Sweller et al.,  N. Sweller, A. Shinooka-Phelan, E. Austin (2020). The effects of observing and producing gestures on Japanese word learning. Acta Psychologica, 207 (2020), p. 103079, 10.1016/j.actpsy.2020.103079


Wakefield, E. M., Congdon, E. L., Novack, M. A., Goldin-Meadow, S., & James, K. H. (2019). Learning math by hand: The neural effects of gesture-based instruction in 8-year-old children. Attention, Perception, & Psychophysics, 81(7), 2343–2353. https://doi.org/10.3758/s13414-019-01755-y


The Neurological Benefits of Learning Through Play and Action

    The terms coined as hands-on learning, or learning through play, have long been used as strategies for developing the young minds of children. I worked at a daycare for two years with students that were infants to six year olds. The largest part of our curriculum was creating hand-eye coordination games, or tasks that involved building and stacking items. I always assumed this helped the students learn and improve their motor skills. What I did not realize was that there are long lasting and permanent effects in the brain due to hands-on learning and learning through play.

    After reading Elizabeth Wakefield et. al. article, “Learning math by hand: The neural effects of gesture-based instruction in 8-year-old children” I started to realize the neural effects and benefits that the hands-on tasks I conducted with the students truly had on their developing minds. This idea and learning strategy has commonly been used in school systems for many years. However, what is new is the evidence that shows exactly why and how hands-on learning and learning through play actually improves learning and brain development.

    In the article “Learning through play (early childhood development)” by the authors of Theirworld, they explain the strategy of learning through play and how it affects brain development all the way into adulthood. Theirworld states how simple games and tasks such as peek-a-boo or building a tower can “teach young children about communication, develop their motor skills and help with problem-solving” (Theirworld). Furthermore, these tasks and games allow children to “discover maths and science concepts, including shapes, gravity, balance and counting” (Theirworld). Learning how to count through picking up each stuffed animal on the floor and counting them out loud, or learning categories by practicing putting away toys in labeled totes, all is learning through action. In Wakefield’s research, she found that “learning through action… has lasting effects that continue to influence processing, even when learners are no longer producing any actions at all” (Wakefield 2). This relates to Theirworld’s claim that the learning and development children achieve when they are young, stretches out to affect them all the way into their adulthood. 

    In the Theirworld article, they talk about a case in which poor families in Jamaica had children with stunted growth due to the lack of time spent playing and learning through action. The neurological reasoning behind why these children had stunted growth was because, specifically, learning through play and action “recruits sensory and motor areas more heavily than passively learned information” (Wakefield 2). This all just goes to show how vital the first 8-10 years of a child’s life are in developing their brain properly. In the Theirworld article, they state that “80% of brain development is completed by age three and 90 % by age five” (Theirworld). This means how children learn during these ages is vital to how they will learn and grow mentally in the future.


References:

Learning through play (early childhood development). (2020, October 15). Retrieved October 16, 2020, from https://theirworld.org/explainers/learning-through-play-early-childhood-development

Wakefield, E. M., Congdon, E. L., Novack, M. A., Goldin-Meadow, S., & James, K. H. (2019). Learning math by hand: The neural effects of gesture-based instruction in 8-year-old children. Attention, Perception, & Psychophysics, 81(7), 2343-2353. doi:10.3758/s13414-019-01755-y

Thursday, October 15, 2020

The Benefits of Gesture-Based and Picture-Based Learning in Eight-Year Old Children

        Children are the foundation of our future and giving them the best education possible is one of the most important tasks for current educators. Though, the method of which style of teaching is most beneficial for children, has been debated for decades. Fortunately, current research in the field of behavioral and cognitive neuroscience has suggested a style of learning that may be the most powerful tool for facilitating learning in children. One current study titled, “Learning math by hand: The neural effects of gesture-based instruction in 8-year-old children”, composed by Elizabeth M. Wakefield et al., attempts to gain a better understanding of the underlying neural mechanisms of learning, specifically concerning gesture-based learning in children and their ability to retain math skills (Wakefield et al., 2019). To further illustrate, another article titled, “Learning Foreign Language Vocabulary with Gestures and Pictures Enhances Vocabulary Memory for Several Months Post-Learning in Eight-Year-Old School Children”, also shows the benefits of gesture-based learning, as well as picture-based learning, in retaining foreign language in children (Andrä et al., 2020). Together, these two studies shine light on what method of learning allows children to better retain the information in school, ultimately leading to a more educated generation of children to lead the future.    

         In the first study, researchers utilized functional magnetic resonance imagining (fMRI), a brain imaging tool that exploits the way hydrogen atoms act as a small magnet, which can be utilized to compose a signal that can be recorded through the brain imaging software to produce a functional spatial image of the brain (University of San Diego School of Medicine, 2020). In addition to fMRI, the researchers analyzed their behavioral findings in a collection of twenty children, seven to nine years old. The authors separated the children into two experimental groups, one group where the children learned through speech with gesture strategy, and the other with speech-alone strategy (Wakefield et al., 2019). After the experimental procedure, the researchers analyzed their findings and formulated multiple conclusions to their study. One of their findings suggest that children who were taught the speech and gesture strategy more actively recruited their motor regions, as well as their sub-threshold activation in regions of the brain that are not typically used in the action-learning network (Wakefield et al., 2019). This suggests the children that learned through this speech-gesture method actively used more areas of their brain to better retain the material, specifically the activation of the motor regions. This activation allows the children to not only utilize their prefrontal cortex to retain and learn information, but to simultaneously activate the motor regions, ultimately fortifying the connection between their learning and memory (Wakefield et al., 2019). Overall, through the researchers data and analysis, they suggest that when children learn through the speech-gesture strategy, it leads to a more fortified and embedded neural trace of motor system involvement, where neural mechanisms are activated when children attempt to solve math problems with a gesture associated with the problem (Wakefield et al., 2019). This study is one example of how researchers are actively studying the most efficient, beneficial way to educate children, in order to create a more structured base of knowledge when continuing their educational career. 

        The second study further evaluates the findings of the Wakefield et al., and further studies the effects of gesture-based learning, as well as picture-based learning in children. Andrä and colleagues attempt to discover the advantages of not only gestures, but pictures on eight-year-old children’s ability to retain foreign vocabulary (Andrä et al., 2020). The researchers employed three distinct experiments, with a total of fifty-four German children enrolled in primary school in Leipzig, Germany (Andrä et al., 2020). Constant in each experiment, the children underwent training over a period of five successive days, though in in the first group, the children were presented the foreign word auditorily with self-performed gestures, whereas the second group received the word without the accompanied gesture (Andrä et al., 2020). In the third group, gesture-based learning was used, along with picture-based learning, where the words are presented auditorily with pictures, instead of the gesture (Andrä et al., 2020). The first and second groupings allow for a comparison between gesture-based and picture-based learning, whereas the second group acts as a control or baseline when comparing the data in the analysis. After all of the test sessions, the children are assed on their ability to recall and translate to learned foreign words in three days, two months, and six months following the learning (Andrä et al., 2020). The researchers were surprised to find the gesture-based and the picture-based learning both enhanced the children’s scores on the post-learning assessment, as compared to non-enriched learning, with retention of the words lasting till the six-month assessment (Andrä et al., 2020).  Interestingly enough, the authors hypothesized that the gesture-based learning method would yield higher scores on the assessments, due to previous literature such as the study mentioned above, although they found that both methods of learning produced statistically similar results and benefits to the children’s learning (Andrä et al., 2020).


        Thus, these two studies, both equally important, shed light into the question of which learning method is best employed when educating young children, specifically eight-year-old children. In the study conducted by Wakefield et al., the authors provide an insight to how beneficial gesture-based learning is to children. This novel study provided the foundation for many future researchers, such as the study conducted by Andrä et al. Although, this study also showed that picture-based learning is equally as useful in educating children. With this in mind, these findings may suggest the most beneficial and efficient way to educate and build a strong foundation of knowledge in children is to utilize a combination of gesture based and picture-based learning, for maximum retention and recall. These studies are crucial in solving these global dilemmas such as child education and development, due to the alarming rate of children who suffer learning and attention issues, which is cited in literature to be one in five children in the United States alone (The State of LD: Understanding the 1 in 5, 2019). Further research is required to determine the true best method of educating children, though studies such as these provide the framework into which we may potentially discover the most beneficial method, ultimately allowing for a more educated, knowledgeable future for our children.   


References


Andrä, C., Mathias, B., Schwager, A., Macedonia, M., & von Kriegstein, K. (2020). Learning Foreign Language Vocabulary with Gestures and Pictures Enhances Vocabulary Memory for Several Months Post-Learning in Eight-Year-Old School Children. Educational Psychology Review, 32(3), 815–850. https://doi.org/10.1007/s10648-020-09527-z

The State of LD: Understanding the 1 in 5. (2019, October 23). NCLD. https://ncld.org/news/newsroom/the-state-of-ld-understanding-the-1-in-5

University of San Diego School of Medicine. (2020). What Is FMRI? - Center for Functional MRI - UC San Diego. Center for Functional MRI. https://cfmriweb.ucsd.edu/Research/whatisfmri.html

Wakefield, E. M., Congdon, E. L., Novack, M. A., Goldin-Meadow, S., & James, K. H. (2019). Learning math by hand: The neural effects of gesture-based instruction in 8-year-old children. Attention, Perception, & Psychophysics, 81(7), 2343–2353. https://doi.org/10.3758/s13414-019-01755-y