Do I Know You?

Do I Know You?

The complexity of a human is emphasized when we are compared to animals in experiments that strive to explain what makes us so special and different. However, it has been known in neuroscience that animals may be some of the most useful models in studying the wiring of our brain. Specifically, Macaque monkeys, who have structural and functional similarities with the wiring of the human brain.

This similarity between Macaque monkeys and humans allowed two biologists, Le Chang and Doris Y. Tsao, from Caltech to "decipher the code of how faces are recognized" by studying "face cells" in macaque monkeys and their relative triggering to manipulation of 2,000 faces of humans. The "face cells" that were being targetted are neurons that fire electrical signals when the retina is presented with an image of a face. They used an electrical recording that was probed into face cells of macaque monkeys, first identified by an MRI,  to perform the experiment and ultimately were able to construct the dimensions that wre used by the primate brain to decode faces. The monkeys were shown manipulated photos of human faces that were distinguished by size and appearance. 

The article described the facial recognition system in both humans and macaque monkeys as being grouped into "patches" of at least 10,000 face cells each. These patches are six-fold on each side of the brain. Before the researchers of Caltech discovered the ways in which the brain encodes faces, it was speculated that the brain dedicated a cell to each face. However, Caltech has debunked this idea and found that the "brain's face cells respond to the dimensions and features of a face in an elegantly simple, though abstract, way" that helps explain why the brain identifies and perceives a familiar face we have never seen before. The Caltech team also claims that there are "50 such dimensions [that] are required to identify a face" which allows the brain to create a mental "face space" in which any number of faces may be recognized, parallel to forming a long term store of information. 

https://ocw.mit.edu/courses/brain-and-cognitive-sciences/9-01-introduction-to-neuroscience-fall-2007/

The article along with the findings of the Caltech research team further enhance the evolutionary field of neuroscience and pose an interesting question towards object recognition. Whether or not there are more dimensions to what it takes to recognize a face is an issue that must be researched further. However, it is interesting to note the remarkable ability of humans and monkeys, as social animals, to have the ability of recognizing faces of familiarity and distinguishing them from those that may pose a threat to their survival. 

Wade, Nicholas. “You Look Familiar. Now Scientists Know Why.” The New York Times, The New York Times, 1 June 2017, www.nytimes.com/2017/06/01/science/facial-recognition-brain-neurons.html?rref=collection/sectioncollection/science&action=click&contentCollection=science®ion=stream&module=stream_unit&version=search&contentPlacement=16&pgtype=sectionfront.

Live in this Moment with Me

         

            It is fair to say that during one’s thought process on a memory or prospections towards future, one does not actively think about what they are thinking until they get to the final end of the thought. That is to say that while we are thinking, the end goal of that thought is what we care for the most, disregarding the steps we need to take to get there until we invest conscious awareness of the task at hand. An interesting article published by the New York Times titled, “We Aren’t Built to Live in the Moment” by Martin E.P. Seligman and John Tierney suggests that our immediate thoughts and moods are not that immediate because our subconscious mind has us running through prospections of the future to assist in trying to figure out how we feel in the present moment.

            The article explains how studies cast onto 500 citizens of Chicago, who were asked to record their immediate thoughts and moods throughout the day. The study showed how the people were focusing on the future, rather than the past, when focusing on a certain thought. Those that thought about the past, only thought about it in order to consider what will happen to them in the future. It is intuitive to understand that when we are planning and organized about what we wish to get down, we are calm and happy. The reverse of this notion would be correct as well, though it is important to note the idea of prospection as is influenced based on past experiences. A happy past will lead for better views of the future, whereas a traumatic past leads less, if any, positive thoughts on the future. The article further explains how behaviorists dub the explanation of learning as repetition and reinforcement in order for one to engrain certain habits to long term memory. Furthermore, Seligman emphasizes how the long term memory of the brain actively rewrites our past as it conforms to the context we are presented with.

            This exploration brings researchers in understanding how humans layout and plan their lives. Essentially the goal is to prevent the idea of prospection to reach a morbid level. We clearly do not want anyone planning out their own deaths, let alone executing the plan. It is fair to mention that less than 1% of the tested group from the Chicago study had thoughts involving death in general. It is interesting how the fluidity of the brain and its long-term memory allow for one to effectively create a prospection of the future. That being said, it comes to question how one can essentially alter certain memories based on sheer focus on the past in order to plan for the future. Alteration of the conscious thought process can allow for a change in long-term encoded memory, thus effectively allowing one to change their beliefs and conform them in order to lead a better future. Is it fair to say that the brain is constantly rewiring itself for the safety of the individual? Is it a defense mechanism we have to keep ourselves in “sane” manner of living?

Source: https://www.nytimes.com/2017/05/19/opinion/sunday/why-the-future-is-always-on-your-mind.html

Losing Memories Over Time

The concept of having and losing memories can be very confusing when looked at in depth. Pam Belluck in the New York Times, writes about a new study suggesting that memories weaken when not reinforced. Originally there has been two theories on memory retention. The two major theories are interesting and the difference between them is very important. The first theory described is where memories do not completely go away but are overshadowed by new memories. The other is where old memories are degraded as new information is pulled to the mind so that there is no interference. These theories are significant due to the difference being whether memories can be pulled back or not. If old memories are simply overshadowed, there is a possibility of them being recovered.

There was a study performed in Birmingham and Cambridge, England that tested memory association. The study associated pictures with words and then tested individuals on their ability to recall the correct association. The results of the association study showed that most likely competing memories become weaker. After that researchers looked at the neural patterns during the test. When certain associations were stated, the other word pairing was slowly degraded. The brains physically produced fewer traces of the word that was not being reinforced. Scientists that were not a part of the study stated they believed the results to confirm the degradation of memories. If certain memories are not reinforced, they will eventually weaken and possibly degrade to make room for a competing memory.

These findings are vital in numerous ways. It can provide helpful insight into patients with memory loss and even other mental illnesses. If memories are not truly overtly degraded, then perhaps certain markers can bring them back out. Although, the lack of degradation can be problematic in those that actively seek to forget certain traumatizing memories. The findings that memories can be weakened and degraded through competing memories is good for certain patients such as ones with PTSD.

https://www.nytimes.com/2015/03/17/science/memories-become-weaker-without-reinforcement-study-finds.html?rref=collection%2Fsectioncollection%2Fscience&action=click&contentCollection=science&region=stream&module=stream_unit&version=search&contentPlacement=14&pgtype=sectionfront

Scientists Looking for Alternative Options to Opioids

In modern medicine, opioids have become the staple drug solution to pain relief. Unfortunately, opioids as a solution also brings in risk of addiction. John Hamilton, author of the NPR article, "Brain Scientists Look Beyond Opioids To Conquer Pain," reports that at least 25 million people each year suffer from chronic illness. With those numbers, it's easy to see why America is currently undergoing an opioid crises, however, according to Hamilton, alternative drugs that decrease pain without activating the brain's pleasure and reward "circuits" like opioids have been proven less effective, coming with dangerous side effects as well. On a brighter note, Edward Bilsky, a pharmacologist  and chief academic officer at Pacific Northwest University of Health Sciences, finds snail venom to be a promising chemical.

Hamilton then suggests a new approach to pain management, which includes targeting "brain circuits," which I presume Hamilton means neurons, that amplify perception of pain. To illustrate what he means, the author claims that anticipating pain, such as when you are at the dentist, actually heightens a person's perceived pain. Feelings such as depression and isolation also increase pain. Hamilton implicates that "brain scientist's" are looking to tweak these "circuits" in such a way that it lowers a perceived pain, as doctors are already beginning to prescribe antidepressants for those with chronic pain.

Unfortunately, John Hamilton of NPR, did not cite the studies in which he claims that "brain scientists" are looking to tweak "brain circuits," but it does call into question how America should deal with this opioid crisis, as many cases of opioid abuse begins with a prescription. By exploring how pain is registered in the brain, research might uncover alternative methods to pain relief, rather than relying on what we have to offer at the moment.

https://www.npr.org/sections/health-shots/2017/11/13/563281808/brain-scientists-look-beyond-opioids-to-conquer-pain

Reinforcement Learning Signal Predicts Social Conformity

As we all know as people we often revise our decisions and judgements to conform to what we call normal group behavior, what is popular. Conformity refers to the act of changing one's behavior to match the response of others. Yet there is miniscule information in our reach as to how neural mechanisms of social conformity work. In this study done by Donders Institute for Brain, Cognition, and Behaviour, the use of functional magnetic resonance imaging (fMRI) deduced that conformity is established on mechanisms that comply with the principles of reinforcement learning. Their findings provide evidence that social group norms elicit conformity as a result of learning mechanisms reflected in activity in the region pertaining to the rostral cingulate zone and ventral striatum. Human behavior is advised by subjective values and/or attitudes, as well as by the perceived behaviors of those around the individual, particularly by social norms.

There are three central motivations for conforming behavior are suggested in social psychology:

1. A desire to be accurate by properly interpreting reality and behaving correctly.

2. To obtain social approval from others.

3. To maintain a favorable self-concept.

Researchers developed an archetype consistent of the subject's initial judgments of facial attractiveness were susceptible to influence via group opinion. Facial attractiveness is a decidedly prominent social characteristic as well as a daily target of normative influence used in everyday things such as fashion magazines and cosmetic commercials.

With this study, the conflict between the subject's own judgement and the normative group opinion. During fMRI participants rated the attractiveness of 222 female faces and were informed of a group rating of the face afterwards. To assess whether group opinions had an effect on perceived facial attractiveness, subjects were unexpectedly asked to rate the faces once again during a behavioral session approximately thirty minutes after scanning. The findings result in participants changing their ratings of attractiveness, coordinating themselves with group ratings.

This article culminated my curiosity in the brain's ability to bypass the feeling of the need to conform to social norms. In individuals who seemingly do not conform to social norms, is there different neural mechanisms that result in their ability to not care?

http://www.cell.com/neuron/pdf/S0896-6273(08)01020-9.pdf

How Storing Trivial Memories Works

We often believe that we forget things that are not important but in actuality, the memories are stored deep inside. According to Benedict Carey in the New York Times, the brain stores memories that happened before an emotional moment such as embarrassment or disappointment occurred. Why trivial memories are stored in the brain is studied in Carey's article, "How the Brain Stores Trivial Memories, Just in Case."

In older research, it was found that in animals and humans when it came to the effects of memory that it made past memories stronger when something was happening now which recalled them. This is called retroactive consolidation. Though, researchers are not sure what emotional events trigger retroactive consolidation nor the limit of time memories go back to. Another study done at New York University where over 100 participants sat at a computer and had to decide whether the photographs belonged to the tools or animals category. A couple minutes later, the same test was given but one group was given electric shocks when they placed photographs in the tools category and vice versa with animals. The test was given again but as a surprise. One group who took it immediately after showed that they remembered tools and animals the same. The other groups who took it a couple hours or days later showed that they remembered 7% more items from the category they were shocked in. This experiment showed that the memories were strengthened by the electric shock.

This study brings many questions when it comes to what affects memory. One thing that researchers wish to know is whether there is a timing difference when it comes to how long the memories can be stored. What is interesting about this study is that the electric shock was administered not to be painful but only to make the participant feel uncomfortable. This brings questions in whether PTSD victims keep the memories until recalled just as this experiment.

https://www.nytimes.com/2015/01/22/health/study-shows-brain-stores-seemingly-trivial-memories-just-in-case.html

Key Brain Protein Has Implications for Psychiatric Disorders

Proteins can be thought of as the building blocks of the brain. They provide it with the necessary amino acids for it to function. One type of protein, Brain-derived neurotrophic factor (BDNF), belongs to family of proteins called neurotrophins which regulate growth, connection, differentiation and survival of neurons. BDNF is expressed in the brain in reaction to sensory stimulation, contributing to neuronal plasticity, learning and memory. It has been investigated among individuals with a range of psychiatric conditions, specifically those with schizophrenia, bipolar disorder, and depression have lower levels of BDNF in blood compared to the controls.
In a recent study by Raluca Armeanu, Mikael Mokkonen, and Bernard Crespi, they used a meta-analytic method to see whether peripheral amounts of BDNF is altered in autism. There has been some studies done beforehand on this relationship, but they range from having higher levels of BDNF to lower or non-significant differences. They tallied and analyzed 15 studies totaling 1242 participants finding that there is a small to medium size statistical effect, meaning that there was higher levels of BDNF in autistic subjects compared to controls. They then compared them to people with Angelman syndrome, where it also exhibits higher levels of BDNF. This suggests, according to the authors, that the model of autism being diametrically opposed to psychotic-affective disorders is correct and consistent.

By monitoring this protein level, the data suggests that peripheral BDNF levels are a potential biomarker for autism. BDNF is the most abundant neurotrophin in the central nervous system that can cross the blood-brain barrier. We can then measure the level in the blood and have confidence that it is in the cerebrospinal fluid. Having increased BDNF levels could result in overgrowth of brain tissue, which is also found in autistic children. Being able to analyze this brain development in children with autism relies on accurate detecting of BDNF levels.

https://www.psychologytoday.com/us/blog/the-imprinted-brain/201608/key-brain-protein-has-implications-psychiatric-disorders

Optimizing learning and memorization for college students

A recent review written by Jeffrey D. Karpicke, PhD from Purdue University, explained why retrieval is one of the most effective methods of learning and memorization for college students. To recap, retrieval is the ability to access different types of information from your memory whenever you need it. In one study reviewed (Karpicke & Blunt, 2011), students were put into two groups and told to read pages of a science book. The first group was told to write down as much as they could remember and then to practice retrieving that information as well. While the other group was told to draw out concept maps that linked information they learned while reading their textbook. After one week, both groups were given two types of exams that assessed how well they retained what they learned. The first exam was a short answer exam that tested concepts directly from the textbook. While the second asked students to draw out a concept map to show what they learned. Surprisingly, the students who practiced retrieval not only proved to be better on the short answer test, but also did better on the concept map test than the group that studied by drawing them out.

In today’s society we have access to endless amounts of information. This comes with many benefits, but there are also drawbacks. For students, it’s the difficulty in digging through the heaps of useless techniques to find the best ones. Practicing retrieval when studying may seem so simple that students must use it as a studying technique most of the time, but that’s not true. In fact, the review cited a survey (Karpicke, Butler, & Roediger, 2009) that asked college students what studying techniques they used and which ones they used the most. The results showed that the most frequent strategies used were rereading textbooks and looking over notes.

The best thing about utilizing retrieval methods is they don’t require sophisticated technology and practicing is simple. Students only need to review the information ,set it to the side, and then try to recall it. Different techniques that students can use to utilize retrieval during studying are things like practice tests or flashcards. Even looking at notes at the end of a class can be useful, the most important takeaway is that they need to be able to retrieve that information from their memory.

For more information about the review visit http://www.apa.org/science/about/psa/2016/06/learning-memory.aspx

Brain Wave Oscillations and Alzheimer's Disease

   We have learned about the various techniques researchers use in their studies of the brain and how crucial they are to the knowledge of the brain that we have today. A few examples of these techniques are optogenetics, EEG, and tACS. The EEG played an extremely important role in brain studies because it allowed scientists to record electrical activity of groups of neurons in the brain by measuring their voltage changes as they are activated. When these groups of neurons fire, they do so in an oscillating pattern creating distinct patterns of different types of brain waves. Based on the type of brain waves that are occurring, we can use an EEG to record and predict the brain function that is occurring along with a specific brain wave type. For example, delta waves have the lowest frequency and occur during a deep sleep. Other types of brain waves that can be present are theta, alpha, beta, and gamma waves.
    Researcher Li-Huei Tsai and her lab published an interesting study in the scientific journal Nature. These researchers put these various techniques together in order to explore brain waves and their roles in neurodegenerative diseases, such as Parkinson’s disease and Alzheimer’s disease. In this study, they used an EEG to record the brain waves from oscillating groups of neurons in groups of mice created to produce a hallmark sign of Alzheimer's- amyloid-beta plaques. They decided to test this because research has shown that brain waves can become disrupted in these diseases. Beta waves are shown to be increased in the motor areas in individuals with Parkinson’s disease and gamma waves are decreased in those with Alzheimer’s. Tsai and her lab designed flickering lights tuned to a specific frequency in order to have an effect on the brain waves of the mice and clear that amyloid-beta plaque out of the brain. Their interesting finding showed that the Alzheimer’s disease model mice that were exposed to a light from a disco had lower levels of amyloid beta than mice that were kept in the dark. Therefore, from their results it seems like the strobe lights indeed had an effect on the brain waves of the mice and assisted in plaque clearance from some brain areas.
     Another researcher, Randolph Helfrich, is also using techniques like transcranial alternating current stimulation (tACS) to affect brain oscillations.
    The manipulation of brain waves is currently being researched in not only neurodegenerative diseases, but also disorders like insomnia and schizophrenia. Tsai and another researcher, Ed Boyden, did begin testing their research in humans with Alzheimer’s as well. Unfortunately, a lot of the results that come from mice models don’t show the same results in humans. So, there is still a great deal to be done in using these techniques in order to use them in neurodegenerative diseases and other disorders.

Image Source: https://www.sciencenews.org/article/brain-waves-may-focus-attention-and-keep-information-flowing


Article Source: Helen, Thompson. "How Flashing Lights and Pink Noise Might Banish Alzheimer's, Improve Memory, and More" Nature. 28 February 2018.
https://www.nature.com/articles/d41586-018-02391-6

Babies Can Think Logically

It is the norm to believe that one must first know language in order to be able to reason. However, a recent study proves this case wrong. A study just recently published to Science suggests that the ability to think logically does not depend on language as showed in infants. An article entitled “Babies Think Logically Before They Can Talk” by Bret Stetka on Scientific American explains the study’s findings.

Several scientists from European institutions studied infants who have not yet learned language or have started to speak. They showed the infants distinct objects, such as a dinosaur and a flower, then covered the items. The infants were showed an animation where the dinosaur was removed to reveal just the flower remaining. In some instances, however, the flower would disappear and instead there would be two dinosaurs. The experimenters used eye-tracking to follow the infants’ vision patterned. This revealed that the infants started significantly longer on the instances where the unexpected dinosaur appeared. This finding suggests that the infants suspected something wasn’t right and that they were confused. Also noted was the dilation of the pupils when unexpected outcomes occurred which is known to happen to adults when given difficult logical problems, further proving the researchers’ point.

This study can raise a few questions such as what the next step is. Are we born with rational tendencies and logical thinking? Or are infants learning while observing, even before they are able to articulate thoughts? The lead study author, Nicoló Cesana-Arlotti, plans to further study how the logic represented in the infants differs to logic used after speech and verbal development. 

Source: https://www.scientificamerican.com/article/babies-think-logically-before-they-can-talk/