Celebrating Uncertainty

Watch this video! But it’s so long, I know. Do it anyway! Because not only are optical illusions fun, but you’re probably going to learn a thing or two about perception and the human experience.


We've all seen optical illusions before. A typical response is something like "Wow...I guess my senses are tricking me; I guess I know less about my surroundings than I thought." Lotto does something truly profound with optical illusions. He appreciates the gaps between reality and our own perceptions, he sees these inconsistencies as windows into the brain and its functioning. As he explains, “context is everything.” Our awareness of the physical world is limited by our perception, a system that we know can be fooled. According to Lotto, there’s nothing wrong with the inaccuracies in our perception, they’re proof of the patterns in the world on which we base our experience. If humans weren’t able to transform the overwhelming amount of stimuli invading our sensory organs into a concise representation, we wouldn’t be able to function. Lotto explores how our experience-based expectations can be modified and combined. He looks at optical illusions in other species, something I had never considered before. He also explains how one sensory modality can be transformed into another, without a loss of understanding. Fascinating stuff! I don’t know about you, but I’ll be paying a little more attention to my perceptions from now on.

Who Needs Accurate Memories, Anyway?

Last year, Cambridge researchers stumbled across some revealing data on false memories. They were studying the effects of brain damage on memory in rats. Rats were presented with a small, elaborate object and given time to become familiar with its appearance. They were then placed in a normal cage environment, free of wacky objects, for an hour. When presented with the same object as before as well as a new object, rats without brain damage spent significantly more time exploring the new object, ignoring the one they’d seen an hour before. The researchers expected that rats with damage to the perirhinal cortex (involved in visual memory consolidation) would show no preference towards the previously shown object. The brain damaged rats took this hypothesis a step further. They actually spent LESS time investigating the new object than the normal rats, implying they had some sort of familiarity with the object, despite having never seen it before.
 

These findings propelled the research team into a new focus. They wondered if the stimuli in their regular holding environment, coupled with perirhinal damage, resulted in formation of false memories. To test this theory, a similar method was used, but rats were raised in a dark room, devoid of visual input. The visually impaired rats acted as the researchers had initially expected for rats raised in lit cages, supporting their hypothesis.

So what’s going on here? The perirhinal cortex is easily harmed in comparison to other brain areas. Damage to this area is common in diseases classified by memory impairment, such as Alzheimer’s. As it turns out, individuals with these impairments actually perform better on tests of memory if they’ve been in a dark, low-stimulus environment before testing. Connections, connections! According to the Cambridge researcher Lisa Saksida, the perirhinal cortex is responsible for formation of complex visual memories. When the area is damaged, less specialized regions will attempt to recreate memories using generalized environmental stimuli. This disadvantaged form of memory reformation produces what we know as false memories. Could the perirhinal cortex also be involved in sensations of déjà vu? Flashbulb memories? Who knows! I look forward to seeing more research emerge on this subject.

The original article can be found here: http://www.sciencemag.org/content/330/6009/1408.abstract

Cocaine and Cupcakes, One in the Same?

While home in Minneapolis this past weekend, I took some time to catch up on recent Star Tribune articles. I came across the intriguing title, “Some foods as addictive as cocaine?” Apparently, 28 papers on food addiction have been published in this year alone, according to the National Library of Medicine. This is a hot topic, and the food and beverage industry is nervous. Researchers are picking apart the brains of food addicts and obese individuals to understand what makes them addicted to food. It is becoming clearer and clearer that the delicious beverages and foods we love can “hijack the brain in ways that resemble addictions to cocaine, nicotine and other drugs.”

Like me, you may be thinking to yourself “well, duh.” The human body has not evolved for the abundant, sugary, fatty foods common to American culture. The foods we tend to love most are also those that are the worst for us (fries dipped in ice cream, anyone?). Sugars and fats were rare in the hunter-gatherer’s environment, and they taste so great because of evolutionary pressures to search long and hard for them. When you only have access to fats and sugars once in a while, an affinity for them becomes essential for survival. Aside from searching the aisles for the items on our grocery list each week, we don’t do much hunting or gathering these days. The well-liked flavors that once helped us prosper are now killing us. As it turns out, not everyone appreciates this, which is why so many researchers are looking at the mechanisms behind food addiction. They need factual collateral to help the general public understand the ways in which food can modify their brains.

A widespread knowledge that food interacts with the brain in ways similar to that of lethal, illegal drugs could change the way we eat. This idea is frightening for the food and beverage industry, which the Trib article points out, is worth at least one TRILLION dollars. Though there is overwhelming evidence for the addictive nature of certain foods, “food company executives and lobbyists say nothing has been proven.” Ha! We can only hope that one of these days, the CEO of Frito-Lay will wake up in a cold sweat, fiending for his next potato chip fix, and think to himself “What have I done!?” Until then, it’s important to understand that food isn’t just sustenance. It can also be viewed as a delicious, fatty, drug.

Read the original Star Tribune article here: http://www.startribune.com/lifestyle/wellness/133302438.html

No Brain Wave Is Safe

UC Berkeley researchers have recently undertaken a project (see www.nbcbayarea.com/news/tech/Brain-Scanner-Records-Dreams-on-Video-130497213.html) that is both fascinating and incredibly creepy (perfect for a Halloween post!). They utilized fMRI technology to create a visual response database. By showing participants an array of videos, and simultaneously recording brain activity, they collected a cornucopia of data on how the human brain responds to specific visual stimuli. The database allows them to (more or less) reconstruct an image that a subject in an fMRI machine is simply imagining. This means (hypothetically) that if you are sitting in this fMRI machine, and an inappropriate visual memory pops into your head, BOOM. They've caught you, they saw it on their own computer screen. The database has outed your private thoughts. The system is far from perfect, as this video makes clear:



But within a decade or two, as the system is improved, this technology could have some pretty serious implications. We could see what people are dreaming, dive into the subconscious. Revealing, previously unavailable data would become available to numerous research areas. For example, flashbulb memories could be reconstructed on screen, then compared with actual happenings. There is, of course, the terrifying thought of the government getting their hands on this system and going on a brain invasion spree. Let's take a moment to appreciate the premature nature of this technology. Our thoughts are safe...for now.

The Wild World of Mirror Neurons

I think mirror neurons, which provide the connection between the actions of others and our own movements, are the coolest thing...ever. They are essential for empathy, imitation, appreciation of facial expressions, and awareness of body language. V.S. Ramachandran, who has studied mirror neurons extensively, sums up their importance very nicely in this video...



Couldn't have said it better myself! The sudden existance of mirror neurons, and their following adaptations, were an essential part of mammalian evolution. They allowed us to learn from the techniques and emotions of others. As Ramachandran says, they allowed for a "Lamarckian" passing of knowledge, which then allowed for unique cultures. Human existence is completely dependent on these beautiful little neurons. What's most interesting is that by anaesthetizing the skin, we can remove the barrier between our own and others' actions (this is also common in those with mirror-touch synesthesia). We should really be devoting more attention to the role and mechanisms of these neurons, where's the research!? Give me more!

I've Got a Funny Feeling

I’ve blogged recently about both synesthesia, the cross-wiring of the senses, and empathy. As it turns out, there has been research connecting the two. A 2007 study by Michael Banissy and Jamie Ward utilized the unique properties of the synesthetic brain to explore the spectrum of empathic ability. These particular synesthetes have mirror-touch synesthesia, in which observations of physical touch on others elicit a tactile response on one’s own body. Participants were shown another individual being touched on the cheeks and hands, but told to ignore them. They were simultaneously being touched in the same regions and reporting their tactile experience. A control group of non-synesthetes were included for comparison.

What’s interesting about the responses of synesthetic individuals is the variation in their mirrored tactile reactions. For instance, when synesthetes viewed someone being touched on the right cheek, some of them reported feelings on the right cheek, others on the left, and to various extremes. This is typical in studies of synesthetes; it’s also what complicates research in this area. Synesthesia appears in numerous forms, across differing sensory pathways. The experience is slightly variable for each affected individual. For instance, for those who associate numbers and letters with specific colors, color matches vary greatly. Also, some report actually viewing letters/numbers in color, while others are simply aware that they are associated with color.

So how did the synesthetes perform on these tactile response tasks? They reported a significantly higher number of mirror touch errors than controls, meaning they weren’t distinguishing as well between synesthetic response to the touch of another and the feeling of being touched.  However, their response time was faster than that of controls when personal touch matched that of the other individual. Banissy and Ward conclude that empathy is multifaceted, and that these synesthetes are higher than non-synesthetes in emotional reactivity, but not in other areas (social skills, cognitive empathy). The data supports the idea that empathy is dependent upon shared interpersonal experience.

Original article: http://daysyn.com/Banissy_Wardpublished.pdf

Cry Me a River (Or Not)

I’ve been researching the neural mechanisms involved in empathy lately. There are numerous theories on the pathways involved in producing an empathetic response. I came across an article I found especially intriguing. To study deficits in empathy, we typically look at individuals on the autism spectrum. Evidence from these types of studies can only tell us so much, considering the vast range in the levels of social and emotional disabilities involved. An autistic person lacking the mechanistic ability to empathize would also have trouble learning to “fake” an empathetic response, as this would require them to cue into social norms. So, can empathy be learned?

A 2009 study by Danzinger, Faillenot and Peyron sought the answer. They used fMRI technology on a group of subjects suffering from congenital insensitivity to pain. If these individuals couldn’t feel pain themselves, could they still empathize with those that do? Or is the production of an emotional mirroring founded on personal experience and memory? Subjects were shown images of both faces showing painful expressions (to test emotional response) and body parts in painful situations (to test somatosensory response). fMRI scans reported activity in response to these images in comparison with control, non-painful images. Participants were also given a self-reporting empathy survey.

The subjects with congenital insensitivity to pain rated themselves at typical levels of empathy compared with a normal, healthy population. fMRI results revealed that activity in response to facial expressions was generally normal, but represented a distinctly different network of involved structures. Responses to images of body parts in pain were significantly lower than average. Danzinger, Faillenot and Peyron determined that the pathways used by CIP individuals to produce empathy reflected a learning process. Some areas, namely the insula and mid-cingulate cortex, were stimulated in both CIP and non-CIP brains when shown stimuli. Activity seen in the ventromedial prefrontal  and ventral posterior cingulate cortices of CIP subjects only points to the role of association mechanisms. These mechanisms are likely based on what is socially expected when faced with the emotional or physical pain of others.

This study is intriguing, and leaves much to be explored. To what extent are we hard-wired for empathy, and how much of it is learned? How do the pathways for emotional and somatosensory empathetic pathways diverge and converge? I can only hope that by March (when I have to present on this very topic), I have the answer to these and other fascinating questions.

PDF for the original article can be located here: http://www.empathogens.com/empathy/cip-empathy.pdf