Not Knowing: A Variety of Agnosias

            Brains are great. They’re pretty terrific for a variety of reasons, of course, one of which being that when they’re running smoothly, it’s easy to forget how impressively multi-functional they are. Only when something goes wrong do we realize just how much there is to go wrong—which, naturally, also leads to some quite interesting stories of things going wrong.

            Take disorientation. Orientation and navigation aren’t so bad for the average person—maybe you take a wrong turn on your way to the dentist and have to go around the block. Worst case scenario, you pull out your phone and map your location. For some people it’s harder; they’re at the low end of the navigational norm (and they include myself). Then, however, there’s a leap to those far outside the normal spectrum. The full scope of what your brain does to ensure that you recognize your own hand, your neighbor’s face, or the shop on the corner really comes into view with the startlingly broad range of possible orientational disorders.

            For starters, there exists a seemingly endless array of subtleties to being lost. Maybe you have an impaired ability to identify landmarks. Maybe you can identify landmarks, but can’t gain useful directional information from them. Or maybe you have no trouble with landmarks at all, but can’t form a mental map of your surroundings. That final disorder has long been known to result from brain injuries or lesions, as in the case of damage to the posterior parietal cortex, fusiform and lingual gyrus, or hippocampus. However, it has also been more recently discovered as a developmental disorder—developmental topographical disorientation, or DTD—in which otherwise healthy, uninjured individuals experience a highly specific deficit in the creation of mental maps. DTD patients may make up a heterogeneous group in which other orientational deficits are present as well. The Radiolab podcast series does a wonderful segment on the disorder, called “You Are Here,” in their episode Lost & Found. It features Sharon Roseman, a landmark DTD patient, and neuroscientist Dr. Giuseppe Iaria, who diagnosed Roseman’s condition.

            Roseman’s disorder, also known as developmental topographagnosia, joins a host of other agnosias that become even more intriguing when they leave the realm of the topographical and start popping up in areas of life where it would be almost impossible for an unaffected person to become disoriented. Prosopagnosia, or face blindness, is just one example: the inability to recognize faces. (Which Radiolab actually has some excellent segments on also, like “Strangers in the Mirror.”) As is the case with DTD, deficits in the fusiform gyrus have been linked to the disorder. Those affected by prosopagnosia must depend upon ways other than facial recognition, such as recalling hair color, outfits, or characteristics such as one’s walking gait, to identify friends and even family members.

            Autotopagnosia, an inability to correctly orient body parts, is another example. Individuals with autotopagnosia lose the ability to tell left from right, and as a result are unable to correctly perform a task such as touching their left ear with their right forefinger. Like the many nuances to being lost, there are a variety of hypotheses on the cause of the disorder. Two main ones implicate lesions in the parietal lobe, the first proposing a visuospatial element, and the second suggesting a disruption of the patient’s body image. Yet a third hypothesis postulates that the illness is language-related, and connected to lesions in the posterior left hemisphere.

            Undoubtedly, we’ve come a long way from ideas like Franz Joseph Gall’s orderly phrenological interpretation that each bump and crevice on the human skull indicates a neatly packaged area dedicated to a single function. The compelling and frustrating part of orientational disorders (and most neurological disorders, really) is just how interconnected and complex the systems in question are—how much unconscious control occurs to keep us running smoothly. And here I thought a person was simply lost or found.

—Kate Oksas

Sources

http://www.medicaldaily.com/getting-lost-what-happens-when-brains-gps-mapping-malfunctions-245400

http://scienceblogs.com/neurophilosophy/2008/09/23/developmental-topographagnosia/

http://www.neurolab.ca/2010%282%29_Iaria.pdf

http://medical-dictionary.thefreedictionary.com/autotopagnosia

http://www.ncbi.nlm.nih.gov/pubmed/19334306

https://www.psychologytoday.com/blog/brain-babble/201309/prosopagnosia-why-some-are-blind-faces

http://www.empowher.com/wellness/content/what-autotopagnosia

http://www.radiolab.org/story/110079-lost-found/

http://www.radiolab.org/story/91967-strangers-in-the-mirror/

Your Basal Ganglia Don’t Like Brown

My favorite color is blue. Blue like Lake Michigan; like Cerulean Blue, the best type of crayon; like the color of my favorite stuffed animal that I accidentally left on an airplane headed to Amsterdam when I was little; like the sneakers I wore to pieces as a kid.

But why do we have favorite colors? There are a few good places to start in considering that question, including the list of associations I rattled off above. In general, color preference is influenced by personal experience, cultural upbringing and evolutionary history. Experience and culture play a significant role in the development of color preferences—for instance, getting the stomach flu after drinking an orange soda may ruin orange drinks forever, and while in the U.S. white wedding dresses are the norm, other cultures assign different values to the color white, such as mourning. Acknowledging these elements, I’d like to focus on the evolutionary side of color, and with it a sometimes overlooked emotion: disgust.

An evolutionary perspective is an interesting one that also leads to some particularly intriguing tangents. From an evolutionary standpoint, it makes sense why humans have developed aversions to certain groups of colors and attractions to others: survival. There’s a reason few young kids are interested in drab brown sneakers or grayish-green crayons. Those colors more often seen as ugly are ones that are associated with harmful substances such as rot and animal waste, note psychologists Stephen Palmer and Karen Schloss. On the other hand, more attractive colors such as bright, clear blues are associated with valuable items or resources, for instance, clean water.

One factor in determining color preference is, naturally, color aversion—what colors get weeded out? The emotion of disgust is an important factor in survival in that it tells us what to avoid and, as described above, is often linked with color. As researcher and writer Dr. R. Douglas Fields comments, brown tomato juice seems significantly less appealing than the same juice dyed red, simply because of a person’s evolutionary history and learned associations with brown and red objects. Disgust is an emotion of evasion, featuring a characteristic facial expression—a wrinkled nose and brow and a turned-down mouth—that mimics the expression preceding retching. It can also elicit a shudder response or prompt you to stick out your tongue; all these physiological reactions have the goal of getting whatever the disgusting trigger may be as far from you as possible.

While disgust, like other emotions, is likely processed throughout a large network in the brain, rather than in one specific region, two groups of structures have been identified as being particularly important in that processing: the insula and the basal ganglia. The mammalian insular cortex is a small lobe tucked away deep in the Sylvian fissure, which separates the frontal and parietal lobes from the temporal lobe. The basal ganglia, on the other hand, are a set of structures around the thalamus, including the caudate nucleus, putamen, and globus pallidus, that are largely known for their role in the coordination of movement. Researchers at the INSERM Institute in France provided evidence for the role of the insula in the processing of disgust by studying epilepsy patients who had implanted electrodes in preparation for surgery to relieve their condition. The researchers noticed that specific neurons in the insulae were activated when the subjects viewed pictures of disgusted expressions.

Dr. Reiner Sprengelmeyer explored the role of the basal ganglia in disgust in his examination of studies performed with patients suffering from Huntington’s disease, which causes degeneration of basal ganglia structures. Sprengelmeyer explains that several studies have found that Huntington’s patients have difficulty recognizing disgusted faces, as well as vocal stimuli expressing disgust. While the results are not indisputable, he concludes that assessments evaluating the recognition of emotions could be a useful diagnostic tool.

Psychologist Dr. Paul Ekman at one point describes emotions as “having evolved through their adaptive value in dealing with fundamental life tasks,” a wonderfully practical description of sometimes seemingly arbitrary states of mind. The existence of favorite colors, and more generally color preference, provides an interesting insight into the value of disgust and attraction and the mechanisms beneath them. Perhaps my love of the color blue goes beyond a childhood stuffed animal to the evolutionary roots underlying our species.

—Kate Oksas

Sources

https://www.psychologytoday.com/blog/the-new-brain/201104/why-we-prefer-certain-colors

http://www.academia.edu/1031922/Current_Theories_of_Sensory_and_Interpersonal_Disgust

http://www.researchgate.net/profile/Reiner_Sprengelmeyer/publication/6285547_The_neurology_of_disgust/links/0deec529897f228e5e000000.pdf

http://mentalhealth.about.com/library/sci/0203/bleww203.htm

http://www.salon.com/2011/07/24/disgust_interview/

http://www.ncbi.nlm.nih.gov/pubmed/22230626

http://neuroscience.uth.tmc.edu/s3/chapter04.html

http://web.stanford.edu/group/hopes/cgi-bin/hopes_test/the-basic-neurobiology-of-huntingtons-disease-text-and-audio/

https://www.paulekman.com/wp-content/uploads/2013/07/An-Argument-For-Basic-Emotions.pdf

I read this book and so should you: A Teenage Brain

Dr. Frances Jensen is the chair of the Department of Neurology in the Perelman School of Medicine at UPenn. She is incredibly accomplished. Both as a professor and researcher, she has expanded the field of neurology and synaptic plasticity a great deal. She also wrote an incredibly charming, unique, and insightful book about adolescent physiological development. Her book is terrific. It can be found at the Penn bookstore and online and you should read this review and then go read it. 

After reading two short pages in Dr. Jensen’s book, A Teenage Brain, I rushed over to my parents and apologized to them for the way I was as a teenager. To my delight, they accepted my apology and explained that they never took it personally. The first few pages of the book provide a hilarious anecdote of Dr. Jensen’s teenage son having dyed his hair from auburn to jet-black without even commenting on the change. While Dr. Jensen does not set out to describe the physiological motivations behind that specific teenage move, she does wisely explain with diagrams, experiments, and more anecdotes the effects that being a teenager will have on the brain. And they are indeed far-reaching effects.

            The book takes the view of almost of a “how-to” for parents raising teenagers. There are drops of advice and parental stratagem in many of her chapters, but to me I found the book as plain explanation—and sometimes excuse—for so many of the typical emotions and actions that were (and probably are) so typical to my teenage self. Additionally, the book gave me a pretty interesting insight into the mind of a parent. It’s not that I’ve never thought about what it’s like to be a parent, but Dr. Jensen really emphasized how much effort a parent could make to be an effective role model.

            The book is not for the timid or shy. She comes from a place of intense curiosity and an reflexive urge to understand the basis of behavior and change. And boy does she highlight the amazing complexities of the teenage mind! There are paradoxes galore. Why do most teenagers forget to execute a chore but will almost never forget if a parent or friend slips up? How can teenagers learn so much so quickly and then often make the same mistake time after time? Why is it so difficult and fun to actually be a teenager? With these questions in mind, Dr. Jensen investigates drugs and alcohol, sleep and learning, technology and addiction, and at the root of each topic there is a clear physiological explanation and often a clear solution for either the parent or teen reader.

            It goes without saying, but there is still much that needs to be understood about the teenage brain. This stage in life is clearly a time of cultural uniqueness as teens and their loud rock music bands and Twitter feeds are a group that seem to be changelessly changing. There is a method to the teenage madness, and it lies in the circuitry of a brain that seems to be picking up speed and taking off the training wheels at the same time—and the breaks definitely do not work in this teenage bicycle metaphor. Read the book, reflect on your angsty teenage self, write a poem, and while you bask in the glory of emerging from teenagerdom, please thank someone for dealing with  the most difficult version of you.

-David Ney 

Hearing Voices

A number of interesting hits come up when you Google the phrase “hearing voices.” This phenomenon, also known as experiencing auditory hallucinations, is an occurrence that has traditionally provoked a distinctly negative stigma in American culture. Hearing voices is considered by many doctors one of the most common and consistent signs of psychosis, and in America, a majority of individuals affected by voice hearing report negative emotions, such as fear or stress, to be linked to the experience. However, the phenomenon of auditory hallucination is far from homogenous, and in fact, recent research is uncovering more and more variability and complexity in the neurological and cultural components of hearing voices.

The neurology of voice hearing is still being unearthed, but several regions of the brain have been found to contribute to the event. For example, in those experiencing auditory hallucinations, language-processing areas in the left perisylvian region, including Broca’s area and Wernicke’s area, have been found to have a reduced density of gray matter. Research also suggests that this structural abnormality may be caused by low glutamate concentrations in the brain. A lack of glutamate, a major excitatory neurotransmitter, could lead to defective communication between neurons. Additionally, schizophrenics have been found to have abnormally high activity in the right middle temporal gyrus. The right and left middle temporal gyri respond to external speech, but in most people there is more activity in the left than the right. A hyperactive right region suggests that the brain may be attempting to compensate for a malfunction in left-brain language processing.

In addition to biological factors, social and cultural perceptions of hearing voices play a role in affected individuals’ experiences of the phenomenon. Stanford anthropologist Tanya Luhrmann provides an insightful examination into the effects of culture upon the event of auditory hallucinations in a talk she delivered for the Foundation for Psychocultural Research. Luhrmann compares the experiences of individuals who hear voices in three different locations: California, Ghana and India. She notes that the Americans interviewed were more likely than the others to describe their voices as symptoms of a disease, to report that they did not know their voices, and to report violent or hurtful voices. Other subjects, while still reporting majority negative experiences, described different relationships with their voices. Indian subjects were most likely to identify their voices as familiar—namely family members—while Ghanaians were most likely to report hearing the voice of God. Luhrmann traces these disparities partly to the way that auditory hallucinations are viewed in various cultures. Since American medicine interprets voice hearing as the sign of a “violated mind,” she suggests that the violence of the American subjects’ voices may be intensified by the impact of this viewpoint upon affected individuals.

As research has uncovered more of the complexity of auditory hallucinations, it has become clear that there are many types of voice hearing, accompanied by a wide array of emotions, tactile sensations, and other aspects. Researchers such as Luhrmann suggest that a more holistic approach to treating and understanding those impacted by voice hearing, which seeks to avoid giving affected individuals the viewpoint that their mind has been maliciously infiltrated, may help us create more effective treatments. Undoubtedly, a good deal is still to be understood about the experience of auditory hallucinations, which exist at a striking intersection of neurological, psychological and cultural elements.

-Kate Oksas

Sources

To view the video of Tanya Luhrmann’s talk, visit: https://www.youtube.com/watch?v=L44uHPNiUaM

http://www.sciencedaily.com/releases/2015/03/150310205707.htm

http://news.stanford.edu/news/2014/july/voices-culture-luhrmann-071614.html

http://brainblogger.com/2009/09/22/hearing-voices-underpinnings-of-auditory-hallucinations/

http://cercor.oxfordjournals.org/content/14/1/91.full

http://www.hearing-voices.org/

http://www.ncbi.nlm.nih.gov/pubmed/15597383

http://en.wikipedia.org/wiki/Glutamate_receptor

Don't Fear, Botox is Here

It’s time to turn that frown upside down, literally (and scientifically).

We all have our bad days now and then, but for some, those bad days seem to never end. There may be no definitive “cure” for depression, but fortunately, a new scientific finding has potentially found an alternate, less conventional solution for our bad days—Botox, a widely popularized cosmetic surgery procedure in America. In fact, Botox was ranked as the top minimally invasive procedure in 2013. Shocker. Most Americans want at least a sip (or in this case, an injection) from the fountain of youth. And Botox, in many ways, has become synonymous with American culture—or at least, in the superficial, skin-deep sense. But perhaps Botox penetrates the skin deeper than we think. Perhaps it is more than an artificial tool for external beauty. Perhaps it is more about enhancing who we are internally.

Before we examine the ways in which Botox can psychologically alter our lives, let us first take a look at how this magical Botox scientifically operates in our bodies.    

Botulinum toxin is administered by diluting the powder in saline and injecting it directly into neuromuscular tissue. Once injected, the toxin works to inhibit the signal pathway from the nerve cells to the muscles, essentially leaving the muscles without instructions from the brain to contract and thus, total paralysis. In order for muscles to contract normally, nerves release the neurotransmitter and chemical messenger, acetylcholine, at the neuromuscular junction, where nerve endings meet muscle cells. The acetylcholine binds to receptors on the muscle cells, generating a post-synaptic potential that will cause the muscle cells to contract or shorten. However, with Botox, the release of acetylcholine is inhibited, preventing the contraction of the muscle cells. Because there is a reduction in muscle contraction, the muscles become more flexible and—voilá—bye, bye wrinkles!

While the success of Botox is due to its neuroscientific ability to eliminate wrinkles, contemporary scientific research suggests that its capabilities extend far deeper. In a forthcoming study in the Journal of Psychiatric Research conducted by Eric Finzi, a cosmetic dermatologist, and Norman Rosenthal, a professor of psychiatry at Georgetown Medical School, it has been suggested that Botox can treat depression by paralyzing key facial muscles and thus preventing patients from frowning. Finzi and Rosenthal randomly assigned 74 patients with major depression to receive either Botox or saline injections in their forehead muscles (because the contraction of these muscles completely prevents frowning). After six weeks, 52% of patients who received Botox showed relief from depression, compared to the 15% who received the saline placebo. Other studies have also corroborated this evidence, and as a result, our preexisting ideas about not only Botox, but also the nature of emotion have turned inside out. This “facial feedback” seems unnatural, yet the Botox studies suggest “a circuit between the brain and the muscles of facial expression in which the brain monitors the emotional valence of the face and responds by generating the appropriate feeling.” In other words, by changing our expression we change our mood—an “‘outside-in’ somatic therapy” as Friedman calls it. Because of this new understanding of Botox, we have the potential to entirely alter the way we approach and treat depression. And while it remains unclear whether Botox could serve as a beneficial antidepressant, the possibility for this use raises the question of whether cosmetic surgery should be administered as a widespread prescription for depression and other medical diagnoses in the future.

The origins of the facial feedback system proposed by Finzi and Rosenthal can be traced back to the 19^th century hypothesis of scholars James and Lange, who argued that by producing a response that is characteristic of a particular emotion, you experience that emotion. Since then, many alternate theories about emotion have been proposed, but substantial research still exists corroborating James and Lange’s original ideas. Other cosmetic studies have also been conducted to determine the psychological and emotional implications of Botox.

For many, Botox will not be the answer to their problems, mainly because there is still not enough evidence to legitimize its use as a “medication.” And after all, it is cosmetic surgery, a topic of ongoing ethical debates. But if there is anything we should gain from this, it is that turning your frown upside down (naturally, not surgically) can scientifically transform your bad days into good days—at least for a little while.

-Isabella Cuan

Sources:

http://www.nytimes.com/2014/03/23/opinion/sunday/dont-worry-get-botox.html?_r=0

http://www.harpersbazaar.com/beauty/health/news/a3630/botox-treating-depression-1014/

http://www.medicalnewstoday.com/articles/158647.php