Cognitive Neuroscience, Group E

Autism: What Is It?

Autism.  A disorder that has run the gamut of titles, symptoms, and diagnoses, yet still seems to elude doctors and scientists as to its cause and origin.  The cause of Autism Spectrum Disorder (ASD) may be unknown, but its characteristics include difficulties in social interaction, verbal and nonverbal communication, and repetitive behaviors, all in varying degrees.  From an early age, children with ASD may become overly focused on certain objects, may fail to engage in typical babbling with their parents, and rarely make eye contact.  Currently, all autistic disorders have been merged under the umbrella of ASD. Previously, the DSM featured distinct sub-types of Autism, including childhood disintegrative disorder, pervasive developmental disorder-not otherwise specified (PDD-NOS), and Asperger syndrome.  Statistics from the U.S. Centers for Disease Control and Prevention (CDC) identify around 1 in 68 children in America as on the autism spectrum.  This is a 10x increase in prevalence in 40 years.

Figure 1 displays the current Autistic Spectrum Disorder umbrella and all of the previous autism sub-types that are now within this umbrella.

ASD: What do we know?

Risk Factors

While a precise cause of ASD remains unidentified, there are a number of risk factors that, in combination with a genetic predisposition, seem to further increase the probability of developing ASD symptomatology.  The most evidentially supported of these ASD risk factors involves events before and during birth such as older maternal age during pregnancy and the occurrence of oxygen deprivation to the brain during birth.

Symptomatology

The most easily recognizable symptoms of ASD, such as lack of eye contact, occur within social settings.  Specific social deficits include false belief, a lack of empathizing, difficulty regarding social interaction, and the inability to detect intentionality from eye gaze.  With each deficit is a proposed theory as well as associated brain regions. However, though previous research supports the associated brain regions as potentially explanatory for the theories, no single theory has acquired enough support to implicate with finality that these regions are where ASD originates.  These theories regarding underlying neural irregularities or impairments are based upon behavioral deficit characteristics of ASD.  There is no specific biological markers identified for ASD which makes it impossible to detect it before birth. The following chart provides the specific deficits of ASD, the proposed causal theories, as well as the brain regions that are associated with each deficit:

ASD Deficits, Theories, and Associated Brain Regions

All that said, deficits, theories, and proposed affected brain regions are NOT mutually exclusive. Additionally, ASD is a complicated disorder; no single theory is considered most probable, though the Broken-Mirror Theory is continuously accumulating supporting evidence. While the brain regions provided may be those primarily causing major symptoms, it is highly unlikely that all ASD symptomatology can be attributed exclusively to these regions.

Prevention and Helpful Tips

There is research which suggests that women can decrease their risk of having a child with ASD by taking prenatal vitamins containing folic acid.   Groups such as Autism Speaks are promoting awareness and investigation regarding the role of the immune system in ASD. Some helpful tips to follow in regards to parenting a child with ASD  include the following:

1. Provide structure and safety
2. Find nonverbal ways to connect
3. Create a personalized ASD treatment plan
4. Find help and support

ASD + Savant Skills

While ASD can be socially debilitating, savant skills can also co-occur.  Savant skills can manifest into Savant Syndrome which is characterized by extreme capability ranging from incredibly specific to vastly broad, usually regarding one specific category, which differs depending on the individual.  Therefore, savant syndrome cannot be attributed to any particular region of the brain, though it has been hypothesized that savant skills tend to be right hemisphere dominant (non-symbolic, artistic, concrete, direct perceived).  Savant syndrome and ASD are not mutually exclusive, however, it has been found that 50% of people with Savant syndrome also have ASD.  The most prominent skill subsets include music, art, calendar calculating, mathematics, and mechanical or spatial skills.  Not only are the specific skills dependent upon the person, but the degree of mastery and detail also varies.

Savant Skill Subsets

Some may have what are called “splinter skills” which includes obsessive preoccupation with and memorization of relatively trivial facts and skills such as sports statistics, license plate numbers, and even obscure things such as being able to reproduce the sounds that a vacuum cleaner makes.  This is the most common savant subtype and even neurotypical brains can display this type of specified skill interest.

Others may be deemed “talented savants” by their particularly prominent musical or artistic abilities despite their cognitive impairment.  The skill is usually within an area of single expertise and stands out conspicuously, relative to the cognitive impairment’s overall effect.  A present day example of this type of savant is Stephen Wiltshire, aka: the human camera.  Wiltshire is capable of accurately drawing intensely detailed landscapes of a city after seeing it once.  The remarkable part is that as a young child he was mute and was diagnosed with ASD.  He was placed in a special school and discovered his love for painting and learned to communicate through art.  The following video shows just how extraordinary Stephen is.

Even still, there are some savants who are considered prodigious.  This category is reserved for those extraordinarily rare individuals for whom the special skill is so remarkable that it would be incredible even if it were to happen to a non-impaired person.  This title has been bestowed upon fewer than 100 living people worldwide.  Daniel Tammet is a brilliant example of a prodigious savant.  He demonstrates exceptional mathematical and language abilities, having mastered 9 languages and being able to recite pi from memory up to 22,514 decimal places.  Daniel suffered from bouts of epilepsy along with ASD which seems to be what brought about his savant abilities.  

While these three subcategories do have differences, all three seem to deal with a massive memory capacity within one very narrow skillset; hence the term “savant”.  Savants follow a general rule of development:

1) Savants are first able to replicate something flawlessly (i.e. a piano composition)

2) Savants typically then begin to improvise something learned, indicating that they have become so comfortable with the piece that they are bored.

3) Savants lastly will begin creating works themselves (be it art, music, memory sets, or number patterns).

The cause for savant syndrome is unknown but remarkable brain plasticity is consistently found in cases of both congenital and acquired types.  D.A. Teffert says it beautifully when he says “The concept of one brain area being ‘recruited’ to take over the function of some other damaged area, paradoxical functional facilitation, is central to explaining savant syndrome.”

ASD + Savant Syndrome: A Case Study

It might be helpful to understand how all the pieces of ASD and savant syndrome are connected by looking at a case study involving both of these disorders.  In a case study of a dual-skill talented savant with ASD, neuropsychological function and brain morphometry were studied.  In this case, savant syndrome was congenitally present with ASD.  Patient GW was a 42 year old male diagnosed with Asperger’s syndrome (before all subtypes of ASD were meshed together under ASD) as an adult, who demonstrated both superior calendar calculation skill and high-level artistic abilities.  His interests seemed to develop in adulthood as opposed to interest as a child.  GW cannot say how he does it but he “just knows” it’s the right answer when it “feels right”.  His drawings have been spectacular since he began drawing and have drawn worldwide acclaim as he has aged.  Researchers found that the superior parietal region of GW’s cortex was the only area thicker than that of a neurotypical group.  They also discovered that other areas such as the superior and medial prefrontal, middle temporal and motor cortices were thinner.  The results of various tests showed that skills in domains that capitalize upon strengths associated with ASD (detail-focused processing, etc.) are further enhanced through over-learning and massive exposure.  This result was reflected in atypical brain structure.   

Savant syndrome provides a way for people with ASD to have an outlet and an area in which they can excel and focus their energy and attention on. 

So, the question now becomes, how do we harness these skills and use them to provide a better life for the owner of the skill and how do we enhance the world around us with them as well?

10 Most Fascinating Savants in the World. (n.d.). Retrieved from http://www.neatorama.com/2008/09/05/10-most-fascinating-savants-in-the-world/

Autism Spectrum Disorder Fact Sheet. (n.d.). Retrieved from http://www.ninds.nih.gov/disorders/autism/detail_autism.htm

Helping Children with Autism. (n.d.). Retrieved from http://www.helpguide.org/articles/autism/helping-children-with-autism.htm

Treffert, D.A. (2009). The savant syndrome: an extraordinary condition. A synopsis: past, present, future. Philosophical Transactions of the Royal Society B, 364, 1351-1357. doi:10.1098/rstb.2008.0326

Underway., N. I. (n.d.). Savant Syndrome: An Extraordinary Condition. Retrieved November 21, 2015.

Wallace, G.L., Happé, F., Giedd, J.N. (2009). A case study of a multiply talented savant with an autism spectrum disorder: neuropsychological function and brain morphometry. Philosophical Transactions of the Royal Society B, 364, 1425-1432. doi:10.1098/rstb.2008.0330

What Is Autism? (n.d.). Retrieved from https://www.autismspeaks.org/what-autism

Dyslexia in the real world: how well does the media portray dyslexia?

Are you, or do you know someone who has dyslexia? chances are you do. One in five people have some form of dyslexia, and it ranges from very mild to very severe. Well what exactly is dyslexia? I personally have always though dyslexics see letters missing parts, jumbled on the page, moving around, or reversed kinda like this:

But is this an accurate portrayal of dyslexia? Lets look at what dyslexia looks like in the media.

Dyslexia in Hollywood

The Cosby show was a very popular and much loved show about an upper middle class African-American family. though a sitcom, it tackled many more serious issues, including dyslexia. In an episode titled “Theo’s Gift Theo is struggling in school, and instead of assuming he’s slow mentally, they take him to a learning specialist, where he is diagnosed with dyslexia. When they understand better what he’s dealing with, Theo learns that he needs to find new strategies to study and improve his grades.

In Percy Jackson and the Lightning Thief, a popular children’s book turned movie, there is another interesting take on dyslexia. the premise of the story is that the main character unknowingly is the son of a Greek god, but before he figures all this out, he struggles in school. whenever he would see words, the letters would literally move around on the page to the point where he never scored above a C in his life. he was diagnosed with Dyslexia in the “real” world, but in the world of the Olympians, his mind was hardwired for ancient Greek! Pretty convenient right. throughout the novels he fights many a mythological Greek villain, and triumph over all. this character trait was intentionally correlated with dyslexia by the author; he wanted to show that people with dyslexia can amount to great things, regardless of the obstacles.

Often people struggling in school are considered to lack intellect, but sometimes it is something different like what dyslexics experience. Often they tend to get frustrated or depressed, because they dont understand why they cant read as fast as other kids, or perform as well in class. The media actually does a very good job at shedding some light on the struggles people with dyslexia encounter in everyday tasks, and also in showing how its possible to overcome. dyslexics simply need more diverse learning strategies, and patience in the classroom. these media portrayals of dyslexia are fairly accurate in terms of the difficulties dyslexics experience, however they do not shed much light on what the actual neurological mechanisms of dyslexia.

So what is it?

Media has portrayed living with dyslexia accurately, but neurologically? what is it? dyslexia is a neuro-biological learning disability characterized by difficulties with spelling and reading abilities that result from a deficit in the phonological (systemic organization of sounds in languages) component of language. dyslexia is not just one deficit, but rather a spectrum. They range from producing errors in phonetic pronunciation, and comprehension, to no semantic errors but sensitivity to correctness, to  sometimes blending elements of two words into one, and recognizing individual letters, but not being able to read single words. It also appears to be caused by malfunctions of many different regions, from the fusiform gyrus, to the temporal lobes. There’s so much diversity within the disorder, that the experience of dyslexics varies widely; so I wouldn’t be so quick call dyslexia a disorder, but rather an umbrella term for all disorders involving difficulties with spelling and reading on a phonological level. I believe its safe to say, though dyslexics struggle with a wide range of issues, it is very possible to live a somewhat normal life with the disorder. More than just live, dyslexics can thrive! Many famous intellectuals such as Albert Einstein and Leonardo Da Vinci struggled with dyslexic, as well as famous business tycoons such as Richard Branson and Shark Tank star Barbara Corcoran (and the list goes on!).

The media shows an accurate portrayal for living with dyslexia, but it talks very little about how much dyslexia varies from person to person. It’s great that they are showing how dyslexics can overcome their situation, but there is definitely more to it then what you see on TV!

References:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2812748/

http://www.entrepreneur.com/article/237669

http://www.theledger.com/article/20080328/NEWS/527509844

Lyon, G.R., Shaywitz, S.E., Shaywitz, B.A. (2003). Defining dyslexia, comorbidity, teachers’ knowledge of language and reading. Annals of Dyslexia, 53.

Demonet, J., Taylor, M., & Chaix, Y. (n.d.). Developmental Dyslexia. The Lancet (british Edition), 363(9419), 1451-1460.

Amnesia is a truly fascinating condition, one which has maintained the attention of scientists and the public for over a century. The simple truth that memories already attained may be lost forever is incredibly intriguing to some, yet incredibly scary to others. One’s self-identity is extremely important and to lose it is akin to losing yourself.

Through the efforts of countless researchers over the years the different types of amnesia and their neurological and psychiatric basis have been mostly elucidated. This understanding, however, is contrasted by Hollywood’s interpretation of such amnesias which is, more often than not, quite inaccurate. An investigation of these discrepancies is conducted for three movies and the three amnesias they are meant to depict:

Shutter Island – Leonardo DiCaprio as U.S. Marshall Edward “Teddy” Daniels – Psychogenic amnesia

Shutter Island (2010) follows DiCaprio’s character, Teddy, as he launches an investigation on a psychiatric facility on Shutter Island. He and his partner, Aule, are searching for a missing patient named Rachel Solando, who had drowned her three children. During the search Teddy begins having migraines, waking visions, and dreams of his dead wife, Dolores Chanal, who had been burned in a building set alight by a man named Andrew Laeddis. Laeddis was also incarcerated on the island and had also escaped. For Teddy, searching for Laeddis is admittedly an ulterior motive for coming to the island.
At one point Teddy is separated from his partner and he happens upon a woman who claims to be the real Rachel Solando. She tells him that the doctors at Shutter Island run experiments on the patients and afterward lobotomize them in the lighthouse. When Teddy hears this he assumes that Aule has been taken to the lighthouse by the doctors and breaks in. He finds the head doctor, Cawley, waiting for him. Cawley explains to Teddy that the whole investigation was setup to break his insanity and that he was Laeddis and had burned his wife alive, Rachel Solando, for murdering their three children. The realization causes Teddy to pass out. He awakes in the hospital with Cawley and Chuck Aule, who is truly Dr. Sheehan, and explains to them everything that had happened in a coherent manner. They are led to believe he has progressed but then he refers to Sheehan as ‘Chuck’ and is taken to the lighthouse to be lobotomized.

Teddy’s inability to remember the events which led to him murdering his wife are typical of dissociative amnesia or psychogenic amnesia. Psychogenic amnesia is characterized by a period of memory loss, normally in the form of inability to retrieve autobiographical information, that occurs following a traumatic event or highly stressful circumstances. Differentiable from other forms of amnesia, psychogenic amnesia cannot be attributed to explicit brain damage. The hippocampus is believed to be involved in this type of amnesia as patients reporting event-related memory loss display decreased hippocampus activation. There are 2 dominant repressor theories attempting to explain the repression: 1) Amygdala Repressor – increased activation in the amygdala simultaneous with the decreased activation in the hippocampus and 2) Dorsolateral Prefrontal Cortex Repressor – overactive dorsolateral prefrontal cortex decreases hippocampal function.
          Shutter Island‘s depiction of psychogenic amnesia is accurate in some regards and inaccurate in others. It is accurate in how it coalesced in Teddy, or Laeddis, being that he watched his three children be murdered and burned his wife alive. That would absolutely qualify as a stressful experience. From a Freudian perspective the total loss of self-identity could be construed as an alternative to suicide. The movie also gives a subtle nod to the notion that Laeddis was malingering the whole time, which may be the case for many people claiming to forget an event. When he is taken to be lobotomized, Teddy turns to Aule and says “Which would be worse–to live as a monster or to die as a good man?” possibly indicating that he was, in fact, aware that he was Laeddis but simply couldn’t stand to bear what he’d done.
          Shutter Island is inaccurate in portraying Teddy as having waking visions. Psychogenic amnesiacs do not report to have such visions. It is also inaccurate in depicting Teddy as unable to form new memories as Cawley reveals to Teddy that he had already conducted the same investigation several times over and he would be lobotomized if he didn’t snap out of it this time. Someone with psychogenic amnesia would be able to remember any events following the stressful episode.

50 First Dates – Drew Barrymore as Lucy Whitmore – Anterograde amnesia

In 50 First Dates Henry Roth, played by Adam Sandler, happens upon a woman, Lucy, in a cafe and introduces himself. They immediately hit it off and when breakfast is over they plan to meet again at the same place the next morning. Henry shows up as planned but when he approaches Lucy she claims to have never met him before. Obviously, Henry is confused, but the restaurant owner Sue explains to him that on October 13th of last year Lucy got in a horrific car accident that rendered her unable to create new memories and so she wakes up every morning thinking it is October 13th. Her father and brother can’t bear to see her relive the accident every day so they follow a script where they place a newspaper from October 13th out, watch the same old Vikings game, and even refill her shampoo bottles.

Henry is not perturbed by the news and courts Lucy anyway. When Lucy’s father and brother find out what Henry is doing they tell him to stop seeing her. Again, Henry isn’t perturbed and begins fabricating reasons to run into Lucy like his car breaking down or setting up a fake road block. The father and brother pick up on Henry’s antics after some time as Lucy would always sing “Wouldn’t It Be Nice” by The Beach Boys on days when she saw Henry.
Henry decides to make a tape for Lucy explaining everything that has happened and shows it to Lucy. She is hurt but then decides to move on and that Henry needs to move on as well. He is upset, but grudgingly agrees and destroys all the records of his past with Lucy. When he is preparing to leave on a sailing trip, however, Lucy’s brother tells him that she is living at a brain institute and sings often and then gives him a Beach Boys CD. The CD convinces Henry that Lucy remembers him and he goes to her to discover that she has been dreaming of him and painting him even though she doesn’t realize who it was. The movie ends with Lucy waking up on a boat to a video of her wedding with Henry.

The symptoms Lucy exhibits in the film correlate mostly with anterograde amnesia. This particular type of amnesia constitutes the inability to form new memories of events occurring after brain damage. Research has revealed that damage to the hippocampus, thalamus, and mammillary bodies will result in anterograde amnesia. It will commonly manifest in frequent “awakenings” in which patient loses information as soon as focus is diverted.
          50 First Dates illustrates anterograde amnesia surprisingly accurately relative to other Hollywood depictions of amnesia. Firstly, though, it should be noted that her condition was called “Goldfield’s Syndrome” in the film, which doesn’t exist at all, and that most people with amnesia live in a hospital setting due to the extent of how deeply anterograde amnesia interferes with one’s daily life. Besides those two points, however, the movie does a pretty good job.

Lucy living everyday thinking it’s the day she suffered the brain damage causing her amnesia is possible. Individuals with anterograde amnesia do create new memories but those memories cannot then be accessed, and Lucy therefore would only recall the day before her injury. This is contrasted by the character nicknamed “10 Second Tom” who, as him name indicates, could only hold onto memories for ten seconds before losing them forever. This discrepancy is validated by the type and extent of brain damage between the two characters. A real life comparison may be drawn with an English man named Clive Wearing, who could only remember things for 7 seconds.

Another thing from the movie that is in actuality possible is how Lucy would paint Henry without knowing who he was, even if it’s extremely cheesy. Anterograde amnesia prevents people from accessing memories but since they are still creating memories they are still affected by them. In Clive Wearing’s case he was told by his doctors to keep a journal. Clive would and even though he would say he knew not of any journal of his existing he did know it was kept. He also wouldn’t show any surprise or inability to recognize his wife even after 20 or 30 years. So in concept, Lucy could be able to paint Henry without realizing who it was.

In conclusion, Hollywood does tend to take certain artistic liberties when depicting individuals with memory deficits. They are able to due to a lack of understanding of the population at large and adding a few elements to an amnesia like waking visions or headaches only makes things more interesting to an ignorant audience. Some movies (Shutter Island) are worse than others (50 First Dates) but as amnesia will continue to provide intriguing material to directors we are sure to see many more movies centering on amnesias in the future.

Sources:

1. https://en.m.wikipedia.org/wiki/Dissociative_amnesia
2. https://en.m.wikipedia.org/wiki/Shutter_Island_(film)
3. https://www.psychologytoday.com/blog/psychologist-the-movies/201212/amnesia-in-50-first-dates
4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC535990/?tool=pmcentrez
5. Diagnostic Statistics Manual
6. Kikuchi et al. (2009): “Memory repression: brain mechanisms underlying dissociative amnesia”
7. Yasuno et al. (2000): “Functional anatomical study of psychogenic amnesia”.
8. Kopelman (2000): “Disorders of Memory”.
9. Textbook.
10. Harding et al. (2000): “Degeneration of anterior thalamic nuclei differentiates alcoholics with amnesia”.
11. Deborah Wearing: “Forever Today: A True Story of Lost Memory and Never-Ending Love” (2005).
12. Nahum et al. (2014): “Neural correlate of anterograde amnesia in Wernicke-Korsakoff syndrome”.

History: The Establishment of the Fusiform Gyrus as Involved in Face Recognition

In 1992, a research team led by Dr. Justine Sergent published an article in Brain: Journal of Neurology, which presented the results of a Positron Emission Tomography (PET) study aimed at identifying the underlying neural structures involved in face and object processing. What Sergent et al. found would result in the generation of an entire new field within Cognitive Neuroscience.

Analysis of the PET data collected from the study revealed that a brain region called the Fusiform Gyrus was highly active during tasks that required face processing, but that the area was not active during object processing tasks. Sergent et al. concluded that the results offered, “new information about the dissociation between face and object processing” [1].

Figure 1. PET images displaying Fusiform Gyrus activation.

The attention of the Cognitive Neuroscience community had been captured. Yet, it would be five years later when the Fusiform Gyrus and its functional purpose would really become such a highly debated topic. In 1997, an fMRI study performed by Kanwisher et al. found the Fusiform Gyrus to be more active during face recognition tasks than in tasks requiring recognition of objects or other body parts. The experiment included multiple tests, all of which compared face recognition to recognition of a different category. Analysis of the data resulted in a consistent pattern of increased activity demonstrated by the Fusiform Gyrus during face recognition tasks. From their results, Kanwisher et al. concluded that the Fusiform Gyrus was “selectively involved in the perception of faces”, and renamed the Fusiform Gyrus as the Fusiform Face Area (FFA) [2].

The Expertise Hypothesis

Kanwisher et al.’s strong and confident claims about the relatively novel notion that “faces are special” resulted in a cascade of follow-up research on the FFA and its functional purpose. Though a large majority have found the FFA to be involved in face recognition, not all support the assertion that the brain region is “selectively involved in the perception of faces”. In fact, a large portion of the research conducted contends that the FFA is a region not simply specialized for face recognition, but rather that it more generally specializes in areas of expertise. The Expertise Hypothesis purports that the FFA can be invoked by any domain of expertise and explains that face recognition activates the FFA because people are experts at recognizing faces.

Controversy

In essence, there appears to be a division within the existing body of research regarding the assertion that “faces are special”. Equally valid and reliable research exists both in support and in negation of the notion. And so the controversy presents itself: “are faces special?”

“Faces are Special.”

Figure 2. Examples of Greebles.

Duchaine et al. (2004) would tend to support the notion that “faces are special” after conducting a study on prosopagnosic patient, Edward. Prosopagnosia is defined as a deficit in the ability to recognize familiar faces. However, other than the prosopagnosia, Edward had no other mental or physical impairments, and he scored within the normal range on both vision tests and object recognition tests. Duchaine et al. administered Greeble Training to Edward in order to test Edward’s abilities to acquire expertise. Greebles are novel figures that demonstrate distinct features that allow for distinguishability. There are sixty Greebles which can be categorized at the family, gender, and individual levels. Greeble Training results in acquiring a level of Greeble Expertise, in which one can consistently recognize the distinguishments and identify the Greeble [3]. Duchaine et al. found Edward to perform normally throughout standard Greeble Training procedure, indicating that face recognition and greeble recognition must rely on separate mechanisms [4]. Edward was able to acquire the level of Greeble Expertise, despite his severe impairments in recognizing faces, suggesting that “faces are special”, due to the fact that face recognition is a process that can be selectively impaired.

“Faces are not Special.”

Figure 3. Examples of Car and Face stimuli.

Yet, McKeef et al. (2010) would tend to disagree with the notion that “faces are special”. In McKeeff et al.’s investigation regarding the effect of object expertise on face processing, car experts and car novices were administered a task which required participants to search for a target, a face or a watch, amongst distractors, which included faces and cars. Results demonstrated that car experts exhibited a higher response time than car novices when identifying faces amongst task irrelevant cars, but a lower response time than car novices when identifying watches amongst task irrelevant cars. McKeeff et al.’s findings suggest that object expertise results in greater functional overlap between the object of expertise and faces and less functional overlap between the object of expertise and other objects [5].  These findings also suggest that object expertise can interfere with face recognition. The conclusions drawn by McKeeff et al. negate the notion that “faces are special”, because face recognition does not appear to be an exclusive process; furthermore, the conclusions support the Expertise Hypothesis, as recognition of faces and objects of expertise appear to rely on a shared neural mechanism.

“So… Are Faces Special?”

Bilalic et al. (2011) conducted an fMRI study that compared FFA activity of chess experts and chess novices during a series of tasks that included face recognition and chess-related recognition. Chess experts did demonstrate higher levels of FFA activity than chess novices during chess-related tasks. However, in a task that required participants to passively view faces and chessboards, FFA activation was highest for both chess experts and chess novices, when face stimuli were presented [6]. The results of Bilalic et al.’s fMRI experiment indicate that while the FFA is probably a general expertise module specialized for individuation and differentiation, the assertion that “faces are special” can be supported due to the extraordinary amount of FFA activation associated with the presentation of face stimuli.

Ultimately, the question of whether or not “faces are special” cannot completely be answered with a direct “yes” or “no”; rather, the existing body of research presents the answer as lying somewhere in between the two. A precise answer may never be found, but only further Cognitive Neuroscience research will continue to expand the knowledge and understanding of face recognition and the FFA, providing the opportunity to move closer and closer to a resolution of the long-debated controversy: “are faces special?”

References

[1] Sergent, J., Ohta S., & MacDonald, B. 1992. Functional neuroanatomy of face and object processing. A positron emission tomography study. Brain, 1, 15-36.

[2] Kanwisher, N., McDermott, J., & Chun, M.M. (1997). The fusiform face area: A module in human extrastriate cortex specialized for face perception. The Journal of Neuroscience, 17(11), 4302-4311.

[3] Gauthier, I, & Tarr, M.J. (1997). Becoming a “greeble” expert: Exploring mechanisms for face recognition. Vision Research, 37(12), 1673-1682.

[4] Duchaine, B.C., Dingle, K., Butterworth, E., & Nakayama, K. (2004). Normal greeble learning in a severe case of developmental prosopagnosia. Neuron, 43(4), 469-473. doi: 10.1016/j.neuron.2004.08.006

[5] McKeeff, T.J., McGugin, R.W., Tong, F., & Gauthier, I. 2011. Expertise increases the functional overlap between face and object perception. Cognition, 117(3), 355-360. doi: 10.1016/j.cognition.2010.09.002

[6] Bilalić, M., Langner, R., Ulrich, R., & Grodd, W. 2011. Many faces of expertise: Fusiform face area in chess experts and novices. The Journal of Neuroscience, 31(28), 10206-10214. doi: 10.1523/JNEUROSCI.5727-10.2011

Have you ever been told you’re right or left brained?  Have you ever been posed with this question in a job interview or major declaration?  Should these important decisions really be based off of an idea that one side of your brain is more dominant than the other? Most people can agree that there are more factors that make up our personalities, the decisions we make, and how we take in the world around us than which side of our brain is more dominant.  There may be some truth to the idea that each hemisphere is responsible for different functions, but whether or not one is more dominant, and thus more prominent, in our personalities is something that needs to be investigated more thoroughly.  There is evidence, however, that one hemisphere may be more dominant in the way that we process information.  This could play a major part in our personalities and thus how we interpret our surroundings.

Dominance in the Brain

What exactly is “hemispheric dominance” and where did the idea come from?  To put it simply, hemispheric dominance is the idea that the two hemispheres of the brain are specialized to perform different functions and that individuals show a preference towards using one hemisphere more than the other.  It is widely believed that hemispheric dominance originated from the misinterpretations of Roger Sperry’s split-brain experiments.  Split brain is a term used to describe individuals who have had their corpus callosum severed (in response to epileptic seizures), which stops most, if not all, communication from the left and right hemispheres.  Patients who have had this procedure show no loss of cognitive ability, however they have been known to show odd behavioral and linguistic responses.  These experiments did demonstrate the existence of hemispheric dominance for some functions, but not all.

Is it Written in the Stars?

The idea of hemispheric dominance has been perpetuated largely due to people striving to better understand themselves. For many people, there is a comfort in saying “I’m a left-brained thinker”. The human mind likes to organize and categorize information. Therefore, when people are able to “categorize” their personalities into either left-brain or right-brain dominant, they are able to have a better “understanding” of how they take in and process information…or so they think.

 An abundance of brain dominance tests have been developed that attempt to dissect people’s brains into categories as either left or right brain dominant. One can search “hemispheric dominance” on Google and find that nearly half of the first page consists of links to brain dominance tests. The other half contains links to websites explaining myths about hemispheric dominance. However, people tend to care less about disproving theories. Instead, they scroll aimlessly through the various quizzes available as part of the journey to “discover” more about themselves.

Many of the theories behind left and right brain dominance vary extremely in their understanding, scientific evidence, and audience. Some theories are driven by psychological differences in personality. Others are driven by ideas as extreme as astrology signs. Astrological principles have been applied to map out the left and right sides of the brain. Through this particular theory, it aims to explain left and right brain “dominance” by incorporating psychological classifications of personality, including thinking/doing and seeing/feeling. There is a “cross-over” that occurs so left and right sides of the body can interact, but it is “dominated” by one hemisphere depending on astrological signs. For example, earth and air signs such as Leo or Gemini are dominated by left-brain ideas such as logic and material thought.

Although some sources have more scientific validity than others, individuals tend to find comfort in “understanding” how they think and how their brains “work”. Additionally, such tests allow individuals to attain a baseline from which they may train their brains and become smarter. Most tests supply a “guide” of sorts on their results page describing how, for example, a right-brained thinker can strengthen their left-brain by practicing making lists or more set schedules, therefore becoming “smarter” by strengthening the weak side of their brain.

The idea of “brain training” is a very popular one and is now being utilized by companies for profit. Most notably, the website Lumosity claims to train your brain to enhance things like attention, speed, memory, and problem-solving, all for a small fee of $13 a month. With over 70 million subscribers, Lumosity is the web’s most popular “brain-trainer,” which is interesting since a study has found that the video game Portal 2 proved to be more effective in improving cognitive skills. A video game. But hey, Lumosity says their training is based on neuroscience so it must be true! (The power of play: The effects of Portal 2 and Lumosity on cognitive and non-cognitive skills, Computers & Education, Volume 80, January 2015, Pages 58–67.)

So, what’s the real deal?

Well, we know that the brain does in fact have two distinct hemispheres that are each responsible for performing certain tasks and cognitive functions.  We know that both sides connect but the way information is processed is different. For example, areas designated to understanding and producing language are highly lateralized in a consistent fashion. Over 90% of people show significant left hemisphere dominance for language. This consistency however is affected by other factors, like handedness (70% of left handed people are left-brain dominant for language vs 90) and gender (males are more lateralized than females in general). Though there is a factor of variance, the majority of people demonstrate this consistent laterality.

Though the left hemisphere dominates language processing, the right hemisphere has its own contribution to understanding language. The right hemisphere is focused on visuospatial processing (guiding, grasping,manipulations of objects, facial recognition, and recognizing emotional cues).  In summation, though the left hemisphere may be dominant for language processing, the right hemisphere helps with interpreting the information given.  when someone is talking, you need your left hemisphere to understand and interpret the words that they are saying, but you need your right hemisphere to recognize who you’re talking to, what you’re talking about, and catch any subtle undertones that the other hemisphere might miss. therefore, one may be dominant in its own way, but both are necessary for complex processing.  It seems safe to say that both hemispheres work together to form our personalities, behaviors, and the decisions we make, but that the way we think about things and the way we process things around us may suggest a slight hemispheric dominance in that area.  

Sources

1. http://rationalwiki.org/wiki/Hemispheric_dominance
2. http://s3.amazonaws.com/Edcanvas/9007/local/split%20brain%20in%20man.pdf
3. http://s3.amazonaws.com/Edcanvas/9007/local/split%20brain%20in%20man.pdf
4. http://lucenaturale.com/HowAstrologyMapsToTheHemishperes.htm
5. http://www.livescience.com/32935-whats-the-difference-between-the-right-brain-and-left-brain.html