Thursday, March 7, 2013

Apperceptive vs. Associative: Will the Distinctions Make a Difference?

Apperceptive with elements of associative prosopagnosia. In plain English, that description essentially means Chuck cannot distinguish between faces he knows and those he doesn't, although he can recognize a face as such. Typically, this processing impairment results from damage to the right occipital temporal lobe -- the opposite side from Chuck's temporal lobectomy. In general, the associative aspect refers to his difficulty determining whether photos of two faces capture the same person or two different people, and then identifying someone from his or her photo. This memory "linking" impairment also is commonly associated with the brain's right anterior temporal region.

However, Chuck is left-handed -- or, more accurately, "mix-handed," which might have affected the location of face recognition functions in his brain. He's not exactly ambidextrous but he does perform a number of functions with his right hand. Did he develop that ability innately? Did his parents try to "re-train" him at a young age when he was performing tasks with his left hand? Did congenital damage to the right side of his brain prompt certain neurological functions to "migrate" to the left side? Any of these scenarios might have played a role in the development of his brain and the location of facial recognition centers. We'll never know the answer and, ultimately, it doesn't matter. The more important question is whether Chuck -- or potentially other prosopagnosia patients -- might benefit from the Face Training Program at the Human Vision and Eye Movement Lab in the University of British Columbia's Department of Ophthalmology and Visual Sciences.

This week's baseline visit to Jason Barton's lab offered some important clues. Over the course of four days, Chuck took a battery of tests.

Using the Cambridge Face Perception Test, he compared a "target" face to a range of similar faces, with one minute to rank the choices from farthest to closest to the target. 

The O'Toole Dynamic Face Recognition Test assessed his ability to identify short video clips of faces.

The "George" Component Test examined whether one of six facial features -- chin, forehead, eye size and distribution and mouth size and distribution -- was dissimilar in one face on a screen compared to two others.

The Cambridge Memory Test of Faces measured Chuck's ability to memorize faces shown in three orientations and then identify which of the faces he'd seen previously.

And the Warrington Memory Test of Faces and Words evaluated his ability to recognize previously seen faces and words.

Chuck also underwent a two-hour functional MRI, an electroencephalogram (EEG) and various ancillary studies, including face and voice matching, eye-tracking and word length effect.

Early results suggest Chuck performed below average in every test -- no surprise -- and no better than chance in some of them. In the components test, for instance, his performance was less accurate than random selection. Could the Face Training Program improve his score and, even more important, enhance his ability to identify the faces of family and friends in the real world? Only time will tell.

We'll be on our way home in the morning. The next step of Chuck's journey is just beginning.

Wednesday, March 6, 2013

Expanding the Boundaries of Face Blindness

Because prosopagnosia isn't life-threatening, research into the condition didn't exactly spread like wildfire. After Chuck was diagnosed with face blindness, we asked his medical team what resources were available to help him cope with the condition. For the most part, they could only refer to the textbook definition and wish him well. None of them had seen an actual case. They told us that cases of prosopagnosia largely affected patients who were critically ill with other conditions, such as disabling strokes that had bled into both sides of the brain or tumors that had spread into multiple brain regions. Chuck's doctors said that, for these patients, face blindness was the least of their problems -- hardly a heartening perspective for someone facing a life-changing diagnosis.

As a freelance writer who specialized in health care, I began searching the term "prosopagnosia" occasionally on medical websites, such as the National Institutes of Health. These attempts were pretty primitive; after all, this was in the days before search engines.

Although PubMed featured scholarly publications describing prosopagnosia, for years searches for clinical studies came up empty. Around 1997, I got a hit on the NIH website, but my excitement turned to disappointment when the prosopagnosia page was empty. (To this day, lists no studies for prosopagnosia or face blindness.)

Although the introduction of Google in 1998 made searching easier, it was 2005 before a search directed me to the website I literally ran to get Chuck, and we poured over the website, where he completed a questionnaire about face recognition difficulties. That response led us to Brad Duchaine, a researcher and lecturer at University College London who's now associate professor and head of the Social Perception Lab at Dartmouth College.

At the time, Duchaine and colleagues were focused on face recognition deficits in developmental disorders, but they were collecting names and contact information for individuals who might be interested in future research projects in prosopagnosia. Without hesitation, Chuck added his name to the list.

Several more years passed. In February 2008, we received an email from Duchaine, which read, in part:

"A group of researchers, including myself, have begun a large-scale study of acquired prosopagnosia, and we're interested in recruiting as many subjects as possible. Most of the testing will take place in Vancouver with a group of neurologists and psychologists coordinated by Jason Barton in the Human Vision/Eye Movement Center at the University of British Columbia.

"Our understanding of face processing and its dysfunction has benefited greatly from studies of people who have lost their ability to recognize faces due to brain damage experienced after maturity (acquired prosopagnosia). However, because the condition is relatively rare, few subjects have been studied by labs that specialize in face processing, so much remains to be learned about acquired prosopagnosia.

"Our study involves a large battery of behavioral tests measuring a wide range of abilities (face memory, face perception, face detection, expression recognition, object recognition, low-level visual abilities, etc.) and several scans that provide a detailed view of brain structure and activity in response to visual stimuli. Participants also have the option of enrolling in an experimental trial of perceptual training that we hope will improve face recognition ability."

In May 2010, Chuck's adventures in prosopagnosia research began with a visit to Barton's lab in Vancouver for "a functional MRI study of facial perception in normal subjects, prosopagnosic patients and patients with cerebral infarcts." Findings from that study -- for which I volunteered as a control -- concluded Chuck had a general diagnosis of intermediate prosopagnosia, including "significant problems with recognizing faces, which also extends to other object categories."

Fast forward to this week, when we returned to Barton's lab so Chuck could participate in a face training program. Following the first day of testing, which concluded with a functional MRI, Chuck received a more defined diagnosis of "apperceptive with elements of associative" prosopagnosia. In addition, we heard for the first time in 20 years that facial recognition may -- potentially -- be a skill that can be re-acquired or re-learned, thanks to neuroplasticity. Much work to do, but finally the prospect of "seeing" faces once again.

Sunday, March 3, 2013

And the Oscar Goes to...

Along with 40 million of our closest friends, Chuck and I watched the annual glamfest known as The Oscars. For Chuck, however, the awards show was more than a parade of gowns, speeches and bad jokes. It was also a sharp reminder of the limitations of movies, TV shows and theater for viewers with prosopagnosia.

In the old days before Chuck's face blindness, we could select a movie on a whim, simply because the story sounded compelling. Prosopagnosia has changed that. Trying to follow a complicated plot is hard work, not entertainment, for Chuck. As each character is introduced, he must quickly absorb something distinctive -- purple hair, a lisp, an eye patch, use of a wheelchair or cane -- since he can't recognize faces. When characters are introduced one at a time or in a small, diverse group -- like the eccentric family in Little Miss Sunshine -- he can differentiate them more easily. That's important, because as each new scene unfolds and the actors change costumes and sets, he must piece together their identities all over again. The faster he can do that, the more he can absorb of the story.

The challenge is greater with some movies than others. For instance, Chuck can keep up with James Bond, though he may be fuzzy on the minor characters. It's easier to follow a plot if he's read the book, like Marley & Me, which also featured a small cast -- and the lead character was a dog.  He has little difficulty identifying Meryl Streep in almost any movie, despite the fact -- or maybe because -- she lights up every scene. And biographies are favorites. Chuck thoroughly enjoyed Ray and The King's Speech -- of course, the films also featured a blind man and a monarch with a stutter, respectively. Different is better when it comes to picking a movie that someone with prosopagnosia can enjoy.

The opposite also is true. If a film begins with a rapid-fire montage -- think Saving Private Ryan or Gladiator -- it's so difficult to pick out the lead characters and learn something distinctive about them that it's an uphill battle to find them in ensuing scenes. Chuck watched both of these movies, but plot nuances were lost on him as he focused most of his energy on searching for the important characters in each scene.

While most people read reviews or talk with friends to decide whether or not to attend a given movie, we use a fairly unusual decision tree. War epic? Usually not, because a bunch of men wearing the same uniforms makes for a very difficult plot for Chuck. Ensemble cast? Not likely, unless they're strikingly different, such as the safe-cracking team of The Italian Job. Girl meets boy? Depends on how many girls and boys. Plenty of men protest about watching chick flicks -- even if they're classics like Pride and Prejudice or Sense and Sensibility -- but not for the same reason as Chuck. Musicals? Even if the plot is dense, songs can compensate. And let's face it, unless they're performing in A Chorus Line or TV's Glee, most singers and dancers are anonymous by design so Chuck doesn't have to look for them in each scene.

Of course, there are exceptions to these movie rules, and 2012 was full of them. Which brings me to the year's award-winning films. The first rule we broke was to watch Argo, which Chuck enjoyed but struggled to follow. Not surprising, considering the movie starts with hundreds of unnamed extras storming the U.S. embassy in Tehran. The upside: We lived through the Tehran crisis, which helped him to track the plot, even if some of the characters blended together.

Skyfall? Bond. Done.

Despite the spectacle, Chuck enjoyed Les Miserables. A musical, of course, and hard to top for the artistry of the sung performances. It helped that we'd seen the stage version and Chuck knew the general story.

Both Lincoln and Zero Dark Thirty were challenging. Although the main characters jumped off the screen, others in the large ensemble casts quickly melted together. During scenes without the leads, Chuck had to guess who was talking and how that dialogue factored into the plot. Fortunately, the context of both stories -- one from the history books and the other from recent history -- and the power of both films helped him to keep up.

We haven't yet seen Life of Pi, but a boy and a tiger? Sounds like a slam dunk. It's on our list.

But for Chuck, the most watchable movie of the awards season was Silver Linings Playbook, which featured four distinct and memorable characters. Even some of the cameo roles -- Chris Tucker as Pat's sad-luck friend and Anupam Kher as his court-ordered psychiatrist -- were sufficiently different that Chuck could spot them quickly as the story unfolded.

Filmmakers don't always load their movies with idiosyncratic characters, nor should they. But for someone with prosopagnosia, watching a small film with quirky personalities is the closest it gets to true entertainment. That said, movies do have one advantage over real life: they never change. The characters don't age, develop wrinkles and sags, gain or lose weight or cut and color their hair. The films Chuck watched before his surgery in 1993, when he could still recognize and form memories of a face, live forever. He can enjoy them as much today as he did 20 years ago.