Tuesday, July 8, 2008
I'll make conversation while monitoring for verbal clues
Given my stunning performance on the Cambridge Face Perception Task, the postdoctoral researcher at the Jamaica Plain Veterans Administration who is looking for prosopagnosics was eager for me to come to the lab. We reviewed my experience of face-perception difficulty and he decided to start off by checking some of skills that often accompany face perception difficulties: gender, age and attractiveness identification. This battery, The Philadelphia Face Perception Battery (pdf), also had an upright only face discrimination task (choose which of two choices was most similar to a target face). Surprise: I was normal on all 4 tasks.
The researcher later emailed me:
From the tests you've taken so far, it seems like you have a moderate form of prosopagnosia that is somewhat specific to facial identity. However, there are a couple tests that you were able to "beat", most likely through employing compensatory strategies.
The stategies were simple: I used skin tone, and fat/thin face shape. On the Philadelphia Battery, I only had to look at three faces and make one decision. In contrast, the CFPT is crazy hard, because on a single trial one is confronted with 7 faces: a target and 6 faces that have to be put in order. I now think that my problem with the CFPT was that there were so many faces that I couldn't pick out similar/differnet features. As I scanned across the row of faces, they all looked equally dissimilar to the target. Consistent with prosopagnosia, I showed no inversion effect (as noted in prior post).
My hypothesis is that my face perception abilties are good enough to process three faces at a time, but I break down under conditions of heavy cognitive demand.
Along these lines: I had some problems watching a DVD last night, La Guerre est finie. It was a black&white 1960s movie about anti-Fascist Communist revolutionaries scuttling back and forth between Spain and France, in French with English subtitles. I couldn't keep straight who was the main character vs. one of at least two other white mid-40s males with short black hair wearing a suit and tie. I've had this problem frequently before, but it seemed really acute in this particular movie. To figure out the political machinations I had to at least know who was the undercover agent from Spain vs. his friend in Paris. I just gave up and fortunately after this first half hour got used to his face and voice enough and the friend had receded in importance so only the main character was mostly in view, etc.
This fits the hypothesis of information overload. My face processing is exacerbated by on-going cognitive demands. The movie was black and white, so it was already a difficult person-detection task because of reduced cues for skin color, hair texture, clothing, AND I had to read subtitles so had less time to even look at the characters.
Yes, I'm mostly a single-channel processor. I dislike concurrent processing and turn off TVs, radios when I need to work, I find even a background babble of speech (like a TV in a distant room) annoying because it tugs at my attention (nonspeech is okay).
So... I have mild prosopagnosia compounded by poor concurrent processing, whaddaya think? And remind me of your name when we meet (smile).