Medical

The curious case of the man who can't see numbers

The curious case of the man wh...
Looking at any digit between 2 and 8, patient RFS could only see a spaghetti-like scramble of lines and colors, as depicted here
Looking at any digit between 2 and 8, patient RFS could only see a spaghetti-like scramble of lines and colors, as depicted here
View 2 Images
Looking at any digit between 2 and 8, patient RFS could only see a spaghetti-like scramble of lines and colors, as depicted here
1/2
Looking at any digit between 2 and 8, patient RFS could only see a spaghetti-like scramble of lines and colors, as depicted here
Patient RFS attempts to draw the number displayed onscreen
2/2
Patient RFS attempts to draw the number displayed onscreen

Damaged brains have given us an incredible treasure trove of information to help us untangle the mysteries of the human mind. A tiny brain lesion can shift a person's reality in bizarre and tragic ways, as anyone who's read The Man Who Mistook His Wife for a Hat can attest, and their ability to fully describe their condition can lead us toward a fuller understanding of how our incredibly complex mental processes work. Here's another oddity to put on the pile.

Johns Hopkins researchers have described a patient they have called RFS, whose rare degenerative brain disease has caused "extensive atrophy in the cortex and basal ganglia." RFS suffered the typical muscle spasms and memory issues you'd expect in such a patient, but also started experiencing some very strange issues with numbers.

While RFS had no trouble reading or identifying letters of the alphabet, and 1 and 0 would appear normally, the digits between 2 and 9 would turn into "spaghetti" when he looked at them, and he'd have no idea what number he was looking at. Trying to draw what he was seeing produced abstract collections of lines, dots and splashes of color.

To make things even stranger, placing a number on top of a picture of a familiar object like a violin would scramble the whole thing, so he couldn't identify the violin or the number. Gradually moving the violin image away from the number, there was a point at which the violin popped back into his perception.

The Johns Hopkins team, led by former grad students Teresa Schubert and David Rothlein, did some experiments using electroencephalography (EEG) to monitor RFS's brain activity during various tasks. When shown a face with a number on it, RFS was completely unaware there was a face or a number in what he was seeing, and yet his EEG activity indicated that his brain was responding just as if he was looking normally at a face.

Patient RFS attempts to draw the number displayed onscreen
Patient RFS attempts to draw the number displayed onscreen

"These results show that RFS's brain is performing complex processing in the absence of awareness," Rothlein says. "His brain detected the faces in the digits without his having any awareness of them."

Similarly, when shown words with digits embedded in them, RFS saw nothing but a scrambled mess – and yet the EEG showed his brain was getting the full picture.

"He was completely unaware that a word was there, yet his brain was not only detecting the presence of a word, but identifying which particular word it was, such as 'tuba'," Schubert says.

So what can we learn from this wonderfully weird condition? The team says it points to a separation of perception and awareness. The brain can identify faces, words, and pictures, but there's some additional level of neural processing required to bring them to our awareness. This, the team hypothesizes, is where the damage lies in RFS's brain tissue.

The research is available in PNAS.

Source: Johns Hopkins University via Medical Xpress

7 comments
BohdanUke1
Another layer uncovered. If we only knew how many layers there are to understand our brains...
Username
What does he see when he looks at his "spaghetti" drawings?
Christian Lassen
Got a close friend who had a mini-stroke a few months ago that made it so he can't read or recognize words like he used to. No other symptoms. Had a bad headache one night and that was about all. Afterward he could only read like a kindergartner, sounding out each letter at a time to put the words together, he can't glance at a word and recognize it anymore. No trouble speaking or spelling, just the "visual dictionary" of his mind was lost and he's having to get it back slowly. Right now he says he's at a 3-4th grade reading level.
drBill
He can see and perceive correctly 0, and the letter o. Since at least one version of 8 is just oo (sideways) I wonder what would be drawn if oo (eight) were presented to him sideways.
paul314
If the numbers are interfering with his recognition of other things, it sounds as if some part of his brain still "recognizes" the numbers well enough to actively not see them. Deeply weird. And sad.
ARF!
never been able to do anything beyond basic (everyday) fractions in my head, I can do multiplications since it's usually done one digit at a time but a division problem just melts together in my head, I just can't hold onto em since numbers aren't even real in the first place.
Terence Kuch
From the photo, I see he's a left-hander. As a fellow leftie, I wonder if that has anything to do with his condition.