A Patient With A Rare Disease Sees Numbers But Cannot Recognize Them

A patient with a rare disease sees numbers but cannot recognize them

Scientists suggest that the problem lies in the disruption of information processing in the brain: the information received does not transform into a familiar image.

Photo: pnas.org

Scientists at Johns Hopkins University have described a highly unusual symptom in a neurological patient. Degenerative brain disease manifested itself in the fact that the man lost the ability to parse the written numbers. The case report is published in Proceedings of the National Academy of Sciences.

The patient, whom the authors of the scientific work called RFS (RFS), suffers from degenerative brain damage - widespread atrophy in the cortex and basal ganglia. Typical symptoms of the disorder are muscle cramps and memory impairments. An unusual manifestation was the violation of the perception of numbers.

RFS had no difficulties with reading and recognizing letters. He also normally recognized the numbers 1 and 0. But the numbers from 2 to 9 turned for the patient in "spaghetti" when he looked at them. When scientists asked him to draw what he saw, a set of abstract lines, dots and flashes of color came out. When, in the experiment, scientists put the cut out number on objects familiar to the RFU, he ceased to distinguish between them until the number was removed.

When RFS in experiments identified various objects and numbers, the authors of the study carried out in parallel electroencephalography (EEG). They argue that this complementary research method showed that the patient does not really see numbers.

Likewise, the patient did not recognize the words when they were inscribed in numbers. The EEG showed that the brain saw the big picture, but could not recognize anything.

Scientists believe they are faced with an interesting case of separation of perception and recognition. The brain sees faces, objects, words, pictures. But recognition requires the brain to process this information. The authors of the study believe that it is at this level of brain functioning that the problem of RFR lies.