home *** CD-ROM | disk | FTP | other *** search
- THE WEEK, Page 20HEALTH & SCIENCEWhat Has Four Legs . . .
-
-
- A woman's trouble naming animals helps show how the brain works
-
-
- Neurologists and psychologists learned long ago that brain
- injuries can be a powerful tool for investigating how human
- thought and memory are organized. A case study by two Johns
- Hopkins researchers, reported in Nature, is but the latest
- example. A 70-year-old retired librarian who suffered such an
- injury developed a remarkable symptom: she lost the ability to
- name animals, though she could still name other living things,
- such as plants, and inanimate objects. Nor could she assign
- physical attributes to animals -- she could not, for example,
- answer the question "What color is an elephant?" Yet she could
- answer nonphysical questions, about whether a given animal lived
- on land or in the sea, or whether it was normally kept as a pet.
- And when shown a picture of, say, a lion with a horse's head,
- she could tell right away that the two didn't match.
-
- So what does it mean? Evidently, the brain has distinct
- systems for classifying different types of objects, and it
- stores categories of information, such as physical versus
- nonphysical characteristics, in different ways. Moreover, the
- study shows that the brain has two classification systems, one
- language based and one sight based, and that one can be
- destroyed while the other stays intact.
-
-
-
-
-
-
-