PET Studies of Components of High-Level Vision.
Abstract
We have finished analyzing the data from our first PET experiments and written a report of the results. As noted earlier, we have strong evidence (p = .0001) that primary visual cortex is activated selectively during visual mental imagery. In our next PET experiment we will study how objects are identified when seen from unusual points of view. Warrington and Taylor (1973) found that patients with right-parietal lesions have a very difficult time recognizing objects seen from unusual points of view. Kosslyn, Flynn, Amsterdam and Wang (1990) explain this result by positing a top-down, hypothesis testing mechanism that is called into play when a stimulus does not immediately match a stored memory very well. This mechanism not only relies on processes in the parietal lobe to shift attention, but also on processes in the frontal lobe formulate hypotheses. To test these ideas, subjects will see a series of pictures, either of objects seen from a canonical point of view or of objects seen from an unusual point of view. One sec after seeing a picture, a word will be presented, and the subject will decide whether the word names the pictured object. Counterbalancing will ensure that the same objects and words appear equally often in the two conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1991
- Accession Number
- ADA240202
Entities
People
- Stephen M. Kosslyn
Organizations
- Harvard University