We scan the visual world by making rapid eye movements (saccades) and serially focusing on objects of interest. Despite abrupt retinal image shifts, we see the world as stable. Remapping contributes to visual stability by updating the internal image with every saccade. Neurons in macaque lateral intraparietal cortex (LIP) and other brain areas update information about salient objects around the time of a saccade. Information about salient objects is transferred from neurons that currently encode their screen locations to other neurons that will encode their locations after the saccade. The depth of information transfer remains to be thoroughly investigated. Area LIP, as part of the dorsal visual stream is regarded as a spatially selective area. Yet there has been increasing evidence that LIP neurons also encode object features.
We sought to determine whether LIP remaps shape information. Such insight is required for understanding what information is retained from each glance and how the visual percept is built (transsaccadic perception). First, we presented shapes in the future location of the receptive field around the time of the saccade and tested for shape selectivity during remapping. Second, we presented the same shapes within the receptive field and tested for shape selectivity in the fixation task. Finally, we compared selectivity in the two tasks. We found that LIP neurons automatically encode and remap shape information. Selectivity in the two tasks was comparable. Our results provide critical evidence for the idea that remapping may be a mechanism for transsaccadic perception of features.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-08162011-152337 |
| Date | 14 September 2011 |
| Creators | Subramanian, Janani |
| Contributors | Carol Colby, Daniel Simons, Neeraj Gandhi |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-08162011-152337/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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