IOVS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Originally published In Press as doi:10.1167/iovs.08-2517 on October 20, 2008
 (Investigative Ophthalmology and Visual Science. 2009;50:1221-1226.)
© 2009 by The Association for Research in Vision and Ophthalmology, Inc.
doi:10.1167/iovs.08-2517
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
iovs.08-2517v1
50/3/1221    most recent
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Battista, J.
Right arrow Articles by McKendrick, A. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Battista, J.
Right arrow Articles by McKendrick, A. M.

Spatial Summation Properties for Magnocellular and Parvocellular Pathways in Glaucoma

Josephine Battista,1 David R. Badcock,2 and Allison M. McKendrick1

1From the Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Australia; and the 2School of Psychology, University of Western Australia, Crawley, Australia.

PURPOSE. To examine the spatial summation properties for the magnocellular (M) and parvocellular (P) visual pathways in participants with glaucoma and approximately age-matched controls in central and midperipheral retinal eccentricities.

METHODS. Contrast discrimination thresholds were measured for six different stimulus array sizes, using steady- and pulsed-pedestal paradigms designed to measure function of the M and P pathways, respectively. This study involved 15 participants with glaucoma and 17 approximately age-matched controls. All participants completed trials foveally and at 12.5° eccentricity. The peripheral stimulus location for each glaucoma participant was within a quadrant of early visual field loss, and locations were matched for the control group.

RESULTS. The glaucoma group demonstrated significantly elevated thresholds compared with the control group (F(1,30) = 16.29; P < 0.001). Thresholds were also significantly dependent on the stimulus sizes, testing location, and pedestal condition. Data obtained for the steady-pedestal paradigm were fit with an exponential decay function, whereas the pulsed-pedestal data were fit with a linear function, demonstrating different spatial summation properties for the M and P pathways, consistent with previous studies using this methodology. Analyses of the curve parameters obtained from the curve fits indicated no significant difference in the shape of the curves between glaucoma and control participants.

CONCLUSIONS. Although spatial summation properties are different for presumed M- and P-mediated pathways, the underlying spatial summation properties associated with these pathways are similar in the control and glaucoma participants in this study, centrally and midperipherally.




This article has been cited by other articles:


Home page
 Schizophr BullHome page
P. D. Butler, I. Y. Abeles, N. G. Weiskopf, A. Tambini, M. Jalbrzikowski, M. E. Legatt, V. Zemon, J. Loughead, R. C. Gur, and D. C. Javitt
Sensory Contributions to Impaired Emotion Processing in Schizophrenia
Schizophr Bull, November 1, 2009; 35(6): 1095 - 1107.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by the Association for Research in Vision and Ophthalmology