Abstract

To assess the contributions of orientation and spatial scale to the processing of relative-position information for broadband spatial targets, we measure misalignment thresholds for dots separated by as much as 6 deg, in the presence of one-dimensional spatial noise. For all the dot separations, thresholds for misalignment are raised most when the mask is oriented at approximately 20 deg to either side of true alignment. This bimodal orientation tuning function appears to be fundamental to the alignment judgment, including abutting vernier acuity for equally visible lines [ Vision Res. 33, 1619 ( 1993)]. With increasing dot separation the spatial frequency at which peak masking occurs becomes progressively lower, a finding that suggests that the spatial mechanisms important for processing this information become larger. However, the rate of increase in size of these putative mechanisms is insufficient to account for the increase in relative-position thresholds for increasingly separated stimuli (i.e., Weber’s law for alignment). In addition, oriented masks placed between two target lines lead to threshold elevation, revealing that the collection of positional information between target features may be important for optimal processing of misalignment thresholds. The findings of this study suggest that, although shifts in spatial scale of the underlying low-level oriented mechanisms may contribute to increased misalignment thresholds with increasing separation, additional factors, such as positional uncertainty associated with eccentricity per se, are limiting.

© 1995 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Elevation of Vernier thresholds during image motion depends on target configuration

Harold E. Bedell, Susana T. L. Chung, and Saumil S. Patel
J. Opt. Soc. Am. A 17(6) 947-954 (2000)

Position sense of the peripheral retina

Stanley A. Klein and Dennis M. Levi
J. Opt. Soc. Am. A 4(8) 1543-1553 (1987)

Scaled position integration areas: accounting for Weber’s law for separation

Christina A. Burbeck and Scott Hadden
J. Opt. Soc. Am. A 10(1) 5-15 (1993)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (7)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (1)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (2)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription