Surface convexity and extremal edges in depth and figure-ground perception

T. Ghose; S. E. Palmer

doi:10.1167/5.8.970

Surface convexity and extremal edges in depth and figure-ground perception

Journal of Vision ◽

10.1167/5.8.970 ◽

2005 ◽

Vol 5 (8) ◽

pp. 970-970 ◽

Cited By ~ 3

Author(s):

T. Ghose ◽

S. E. Palmer

Keyword(s):

Extremal Edges

Task set and instructions influence the weight of figural priors: A psychophysical study with extremal edges and familiar configuration

Attention Perception & Psychophysics ◽

10.3758/s13414-021-02282-5 ◽

2021 ◽

Author(s):

Tandra Ghose ◽

Mary A. Peterson

Keyword(s):

Medial Temporal Lobe ◽

Perirhinal Cortex ◽

Shape Prior ◽

Task Set ◽

Cross Border ◽

Within Subjects ◽

Extremal Edges ◽

Psychophysical Study ◽

Ground Organization ◽

Familiar Objects

AbstractIn figure–ground organization, the figure is defined as a region that is both “shaped” and “nearer.” Here we test whether changes in task set and instructions can alter the outcome of the cross-border competition between figural priors that underlies figure assignment. Extremal edge (EE), a relative distance prior, has been established as a strong figural prior when the task is to report “which side is nearer?” In three experiments using bipartite stimuli, EEs competed and cooperated with familiar configuration, a shape prior for figure assignment in a “which side is shaped?” task.” Experiment 1 showed small but significant effects of familiar configuration for displays sketching upright familiar objects, although “shaped-side” responses were predominantly determined by EEs. In Experiment 2, instructions regarding the possibility of perceiving familiar shapes were added. Now, although EE remained the dominant prior, the figure was perceived on the familiar-configuration side of the border on a significantly larger percentage of trials across all display types. In Experiment 3, both task set (nearer/shaped) and the presence versus absence of instructions emphasizing that familiar objects might be present were manipulated within subjects. With familiarity thus “primed,” effects of task set emerged when EE and familiar configuration favored opposite sides as figure. Thus, changing instructions can modulate the weighing of figural priors for shape versus distance in figure assignment in a manner that interacts with task set. Moreover, we show that the influence of familiar parts emerges in participants without medial temporal lobe/ perirhinal cortex brain damage when instructions emphasize that familiar objects might be present.

Extremal Edges and Gradient Cuts: New Cues to Depth and Figure-Ground Perception

PsycEXTRA Dataset ◽

10.1037/e527342012-288 ◽

2007 ◽

Author(s):

Stephen E. Palmer ◽

Tandra Ghose

Keyword(s):

Extremal Edges

Psychonomic Bulletin & Review ◽

10.3758/s13423-014-0751-x ◽

2014 ◽

Vol 22 (4) ◽

pp. 961-966 ◽

Cited By ~ 5

Author(s):

Ralph G. Hale ◽

James M. Brown ◽

Benjamin A. McDunn ◽

Aisha P. Siddiqui

Keyword(s):

Boundary Extension ◽

Extremal Edges