Biomedical subjects

Fauzia Mosca

Publications and source records attributed to Fauzia Mosca.

3 recordsLinked to original sources

PubMed2004

Illusory surfaces affect the integration of local motion signals.

A 2IFC paradigm was used to measure speed discrimination thresholds for pairs of Gabor patches. When one of these patches was phenomenally placed over an illusory surface (IS), we observed higher thresholds relative to control conditions without ISs. Additional controls demonstrated that this effect was due to the placement of the patch on a different phenomenal depth plane rather than to the mere presence of an IS. We conclude that (i) ISs can affect the long-range integration of local motion signals, and (ii) long-range motion integration obeys a coplanarity principle.

Depth Perception↗

PubMed2004

Early computation of contour curvature and part structure: evidence from holes.

We used holes to study unilateral border ownership and in particular the information carried by the sign of the curvature along the contour (ie the difference between convex and concave regions). When people perceive a hole, its shape has a reversed curvature polarity (ie a changed sign of curvature) compared to the same region perceived as an object. Bertamini (2001 Perception 30 1295-1310), and Bertamini and Croucher (2003 Cognition 87 33-54) suggested and found evidence to support the hypothesis that, because convex regions are perceived as parts, positional information is more readily available for convex regions. Therefore a change is predicted when a given region is perceived as either a hole or a figure. We confirm that finding in this study, using holes defined by binocular disparity. We conclude that a change from figure to hole always reverses the encoding of curvature polarity. In turn, polarity obligatorily affects perceived part structure and the processing of position.

Analysis of Variance↗

PubMed2004

Amodal completion in visual search: preemption or context effects?

In a previous study, search for a notched-disk target abutting a square among complete-disk nontargets and squares was inefficient in 250-ms exposures, but relatively efficient in 100-ms exposures. This finding was interpreted as evidence that amodal completion proceeds through a mosaic and then a completion stage, with the latter preempting the former. We used the same target but changed its context: Nontargets were instead notched disks near squares. Task set was also different: Participants searched for a complete disk. Contrary to the prediction of the preemption model, search was efficient in the 100-ms condition and inefficient in the 250-ms condition. We propose that in both the present and the previous studies, the target was ambiguous, and task set and context affected how it was perceived. In both experiments, set effects were evident for 100-ms exposures; context effects were evident for 250-ms exposures.

Affect↗