ILAV   21219
INSTITUTO DE INVESTIGACION EN LUZ, AMBIENTE Y VISION
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Interactions between integration and segmentation in motion perception
Autor/es:
BARRAZA J.F.; MARTÍN A.; COLOMBO E.M.
Lugar:
Buzios, Brasil
Reunión:
Simposio; Simposio sobre Psicofísica de la Visión: Estudios Básicos, 1er Congreso Iberoamericano y del Caribe de Neurociencia “Neurolatam 2008”; 2008
Institución organizadora:
Universidad de San Pablo, Brasil
Resumen:
<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US; mso-fareast-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> It remains unclear how the visual system uses speed cues to segment images. Verghese and Stone (1997. Vision Research,Vol.37, Nº4 pp397-406) showed that speed discrimination increases for segmented stimuli, suggesting that each discrete entity provides an independent estimate of speed, which are combined across space. We hypothesized that this improvement should be forwarded to those tasks concerning the speed cue. In this work we present evidence that segmentation by speed is constrained by the spatial layout in the same direction as in Verghese and Stone. We explored two different types of segmentation. In the first experiment, we tested whether the spatial configuration affects the position discrimination of illusory contours defined by the differences in speed of two adjacent surfaces. In the second experiment, we investigated whether this effect appears in motion transparency. We found that the smallest threshold was obtained for the maximally separated patches configuration and they increased as the patches were brought closer. Results suggest that the effect of parsing the image into entities on speed discrimination facilitates the segmentation by speed cues.