Selection of visual information for lightness judgements by eye movements

Authors: Toscani, M., Valsecchi, M. and Gegenfurtner, K.R.

Journal: Philosophical Transactions of the Royal Society B: Biological Sciences

Volume: 368

Issue: 1628

eISSN: 1471-2970

ISSN: 0962-8436

DOI: 10.1098/rstb.2013.0056

Abstract:

When judging the lightness of objects, the visual system has to take into account many factors such as shading, scene geometry, occlusions or transparency. The problemthen is to estimate global lightness based on a number of local samples that differ in luminance. Here,we showthat eye fixations play a prominent role in this selection process. We explored a special case of transparency for which the visual system separates surface reflectance from interfering conditions to generate a layered image representation. Eye movements were recorded while the observers matched the lightness of the layered stimulus. We found that observers did focus their fixations on the target layer, and this sampling strategy affected their lightness perception. The effect of image segmentation on perceived lightness was highly correlated with the fixation strategy and was strongly affected whenwe manipulated it using a gaze-contingent display. Finally, we disrupted the segmentation process showing that it causally drives the selection strategy. Selection through eye fixations can so serve as a simple heuristic to estimate the target reflectance. © 2013 The Author(s) Published by the Royal Society. All rights reserved.

Source: Scopus

Selection of visual information for lightness judgements by eye movements.

Authors: Toscani, M., Valsecchi, M. and Gegenfurtner, K.R.

Journal: Philos Trans R Soc Lond B Biol Sci

Volume: 368

Issue: 1628

Pages: 20130056

eISSN: 1471-2970

DOI: 10.1098/rstb.2013.0056

Abstract:

When judging the lightness of objects, the visual system has to take into account many factors such as shading, scene geometry, occlusions or transparency. The problem then is to estimate global lightness based on a number of local samples that differ in luminance. Here, we show that eye fixations play a prominent role in this selection process. We explored a special case of transparency for which the visual system separates surface reflectance from interfering conditions to generate a layered image representation. Eye movements were recorded while the observers matched the lightness of the layered stimulus. We found that observers did focus their fixations on the target layer, and this sampling strategy affected their lightness perception. The effect of image segmentation on perceived lightness was highly correlated with the fixation strategy and was strongly affected when we manipulated it using a gaze-contingent display. Finally, we disrupted the segmentation process showing that it causally drives the selection strategy. Selection through eye fixations can so serve as a simple heuristic to estimate the target reflectance.

Source: PubMed

Selection of visual information for lightness judgements by eye movements

Authors: Toscani, M., Valsecchi, M. and Gegenfurtner, K.R.

Journal: PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES

Volume: 368

Issue: 1628

eISSN: 1471-2970

ISSN: 0962-8436

DOI: 10.1098/rstb.2013.0056

Source: Web of Science (Lite)

Selection of visual information for lightness judgements by eye movements.

Authors: Toscani, M., Valsecchi, M. and Gegenfurtner, K.R.

Journal: Philosophical transactions of the Royal Society of London. Series B, Biological sciences

Volume: 368

Issue: 1628

Pages: 20130056

eISSN: 1471-2970

ISSN: 0962-8436

DOI: 10.1098/rstb.2013.0056

Abstract:

When judging the lightness of objects, the visual system has to take into account many factors such as shading, scene geometry, occlusions or transparency. The problem then is to estimate global lightness based on a number of local samples that differ in luminance. Here, we show that eye fixations play a prominent role in this selection process. We explored a special case of transparency for which the visual system separates surface reflectance from interfering conditions to generate a layered image representation. Eye movements were recorded while the observers matched the lightness of the layered stimulus. We found that observers did focus their fixations on the target layer, and this sampling strategy affected their lightness perception. The effect of image segmentation on perceived lightness was highly correlated with the fixation strategy and was strongly affected when we manipulated it using a gaze-contingent display. Finally, we disrupted the segmentation process showing that it causally drives the selection strategy. Selection through eye fixations can so serve as a simple heuristic to estimate the target reflectance.

Source: Europe PubMed Central