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Cesar Echavarria, Po-Jang Hsieh; Exogenous Attention Improves Object Recognition Without Affecting Apparent Contrast. Journal of Vision 2013;13(9):53. doi: 10.1167/13.9.53.
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© ARVO (1962-2015); The Authors (2016-present)
The effect of selective attention on object recognition remains largely unexplored. Here, we test whether selective attention enhances viewers’ ability to recognize objects with an object-naming task. We control the amount of object information within a given object image by gradually scrambling the Fourier phase. In this manner, we obtain a set 8 different images for each object, each having a coherence level ranging from 30% to 100%. At the start of each trial, a small red dot probe is presented on either side, or on both sides of fixation in order to direct exogenous attention, followed by a brief presentation of two object images with an equal level of coherence. At the end of the trial, subjects were asked to identify the object depicted within one of these 2 images. Trials were classified as neutral if probes appeared on both sides of fixation. Congruent and incongruent trials were classified depending on whether the location of the queried image matched the location of the probe. We find a significant effect of attention when the object stimuli are presented at 70% coherence and no difference otherwise between attention conditions. In a second experiment, we test whether the observed difference in performance can be attributed to the modulation in perceived contrast reported using similar paradigms. We tested this hypothesis by attempting to null the predicted effects of exogenous attention on perceived contrast. Therefore, for congruent trials we decrease the contrast of the queried image by 10%, 20%, 30%, 40%, or 50%. For incongruent trials, we increase the contrast of the queried image by the same amount. We find no effect of contrast modulation on the attentional effect from experiment 1. These results suggest that the effect of exogenous attention on object recognition cannot be attributed to modulation of perceived contrast.
Meeting abstract presented at VSS 2013
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