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Gaze bias both reflects and influences preference. Shimojo, S., Simion, C., Shimojo, E. & Scheier, C. (2003). Nature Neuroscience, 6, 1317-1322. Hao-Hsiang 1/2/06’. Introduction. Preference formation of human face An attractiveness ‘template’
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Gaze bias both reflects and influences preference Shimojo, S., Simion, C., Shimojo, E. & Scheier, C. (2003). Nature Neuroscience, 6, 1317-1322 Hao-Hsiang 1/2/06’
Introduction • Preference formation of human face • An attractiveness ‘template’ • Averageness, symmetry, complexity, resemblance to self, evolutionary benefit… • Social interaction cue • Mere exposure effect, gaze contact
Introduction • Gaze • An orienting behavior • Establish exposure to a stimulus and gather information about its characteristics • Gazing for deeper sensory processing • This study investigates “gazing” role in preference formation • Gazing not only reflects, but also emerges the process of preference formation
Experiment • Presented observers with 2 human faces and asked them to choose the more attractive face • Track their eye movement (http://www.mediaanalyzer.com/) • Track 30 samples per second; choose the last 50 samples(1.67s) prior to the decision and calculate the correlation with the decision
Experiment 1 • Stimulus (face) • Database • Ekman face (http://www.paulekman.com/) • AR face (http://rvl.www.ecn.purdue.edu/RVL/) • Rate all the faces from 1(bad)~7(good) and calculate the average rating for each • Face-attractiveness-difficult task • In each pair, difference in the average rating is lower than 0.25 points. • Face-attractiveness-easy task • In each pair, difference in the average rating is higher than 3.25 points.
Experiment 1 • To rule out other factors (such as selection bias or memorization of response), two control experiments • Face-roundness task • Choose the rounder one • Face-dislike task • Choose the unattractive one
Experiment 1: Result • a, b tasks(attractiveness) and c,d tasks are significant different • Before decision, a, b did not reach a saturation level, but the control tasks did. • Gaze bias is continually reinforced when attractiveness comparisons to be made. • Gaze cascade effect
Experiment 1: Result • Dual-contribution model of preferential decision making • Cognitive assessment systems • Orienting behavior structure • Larger ‘cascade effect’ in difficult task • When cognitive biases are weak, gaze would contribute more to the decision making
Experiment: 1e • Compare 2 abstract shapes: • When cognitive bias are weaker, gaze bias help it
2 questions • Is the effect in any situation or only when the stimuli are novel? • Can we manipulate gaze to influence one’s preference?
Two-session face attractiveness task All three cases show ‘cascade effect’ Gaze really reflect it
Experiment 2: gaze manipulation • Is Audrey Hepburn more attractive, right? • 7 conditions in exp2 • Gaze manipulation 2 reptitions • Gaze manipulation 6 reptitions • Gaze manipulation 12 reptitions • Gaze manipulation vertical • 3 control conditions
Experiment 2: Result • The face you spent more time to gaze will be more attractive
Summary • Gaze bias both reflects and influences preference • Orienting behavior feeds into a decision making