Browsing by Subject "gaze cascade effect"

People tend to first look evenly at both objects when they are making a decision between them. Gaze starts to get directed more to the object which is eventually chosen before selecting it consciously. One explanation for the phenomenon is the gaze cascade model, which states, that directing of gaze is related to making decisions based on preference. It also states that the gaze bias is influenced by cognitive models people have about the perceived stimulus. Gaze bias should be greater the less one has previous experience, i.e. cognitive models about the objects. This study evaluates these two assumptions by the gaze cascade model. 64 subjects participated in the experiment from which 54 subjects' data was used in the final analysis (average age 27.7, range 18–47 years). Stimuli consisted from images of cheese packages which are sold in Finland, images of cheese packages sold abroad and abstract images. The assumption was that the subjects would have most cognitive models about the packages sold in Finland, the second most about the packages sold abroad and least about the abstract images. Subjects made choices about the stimuli by preference, size and ecology. Direction of gaze during decision making was recorded with gaze tracking goggles. Likelihood that the subjects were looking at the stimulus which they chose was estimated for 53 sampling points, 1.77 seconds before the conscious decision. Likelihood scores were fitted to sigmoid functions by least square method. The amount of gaze bias during different decision making instructions and stimuli was compared with a two sample Kolmogorov-Smirnov test. Gaze bias was greater the less subjects had previous experience about the stimuli. Large gaze bias was perceived also in other tasks than preference selection. For this reason gaze cascade model does not seem to provide a good explanation for gaze bias during decision making. There was also found an interaction between the used decision criteria and stimulus type. Earlier studies have usually focused on examining either the effect of the decision criteria or the used stimulus type to the gaze bias. This study shows that the interaction between decision criteria and stimulus type should be taken into consideration when examining the gaze bias during decision making. One possible explanation for the interaction might be the difficultness of the choice. Gaze bias during decision making might be especially related to situations where the difference between two stimuli evaluated by given criteria is very small.