While this image of visual attention seems bottom-up and data-driven, other evidence suggests that these formal features come to be seen by children as corresponding to the presentation of more or less meaningful content and it is this second factor, the meaningfulness or comprehensibility of the presentation, that guides visual attention. For example, Anderson, et al. (1981) found that visual attention to segments of Sesame St. was greater for normal segments than for the same visual presentation for which comprehensibility was experimentally reduced by using backward speech or a foreign language. Anderson and Lorch (1983) hypothesize that through extensive viewing experience, children come to acquire knowledge about the associations between the typical use of various formal features and the likelihood that the corresponding content will be meaningful and interesting. For example, men's voices may be perceived as generally corresponding to adult-oriented content which is less comprehensible and less interesting to children, and thus male voices do not recruit their visual attention.