Abstract
There is an ongoing debate whether gaze in natural scene viewing is primarily guided by image salience or by high-level scene content, such as objects. Put to the extreme, in a "salience view" fixations are exclusively guided by low-level image features. In contrast, the "object view" stipulates that objects drive fixations. In this view, any relation between low-level features and fixations is epiphenomenal. A recent study found salience effects to decrease with age. However, the question of object-based fixation guidance has not been investigated in the elderly. To fill this gap, we investigated object-based fixation guidance in images of natural scenes for young (N=42; 18-29 years) and elderly (N=34; 66-83 years) observers. We used an analysis framework based on Generalized Linear Mixed Models (GLMMs). The GLMMs quantified the unique contributions of object salience, object size, and distance between object and scene center. Salient objects were fixated with higher probability than less salient objects. This effect was stronger in the group of elderly observers. In contrast, when analyzing fixation guidance independent of objects, salience effects were weaker in the elderly, replicating earlier findings. Our results reconcile the two views: fixation guidance has a strong object-based component, but objects are prioritized based on salience. Object-based and object-independent salience exhibit distinct patterns for the two age groups: object-independent salience is stronger in young than in old observers, while salience-based object prioritization is stronger in the elderly. We interpret these findings as an increase of object-related attention guidance with age.
Meeting abstract presented at VSS 2018