Disentangling bottom-up versus top-down and low-level versus high-level influences on eye movements over time
- Bottom-up and top-down as well as low-level and high-level factors influence where we fixate when viewing natural scenes. However, the importance of each of these factors and how they interact remains a matter of debate. Here, we disentangle these factors by analyzing their influence over time. For this purpose, we develop a saliency model that is based on the internal representation of a recent early spatial vision model to measure the low-level, bottom-up factor. To measure the influence of high-level, bottom-up features, we use a recent deep neural network-based saliency model. To account for top-down influences, we evaluate the models on two large data sets with different tasks: first, a memorization task and, second, a search task. Our results lend support to a separation of visual scene exploration into three phases: the first saccade, an initial guided exploration characterized by a gradual broadening of the fixation density, and a steady state that is reached after roughly 10 fixations. Saccade-target selection during theBottom-up and top-down as well as low-level and high-level factors influence where we fixate when viewing natural scenes. However, the importance of each of these factors and how they interact remains a matter of debate. Here, we disentangle these factors by analyzing their influence over time. For this purpose, we develop a saliency model that is based on the internal representation of a recent early spatial vision model to measure the low-level, bottom-up factor. To measure the influence of high-level, bottom-up features, we use a recent deep neural network-based saliency model. To account for top-down influences, we evaluate the models on two large data sets with different tasks: first, a memorization task and, second, a search task. Our results lend support to a separation of visual scene exploration into three phases: the first saccade, an initial guided exploration characterized by a gradual broadening of the fixation density, and a steady state that is reached after roughly 10 fixations. Saccade-target selection during the initial exploration and in the steady state is related to similar areas of interest, which are better predicted when including high-level features. In the search data set, fixation locations are determined predominantly by top-down processes. In contrast, the first fixation follows a different fixation density and contains a strong central fixation bias. Nonetheless, first fixations are guided strongly by image properties, and as early as 200 ms after image onset, fixations are better predicted by high-level information. We conclude that any low-level, bottom-up factors are mainly limited to the generation of the first saccade. All saccades are better explained when high-level features are considered, and later, this high-level, bottom-up control can be overruled by top-down influences.…
Author details: | Heiko Herbert SchüttORCiDGND, Lars Oliver Martin RothkegelORCiDGND, Hans Arne TrukenbrodORCiD, Ralf EngbertORCiDGND, Felix A. WichmannORCiD |
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DOI: | https://doi.org/10.1167/19.3.1 |
ISSN: | 1534-7362 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/30821809 |
Title of parent work (English): | Journal of vision |
Publisher: | Association for Research in Vision and Opthalmology |
Place of publishing: | Rockville |
Publication type: | Article |
Language: | English |
Date of first publication: | 2019/03/01 |
Publication year: | 2019 |
Release date: | 2021/03/18 |
Tag: | eye movements; fixations; natural scenes; saliency; visual search |
Volume: | 19 |
Issue: | 3 |
Number of pages: | 23 |
Funding institution: | Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [WI 2103/4-1, EN 471/13-1]; University of Tubingen |
Organizational units: | Humanwissenschaftliche Fakultät / Strukturbereich Kognitionswissenschaften / Department Psychologie |
DDC classification: | 1 Philosophie und Psychologie / 15 Psychologie / 150 Psychologie |
Peer review: | Referiert |
Publishing method: | Open Access / Gold Open-Access |
DOAJ gelistet | |
License (German): | CC-BY - Namensnennung 4.0 International |