|
ИСТИНА |
Войти в систему Регистрация |
ФНКЦ РР |
||
Eye movements control in the visual search process: Influence of low and high level factors //Fechner Day 2016статья Тезисы
- Авторы: Blinnikova I.V., Semenova M.A., Izmalkova A.I.
- Сборник: Fechner Day 2016 -- Proceedings of the 32st Annual Meeting of the International Society for Psychophysics
- Год издания: 2016
- Место издания: Институт психологии РАН Москва
- Первая страница: 42
- Последняя страница: 43
- Аннотация: Visual search is an ecologically valid and important task. In recent years we have seen an increasing interest in the study of visual search of more complex and semantically loaded objects1. In the present study we have modeled a web search task and examined the dependence of eye movements in the visual search process on low-level factors, such as the chromaticity of the stimulus matrix, and on high-level factors, such as the format of presentation of the target stimulus. The stimulus matrix was either black and white or colored. We assumed that the introduction of color would complicate the search for incentives that would be reflected in the change of the search parameters. The target of the search was set either by a picture or by a word. If the target was set by a picture, the subject had to hold it in the working memory and to compare it with those he saw on the screen. If the goal was set by a word, subjects were required to mentally produce possible images of objects which they had to look for. The second situation was less certain and more complicated, and we assumed that it would increase time costs and affect the strategy of eye movements activity. 63 healthy volunteers took part in this experiment; 41 females and 22 males ranging in age from 18 to 48 years; mean age 22 y 3 m. The participants were seated 0.65 m away from a 19 inch computer screen. They were to find symbolic images of real-life objects (such as butterfly, cactus, book, etc.) among a variety of other objects. Image stimuli were arranged in rectangular full screen stimulus matrix 9x9. Each matrix contained 81 objects, one of which was the target. The target stimulus was situated in one of 8 quadrants (the central quadrant was not used). 32 matrices were shown, half of which were black and white, the other half was colored (Chromaticity Factor). The stimuli consisted of black circles or squares with either white or colored image of a symbolic object placed in the center. In half of the cases the target stimulus was set in the form of words, in other cases it was shown in the form of accurate copies of the searched image, but done in a gray color (Format of the target stimulus Factor). We recorded search time and eye movement data. Eye movements were sampled monoculary at 250 Hz using SMI iView X RED 4 (FireWire) tracking system with on-line detection of saccades and fixations and a spatial accuracy < 0.5°. The results of the study showed that the Chromaticity Factor had no significant influence on either search time or eye movements parameters. On the contrary, the format of presentation of the stimulus not only led to significant changes in search time, but also significantly altered the indicators of oculomotor activity. In case the target stimuli was set by a word the search took more time (mean time ~ 2 sec.) compared to picture-based search. Moreover, in case the target stimuli was set by a word, relatively long fixations and short slow saccades were observed. When the test stimulus was set by a picture, shorter fixations and longer faster saccades were observed. Besides, a significant interaction between the two factors was found. The color played the role of a distraction factor in those cases when the target stimulus was set by a word and, by contrast, accelerated the search and decision process when the target was set as an image. In general, this is consistent with the results of other research that studies the influence of low and high level factors on the control of eye movements2. Note This research is supported by the Russian Foundation of Basic Research; Grant №14-06-00371. References 1. M. P. Eckstein, J. Vision, 11(5), 1–36. (2011) 2. M.Nyström, K. Holmqvist, J. Eye-Movement Res., 2(2), 2–11 (2008).
- Добавил в систему: Блинникова Ирина Владимировна