Department of Neurobiopsychology, Institute of Cognitive Science, University of Osnabrück Osnabrück, Germany.
Front Psychol. 2010 Nov 25;1:207. doi: 10.3389/fpsyg.2010.00207. eCollection 2010.
Despite the growing interest in fixation selection under natural conditions, there is a major gap in the literature concerning its developmental aspects. Early in life, bottom-up processes, such as local image feature - color, luminance contrast etc. - guided viewing, might be prominent but later overshadowed by more top-down processing. Moreover, with decline in visual functioning in old age, bottom-up processing is known to suffer. Here we recorded eye movements of 7- to 9-year-old children, 19- to 27-year-old adults, and older adults above 72 years of age while they viewed natural and complex images before performing a patch-recognition task. Task performance displayed the classical inverted U-shape, with young adults outperforming the other age groups. Fixation discrimination performance of local feature values dropped with age. Whereas children displayed the highest feature values at fixated points, suggesting a bottom-up mechanism, older adult viewing behavior was less feature-dependent, reminiscent of a top-down strategy. Importantly, we observed a double dissociation between children and elderly regarding the effects of active viewing on feature-related viewing: Explorativeness correlated with feature-related viewing negatively in young age, and positively in older adults. The results indicate that, with age, bottom-up fixation selection loses strength and/or the role of top-down processes becomes more important. Older adults who increase their feature-related viewing by being more explorative make use of this low-level information and perform better in the task. The present study thus reveals an important developmental change in natural and task-guided viewing.
尽管人们对自然条件下的固定选择越来越感兴趣，但文献中关于其发展方面的内容却存在很大的空白。在生命早期，自下而上的过程，如局部图像特征——颜色、亮度对比度等——引导的观察，可能很突出，但后来会被更多的自上而下的处理所掩盖。此外，随着老年人视觉功能的下降，众所周知，自下而上的处理会受到影响。在这里，我们记录了 7 至 9 岁儿童、19 至 27 岁成年人和 72 岁以上老年人的眼球运动，他们在执行补丁识别任务之前观看自然和复杂的图像。任务表现显示出经典的倒 U 形，年轻成年人的表现优于其他年龄组。随着年龄的增长，局部特征值的注视点辨别性能下降。虽然儿童在注视点显示出最高的特征值，表明存在自下而上的机制，但老年成年人的观察行为较少依赖特征，类似于自上而下的策略。重要的是，我们观察到儿童和老年人在主动观察对特征相关观察的影响方面存在双重分离：探索性与年轻时期的特征相关观察呈负相关，与老年成年人的特征相关观察呈正相关。研究结果表明，随着年龄的增长，自下而上的固定选择会失去力量，或者自上而下的过程变得更加重要。通过更加探索性地增加特征相关观察的老年成年人会利用这种低层次的信息，并在任务中表现得更好。因此，本研究揭示了自然和任务引导观察方面的一个重要发展变化。
