Department of Psychology, The University of York, York, North Yorkshire, UK.
Cognition. 2018 Nov;180:24-37. doi: 10.1016/j.cognition.2018.06.022. Epub 2018 Jul 5.
Humans have an ability to remember up to 10,000 previously viewed scenes with apparently robust memory for visual detail, a phenomenon that has been interpreted as suggesting a visual memory system of massive capacity. Attempts at explanation have largely focused on the nature of the stimuli and been influenced by theoretical accounts of object recognition. Our own study aims to supplement this by considering two observer-based aspects of visual long-term memory, one strategic, whether the observers are aware or not that their memory will subsequently be tested and the other executive, based on the amount of attentional capacity available during encoding. We describe six studies involving visual scenes ranging in difficulty from complex manmade scenes (d' = 2.54), to door scenes with prominent features removed (d' = 0.79). To ensure processing of the stimuli, all participants have to make a judgement of pleasantness (Experiments 1 and 2) or of the presence or absence of a dot (Experiment 3). Intention to learn influence performance only in the most impoverished condition comprising doors with prominent features removed. Experiments 4-6 investigated the attentional demands of visual long-term memory using a concurrent task procedure. While the demanding task of counting back in threes clearly impaired performance across the range of materials, a lighter load, counting back in ones influences only the most difficult door scenes. Detailed analysis of error patterns indicated that clear differences in performance level between manmade and natural scenes and between unmodified and modified door scenes was reflected in false alarm scores not detections, while concurrent task load affected both. We suggest an interpretation in terms of a two-level process of encoding at the visual feature rather than the whole scene level, with natural images containing many features encoded richly, rapidly and without explicit intent. Only when scenes are selected from a single category and with distinctive detail minimised does memory depend on intention to remember and on the availability of substantial executive capacity.
人类能够记住多达 10000 个之前看过的场景，并且对视觉细节有着明显的记忆能力，这种现象被解释为暗示了一个具有巨大容量的视觉记忆系统。解释的尝试主要集中在刺激的性质上，并受到物体识别理论的影响。我们自己的研究旨在通过考虑视觉长期记忆的两个基于观察者的方面来补充这一点，一个是策略性的，即观察者是否意识到他们的记忆随后将被测试，另一个是执行性的，基于编码期间可用的注意力容量。我们描述了六项研究，涉及从复杂的人造场景（d'=2.54）到特征明显缺失的门场景（d'=0.79）的视觉场景，难度各不相同。为了确保对刺激的处理，所有参与者都必须对愉悦度做出判断（实验 1 和 2）或判断是否存在点（实验 3）。只有在最贫困的条件下，即特征明显缺失的门，意图学习才会影响性能。实验 4-6 使用并发任务程序研究了视觉长期记忆的注意力需求。虽然倒数三的困难任务明显影响了所有材料的表现，但较轻的负荷，即倒数一，只影响了最困难的门场景。对错误模式的详细分析表明，人造场景和自然场景之间以及未修改和修改门场景之间的性能水平差异明显反映在误报分数而不是检测分数上，而并发任务负荷则同时影响两者。我们建议用一种两级编码过程来解释，即视觉特征而不是整个场景水平，自然图像包含许多特征，这些特征被快速、丰富地编码，而不需要明确的意图。只有当场景从单一类别中选择，并且特征细节最小化时，记忆才取决于记忆的意图和可用的大量执行能力。
