Divide and Conquer: How Perceived Reference Axes Help Maintain Memory for Locations

为了在环境中成功地互动，人们必须足够准确地记住重要物体的位置，以便在这些物体不再出现时找到它们。否则，钥匙、鞋子和帽子将永远丢失在典型的家庭或办公室的杂乱中。大多数研究位置记忆特征的研究都集中在人们在记忆中代表了什么。例如，人们是表示一组键在计算机左侧两英寸，还是表示键与计算机相隔一臂长？虽然所代表的是一个基本问题，但这项研究将考察一个不同但同样重要的问题：人们如何在记忆中保持位置信息？这个问题是及时的，因为最近对非人类灵长类动物的研究发现，大脑中的几个区域有助于保持记忆中的位置信息。因此，人们对大脑如何在记忆中保持位置信息活跃有了越来越多的了解。然而，很少有人的研究与这一新兴的知识基础相联系。这项研究将在人类记忆地点的行为研究和有关大脑功能的文献之间建立联系。这项研究的核心是人们如何每时每刻都使用感知线索来帮助保持记忆中的信息。来自各种研究的证据表明，人们依靠可见的参考轴，例如桌子的边缘，计算机屏幕的边缘，来帮助他们记住目标物体的位置。使用这样的感知线索可以帮助记住的信息保持在正确的位置(钥匙在桌子的左边，而不是电脑的上方)。然而，这是有代价的，因为该存储器在参考轴附近被系统地扭曲。具体地说，当人们被要求再现隐藏物体的位置时，他们夸大了参照轴与物体实际位置之间的距离。这些内存错误的信息量特别大，因为它们的大小随着内存延迟的增加而增加。因此，远离参考轴的误差提供了进入用于在存储器中保持位置信息的秒到秒过程的窗口。这项研究将测试这些维持过程的数学模型，该模型指定神经元网络如何导致人类犯下的记忆错误类型。九个实验将测试这个位置记忆如何工作的模型。前五个实验将测试该模型的具体预测。这些实验将确定人们是否会犯模型预测的特定类型的记忆错误，以及这些错误是否确实是由于使用参考轴造成的。最后四个实验将检验该模型对新情况的通用性。例如，当成年人在记忆延迟期间被迫注意非目标位置时，他们会犯同样类型的记忆错误吗？完成后，该项目将提供第一个在短期延迟期间在内存中维护位置信息的过程的正式模型。这个模型和相关的经验数据可能会有广泛的影响。例如，该模型将提供对哪些线索最有效地保持记忆中的信息的洞察。这可能会为那些在工作记忆中难以保持信息的人，如老年参与者和阿尔茨海默病患者，带来环境的知情重建。该模型还可以预测当人们缺乏技能时(例如，发育早期)最有可能出现的错误模式，以及在压力或紧张条件下，哪些过程可能受到最严重的干扰(例如，睡眠不足、视觉处理受损、脑损伤)。

To interact successfully in the environment, people must remember the locations of important objects accurately enough to find these objects when they are no longer in view. Otherwise, keys, shoes, and hats would be lost forever in the clutter of the typical home or office. The majority of research investigating the characteristics of location memory has focused on WHAT people represent in memory. For instance, do people represent that a set of keys is two inches to the left of a computer, or do they represent that the keys are one arms-length away? Although what is represented is a fundamental question, this research will examine a different, but equally important question: HOW do people maintain location information in memory? This question is timely because recent studies with non-human primates have identified several brain regions that contribute to the maintenance of location information in memory. Thus, there is a growing understanding of how the brain keeps location information active in memory. Nevertheless, few studies with humans have interfaced with this emerging knowledge base. This research will establish a link between behavioral studies of how humans remember locations and the literature on brain function. Central to this research is how people use perceptual cues from second-to-second to help maintain information in memory. Evidence from a variety of studies suggests that people rely on visible reference axes, e.g., the edges of a table, the edges of a computer screen, to help them remember the locations of target objects. Use of such perceptual cues can help keep remembered information in the right ballpark (the keys are near the left edge of the table and not over by the computer). Nevertheless, there is a cost, in that memory is systematically distorted near reference axes. Specifically, when people are asked to reproduce the location of a hidden object, they exaggerate the distance between the reference axis and the actual location of the object. These memory errors are particularly informative because they increase in magnitude as memory delays increase. Thus, errors away from reference axes provide a window into the second-to-second processes that serve to maintain location information in memory. This research will test a mathematical model of these maintenance processes, a model that specifies how a network of neurons can give rise to the types of memory errors humans make. Nine experiments will test this model of how location memory works. The first five experiments will test specific predictions of the model. These experiments will establish whether people make the particular types of memory errors predicted by the model, and whether these errors do, in fact, result from the use of reference axes. The final four experiments will examine the generality of the model to novel situations. For instance, do adults make the same types of memory errors when they are forced to attend to non-target locations during a memory delay? When completed, this project will provide the first formal model of the processes that maintain location information in memory over short-term delays. This model and the associated empirical data may have broad implications. For instance, the model will provide insights into what cues most effectively maintain information in memory. This could lead to an informed re-structuring of the environment for people who have difficulty maintaining information in working memory, such as elderly participants and patients suffering from Alzheimer's Disease. The model could also predict what patterns of error are most likely when people are unskilled (e.g., early in development), and what processes might be most severely disrupted under conditions of stress or strain (e.g., sleep deprivation, impaired visual processing, brain injury).