分离水平和空间位置对三维物体识别的影响

物体识别的两大理论一直存在争议。以物体为中心理论认为不管物体出现在什么位置,识别均与空间位置无关,而以观察者为中心理论认为识别与空间位置有关。研究参照物体识别的“小几何体”思想自制实验材料,采用启动范式下的分类任务,通过操纵物体自身的结构信息和相对的结构信息,考察了三维物体识别的影响机制。结果发现：（1）物体自身组成部分之间的分离水平和物体之间的相对空间位置对物体识别的影响均呈层级式。支持以观察者为中心理论的整体表征观;（2）不分离水平和相同位置上,整体启动快于部分启动;全分离水平和远距离位置上,部分启动快于整体启动。支持以物体为中心理论的小几何体优先加工观。实现两大理论的融合需要进一步厘清“What + Where”两通路联合表征的二级子层级。     

可操作性在物体表征中的作用

近10年来, 越来越多的研究表明, 对可操作物体的识别不仅依赖物体的视觉信息, 同时也依赖操作它的动作信息和知识, 即可操作性。来自行为实验、脑成像和脑损伤病人的研究都表明, 物体的可操作性在物体识别中会被激活, 并起着重要的作用。可操作性的研究不但重新解释了生物与非生物、名词与动词的分离现象, 而且对于研究物体表征, 以及视觉物体识别的神经通路有着重要的理论意义。     

物体识别中的视点问题

视点问题是物体识别研究中的热点问题。文章回顾了两个主要的物体识别理论：结构描述模型和基于图像的模型,前者认为物体识别是视点独立的（viewpoint-invariant）,后者认为物体识别是视点依赖的（viewpoint-dependent）。在介绍了物体识别领域的一些最新研究进展和分析了当前研究存在的问题之后,文章进一步探讨解决视点争论的可能的途径:完善现存的物体心理表征模型     

整体与部件表征在物体图形识别中的作用

研究通过三个实验探讨了物体表征及其对识别的影响,特别是整体与部件的关系。实验一主要研究物体整体与部件分别对物体识别的影响;实验二考察部件之间的相对距离、分割方式对物体识别的影响;实验三对自然分割和非自然分割的信息表征特点进行了进一步探讨。结果表明：（１）被试在识别被人为分成几个部分的图形时,可能运用心理操作将各部分“拼凑”起来,然后再进行识别。（２）对物体的表征是多元的,既可以通过整体特征达到对物体的识别,也可以通过局部特征识别物体。（３）部件的表征具有一定独立性,可以通过部分信息完形出整体,而不受物体熟悉度的影响。如果能够识别构成物体的部件以及确定其间的空间关系,就可以实现对物体整体的识别,但部件识别不是物体识别的绝对前提。     

物体识别的视角依赖与心理旋转

物体识别的绩效随物体的视角变化而变化,这一物体识别的视角依赖现象引发了研究者对物体识别的机制的广泛讨论。有研究者认为,心理旋转是导致物体识别视角依赖的原因,而另一种观点认为物体识别中不包含心理旋转过程。两种观点都有来自于行为和神经机制两方面研究的证据。然而,现有的行为证据都是间接的证据,缺乏说服力。进一步的研究应注重直接操纵影响心理旋转与物体识别过程的因素,并把行为研究与能进行实时监测的眼动、脑成像等研究结合起来     

空间隐喻和形状变化对物体内隐时间概念加工的影响

通过2个实验, 考察了空间隐喻和形状变化对物体内隐时间概念加工的影响。实验1通过对隐含时间关系的词对的语义相关判断发现, 形状变化物体隐含的“先前/后来”的时间概念与“左/右”的空间概念存在着对应关系, 断裂式变化(形状变化大)的物体比渐进式变化(形状变化小)的物体激发了更加明显的时间变化感, 但物体形状变化类型并未明显地影响对词对语义相关判断的速度和准确性。实验2通过对隐含时间关系的物体图片对的语义相关判断发现, 物体形状变化隐含的“先前/后来”的时间概念与“左/右”的空间概念亦存在着对应关系, 而且物体形状变化类型影响对物体图片对语义相关判断的速度和准确性, 被试对渐进式变化物体的语义相关判断显著快于对断裂式变化物体的语义相关判断, 错误率亦低。整个研究表明, 在物体形状变化内隐时间概念的表征中, 既存在着抽象的符号表征, 又存在着具体的形状知觉表征。研究结果支持概念双加工理论的预言。     

场景知觉中物体加工的背景效应

在场景中加工物体信息时, 与物体相伴随的背景会影响对物体的加工。这种物体加工的背景效应在很多的研究中得到了证实。场景知觉中的背景效应有不同的表现, 对于场景中物体识别和背景的关系, 研究者从功能独立、相互作用和背景引导等理论角度给予了解释。其次, 自然场景材料和非自然场景材料所提供的背景信息不同, 研究者从不同的刺激水平探讨了这二者之间的背景效应存在的差异。同时, 随着技术的进步, 研究者也在探讨场景知觉过程中物体加工背景效应的生理机制, 并发现了一些与物体识别的背景效应有关的脑区定位。这些相关的研究为深入了解人是如何知觉和加工真实而复杂的环境提供了新的研究内容和视角。     

三维情境中类别空间关系加工的影响因素研究——观察角度、刺激位置及背景属性

研究采用目标-类别范式,通过两个实验探讨三维情境中观察角度、靶刺激所在物体颜色和形状的相似性、靶刺激空间距离及离开水平方向的角度对类别空间关系加工的影响。研究结果表明,在不同的观察角度,获得物体的信息越多,类别空间关系判断越容易;背景颜色相似性高类别空间关系加工的效率较低;两个靶刺激之间的距离对于类别空间判断影响较小;靶刺激观察角度为竖直和水平方向时,类别空间关系判断的效率较低。     

三维场景中内隐记忆的空间更新

空间更新效应是指个体在三维空间中移动时,对周围物体与自身位置之间相对关系进行的自动更新。本研究以背景线索效应为例,考察三维空间中的内隐空间记忆是否存在空间更新。实验采用2(观察者移动与否)×2(场景旋转与否)的被试间设计,探究学习阶段的背景线索效应在不同的实验条件下能否迁移到测试阶段。结果发现:观察者移动组、控制组效应能够迁移,场景旋转组、场景旋转且观察者移动组效应不能迁移。结果证明,三维场景的内隐记忆中也存在空间更新。     

儿童对观察者预期造成的模糊刺激解释多样性的理解

研究考察6~8岁儿童在由观察者预期造成的对模糊信息有多样解释上的理解.操纵影响观察者预期的因素,包括知觉经验、知识水平、先前经历和偏见,要求儿童预测观察者对局限视野图形或两可动作信息的解释.结果表明,6岁儿童仅对观察者偏见影响其对行动者行为的解释拥有部分理解,他们还不能理解知觉经验和知识水平会影响观察者对视觉刺激的解释,以及先前经历会影响观察者对行动者行为的解释.7岁儿童除了知识水平外,其它三方面的理解都已发展起来.8岁儿童可以理解多种观察者预期造成的解释差异,解释性心理理论比较稳定,但离完全成熟的理解还有一段距离.     

Object recognition is mediated by extraretinal information

Many previous studies of object recognition have found view-dependent recognition performance when view changes are produced by rotating objects relative to a stationary viewing position. However, the assumption that an object rotation is equivalent to an observer viewpoint change ignores the potential contribution of extraretinal information that accompanies observer movement. In four experiments, we investigated the role of extraretinal information on real-world object recognition. As in previous studies focusing on the recognition of spatial layouts across view changes, observers performed better in an old/new object recognition task when view changes were caused by viewer movement than when they were caused by object rotation. This difference between viewpoint and orientation changes was due not to the visual background, but to the extraretinal information available during real observer movements. Models of object recognition need to consider other information available to an observer in addition to the retinal projection in order to fully understand object recognition in the real world.     

Perceiving Real-World Viewpoint Changes

Retinal images vary as observers move through the environment, but observers seem to have little difficulty recognizing objects and scenes across changes in view. Although real-world view changes can be produced both by object rotations (orientation changes) and by observer movements (viewpoint changes), research on recognition across views has relied exclusively on display rotations. However, research on spatial reasoning suggests a possible dissociation between orientation and viewpoint. Here we demonstrate that scene recognition in the real world depends on more than the retinal projection of the visible array; viewpoint changes have little effect on detection of layout changes, but equivalent orientation changes disrupt performance significantly. Findings from our three experiments suggest that scene recognition across view changes relies on a mechanism that updates a viewer-centered representation during observer movements, a mechanism not available for orientation changes. These results link findings from spatial tasks to work on object and scene recognition and highlight the importance of considering the mechanisms underlying recognition in real environments.     

View-specific effects of depth rotation and foreshortening on the initial recognition and priming of familiar objects

In a series of three experiments, we examined, first, the effects of viewpoint in depth on the efficiency of initial picture naming and, second, the effects of priming on subsequent naming. On initial presentation, foreshortened views were harder to name than were more typical (nonforeshortened) views. In addition, priming increased as a function of the similarity of the prime and target. Indeed, if a foreshortened view of an object had already been named, the subjects named a subsequent foreshortened view of that object as fast as or faster than they named a subsequent, more typical view. These results provide evidence against theories that predict full view-invariant object recognition and view-invariant priming of object recognition. Instead, the results support theories that suggest that object recognition is mediated by stored representations that are both view- and object-specific.     

Recognition memory for object form and object location: An event-related potential study

In this study, the processes associated with retrieving object forms and object locations from working memory were examined with the use of simultaneously recorded event-related potential (ERP) activity. Subjects memorized object forms and their spatial locations and made either object-based or location-based recognition judgments. In Experiment 1, recognition performance was higher for object locations than for object forms. Old responses evoked more positive-going ERP activity between 0.3 and 1.8 sec poststimulus than did new responses. The topographic distribution of these old/new effects in the P300 time interval was task specific, with object-based recognition judgments being associated with anteriorly focused effects and location-based judgments with posteriorly focused effects. Late old/new effects were dominant at right frontal recordings. Using an interference paradigm, it was shown in Experiment 2 that visual representations were used to rehearse both object forms and object locations in working memory. The results of Experiment 3 indicated that the observed differential topographic distributions of the old/new effects in the P300 time interval are unlikely to reflect differences between easy and difficult recognition judgments. More specific effects were obtained for a subgroup of subjects for which the processing characteristics during location-based judgments presumably were similar to those in Experiment 1. These data, together with those from Experiment 1, indicate that different brain areas are engaged in retrieving object forms and object locations from working memory. Further analyses support the view that retrieval of object forms relies on conceptual semantic representation, whereas retrieving object locations is based on structural representations of spatial information. The effects in the later time intervals may play a functional role in post-retrieval processing, such as recollecting information from the study episode or other processes operating on the products of the retrieval process, and presumably are mediated by right frontal cortical areas. The results support the view of functionally dissociable object and spatial visual working memory systems.     

客体投影方式对空间问题解决和再认的影响

通过设置四种实验条件,旨在阐明空间问题解决和再认的水平是如何受到客体不同投影方式的影响。除进一步支持了正投影问题的解决是以一个具有三维结构特性的心理表征为基础而并非是对二维正投影信息进行了充分识别的观点外,研究结果还表明：（１）这个具有客体三维结构特性的心理表征是建构于对正投影问题解决而非轴测投影图的再认过程中;（２）正投影问题解决的复杂性显著地高于轴测投影图问题解决而且一个建构于正投影问题解决中     

The effects of different aperture-viewing conditions on the recognition of novel objects

The process of learning the structure of novel objects involves the selective use of information available in the distal stimulus. By allowing participants to explore the object within a limited field of view, we were able to examine more rigorously what regions of the object are actually selected in the learning process. Participants explored objects either by moving a circular aperture over a stationary novel object (the aperture-movement condition), or by moving the object behind a stationary aperture (the object-movement condition). Given the differences in how the spatial layout of object parts is revealed in the two study conditions, we expected that exploration would be more systematic in the aperture-movement condition than it would be in the object-movement condition, and would lead to better object recognition. We show evidence that in the aperture-movement condition exploration patterns were more related to the structure of the object and, as a consequence, the aperture-movement condition resulted in more accurate recognition in a later old--new discrimination test.     

VIEWPOINT DEPENDENCE IN SCENE RECOGNITION

Abstract— Two experiments investigated the viewpoint dependence of spatial memories. In Experiment 1, participants learned the locations of objects on a desktop from a single perspective and then took part in a recognition test, test scenes included familiar and novel views of the layout. Recognition latency was a linear function of the angular distance between a test view and the study view. In Experiment 2, participants studied a layout from a single view and then learned to recognize the layout from three additional training views. A final recognition test showed that the study view and the training views were represented in memory, and that latency was a linear function of the angular distance to the nearest study or training view. These results indicate that interobject spatial relations are encoded in a viewpoint-dependent manner, and that recognition of novel views requires normalization to the most similar representation in memory. These findings parallel recent results in visual object recognition     

Attention to distinguishing features in object recognition

This study advances the hypothesis that, in the course of object recognition, attention is directed to distinguishing features: visual information that is diagnostic of object identity in a specific context. In five experiments, observers performed an object categorization task involving drawings of fish (Experiments 1–4) and photographs of natural sea animals (Experiment 5). Allocation of attention to distinguishing and non-distinguishing features was examined using primed-matching (Experiment 1) and visual probe (Experiments 2, 4, 5) methods, and manipulated by spatial precuing (Experiment 3). Converging results indicated that in performing the object categorization task, attention was allocated to the distinguishing features in a context-dependent manner, and that such allocation facilitated performance. Based on the view that object recognition, like categorization, is essentially a process of discrimination between probable alternatives, the implications of the findings for the role of attention to distinguishing features in object recognition are discussed.     

Deletion of the GluA1 AMPA receptor subunit impairs recency-dependent object recognition memory

Deletion of the GluA1 AMPA receptor subunit impairs short-term spatial recognition memory. It has been suggested that short-term recognition depends upon memory caused by the recent presentation of a stimulus that is independent of contextual-retrieval processes. The aim of the present set of experiments was to test whether the role of GluA1 extends to nonspatial recognition memory. Wild-type and GluA1 knockout mice were tested on the standard object recognition task and a context-independent recognition task that required recency-dependent memory. In a first set of experiments it was found that GluA1 deletion failed to impair performance on either of the object recognition or recency-dependent tasks. However, GluA1 knockout mice displayed increased levels of exploration of the objects in both the sample and test phases compared to controls. In contrast, when the time that GluA1 knockout mice spent exploring the objects was yoked to control mice during the sample phase, it was found that GluA1 deletion now impaired performance on both the object recognition and the recency-dependent tasks. GluA1 deletion failed to impair performance on a context-dependent recognition task regardless of whether object exposure in knockout mice was yoked to controls or not. These results demonstrate that GluA1 is necessary for nonspatial as well as spatial recognition memory and plays an important role in recency-dependent memory processes.