客体信息在视觉工作记忆编码和维持阶段的不同注意选择模式

视觉工作记忆不同加工阶段(编码、维持)对多特征客体信息的注意选择模式是否相同目前仍存在争议。本研究采用变化觉察范式,引入前注意线索和后注意线索,分别探测在视觉工作记忆编码和维持两个阶段中的注意选择模式。3个实验结果显示,在前注意线索试次中,被试对任务相关特征变化的觉察显著受到任务无关特征变化的干扰,表现为任务无关特征变化条件相比于不变条件的反应更慢,报告标准更低;且该干扰效应并不受记忆负荷的影响。而在后注意线索试次中,仅在低记忆负荷条件下(实验1a/1b)存在干扰效应,当记忆负荷增大后(实验2/3)干扰效应消失。结果表明,在视觉工作记忆编码阶段,客体中任务相关与无关特征均被编码进视觉工作记忆并相互竞争注意资源;而在维持阶段,任务无关特征仅在低记忆负荷条件下得到加工。结果揭示,在编码阶段的注意选择模式是基于客体的;而维持阶段的注意选择模式是基于特征的,且受到记忆负荷的调控。     

基于客体的注意对客体工作记忆的复述作用

客体工作记忆对选择性注意具有自动导向作用.本研究采用自然图片为材料考察了基于客体的选择性注意对客体工作记忆积极保持信息表征的复述作用.根据实验中阻止基于注意的复述的方式不同,本研究共进行了两个实验:实验一通过不呈现记忆匹配项来阻止基于注意的复述,实验二通过突显将注意转移至非记忆匹配项来阻止基于注意的复述.实验结果表明,基于客体的选择性注意对客体工作记忆积极保持物体表征起着重要的复述作用.     

选择性注意与视觉空间工作记忆的交互作用

传统上只是从单方面讨论了选择性注意与视觉空间工作记忆之间的关系,即认为注意选择有限信息以进入工作记忆。近期的一些研究发现,视觉空间工作记忆的内容影响选择性注意的分配,注意选择工作记忆中保持的空间或物体表征,选择性注意对于正确保持空间或物体信息是必需的认知调节。文章最后指出,关于选择性注意与视觉空间工作记忆交互作用的研究为将来进一步揭示基于空间与基于物体的注意选择之间的交互作用关系提供了一个很好的途径。     

注意次级任务对客体与空间工作记忆信息保持的选择性干扰

通过两个行为实验,考察两种选择性注意干扰任务是否分别对客体与空间信息的保持产生选择性干扰,及干扰效应是否受记忆对象言语命名和编码难易程度的影响.实验1采用言语命名和编码容易的记忆任务,没有发现任何显著的干扰效应.实验2采用了言语命名和编码困难的记忆任务,结果分析发现:空间选择性注意次级干扰任务对空间工作记忆成绩存在显著的干扰效应,而基于客体的选择性注意次级干扰任务则对客体工作记忆成绩产生了显著的干扰.实验结果说明,基于客体的选择性注意和空间选择性注意分别在言语命名和编码困难客体与空间信息的保持加工中发挥作用,但当面对言语命名和编码容易的客体与空间记忆目标时,不再发生作用.     

视觉工作记忆中特征绑定关系的记忆机制

弱客体理论认为, 视觉工作记忆系统是由众多特征存储的子系统组成, 不同纬度的特征独立存储在相应的有限容量的子系统中, 相互之间不会竞争记忆资源。而对于特征之间绑定关系的记忆存在不同的观点。一种观点认为绑定关系的记忆需要注意维持, 因此绑定关系的记忆会占用到特征记忆的资源; 另一种观点认为绑定关系的记忆是自动发生的, 不需要注意的维持。本实验的目的是探究特征绑定关系的记忆是否是自动发生的。在实验中, 我们设计了两种任务, 一种任务是只记忆颜色, 另一种任务是记忆颜色跟位置及其之间的绑定关系, 并测试分析视觉工作记忆相关的ERP成分CDA。结果发现两种任务条件下的CDA波幅之间没有显著差异, 说明视觉工作记忆中的特征绑定是自动发生的。     

工作记忆内容对空间返回抑制的影响

工作记忆内容能够以相对自动化的方式引导视觉选择性注意。研究的目的在于考察工作记忆内容对空间返回抑制的影响。实验一要求被试在客体工作记忆保持阶段完成返回抑制任务,结果发现无论返回抑制任务目标是否与工作记忆内容匹配都出现了返回抑制效应。实验二要求被试在空间工作记忆保持阶段完成返回抑制任务,结果发现当目标落在记忆空间上时返回抑制效应消失。因此,空间返回抑制仅会受到基于空间工作记忆的视觉注意引导的影响。     

奖赏预期对选择性注意的影响——基于客体和空间的注意的区别

为了探究奖赏预期对选择性注意的影响,结合金钱激励延迟任务和双矩形范式,通过两个实验分别考察了奖赏预期的有无以及高低对选择性注意的影响。实验结果表明,在有奖赏预期的情况下,选择性注意更快,奖赏预期的有无对基于空间的注意影响区别不大,但奖赏预期几乎消除了基于客体的注意效应。在低奖赏预期条件下,基于客体和空间的注意均存在;而高奖赏预期条件下,基于空间的注意仍然存在,基于客体的注意几乎被消除了。结果表明奖赏预期可以影响选择性注意,并对基于空间和客体的注意产生不同影响。     

视觉与言语工作记忆表征对视觉注意的引导

通过三个实验,探讨不同时间进程下视觉和言语工作记忆表征对视觉注意的引导。实验1采用注意引导与注意探测任务同时呈现的范式,探讨不同记忆项与注意项时间间隔(SOA)条件下言语工作记忆表征对视觉注意的引导。结果发现,当SOA较短时言语工作记忆表征对视觉注意有引导效应,而SOA较长时未观察到引导效应;实验2、3采用注意引导任务与注意探测任务分离范式,分别探讨在不同SOA条件下言语和视觉工作记忆表征对视觉注意的引导。结果发现,不同SOA条件下言语和视觉工作记忆表征均能引导视觉注意。研究表明,不同实验范式对言语工作记忆表征对视觉注意的引导有明显影响,视觉比言语工作记忆表征能在更广泛条件下引导视觉注意。     

视觉工作记忆中基于客体的存储机制：来自ERPs的证据

该研究以简单形状和颜色构成的客体为材料,采用延迟匹配范式,通过记录事件相关电位,以反映工作记忆表征与知觉输入间冲突的N270为指标,就视觉工作记忆中的客体存储机制进行了探讨。结果发现,无关维度特征变化与目标维度特征变化均可诱发N270。该结果表明,视觉工作记忆对客体目标特征进行存储时,无关特征亦自动得到选择加工,支持基于客体的存储说。     

客体相似性对不同认知方式个体视觉工作记忆表征的影响

采用整体检测的变化察觉范式,探讨客体的相似性对客体—空间型认知方式个体视觉工作记忆表征的影响。行为结果显示,在不相似客体的视觉工作记忆表征任务中,客体型者在长延时条件的成绩优于空间型者,而在相似客体的视觉工作记忆表征任务中,两者无差异;ERP结果显示,在不相似客体视觉工作记忆表征任务中,与客体型者相比,空间型者在大脑皮层诱发出更大的负SP。以上结果表明,客体型者比空间型者对不相似客体视觉工作记忆加工具有优势,其潜在机制可能在于,客体型者对不相似客体视觉工作记忆表征时的神经活动效能更高。     

Does maintaining bindings in visual working memory require more attention than maintaining features?

ABSTRACT

Whether more attention is required for maintaining bindings than maintaining features in visual working memory (VWM) remains an open question. If maintaining bindings in VWM does not require more attention than maintaining features, is it related to the stability of binding representations? In this study, we explored whether maintaining bindings requires more attention than maintaining features for similar and dissimilar objects by inserting a feature report task into the maintenance phase of VWM in Experiments 1 and 2. We also investigated whether the effect of similarity on the attentional requirement for maintaining bindings and features is due to the stability of VWM representations by inserting a suffix during the maintenance phase of VWM in Experiment 3. The results showed that when object-based attention was consumed, bindings were more impaired than features for dissimilar objects but not for similar objects. We also found that the bindings of similar objects were less interfered by the suffix than those of dissimilar objects. Our findings suggest that maintaining bindings does not require more attention than maintaining features when the binding representations are stable in VWM and similarity improves the stability of binding representations.     

基于空间与基于物体的视觉选择的交互作用

已有的大量实验证据表明,基于空间和基于物体的注意成分都存在于视觉系统中,两者并不是相互排斥的。然而,过去对基于空间和基于物体的视觉选择的研究是分别在非常不同的实验范式下进行的,从而导致对两种注意成分之间的内在关系的理论争论。本文介绍近十年来在单任务范式下对基于空间和基于物体的注意的内在关系的研究,并指出未来的研究应该重点从神经生理水平上揭示两种注意成分之间的交互作用关系。     

Interference between object-based attention and object-based memory

Research has shown that there are at least two kinds of visual selective attention: location based and object based. In the present study, we sought to determine the locus of spatially invariant object-based selection using a dual-task paradigm. In four experiments, observers performed an attention task (object feature report or visual search) with a concurrent memory task (object memory or spatial memory). Object memory was interfered with more by a concurrent object-based attention task than by a concurrent location-based attention task. However, this interference pattern was reversed for spatial memory, with greater interference by a location-based attention task than by an object-based attention task. These findings suggest that object-based attention and locationbased attention are functionally dissociable and that some forms of object-based selection operate within visual short-term memory.     

Bindings in working memory: The role of object-based attention

Over the past decade, it has been debated whether retaining bindings in working memory (WM) requires more attention than retaining constituent features, focusing on domain-general attention and space-based attention. Recently, we proposed that retaining bindings in WM needs more object-based attention than retaining constituent features (Shen, Huang, & Gao, 2015, Journal of Experimental Psychology: Human Perception and Performance, doi: 10.1037/xhp0000018). However, only unitized visual bindings were examined; to establish the role of object-based attention in retaining bindings in WM, more emperical evidence is required. We tested 4 new bindings that had been suggested requiring no more attention than the constituent features in the WM maintenance phase: The two constituent features of binding were stored in different WM modules (cross-module binding, Experiment 1), from auditory and visual modalities (cross-modal binding, Experiment 2), or temporally (cross-time binding, Experiments 3) or spatially (cross-space binding, Experiments 4–6) separated. In the critical condition, we added a secondary object feature-report task during the delay interval of the change-detection task, such that the secondary task competed for object-based attention with the to-be-memorized stimuli. If more object-based attention is required for retaining bindings than for retaining constituent features, the secondary task should impair the binding performance to a larger degree relative to the performance of constituent features. Indeed, Experiments 1–6 consistently revealed a significantly larger impairment for bindings than for the constituent features, suggesting that object-based attention plays a pivotal role in retaining bindings in WM.     

Feature binding in visual working memory evaluated by type identification paradigm

Memory for feature binding comprises a key ingredient in coherent object representations. Previous studies have been equivocal about human capacity for objects in the visual working memory. To evaluate memory for feature binding, a type identification paradigm was devised and used with a multiple-object permanence tracking task. Using objects defined by shape and color, observers identified types of changes in feature combinations across an occlusion event, and the effects of object motion and number of switches were investigated. With only one switch, task performance was impaired even under stationary conditions, suggesting highly limited capacity of binding memory. Second switch improved performance only in the stationary condition, suggesting that object motion strongly disrupts feature binding. Further analyses and experiments suggest that improvement by the second switch reflects transition of binding memory by selective attention.     

Attention is required for maintenance of feature binding in visual working memory

Working memory and attention are intimately connected. However, understanding the relationship between the two is challenging. Currently, there is an important controversy about whether objects in working memory are maintained automatically or require resources that are also deployed for visual or auditory attention. Here we investigated the effects of loading attention resources on precision of visual working memory, specifically on correct maintenance of feature-bound objects, using a dual-task paradigm. Participants were presented with a memory array and were asked to remember either direction of motion of random dot kinematograms of different colour, or orientation of coloured bars. During the maintenance period, they performed a secondary visual or auditory task, with varying levels of load. Following a retention period, they adjusted a coloured probe to match either the motion direction or orientation of stimuli with the same colour in the memory array. This allowed us to examine the effects of an attention-demanding task performed during maintenance on precision of recall on the concurrent working memory task. Systematic increase in attention load during maintenance resulted in a significant decrease in overall working memory performance. Changes in overall performance were specifically accompanied by an increase in feature misbinding errors: erroneous reporting of nontarget motion or orientation. Thus in trials where attention resources were taxed, participants were more likely to respond with nontarget values rather than simply making random responses. Our findings suggest that resources used during attention-demanding visual or auditory tasks also contribute to maintaining feature-bound representations in visual working memory—but not necessarily other aspects of working memory.     

Selective working memory disables inhibition of visual features

Recent research suggests that information held in working memory can facilitate subsequent attentional processing. Here, we explore the negative corollary of this conception: Under which circumstances does information in working memory disrupt subsequent processing? Seventy participants performed visual discriminations in a dual-task paradigm. They were asked to judge colors or shapes in an online attention task under three different working-memory conditions: Same, Switch, or Unknown. In the Same condition, participants selectively maintained one visual feature in working memory, from the same dimension as in the online attention task. In the Switch condition, participants selectively maintained one visual feature in working memory, but had to focus on another visual dimension in the online attention task. In the Unknown condition, participants could not predict which visual feature would be relevant for the working-memory task. We found that irrelevant features in the online attention task were particularly difficult to ignore in the Switch condition, that is, when the irrelevant features belong to a visual dimension that is simultaneously prioritized in selective working memory. The findings are consistent with accounts in terms of neural overlap between working-memory and attention circuits, and suggest that mechanisms of selection, rather than resource limitations, critically determine the extent of visual interference.     

Evidence for covert attention switching from eye-movements. Reply to commentaries on Liechty et al., 2003

We argue that our research objectives in Liechty, Pieters, and Wedel (2003) are to provide generalizable insights into covert visual attention to complex, multimodal stimuli in their natural context, through inverse inference from eye-movement data. We discuss the most important issues raised by Feng (2003) and Reichle and Nelson (2003), in particular the task definition, inclusion of ad features, object-based versus space-based attention and the evidence for the where and what streams.Author names are in reverse alphabetical order.     

Visual short-term memory always requires general attention

The role of attention in visual memory remains controversial; while some evidence has suggested that memory for binding between features demands no more attention than does memory for the same features, other evidence has indicated cognitive costs or mnemonic benefits for explicitly attending to bindings. We attempted to reconcile these findings by examining how memory for binding, for features, and for features during binding is affected by a concurrent attention-demanding task. We demonstrated that performing a concurrent task impairs memory for as few as two visual objects, regardless of whether each object includes one or more features. We argue that this pattern of results reflects an essential role for domain-general attention in visual memory, regardless of the simplicity of the to-be-remembered stimuli. We then discuss the implications of these findings for theories of visual working memory.