Directed forgetting of a single item

In two experiments, we investigated directed forgetting of a single item. We presented participants with two phone numbers to remember and instructed half of the participants to forget the first phone number. The first number was either learned on a single trial (Experiment 1) or on three trials (Experiment 2). In Experiment 1, there was evidence of directed forgetting as a result of differential encoding; the forget instruction affected recall and recognition for both phone numbers. In Experiment 2, the evidence favored differential rehearsal because the forget instruction affected recall but not recognition. These results indicate that instructions to forget can affect memory of single items.     

重复刺激的末位优势效应

探讨在RSVP任务中重复刺激的呈现位置和报告方式对重复知盲效应的影响, 检验该研究提出的注意资源最优化假设和末位优势效应。实验1操作了刺激性质和重复刺激位置, 得出了刺激性质和重复刺激位置的交互效应; 实验2操作了刺激性质和情景信息, 结果是交互效应不显著; 实验3操作了刺激性质和报告方式, 出现了刺激性质和报告方式的交互效应。该结果表明: (1)由于注意资源分配的优化, 重复刺激有末位优势效应。(2)重复知盲的产生不是发生在知觉阶段, 而是发生在报告阶段。(3)注意资源分配最优化理论比建构/归因理论能更合理地解释重复知盲的发生。     

Repetition blindness has a perceptual locus: evidence from online processing of targets in RSVP streams

Four experiments tested whether repetition blindness (RB; reduced accuracy reporting repetitions of briefly displayed items) is a perceptual or a memory-recall phenomenon. RB was measured in rapid serial visual presentation (RSVP) streams, with the task altered to reduce memory demands. In Experiment 1 only the number of targets (1 vs. 2) was reported, eliminating the need to remember target identities. Experiment 2 segregated repeated and nonrepeated targets into separate blocks to reduce bias against repeated targets. Experiments 3 and 4 required immediate "online" buttonpress responses to targets as they occurred. All 4 experiments showed very strong RB. Furthermore, the online response data showed clearly that the 2nd of the repeated targets is the one missed. The present results show that in the RSVP paradigm, RB occurs online during initial stimulus encoding and decision making. The authors argue that RB is indeed a perceptual phenomenon.     

RSVP任务下双刺激重复的优势与劣势

本研究探讨重复知盲发生在知觉阶段还是在记忆阶段。采用快速视觉系列呈现(rapid serial visual representation, 简称RSVP)任务, 让被试即时回忆80个词表中呈现的词。操作了词表中目标词的重复数, 分为无重复、单刺激重复(重复一对)和双刺激重复(重复两对)三种, 和目标词的情绪效价, 分为中性词和情绪词两种。结果发现, 对目标词回忆的正确率是：当目标词和非目标词都是中性词汇, 即二者的情绪效价强度相当时(实验1), 在无重复条件与双刺激重复条件下无差异, 二者均大于单刺激重复条件; 当目标词是消极词汇, 非目标词是中性词汇, 即目标刺激的情绪效价强度大于非目标刺激时(实验2), 无重复条件与单刺激重复条件无差异, 二者均大于双刺激重复条件。结果表明：(1)RSVP 任务下词表中有双刺激重复时, 如果刺激的效价强度相当, 出现重复优势; 如果目标刺激的效价强度高于非目标刺激, 出现重复劣势; (2)人们会主动分配更多的注意资源给效价高的刺激, 重复知盲产生在记忆阶段, 支持注意资源分配最优化假设。     

Repetition blindness and illusory conjunctions: errors in binding visual types with visual tokens.

Repetition blindness (Kanwisher, 1986, 1987) has been defined as the failure to detect or recall repetitions of words presented in rapid serial visual presentation (RSVP). The experiments presented here suggest that repetition blindness (RB) is a more general visual phenomenon, and examine its relationship to feature integration theory (Treisman & Gelade, 1980). Experiment 1 shows RB for letters distributed through space, time, or both. Experiment 2 demonstrates RB for repeated colors in RSVP lists. In Experiments 3 and 4, RB was found for repeated letters and colors in spatial arrays. Experiment 5 provides evidence that the mental representations of discrete objects (called "visual tokens" here) that are necessary to detect visual repetitions (Kanwisher, 1987) are the same as the "object files" (Kahneman & Treisman, 1984) in which visual features are conjoined. In Experiment 6, repetition blindness for the second occurrence of a repeated letter resulted only when the first occurrence was attended to. The overall results suggest that a general dissociation between types and tokens in visual information processing can account for both repetition blindness and illusory conjunctions.     

汉语颠倒词加工中重复知盲发生的水平

以汉语中的颠倒词为材料, 探讨汉语重复知盲的发生水平。采用RSVP方式呈现包含颠倒词对(C1和C2)的句子列表或词语列表, 让被试对列表中的词进行全部报告或报告是否存在重复词, 记录报告C2的正确率。三个实验采用3 (词语的重复性: 颠倒重复、完全重复、不重复) × 2 (颠倒词对的意义相似性: 意义不同、意义相似)两因素被试内设计, 结果在全部报告和报告是否存在重复词的实验中都出现重复性和意义相似性的交互效应, 但不同实验任务, 数据模式不同。该结果表明, 在RSVP任务中, 汉语颠倒词加工存在RB效应, 该效应产生的水平受制于不同的实验任务, 在部分报告任务中, 颠倒词的RB效应发生在知觉水平, 在全部报告任务中, 颠倒词的RB效应发生在语义水平。     

汉字部件水平的重复知盲效应

本研究采用不同部件特点的汉字材料考察在汉字部件水平的重复知盲效应。实验1探究在一组刺激序列中,当两个关键刺激R1和R2的相同部件在不同位置时对重复知盲效应的影响。实验1结果表明,不同条件的重复知盲效应存在显著差异,但其中两个关键字中相同部件的位置相同时与部件位置不同时之间的重复知盲效应无显著差异,这表明部件位置对重复知盲现象无显著影响。实验2探究当关键刺激R1和R2为部件包含关系时的重复知盲效应。实验2结果表明,当一个关键刺激为独体字,且是另一个关键刺激的部件时存在重复知盲效应,其效应的大小会受到具有包含关系的两个关键字（合体字和独体字）在刺激序列中出现顺序的影响,当第二个关键刺激为独体字时的重复知盲效应要显著强于第二个关键刺激为合体字条件。研究结论是不同的汉字部件特点会影响重复之盲效应,这表明重复知盲现象很可能发生在在线的知觉加工过程。     

Identity and similarity in repetition blindness: no cross-over interaction

The difficulty in reporting both occurrences of a repeated item is a phenomenon referred to as repetition blindness (RB). RB has been proposed to result from temporal limitations in creating separate episodic tokens for a twice-activated type. Recently, Chialant and Caramazza (Cognition 63 (1997) 79-119) disputed the conventional view that RB for non-identical words (orthographic RB, as in lice and lick) results from the same mechanism as identity RB, and proposed that orthographic RB arises from competition for lexical selection. Supporting evidence was that identical and merely similar words showed different amounts of RB as a function of stimulus onset asynchrony (lag). Four experiments failed to replicate Chialant and Caramazza's finding that identity RB decreases, but orthographic RB increases, as a function of lag. Instead, RB for all stimuli, including homonym pairs, declined monotonically with lag. These results are consistent with a common mechanism underlying RB for identical and orthographically similar words and with prior research suggesting that RB in similar words occurs at a sublexical level.     

Stimulus exposure time and perceptual memory

The recent explosion of research on implicit memory has facilitated the examination of perceptual and conceptual processes in the encoding of information. Nevertheless, stimulus exposure time—the amount of time that a stimulus is physically available to a perceiver’s scrutiny—has received little attention. In the present paper, we examine the effect of stimulus exposure time on three implicit memory measures (word-fragment completion, perceptual identification, and general knowledge) and two explicit memory measures (graphemic cued recall and semantic cued recall). In Experiment 1, we demonstrated that increases in exposure time lead to increases in implicit perceptual memory, but not to implicit conceptual memory, when the encoding task focuses on perceptual features of the stimulus. We replicated this effect in Experiment 2 and demonstrated that increases in exposure time lead to increases in perceptualand conceptual memory when the measures are explicit. Thus, the current experiments demonstrate that manipulations of exposure time lead to dissociations in implicit, but not explicit, memory.     

Study repetition and divided attention: Effects of encoding manipulations on collaborative inhibition in group recall

Two experiments tested the effects of encoding manipulations on group recall and on the magnitude of collaborative inhibition. Collaborative inhibition refers to the phenomenon where by a collaborative group recalls less than do the same number of individuals who work alone and then have their nonredundant responses pooled. Participants studied categorized word lists once or three times (Experiment 1) or under conditions of full versus divided attention (Experiment 2). Study repetition both improved retrieval organization in recall and attenuated collaborative inhibition, and divided attention encoding both reduced retrieval organization in recall and eliminated collaborative inhibition. These experiments are the first to focus on encoding variables and to show that collaborative inhibition can vary as a function of encoding manipulations.     

Variation in the use of cues to guide visual working memory

Across two experiments we examined individual differences in the use of precues and retrocues to guide the selective encoding and maintenance of information in visual working memory (WM). In Experiment 1, we used spatial cues to indicate which item would be tested either before or after the presentation of a memory array. Regression analyses allowed us to separate variance due to visual WM capacity and attention control differences. In Experiment 2, we used categorical cues to indicate from which subset of items the tested item would be drawn, and we measured attention control with two independent tasks. Collectively, the results supported the idea that an element of individual differences in WM is the ability to flexibly allocate attention to encode only relevant information and subsequently select relevant information during maintenance stages.     

合体字与复合词中联结编码和项目编码的关系

本研究通过考察合体字和复合词加工过程中联结记忆和项目记忆的变化,探究了在将不同项目绑定为整体的过程中联结编码和项目编码间的关系,并结合脑电技术比较了合体字和复合词的加工过程在神经机制上的差异。行为结果显示:与不能组成字或词的编码条件相比,合体字和复合词编码条件下的联结记忆成绩有显著提升,且项目记忆成绩没有下降;与复合词编码相比,合体字编码条件下的联结记忆和项目记忆成绩都显著更好。脑电结果显示:复合词编码时晚期负成分(LNC)主要位于额区且发生较早,而合体字编码时的LNC主要位于枕区且发生更晚;合体字编码比复合词编码在α/β频段的神经振荡去同步化更强。这些结果表明,将不同项目绑定为整体的操作可以强化大脑对联结信息的加工,同时不会损害对项目的加工,支持了“只有收益”的观点。本研究也从实证的角度为汉语学习材料的编排提供了参考。     

The revelation effect for item and associative recognition: Familiarity versus recollection

The revelation effect occurs when items on a recognition test are more likely to be judged as being old if they are preceded by a cognitive task that involves the processing of similar types of stimuli. This effect was examined for item (single-word) and associative (word-pair) recognition. We found, in Experiments 1 and 2, a revelation effect for item, but not for associative recognition under normal study conditions. A revelation effect for both item and associative recognition was observed in Experiments 3 and 4 when study time was extremely brief, thus limiting the encoding of information that would support recall or recollection. In Experiment 5, we demonstrated that the revelation effect for item recognition is eliminated when item recognition decisions are made in the context of a study item. The results show that the revelation task influenced recognition decisions based on familiarity, but not decisions that involved recall or recollection.     

Two bs or not two Bs? A signal detection theory analysis of repetition blindness in a counting task

Stimulus repetition usually benefits performance. A notable exception is repetition blindness (RB), in which subjects fail to report a repeated stimulus in a rapid serial visual presentation. Theories differ in attributing RB to either perceptual encoding or memory retrieval and to impaired discrimination versus response bias. In the present study, subjects judged whether one or two letters were imbedded in sequences of digits. Unlike previous studies, false guesses of two unrepeated letters were distinguished from false guesses of two repeated letters. When repeated- and unrepeated-letter trials were randomly intermixed (Experiment 1), RB was entirely attributable to response bias. However, when they were separately blocked (Experiments 2 and 3), RB was manifested in discriminability (d'). The results support perceptual-encoding accounts of RB but indicate that effects on discriminability depend on subjects' processing strategies.     

Perceptual interference at encoding enhances item-specific encoding and disrupts relational encoding: Evidence from multiple recall tests

Interfering with perception during encoding can enhance later memory, a phenomenon known as the perceptual interference effect. This effect is investigated in the context of the item-specific-relational framework (e.g., Hunt & McDaniel, 1993), which suggests that the perceptual interference enhances item-specific encoding and impedes relational encoding. Two experiments performed with multiple recall tests support this view. Prior research indicates that item-specific processing increases item gains across tests, whereas relational processing protects against item losses (e.g., Burns, 1993; Klein, Loftus, Kihlstrom, & Aseron, 1989). Consistent with the item-specific-relational framework, perceptual interference produced significant increases in both item gains and losses relative to a control condition.     

Is this a question? Not for long. The statement bias

Four experiments demonstrate a fundamental ‘statement bias’: questions are more often misremembered as statements than vice versa. The bias increases with increasing item comprehensibility (Experiment 1) and is related to depth of processing at encoding (Experiment 2). When sentences are simply comprehended, the bias is not affected by the truth of the statement underlying the sentence (Experiment 3). The statement bias generalizes to contexts in which people have to express consent with the content of the sentence (Experiment 4) but is somewhat reduced when they are not sure what the correct answer is. Our findings are consistent with the idea that during processing of a sentence the content of the sentence is represented similar to a statement.     

Timing conditions and the magnitude of gender differences on the Mental Rotations Test

In two experiments, we examined the effect of timing conditions on the magnitude of gender differences in performance on the Mental Rotations Test (MRT). In Experiment 1, each of 196 females and 119 males was administered the MRT via a Microsoft PowerPoint presentation in one of five timing conditions (15, 20, 25, 30, and 40 sec). The participants were exposed to each MRT item for the period specified in the assigned timing condition. Experiment 2 was conducted to address flaws found in Experiment 1. Accordingly, each of 105 females and 105 males was individually administered the task in one of three timing conditions (15 sec, 25 sec, or unlimited duration). The results of both experiments showed that the magnitude of gender differences was similar across timing conditions when a conventional scoring method was used. An analysis of guessing behavior generally indicated that men tend to show little effect of timing conditions, whereas women's propensity to guess increases when they are given more time to respond. In general, the results supported an interpretation of gender differences on the MRT that relies on the joint operation of performance factors and level of spatial ability.     

Stimulus-specific processing consequences of pattern goodness

Two issues concerning the effects of visual pattern goodness on information processing time were investigated: the role of memory vs. encoding and the role of individual stimulus goodness vs. stimulus similarity. A sequential “same-different” task was used to provide differentiation of target item or memory effects from display item or encoding effects. Experiment 1 used four alternative stimuli in each block of trials. The results showed that good patterns were processed faster than poor patterns for both “same” and “different” responses. Furthermore, the goodness of the target item had a greater effect on reaction time than did the goodness of the display item, indicating that memory is more important than encoding in producing faster processing of good stimuli. Effects of interstimulus similarity on processing time were minimal, although isolation of good stimuli in a similarity space could explain many of the results. Experiment 2 replicated the results of Experiment 1, despite the fact that differences in similarity space had been minimized by using only two alternative stimuli in each block. In addition, the speed of processing a “same” pair was essentially independent of the particular alternative stimulus in a block. These results suggest that in this task, there is a processing advantage for good stimuli that is stimulus specific, with the effect operating primarily in memory.     

Visual and verbal codes: Spatial information survives the icon

Three experiments are reported to demonstrate partial independence of identity and spatial position information concerning visually presented symbols. Experiment I shows that performance on these forms of information improves at different rates as a function of exposure duration. Experiment II shows that performance on one can be traded against the other. Experiment III demonstrates partial statistical independence of item and position responses and shows that increases in the duration and delay of the probe facilitate performance. Some implications of these experiments for theories involving mandatory verbal encoding of visual symbol-arrays are discussed. A model is proposed comprising visual and name stores with different acquisition rates and capacities. Both are indexed by identity but the visual code can also be interrogated by spatial cues.     

Temporal-spatial memory: retrieval of spatial information does not reduce recency

Factors influencing the shape of serial position curves in non-verbal serial short-term memory were examined, using a task testing memory for the position of dots. Similar recency slopes were found when both position and order were recalled (Experiment 1A) and when order only was required (Experiment 1B). This observation was confirmed and tested further in conditions requiring the same encoding but different amounts of spatial information at retrieval (Experiment 2). However, Experiment 2 also revealed an effect of spatial information retrieval on the overall level of memory for recency items. Overall, the results indicate that spatial items produce bow-shaped serial positions curves in tasks requiring the maintenance of order information and that recency is affected by the demand on spatial information retrieval in terms of the overall level of performance but not in terms of the recency slope. These findings are contrary to what is found in the literature on serial verbal recall when both item and order information are required.