The attentional boost effect really is a boost: Evidence from a new baseline

In the attentional boost effect, participants encode images into memory as they perform an unrelated target-detection task. Later memory is better for images that coincided with a target rather than a distractor. This advantage could reflect a broad processing enhancement triggered by target detection, but it could also reflect inhibitory processes triggered by distractor rejection. To test these possibilities, in four experiments we acquired a baseline measure of image memory when neither a target nor a distractor was presented. Participants memorized faces presented in a continuous series (500- or 100-ms duration). At the same time, participants monitored a stream of squares. Some faces appeared on their own, and others coincided with squares in either a target or a nontarget color. Because the processes associated with both target detection and distractor rejection were minimized when faces appeared on their own, this condition served as a baseline measure of face encoding. The data showed that long-term memory for faces coinciding with a target square was enhanced relative to faces in both the baseline and distractor conditions. We concluded that detecting a behaviorally relevant event boosts memory for concurrently presented images in dual-task situations.     

False recognition without intentional learning

Asked to memorize a list of semantically related words, participants often falsely recall or recognize a highly related semantic associate that has not been presented (the critical lure). Does this false memory phenomenon depend on intentional word reading and learning? In Experiment 1, participants performed a color identification task on distractor words from typical false memory lists. In Experiment 2, participants read the same words. In both experiments, the primary task was followed by a surprise recognition test for actually presented and unpresented words, including the critical lures. False alarms to critical lures were robust and quite equivalent across the two experiments. These results are consistent with an activation/monitoring account of false memory, in which processing of semantic associates can evoke false memories even when that processing is incidental.     

真实记忆与虚假记忆中的生命性效应研究

本研究采用DRM范式,探讨了生命性对真实和虚假记忆的影响。实验1使用类别呈现词语强化类别加工,实验2伪随机呈现词语弱化类别加工并进行即时及延时探测。结果发现：（1）当强化类别加工时,生命性和类别对击中率有相类似的促进效应;（2）当弱化类别加工并进行即时探测时,生命性对击中率的促进作用最强;（3）类别效应促进真实记忆和虚假记忆,但生命性效应仅促进了真实记忆,而不影响虚假记忆的产生;（4）在即时与延时探测中均发现类别效应和生命性效应。本研究证明了：（1）生命性效应的作用机制不同于类别效应;（2）生命性效应对真实和虚假记忆的作用机制不同;（3）类别效应和生命性效应的存在时效长达24小时,但是生命性效应的衰退速度较快。     

Retention performance as a function of the distinctiveness of memory traces and retention task

Summary In the acquisition phase of an incidental learning paradigm, words that are exemplars of categories were judged as to whether or not they belonged to a specified category. This was followed by a forced choice recognition task. The effects of three variables were studied: a) whether the acquisition task called for a positive or a negative response; b) the number of exemplar words per category; and c) whether distractor items in the recognition test came from the same category as the target words or from other categories. The results showed that recognition errors were influenced by all three variables. Unlike the variables a) and c) which showed significant main effects, the effect of number of exemplars per category was significant only for the same category distractor condition. In this condition more exemplars per category led to more recognition errors. The results are explained by assuming that retention performance is determined by two factors. The first factor is the distinctiveness of the memory traces. This is supposed to be a joint product of task-specific encoding and stimulus characteristics. The second factor is the distinctive similarity between the retrieval information and the stored memory traces. Although the results show some sublte effects that are not easy to explain, it is argued that this model offers a good account of the general findings.     

The role of articulatory suppression in immediate false recognition

False memory for critical lures has been widely documented in long-term memory using the Deese/Roediger-McDermott paradigm. Recent evidence suggests that false memory effects can also be found in short-term memory (STM), supporting models that assume a strong relationship between short-term and long-term memory processes. However, no study has examined the role of articulatory suppression on immediate false memory, even though phono-articulatory factors are critically involved in STM performance and are an intrinsic part of all STM accounts. The current study proposes a novel paradigm to assess false memory effects in a STM task under both silent and articulatory suppression conditions. Using immediate serial recognition, in which participants had to judge whether two successive mixed lists of six associated and non-associated words were matched, we examined true recognition of matching lists and false recognition of mismatching lists comprising a critical lure or unrelated distractor in two experiments. Results from both experiments indicated reduced true recognition of matching lists and greater false serial recognition of mismatching lists comprising a critical lure under articulatory suppression relative to silence. These findings provide further support for some current models of verbal short-term memory, which posit a strong relationship between short-term and long-term memory processes.     

The role of articulatory suppression in immediate false recognition

False memory for critical lures has been widely documented in long-term memory using the Deese/Roediger-McDermott paradigm. Recent evidence suggests that false memory effects can also be found in short-term memory (STM), supporting models that assume a strong relationship between short-term and long-term memory processes. However, no study has examined the role of articulatory suppression on immediate false memory, even though phono-articulatory factors are critically involved in STM performance and are an intrinsic part of all STM accounts. The current study proposes a novel paradigm to assess false memory effects in a STM task under both silent and articulatory suppression conditions. Using immediate serial recognition, in which participants had to judge whether two successive mixed lists of six associated and non-associated words were matched, we examined true recognition of matching lists and false recognition of mismatching lists comprising a critical lure or unrelated distractor in two experiments. Results from both experiments indicated reduced true recognition of matching lists and greater false serial recognition of mismatching lists comprising a critical lure under articulatory suppression relative to silence. These findings provide further support for some current models of verbal short-term memory, which posit a strong relationship between short-term and long-term memory processes.     

Role of working memory load on selective attention to affectively valent information

Empirical evidence obtained with neutral stimuli has shown that selective attention relies on working memory functions as distractor processing occurs under conditions of high but not of low working memory load. We investigated whether these findings also hold for affectively valent distractors. In three experiments, participants completed the original Flanker task with famous people (Exps 1 and 2) and an affective Flanker task (Exp. 3) in which positive and negative words were presented superimposed onto happy, angry, and neutral faces under conditions of high or low working memory load. In line with past findings, results showed greater interference effects due to processing of distractors showing known people under high working memory load. In contrast interference effects due to processing of valent distractors occurred regardless of working memory load. The present findings are in contrast with those reported with neutral stimuli as they indicate that automatic evaluation of incoming affectively valent information occurs regardless of task priorities and of working memory load.     

Repetition effects in associative false recognition: Theme-based criterion shifts are the exception, not the rule

Previous reports have demonstrated that false memory for the critical items of associative lists decreases when lists are studied multiple times (Benjamin, 2001). In three experiments, we explored two hypotheses that might account for false memory reductions with repetition. Under an identification hypothesis, repetition decreases false memory because participants realise that critical items are absent from the list at encoding and thus reject them at test. Under a criterion shift hypothesis, repetition decreases false memory because it increases the discriminability of studied words from lures, causing participants to set a higher response criterion for positive recognition responses. Results uniquely supported the criterion shift hypothesis. Furthermore, results showed that participants only changed their criterion on separate recognition tests, not on an item-by-item basis within a single recognition test. The failure to establish separate criteria within a test increased false memory for repeated lists.     

The persistence of distraction: A study of attentional biases by fear,faces, and context

Efficient processing of the visual world requires that distracting items be avoided, or at least rapidly disengaged from. The mechanisms by which highly salient, yet irrelevant, stimuli lead to distraction, however, are not well understood. Here, we utilized a particularly strong type of distractor—images of human faces—to investigate the mechanisms of distraction and the involuntarily biasing of attention. Across three experiments using a novel discrimination task, we provided new evidence that the robust distraction triggered by faces may not reflect enhanced attraction but, instead, may reflect an extended holding of attention. Specifically, the onset of a task-irrelevant distractor initially impaired target performance regardless of the identity of that distractor (fearful faces, neutral faces, or places). In contrast, an extended period of distraction was observed only when the distractor was a face. Our results thus demonstrate two distinct mechanisms contributing to distraction: an initial involuntary capture to any sudden event and a subsequent holding of attention to a potentially meaningful, yet task-irrelevant stimulus—in this case, a human face. Critically, the latter holding of attention by faces was not unique to fearful faces but also occurred for neutral faces. The present results dissociate attentional capture from hold in another way as well, since the capture occurred regardless of the nature of the distractors, but the extended holding of attention was dependent upon the ongoing distractor context.     

Inconsistent handedness and saccade execution benefit face memory without affecting interhemispheric interaction

Individuals who consistently use their dominant hand for most tasks exhibit poorer memory than individuals whose handedness is relatively inconsistent, but consistent-handers' memory can be enhanced by making repetitive saccadic eye movements before attempting retrieval. One account of these effects is that inconsistent handedness and saccade execution are associated with increased interhemispheric interaction, which putatively facilitates retrieval. We tested this account by having participants classify faces as famous or novel. Faces were presented in the left and right visual fields simultaneously (bilaterally) or in one field only (unilaterally). As in prior studies, famous faces were classified more quickly and more accurately given bilateral presentation, but novel faces were not. These bilateral gain effects indicate that interhemispheric interaction specifically facilitates famous-face recognition, and therefore larger gains may reflect greater interhemispheric interaction. However, neither inconsistent handedness nor saccade execution increased the size of bilateral gain. Inconsistent handedness and saccade execution (the latter for consistent-handers only) did increase face-classification accuracy, but the increases were not specific to famous-face recognition, and, in fact, were somewhat stronger for novel-face identification. These results extend the beneficial mnemonic effects of inconsistent handedness and saccade execution to faces, but indicate that these benefits are not caused by increased interhemispheric interaction.     

Sustained conscious access to incidental memories in RSVP

In visual search of natural scenes, differentiation of briefly fixated but task-irrelevant distractor items from incidental memory is often comparable to explicit memorization. However, many characteristics of incidental memory remain unclear, including the capacity for its conscious retrieval. Here, we examined incidental memory for faces in either upright or inverted orientation using Rapid Serial Visual Presentation (RSVP). Subjects were instructed to detect a target face in a sequence of 8–15 faces cropped from natural scene photographs (Experiment 1). If the target face was identified within a brief time window, the subject proceeded to an incidental memory task. Here, subjects used incidental memory to discriminate between a probe face (a distractor in the RSVP stream) and a novel, foil face. In Experiment 2 we reduced scene-related semantic coherency by intermixing faces from multiple scenes and contrasted incidental memory with explicit memory, a condition where subjects actively memorized each face from the sequence without searching for a target. In both experiments, we measured objective performance (Type 1 AUC) and metacognitive accuracy (Type 2 AUC), revealing sustained and consciously accessible incidental memory for upright and inverted faces. In novel analyses of face categories, we examined whether accuracy or metacognitive judgments are affected by shared semantic features (i.e., similarity in gender, race, age). Similarity enhanced the accuracy of incidental memory discriminations but did not influence metacognition. We conclude that incidental memory is sustained and consciously accessible, is not reliant on scene contexts, and is not enhanced by explicit memorization.     

工作记忆内容驱动完全无关刺激捕获注意

研究通过三个实验以检验工作记忆内容能否自动引导注意选择视场中与之匹配的任务完全无关刺激。实验一要求被试在工作记忆保持阶段完成一个视觉搜索任务，结果发现当搜索序列外的无关干扰刺激与工作记忆内容匹配时搜索绩效显著降低；实验二结果表明该干扰效应不能归因于自下而上的启动机制，因为对颜色刺激仅仅进行知觉辨认而没有工作记忆加工时并没有产生启动效应；实验三通过缩短搜索任务刺激的呈现时间以使得被试在完成搜索任务前没有足够时间眼跳至无关干扰刺激，结果发现了与实验一类似的干扰效应，说明在没有眼跳的情况下与工作记忆内容匹配的完全无关刺激可以捕获注意。这些结果表明保持在工作记忆中的信息表征可以自动引导注意选择视场中与之匹配的任务完全无关刺激，为基于工作记忆内容的注意捕获提供了新证据支持。     

Inconsistent handedness and saccade execution benefit face memory without affecting interhemispheric interaction

Individuals who consistently use their dominant hand for most tasks exhibit poorer memory than individuals whose handedness is relatively inconsistent, but consistent-handers’ memory can be enhanced by making repetitive saccadic eye movements before attempting retrieval. One account of these effects is that inconsistent handedness and saccade execution are associated with increased interhemispheric interaction, which putatively facilitates retrieval. We tested this account by having participants classify faces as famous or novel. Faces were presented in the left and right visual fields simultaneously (bilaterally) or in one field only (unilaterally). As in prior studies, famous faces were classified more quickly and more accurately given bilateral presentation, but novel faces were not. These bilateral gain effects indicate that interhemispheric interaction specifically facilitates famous-face recognition, and therefore larger gains may reflect greater interhemispheric interaction. However, neither inconsistent handedness nor saccade execution increased the size of bilateral gain. Inconsistent handedness and saccade execution (the latter for consistent-handers only) did increase face-classification accuracy, but the increases were not specific to famous-face recognition, and, in fact, were somewhat stronger for novel-face identification. These results extend the beneficial mnemonic effects of inconsistent handedness and saccade execution to faces, but indicate that these benefits are not caused by increased interhemispheric interaction.     

知觉负载对负性分心面孔的知觉加工和记忆的影响

本研究采用视觉搜索和意外再认记忆任务,结合事件相关电位技术,考察知觉负载对负性分心面孔的知觉加工和记忆的影响。在视觉搜索任务中,行为上恐惧分心面孔在高负载下干扰任务。ERP结果上,恐惧比中性分心面孔诱发更大的N170和N250;在低负载下恐惧比中性分心面孔诱发更大的N700,在高负载下没有差异。在意外再认记忆中,个体对低负载下的恐惧分心面孔表现出记忆。这些结果说明负性分心物在早期是自动化加工;晚期加工受知觉负载的调节,负载越低对负性分心物的过滤越少,存在对负性分心物的记忆偏向。     

Neural evidence for the contribution of holistic processing but not attention allocation to the other-race effect on face memory

Multiple mechanisms have been suggested to contribute to the other-race effect on face memory, the phenomenon of better memory performance for own-race than other-race faces. Here, two of these mechanisms, increased attention allocation and greater holistic processing during memory encoding for own-race than other-race faces, were tested in two separate experiments. In these experiments event-related potentials were measured during study (the difference due to memory, Dm) and test phase (old/new effects) to examine brain activation related to memory encoding and retrieval, allowing for selective investigations of these memory sub-processes. In Experiment 1, participants studied own-race (Caucasian) and other-race (Chinese) faces under focused or divided attention. In Experiment 2, participants studied own-race (Caucasian) and other-race (African American) faces presented upright or upside down (i.e., inverted). Both experiments showed decreases in memory performance when attention allocation or holistic processing was reduced, but these effects were similar for own-race and other-race faces. Manipulations of holistic processing, but not attention allocation, influenced the neural other-race effects during memory encoding. Inverted own-race faces showed similar neural patterns as upright other-race faces, indicating that when holistic processing of own-race faces was reduced, these faces were encoded similarly as upright other-race faces. No influences of the experimental manipulations on other-race effects during memory retrieval were found. The present study provides the first neural evidence that increased holistic processing during memory encoding contributes to the other-race effect on face memory.     

The effects of social pressure on false memories

The present experiments were designed to examine the effects of social pressure on false memories. Participants studied lists created to elicit false memories and then worked in conjunction with virtual confederates on a recognition memory task. In Experiment 1, participants worked with one or two confederates to complete multiple study-test trials. On the group tests, participants were implicitly pressured to recognize words that did not appear on the studied lists. Experiment 2 was implemented similarly, but utilized a presumably more difficult recognition test involving one long study phase followed by one long test phase. After the purported group tests in both experiments, participants completed surprise individual recognition tests. In both experiments, social pressure influenced participants' responses on group recognition tests and subsequent individual recognition tests. Furthermore, the results indicated that social pressure affected both veridical memories and false memories.     

Comparison of neural activity that leads to true memories,false memories,and forgetting: An fMRI study of the misinformation effect

False memories can occur when people are exposed to misinformation about a past event. Of interest here are the neural mechanisms of this type of memory failure. In the present study, participants viewed photographic vignettes of common activities during an original event phase (OEP), while we monitored their brain activity using fMRI. Later, in a misinformation phase, participants viewed sentences describing the studied photographs, some of which contained information conflicting with that depicted in the photographs. One day later, participants returned for a surprise item memory recognition test for the content of the photographs. Results showed reliable creation of false memories, in that participants reported information that had been presented in the verbal misinformation but not in the photographs. Several regions were more active during the OEP for later accurate memory than for forgetting, but they were also more active for later false memories, indicating that false memories in this paradigm are not simply caused by failure to encode the original event. There was greater activation in the ventral visual stream for subsequent true memories than for subsequent false memories, however, suggesting that differences in encoding may contribute to later susceptibility to misinformation.     

Similarity modulates the face-capturing effect in change detection

We investigated whether similarity among faces could modulate the face-capturing effect in change detection. In Experiment 1, a singleton search task was used to demonstrate that a face stimulus captures attention and the odd-one-out hypothesis cannot account for the results. Searching for a face target was faster than searching for a nonface target no matter whether distractor–distractor similarity was low or high. The fast search, however, did not lead to a face-detection advantage in Experiment 2 when the pre- and postchange faces were highly similar. When participants in Experiment 3 had to divide their attention between two faces in stimulus displays for change detection, detection performance was worse than performance in detecting nonface changes. The face-capturing effect alone is insufficient to produce the face-detection advantage. Face processing is efficient but its effect on performance depends on the stimulus–task context.     

Get the gist? The effects of processing depth on false recognition in short-term and long-term memory

Gist-based processing has been proposed to account for robust false memories in the converging-associates task. The deep-encoding processes known to enhance verbatim memory also strengthen gist memory and increase distortions of long-term memory (LTM). Recent research has demonstrated that compelling false memory illusions are relatively delay-invariant, also occurring under canonical short-term memory (STM) conditions. To investigate the contributions of gist to false memory at short and long delays, processing depth was manipulated as participants encoded lists of four semantically related words and were probed immediately, following a filled 3- to 4-s retention interval, or approximately 20 min later, in a surprise recognition test. In two experiments, the encoding manipulation dissociated STM and LTM on the frequency, but not the phenomenology, of false memory. Deep encoding at STM increases false recognition rates at LTM, but confidence ratings and remember/know judgments are similar across delays and do not differ as a function of processing depth. These results suggest that some shared and some unique processes underlie false memory illusions at short and long delays.