Don’t let it distract you: how information about the availability of reward affects attentional selection

Previous research has shown that attentional selection is affected by reward contingencies: previously selected and rewarded stimuli continue to capture attention even if the reward contingencies are no longer in place. In the current study, we investigated whether attentional selection also is affected by stimuli that merely signal the magnitude of reward available on a given trial but, crucially, have never had instrumental value. In a series of experiments, we show that a stimulus signaling high reward availability captures attention even when that stimulus is and was never physically salient or part of the task set, and selecting it is harmful for obtaining reward. Our results suggest that irrelevant reward-signaling stimuli capture attention, because participants have learned about the relationship between the stimulus and reward. Importantly, we only observed learning after initial attentional prioritization of the reward signaling stimulus. We conclude that nonsalient, task-irrelevant but reward-signaling stimuli can affect attentional selection above and beyond top-down or bottom-up attentional control, however, only after such stimuli were initially prioritized for selection.     

Biased competition and visual search: the role of luminance and size contrast

The biased-competition theory of attention proposes that objects compete for cortical representation in a mutually inhibitory network; competition is biased in favor of the attended item. Here we test two predictions derived from the biased-competition theory. First we assessed whether increasing an object’s relative brightness (luminance contrast) biased competition in favor of (i.e., prioritized) the brighter object. Second we assessed whether increasing an object’s size biased competition in favor of the larger object. In fulfillment of these aims we used an attentional capture paradigm to test whether a featural singleton (an item unique with respect to a feature such as size or brightness) can impact attentional priority even when those features are irrelevant to finding the target. The results support the prediction that a singleton with respect to luminance contrast receives attentional prioritization and extend the biased-competition account to include size contrast, because a large singleton also receives attentional prioritization.     

The role of attention in remembering important item-location associations

When encountering an excess of information, people are able to selectively remember high-value information by strategically allocating attention during the encoding period, termed value-directed remembering. This has been demonstrated in both the episodic verbal and visuospatial memory domains. Importantly, the allocation of attention also plays a crucial role in the binding of identity and location information in visuospatial memory. We examined how taxing attentional resources to various degrees during encoding might affect visuospatial memory and selectivity. Participants studied items paired with point values indicating their value in a grid display and were asked to maximize their point score (a summation of the points associated with correctly remembered information). Participants viewed items under either a sequential or simultaneous presentation format and in either the presence or absence of a secondary tone discrimination task. While participants in the divided attention conditions recalled fewer item-location associations overall, participants in all encoding conditions prioritized high-value information in memory, providing further evidence that selectivity can be maintained even when attentional resources are taxed. However, differences between presentation formats emerged when conducting spatial resolution analyses examining errors. Errors in the simultaneous conditions were only influenced by item value when attention was full during encoding, while errors in the sequential conditions were not influenced by item value, regardless of available attentional resources. The results suggest participants can strategically allocate attention during encoding even under cognitively-demanding conditions and that gist-based visuospatial memory may only be influenced by information importance when adequate attentional resources are available.     

The effect of increased incentive on free recall by learning-disabled and nondisabled children

Immediate free recall by learning-disabled and nondisabled children was compared under two incentive conditions. Recall of the first few words of each list by disabled children and younger nondisabled children was lower than that by older nondisabled children, and receiving a monetary reward increased early list item recall by older disabled and nondisabled learners. These findings suggest that elaborative encoding processes, such as rehearsal, are impaired in younger disabled and nondisabled children and that receiving a reward increased elaborative encoding by older children. Similar recall of the last few list items by all groups suggests that attention and immediate memory are comparable in disabled and nondisabled children of different ages. Receiving a reward increased recall of the last few list items by younger disabled and nondisabled children, suggesting that a reward increased attention, immediate memory, or both, in these groups. Because receiving a reward increased recall equally in all groups, lower motivation did not appear to be responsible for the lower recall by younger nondisabled children and learning-disabled children.     

Ageing and secondary-distinctiveness-based effects: The orthographic distinctiveness effect is more robust than the bizarreness effect

Differences related to ageing were investigated in two cases of secondary-distinctiveness-based effects: the bizarreness effect and the orthographic distinctiveness effect. A secondary distinctiveness effect means that items that are unusual compared to one's general knowledge stored in permanent memory are better remembered than common items. Experiment 1 confirmed that ageing diminishes the facilitative effects of bizarreness in a mixed list design with equal numbers of bizarre and common images. We suggest that the impaired bizarreness effect in older adults (above age 70) may be due to reduced attentional resources, since no bizarreness effect was observed for younger adults in the divided attention condition. Experiment 2 studied the orthographic distinctiveness effect in ageing for the first time. Contrary to our expectations, an orthographic distinctiveness effect was observed for all participants including older adults and younger adults in a divided attention condition. Because reduced attentional resources due to normal ageing or to experimental manipulation did not impact the facilitative effects of orthographic distinctiveness, our findings suggest that the orthographic distinctiveness effect may be mediated by more automatic processing.     

Evaluating the role of distinctiveness in the generation effect

According to the distinctiveness interpretation, generating words from word fragments leads to more distinctive memory traces than reading intact words. As a test of this hypothesis, the generation effect was experimentally compared to three phenomena previously attributed to distinctiveness. Experiments 1 and 2 proved that the generation effect was unlike conceptual and encoding task distinctiveness. In Experiment 3 the generation effect and the effects of orthographic distinctiveness were compared. These two manipulations had similar effects on memory, but the effects were additive—challenging the hypothesis that the generation effect is a result of the unusual appearance of to-be-generated items. Thus, the generation effect is inconsistent with current theories of distinctiveness. The results were consistent with the hypothesis that generated items receive more encoding resources than read items, and that increased attention to generated items may be at the expense of attention to intact items in the list.     

Ageing and secondary-distinctiveness-based effects: The orthographic distinctiveness effect is more robust than the bizarreness effect

Differences related to ageing were investigated in two cases of secondary-distinctiveness-based effects: the bizarreness effect and the orthographic distinctiveness effect. A secondary distinctiveness effect means that items that are unusual compared to one's general knowledge stored in permanent memory are better remembered than common items. Experiment 1 confirmed that ageing diminishes the facilitative effects of bizarreness in a mixed list design with equal numbers of bizarre and common images. We suggest that the impaired bizarreness effect in older adults (above age 70) may be due to reduced attentional resources, since no bizarreness effect was observed for younger adults in the divided attention condition. Experiment 2 studied the orthographic distinctiveness effect in ageing for the first time. Contrary to our expectations, an orthographic distinctiveness effect was observed for all participants including older adults and younger adults in a divided attention condition. Because reduced attentional resources due to normal ageing or to experimental manipulation did not impact the facilitative effects of orthographic distinctiveness, our findings suggest that the orthographic distinctiveness effect may be mediated by more automatic processing.     

Providing support for distinctive processing: the isolation effect in young and older adults

The isolation paradigm is the classic method for studying the effects of distinctiveness on memory (Hunt, 1995). Previous studies using the isolation paradigm with older adults (Bireta, Suprenant, & Neath, 2008; Cimbalo & Brink, 1982; Geraci, McDaniel, Manzano, & Roediger (2009); Vitali et al., 2006) placed the isolated items late in the study list. The current experiments, which are the first to investigate the isolation effect in young and older adults when the isolated item occurs early in the list, were motivated by a new framework for understanding age-related differences in the beneficial effects of distinctive processing. The framework, which is motivated by Hunt's (2006) discussion of distinctiveness and Craik's (1986) environmental support view, proposes that when contextual support is provided for the processing of both the difference and similarity components, older adults are more likely to show beneficial effects of distinctiveness. In Experiment 1, young adults showed both early and late isolation effects, while older adults showed only a late isolation effect. In the first experiment the isolated item was the word "table" in a list of fish names. In Experiment 2, the contrast between the isolated item and background items was increased by isolating numbers in a list of words. In the second experiment older adults, as well as young adults, showed an early isolation effect.     

Tuning characteristics of the top-down attentional setting

Previous studies of top-down attentional guidance have focused generally on the attentional prioritization of a single target feature. The present study focused on how the attentional system would be configured when the target possesses several unique features. These features were perfectly correlated, which meant that monitoring just one of them would be an adequate strategy. The experiments addressed the following questions: (a) If the target is a singleton, would the attentional system be set to monitor the target’s unique features, or would the search strategy default to singleton detection? (b) Can the target’s static and dynamic features be prioritized simultaneously? (c) Are all of the target’s features prioritized, or only those features that are diagnostic of targethood? The results revealed an attentional system that can be flexibly tuned to multiple target features across static and dynamic dimensions. This system can simultaneously be narrowly tuned to monitor a specific target feature and broadly tuned to detect singletons. Finally, the attentional system monitors only those features that are diagnostic of targethood.     

What causes the isolation effect?

Events that are incongruent with their prevailing context are usually very well remembered. This fact often is described as the distinctiveness effect in memory, an effect that has served as explanation not only of memory phenomena but also of various other phenomena, including social judgment. The core laboratory paradigm for studying distinctiveness in memory research has long been the isolation paradigm. This paradigm, sometimes attributed to H. von Restorff, yields better memory for an item categorically isolated from surrounding items than for the surrounding items and a proper control item. The authors offer an interpretation of the isolation effect based on the analysis of the processing of similarities and differences among the items. Two experiments provide evidence for this interpretation. The results are discussed in the context of current theories of distinctiveness effects in memory. An appeal is made for a different conceptualization of distinctiveness effects, one that treats distinctiveness as a discriminative process in memory that requires processing of both similarities and differences among items.     

Congruency effects in part-list cuing inhibition.

In demonstrations of part-list cuing inhibition, subjects who are shown a subset of studied list words recall fewer noncue words than subjects not shown such part-list cues. We propose that part-list inhibition is governed in part by an incongruency principle: Inhibition occurs to the extent that part-list cues induce a retrieval framework different from that used to encode list items. In Experiment 1, word lists were studied followed by a test of free recall either without cues, or with cue words serially organized to be either congruent or incongruent with the order of studied items. In Experiments 2-4, cues consisted of every second study item in the original presentation order (congruent ones) or reordered to form famous names or familiar idioms that had been hidden in the study list (incongruent cues). More part-list inhibition was observed with incongruent cues than congruent cues in all 4 experiments.     

Static items are automatically prioritized in a dynamic environment

Everyday experience provides us with the intuition that dynamic events guide or capture attention—something which has been confirmed in experimental studies. Recently, we showed that there are limitations to the extent to which dynamic items attract attention. In a visual search task where all items, except one, were dynamic, the dynamic items could be ignored and the static item could be efficiently detected. In the present study we investigated whether attention is automatically drawn to the static item. Three visual search experiments, in which the target and the static object were uncorrelated, revealed that the static item was nevertheless prioritized. This result is at odds with some of the current theories on attentional capture, including the “new object” hypothesis. The current study suggests that differences in dynamics, rather than dynamic features per se, determine where attention is allocated.     

Memory Without Consolidation: Temporal Distinctiveness Explains Retroactive Interference

Is consolidation needed to account for retroactive interference in free recall? Interfering mental activity during the retention interval of a memory task impairs performance, in particular if the interference occurs in temporal proximity to the encoding of the to‐be‐remembered (TBR) information. There are at least two rival theoretical accounts of this temporal gradient of retroactive interference. The cognitive neuroscience literature has suggested neural consolidation is a pivotal factor determining item recall. According to this account, interfering activity interrupts consolidation processes that would otherwise stabilize the memory representations of TBR items post‐encoding. Temporal distinctiveness theory, by contrast, proposes that the retrievability of items depends on their isolation in psychological time. According to this theory, information processed after the encoding of TBR material will reduce the temporal distinctiveness of the TBR information. To test between these accounts, implementations of consolidation were added to the SIMPLE model of memory and learning. We report data from two experiments utilizing a two‐list free recall paradigm. Modeling results imply that SIMPLE was able to model the data and did not benefit from the addition of consolidation. It is concluded that the temporal gradient of retroactive interference cannot be taken as evidence for memory consolidation.     

Dissociable parietal systems for primacy and subsequent memory effects

The frequently observed superior memory for the first items on a list is referred to as primacy. The aetiology of this effect in terms of cognitive processes and their neural substrate is subject to an ongoing debate. However, the brain areas generally involved in successful encoding are well described by subsequent memory studies in which activity during encoding is correlated with memory performance. We employed an object-location association paradigm to differentiate the neural correlate of the primacy from the subsequent memory effect. Activity in the intraparietal sulcus predicted memory performance across all encoding positions. Increased activity in the inferior parietal lobe and angular gyrus resulted exclusively in a more efficient encoding of the first item presented. These areas are part of the ventral frontoparietal network involved in stimulus driven attention. Our results implicate the relatively elevated attention to the first item probably due to its contextual distinctiveness, as a major contributor to the primacy effect.     

Multiple high-reward items can be prioritized in working memory but with greater vulnerability to interference

Emerging literature indicates that working memory and attention interact in determining what is retained over time, though the nature of this relationship and the impacts on performance across different task contexts remain to be mapped. In the present study, four experiments examined whether participants can prioritize one or more high-reward items within a four-item target array for the purposes of an immediate cued recall task, and the extent to which this mediates the disruptive impact of a postdisplay to-be-ignored suffix. All four experiments indicated that endogenous direction of attention toward high-reward items results in their improved recall. Furthermore, increasing the number of high-reward items from one to three (Experiments 1–3) produces no decline in recall performance for those items, while associating each item in an array with a different reward value results in correspondingly graded levels of recall performance (Experiment 4). These results suggest the ability to exert precise voluntary control in the prioritization of multiple targets. However, in line with recent outcomes drawn from serial visual memory, this endogenously driven focus on high-reward items results in greater susceptibility to exogenous suffix interference, relative to low-reward items. This contrasts with outcomes from cueing paradigms, indicating that different methods of attentional direction may not always result in equivalent outcomes on working memory performance.     

注意瞬脱范式中的知觉负载对情绪面孔加工的影响

情绪性刺激的加工是否受注意影响目前尚存争论。基于许多操纵空间注意焦点的研究未能在注意资源的分配上进行精确的调节, 本实验将时间维度的注意瞬脱范式与负载理论相结合, 通过调节注意瞬脱中T1刺激物知觉负载水平的高低(箭头朝向相同与否), 观察被试在四种时间延迟条件下(延迟2, 延迟3, 延迟5, 延迟8)T2目标侦测任务恐惧和中性面孔的反应正确率, 从而对情绪性刺激的加工特征进行研究。实验发现：对恐惧面孔侦测的正确率在高知觉负载条件下显著降低, 而中性面孔则不受知觉负载水平影响, 并且这种高知觉负载对恐惧面孔加工的抑制作用仅发生在注意瞬脱中的短延迟条件下。说明在知觉加工资源和注意调节作用同时受限的情况下恐惧面孔的优势加工受到限制, 提示情绪性刺激的加工与中性刺激相比消耗的加工资源较少, 并依赖于注意的调控。     

Affective stimuli capture attention regardless of categorical distinctiveness: An emotion-induced blindness study

Affective stimuli capture attention, whether their affective value stems from emotional content or a history of reward. The uniqueness of such stimuli within their experimental contexts might imbue them with an enhanced categorical distinctiveness that accounts for their impact on attention. Indeed, in emotion-induced blindness, categorically distinctive neutral pictures disrupt target perception, albeit to a lesser degree than do emotional pictures. Here, we manipulated the categorical distinctiveness of distractors in an emotion-induced blindness task. Participants searched within RSVP streams for a target that followed an emotional or a neutral distractor picture. In a categorically homogenous condition, all non-distractor items were exemplars from a uniform category, thus enhancing the distractor's categorical distinctiveness. In a categorically heterogeneous condition, each non-distractor item represented a distinct category. Neutral distractors disrupted target perception only in the homogenous condition, but emotional distractors did so regardless of their categorical distinctiveness.     

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。     

Reward boosts working memory encoding over a brief temporal window

Selection mechanisms for WM are ordinarily studied by explicitly cueing a subset of memory items. However, we might also expect the reward associations of stimuli we encounter to modulate their probability of being represented in working memory (WM). Theoretical and computational models explicitly predict that reward value should determine which items will be gated into WM. For example, a model by Braver and colleagues in which phasic dopamine signalling gates WM updating predicts a temporally-specific but not item-specific reward-driven boost to encoding. In contrast, Hazy and colleagues invoke reinforcement learning in cortico-striatal loops and predict an item-wise reward-driven encoding bias. Furthermore, a body of prior work has demonstrated that reward-associated items can capture attention, and it has been shown that attentional capture biases WM encoding. We directly investigated the relationship between reward history and WM encoding. In our first experiment, we found an encoding benefit associated with reward-associated items, but the benefit generalized to all items in the memory array. In a second experiment this effect was shown to be highly temporally specific. We speculate that in real-world contexts in which the environment is sampled sequentially with saccades/shifts in attention, this mechanism could effectively mediate an item-wise encoding bias, because encoding boosts would occur when rewarded items were fixated.     

When do learners shift from habitual to agenda-based processes when selecting items for study?

Learners presumably attempt to allocate their study time to maximize reward, yet in some contexts, their study choices are driven by reading biases that would not maximize reward. For instance, when presented with items in a horizontal array that are worth different values if correctly recalled, learners will often first select the leftmost item (i.e., a reading bias), even when it is associated with the lowest value. In four experiments, we investigated the degrees to which various factors cause learners to shift to agenda-based regulation. On each trial, participants were presented with three cues and a point value (1, 3, or 5) for each. The participants could select any cue for study (in which case, its target would be presented) in any order. In Experiment 1, participants either selected items for study under time pressure or were given unlimited time to select items. Not limiting selection time increased the likelihood that higher-valued items would be prioritized for study, but reading biases still influenced item selection. In Experiment 2, participants could select only one item per trial, and higher-valued items were prioritized even more for study, but not exclusively so. In Experiments 3 and 4, we ruled out a lack of motivation and inaccurate task beliefs as explanations for why participants would sometimes choose lower-valued items. The results demonstrate the influence of a pervasive reading bias on learners’ item selections, but as importantly, they show that a shift toward agenda use occurs when habitual responding cannot maximize reward.