Combined expectancy effects: an accumulator model

When participants use cues to prepare for a likely stimulus or a likely response, reaction times are facilitated by valid cues but prolonged by invalid cues. In studies on combined expectancy effects, two cues give information regarding two dimensions of the forthcoming task. When the two cues consist of two separable stimuli their effects are approximately additive. When cues are presented as an integrated stimulus, cueing effects interact. A model is presented that simulates effects like these. The model assumes that cues affect different processing stages. When implicit information suggests that expectancies are unrelated, as for instance with separated cues, cueing effects at early and late levels of processing remain independent. When implicit information suggests that expectancies are related, as with integrated cues, however, a mechanism that is sensitive to the validity of the early stage cue, leads to an adjustment of the cueing effect at the late stage. The model is based on neurophysiologically plausible assumptions, it is given explicitly in mathematical terms, and it provides a good fit to a large body of empirical data.     

Combined expectancy effects are modulated by the relation between expectancy cues

Studies of combined expectancies have shown that spatial cueing effects are reduced on trials on which participants have to respond with an unexpected motor response. In the first two experiments the range of reduced expectancy effects is examined. Advance knowledge of the likely response was combined in a trial-by-trial procedure with modality cueing, object cueing, and task cueing. Effects of modality cueing were reduced on trials on which the target requested an unexpected response. However, effects of object cueing as well as effects of task cueing were unaffected by response cueing. Comparing experiments revealed that different types of cues were used in different experiments. To test the effect of type of cue on the interaction of expectancies the third experiment combined spatial cueing with response cueing. When integrated cues were used that cued the likely target location by an arrow and the likely response by an arrow too, spatial cueing effects were reduced on trials with unexpected responses. However, spatial cueing effects remained unaffected by response cueing when separated cues were used consisting in a word cueing the response and an arrow cueing target location. An account for the modulation of combined expectancies by the relation between cues is suggested in terms of the adjusted expectancy model.     

Inhibition of return for the length of a line?

Inhibition of return is most often measured using an exogenous spatial cuing method. The experiments presented here follow up on a small number of studies that have examined whether a similar effect occurs for nonspatial stimulus attributes. In Experiments 1 and 2, the task was to identify a target line as either short or long. In this context, targets on valid trials were of the same length as that of a preceding cue, whereas targets on invalid trials were of a different length than that of a preceding cue. The results were similar to those in spatial orienting studies in that responses were slower for valid than for invalid targets only at stimulus onset asynchronies (SOAs) longer than 300 msec. In Experiment 3, the stimuli were the same but the task was to detect the onset of the target line. This task change resulted in slower responses for valid than for invalid targets at all SOAs. A similar result was observed in Experiment 4, in which validity was defined by color rather than line length, and the task was to identify the target color. The discussion centers on an opponent process approach to interpreting cuing effects, and consequent difficulties in distinguishing spatial and nonspatial cuing effects based on their time course.     

Interaction between endogenous and exogenous orienting in crossmodal attention

Using a cue-target paradigm, we investigated the interaction between endogenous and exogenous orienting in cross-modal attention. A peripheral (exogenous) cue was presented after a central (endogenous) cue with a variable time interval. The endogenous and exogenous cues were presented in one sensory modality (auditory in Experiment 1 and visual in Experiment 2) whereas the target was presented in another modality. Both experiments showed a significant endogenous cuing effect (longer reaction times in the invalid condition than in the valid condition). However, exogenous cuing produced a facilitatory effect in both experiments in response to the target when endogenous cuing was valid, but it elicited a facilitatory effect in Experiment 1 and an inhibitory effect in Experiment 2 when endogenous cuing was invalid. These findings indicate that endogenous and exogenous cuing can co-operate in orienting attention to the crossmodal target. Moreover, the interaction between endogenous and exogenous orienting of attention is modulated by the modality between the cue and the target.     

When words and space collide: Spatial attention interacts with lexical access during word recognition

Recent research has suggested an important role for spatial attention in reading, however the nature of this influence is unclear. Further, it has been shown that intention to engage in linguistic processing can enhance lexical processing. Therefore, we developed a novel paradigm to examine the impact of spatial attention on primed and unprimed lexical processing. In a lexical decision task, targets were preceded by a cue to lexical access and spatial location simultaneously. Results indicated that on spatially valid trials, the lexical cuing effect was large and word processing was enhanced, suggesting that spatial attention influences lexical access. On spatially invalid trials, lexical cuing effects were significantly decreased, resulting in a spatial cuing by lexical cuing interaction. Results from this experiment provide evidence that spatial attention interacts with lexical access during word processing. This novel paradigm provides a new avenue for exploring the relations between spatial attention and reading processes.     

Separate mechanisms recruited by exogenous and endogenous spatial cues: evidence from a spatial Stroop paradigm

The present experiments tested whether endogenous and exogenous cues produce separate effects on target processing. In Experiment 1, participants discriminated whether an arrow presented left or right of fixation pointed to the left or right. For 1 group, the arrow was preceded by a peripheral noninformative cue. For the other group, the arrow was preceded by a central, symbolic, informative cue. The 2 types of cues modulated the spatial Stroop effect in opposite ways, with endogenous cues producing larger spatial Stroop effects for valid trials and exogenous cues producing smaller spatial Stroop effects for valid trials. In Experiments 2A and 2B, the influence of peripheral noninformative and peripheral informative cues on the spatial Stroop effect was directly compared. The spatial Stroop effect was smaller for valid than for invalid trials for both types of cues. These results point to a distinction between the influence of central and peripheral attentional cues on performance and are not consistent with a unitary view of endogenous and exogenous attention.     

An examination of attentional control in the auditory modality: Further evidence for auditory orienting

Four experiments are reported that examine attentional control in the auditory modality. In Experiment 1, the subjects made detection responses to the onset of a monaurally presented pure tone that was preceded by a pure-tone cue. On a valid trial, the cue was presented in the same ear as the target; on an invalid trial, it was presented in the contralateral ear to the target; and on a neutral trial, it was presented in both ears. Overall performance was facilitated on valid trials in comparison with invalid trials. In later experiments, the subjects made choice decisions about the location of the target, and significant cuing effects were found relative to the neutral condition. Finally, performance was assessed in the presence of central (spoken) word cues. Here, the content of the cue specified the likely location of the target. Under these conditions, costs and benefits were found over a range of cue-target stimulus onset asynchronies. The results are discussed in terms of automatic and controlled attentional processes.     

眼睛注视线索提示效应: 内源性注意还是外源性注意?

采用改进的Posner视-空间线索提示范式, 对眼睛注视线索提示效应(eyes gaze cueing effect)的加工机制进行了探讨。实验一考察注视提示线索对空间Stroop效应的影响; 实验二考察注视提示线索对特征抽取和特征整合的影响。实验结果显示: 注视线索提示有效时的空间Stroop效应显著大于提示无效的情景; 在单一特征搜索与特征联合搜索任务中, 注视线索提示效应无差别。这说明, 注视线索通过在头脑里形成空间方位表征诱导注意转移; 注视线索通过影响特征抽取、而非特征整合阶段, 对客体加工产生易化。本研究支持注视线索提示效应属于内源性注意的观点。     

Direct selection by color for visual encoding

In two experiments, we used rapid serial visual presentation tasks to examine the usefulness of color for the direct selection of visual information for perceptual encoding. The participants' task was to make a discrimination as to whether a target letter within a rapid sequence appeared in its upper- or lowercase version, and an advance cue indicated the color in which the target letter was most likely to occur. To maximize the usefulness of the cued color, in validly cued trials, we used sequences in which the target was the only item appearing in the cued color. In both experiments, accuracy was highest for validly cued trials. A cost-benefit analysis revealed a facilitory effect of valid cues and an inhibitory effect of invalid ones. These results support the idea that color cuing allows the direct selection of objects for further perceptual processing.     

Automatic and voluntary control of attention in young and older adults

Young and older adults searched for a target character in a 3-item display. On each trial, both a symbolic cue (arrow at fixation) and a spatial cue (abrupt onset of one item) could indicate the target's position. Participants were told to use the central arrow cue on all trials because it had 75% validity. The onset cue also had 75% validity for half the participants and 25% validity for the other half. Both age groups showed about the same cost and benefit effects for the central arrow cues, but the abrupt onsets had much larger cuing effects for older adults. Young adults were able to suppress at least partially an automatic attentional response to an abrupt onset item when the arrow cue preceded the onset and had a higher validity than the onset cue. Older adults appeared to be less able to inhibit their responses to abrupt onsets and to disengage their attention from invalid onset cues than were the young adults.     

Using response time distributions to examine top-down influences on attentional capture

Three experiments examined contingent attentional capture, which is the finding that cuing effects are larger when cues are perceptually similar to a target than when they are dissimilar to the target. This study also analyzed response times (RTs) in terms of the underlying distributions for valid cues and invalid cues. Specifically, an ex-Gaussian analysis and a vincentile analysis examined the influence of top-down attentional control settings on the shift and skew of RT distributions and how the shift and the skew contributed to the cuing effects in the mean RTs. The results showed that cue/target similarity influenced the size of cuing effects. The RT distribution analyses showed that the cuing effects reflected only a shifting effect, not a skewing effect, in the RT distribution between valid cues and invalid cues. That is, top-down attentional control moderated the cuing effects in the mean RTs through distribution shifting, not distribution skewing. The results support the contingent orienting hypothesis (Folk, Remington, & Johnston, Journal of Experimental Psychology: Human Perception and Performance, 18, 1030–1044, 1992) over the attentional disengagement account (Theeuwes, Atchley, & Kramer, 2000) as an explanation for when top-down attentional settings influence the selection of salient stimuli.     

Aging and shifts of visual spatial attention.

Three experiments examined adult age differences in the efficiency of endogenous (voluntary) and exogenous (involuntary) attention shifts. Younger and older subjects performed a spatial cuing task in which abruptly onset peripheral cues (Experiment 1) or central, symbolic cues (Experiments 2 and 3) were presented before a target stimulus at intervals ranging from 50 to 250 ms. With peripheral cues, the magnitude of cuing effects was at least as great for older as for younger adults and followed a similar time course. Similar results were obtained with symbolic cues, although cuing effects for older adults varied with cue difficulty. The results suggest that cue encoding may decline with advancing age but that the efficiency of the shift process is preserved.     

“Sensory gating” as a mechanism for visuospatial orienting: Electrophysiological evidence from trial-by-trial cuing experiments

Stimuli at attended-to locations in visual space are usually detected with higher speed and accuracy than stimuli at unattended positions. It has been argued that this effect is due to “sensory gating” mechanisms that modulate the flow of perceptual information from attended and unattended positions. In the present experiments, event-related potentials (E32Ps) were recorded to stimuli that were preceded either by a valid or by an invalid positional cue (trial-by-trial cuing). When overt responses were required only to infrequent target stimuli in valid trials (Experiment 2) or to all validly cued stimuli (Experiment 2B), but not to invalid trials, systematic enhancements of early sensory-evoked potentials were found. These effects were smaller when both validly and invalidly cued stimuli required a response (Experiment 2A). These findings are interpreted as evidence that sensory gating processes are activated during the trial-by-trial suing of spatial attention. Furthermore, valid stimuli elicited a greater negativity than invalid stimuli at midline electrodes following the early enhancements of sensory-evoked potentials. This possibly reflects an additional enhanced processing of attended-to locations.     

Configural Processing in Memory Retrieval: Multiple Cues and Ensemble Representations

When retrieving information from memory, a number of contextual cues may interact to determine which ideas will be easily accessible. Even the simplest case in which joint cue action obtains (two cues) is very revealing of the principles of memory access and representation of compounds. Mechanisms by which dual cues interact to constrain retrieval from episodic memory are considered. A holistic mechanism of cue integration is contrasted with two nonholistic mechanisms: a multiplicative or intersection mechanism and an independent-contributions mechanism. Holistic- and intersection-cuing mechanisms are consistent with different variants of compound cue models of priming. The independent cuing mechanism is consistent with spreading activation models of priming. Data from four experiments which examined dual-cued recognition of items from (newly learned) triples demonstrated strongly configural, holistic, action of dual cues. The two cues and test item must form an encoded compound to yield cuing advantages. Two independent cues to the test item are ineffective if the two cues and test were not learned together as a triple; one valid and one invalid cue are also ineffective. This is so despite the availability of pairwise information for each cue–test relation, and despite the fact that these cues are effective when operating alone. A compound cue model which predicts precisely this surprising pattern of priming is developed. The compound cue model also predicts previously obtained configural priming of associative judgments, as well as the bias priming generally observed in item recognition and similar paradigms.     

Of guns and snakes: testing a modern threat superiority effect*

Previous studies suggest that ancient (i.e. evolutionary-based) threats capture attention because human beings possess an inborn module shaped by evolution and dedicated to their detection. An alternative account proposes that a key feature predicting whether a stimulus will capture attention is its relevance rather than its ontology (i.e. phylogenetic or ontogenetic threat). Within this framework, the present research deals with the attentional capture by threats commonly encountered in our urban environment. In two experiments, we investigate the attentional capture by modern threats (i.e. weapons). In Experiment 1, participants responded to a target preceded by a cue, which was a weapon or a non-threatening stimulus. We found a larger cuing effect (faster reaction times to valid vs. invalid trials) with weapons as compared with non-threatening cues. In Experiment 2, modern (e.g. weapons) and ancient threats (e.g. snakes) were pitted against one another as cues to determine which ones preferentially capture attention. Crucially, participants were faster to detect a target preceded by a modern as opposed to an ancient threat, providing initial evidence for a superiority of modern threat. Overall, the present findings appear more consistent with a relevance-based explanation rather than an evolutionary-based explanation of threat detection.     

On the spatial metric of short-SOA costs of exogenous cuing

When the stimulus onset asynchrony (SOA) between the cue and the target is short, exogenous spatial cues usually produce a response time benefit. However, consistent with several recent studies, we have found that a short stimulus onset asynchrony is not sufficient. At least one more factor--the number of cue and target locations--also plays a role. Even more interesting, when 8 cue and target locations are used, the effect of an exogenous cue produces a cost on valid cue trials, and the spatial metric of this negative cuing effect depends on whether the cue remains visible at target onset.     

工作记忆中的部分线索效应:任务呈现方式的影响

以往研究主要在长时记忆中考察部分线索效应,很少关注工作记忆中的部分线索效应及其作用机制。本研究采用项目再认任务,考察了工作记忆中提供部分学习项目作为提取线索,对存储在工作记忆中的已有表征的影响。结果发现：有、无部分线索试次分组呈现时,相较于无部分线索条件,有部分线索条件下再认正确率和d'降低,β升高,反应时间延长;有、无部分线索试次随机混合呈现时,有部分线索条件下再认正确率降低,β升高,但反应时间并无显著延长。结果表明：工作记忆中部分线索的提供降低了目标项目的表征强度;研究结果可用提取抑制假说解释,但工作记忆中部分线索的作用可能受注意资源有限性制约。     

Microsaccadic modulation of response times in spatial attention tasks

Covert shifts of attention are usually reflected in RT differences between responses to valid and invalid cues in the Posner spatial attention task. Such inferences about covert shifts of attention do not control for microsaccades in the cue-target interval. We analyzed the effects of microsaccade orientation on RTs in four conditions, crossing peripheral visual and auditory cues with peripheral visual and auditory discrimination targets. Reaction time was generally faster on trials without microsaccades in the cue-target interval. If microsaccades occurred, the target-location congruency of the last microsaccade in the cue-target interval interacted in a complex way with cue validity. For valid visual cues, irrespective of whether the discrimination target was visual or auditory, target-congruent microsaccades delayed RT. For invalid cues, target-incongruent microsaccades facilitated RTs for visual target discrimination but delayed RT for auditory target discrimination. No reliable effects on RT were associated with auditory cues or with the first microsaccade in the cue-target interval. We discuss theoretical implications on the relation about spatial attention and oculomotor processes.     

Attentional shifts to emotionally charged cues: Behavioural and erp data

Abstract

When information activated in memory involves emotional associations, the ability to shift attention away from an emotional cue is impaired compared to an emotionally neutral cue. The purpose of the present study was to investigate how emotional stimuli modulate attentional processes, and how this is reflected in localised brain electrical activity. Eight emotion and eight neutral words served as cues in a covert attention spatial orienting task. The cues were either valid or invalid indicators of which hemifield the target would be presented to. In the remaining trials, no cue was presented prior to the target. Twenty subjects were instructed to manually respond to the target as fast as possible. Event-related potentials (ERPs) showed an enhanced P3 component to the emotion words. The ERPs to the target showed enhanced P1 and P3 components on invalid trials, with emotional cues. There were faster reaction times (RTs) to validly cued targets, but only when the emotion words served as cues. The results demonstrated that the emotional cues elicited sustained focused attention, facilitating an engage mechanism of spatial orienting.     

Problems inhibiting attentional capture by irrelevant stimuli in patients with frontotemporal dementia

We studied the role of the frontal lobes in orienting spatial attention and inhibiting attentional capture by goal-irrelevant stimuli, using a spatial cueing method in patients with frontotemporal dementia (FTD). Two blocks of trials were presented, one with non-predictive cues and the other with counter-predictive cues. FTD patients showed a global orienting deficit, with a greater difference between invalid and valid trials than age-matched controls. However, they were able to use the (counter-) predictiveness of the cue to reduce the invalid/valid difference when targets occurred most often in the location opposite the cue. Thus, endogenous control of attention in our FTD patients was sufficient to reorient attention on the basis of the probability of events, but not to resist the capture of attention by goal-irrelevant stimuli. These results confirm the role of frontal lobes in the inhibition of attentional capture.