Inhibitory effects of repeating color and shape: inhibition of return or repetition blindness?

There is a current debate regarding whether attention is influenced by stimulus attributes other than location. The present article replicates and extends previous findings that repeating the nonspatial attribute of color leads to a delay in target detection (M. B. Law, J. Pratt, & R. A. Abrams, 1995). Repetition disadvantage effects were found for the stimulus attributes of both color and shape, as well as for location. However, the nonspatial repetition disadvantage disappeared if the stimuli were presented in peripheral locations (Experiments 3a, 3b, and 4) or the cue was presented for 50 ms (Experiment 6). Moreover, the magnitude of the repetition disadvantage tended to decline as the cue-target stimulus-onset asynchrony increased (Experiments 5a, 5b, and 6). These results suggest that a repetition blindness mechanism may underlie the repetition disadvantage effects of nonspatial features, rather than an inhibition of return mechanism.     

Inhibition of return is composed of attentional and oculomotor processes.

Response time can be delayed if a target stimulus appears at a location or object that was previously cued. This inhibition of return (IOR) phenomenon has been attributed to a delay in activating attentional or motor processes to a previously cued stimulus. Two experiments required subjects to localize or identify a target stimulus. In Experiment 1, the subjects' eyes were not monitored. In Experiment 2, the subjects' eyes were monitored, and the subjects were instructed to either execute or withhold an eye movement to a target stimulus. The results indicated that IOR was always present for location and identification responses, supporting an attentional account of IOR. However, IOR was larger when eye movements were executed, indicating that a motor component can contribute to IOR. Finally, when eye movements were withheld, IOR was larger when a target was presented alone than when it was presented with a distractor, suggesting that IOR is larger for exogenous than for endogenous covert orienting. Together, the data indicate that IOR is composed of both an oculomotor component and an attentional component.     

Inhibition of return is composed of attentional and oculomotor processes

Response time can be delayed if a target stimulus appears at a location or object that was previously cued. This inhibition of return (IOR) phenomenon has been attributed to a delay in activating attentional or motor processes to a previously cued stimulus. Two experiments required subjects to localize or identify a target stimulus. In Experiment 1, the subjects’ eyes were not monitored. In Experiment 2, the subjects’ eyes were monitored, and the subjects were instructed to either execute or withhold an eye movement to a target stimulus. The results indicated that IOR was always present for location and identification responses, supporting an attentional account of IOR. However, IOR was larger when eye movements were executed, indicating that a motor component can contribute to IOR. Finally, when eye movements were withheld, IOR was larger when a target was presented alone than when it was presented with a distractor, suggesting that IOR is larger for exogenous than for endogenous covert orienting. Together, the data indicate that IOR is composed of both an oculomotor component and an attentional component.     

Inhibition of return for target discriminations: the effect of repeating discriminated and irrelevant stimulus dimensions

Inhibition of return (IOR) refers to slowed reaction times when a target repeats in the same location as a preceding stimulus. In four experiments, the participants were presented with two successive stimuli, S1 and S2. In Experiments 1 and 2, the participants made a speeded discrimination of the identity or orientation of both S1 and S2 (Experiment 1) or of S2 only (Experiment 2). An IOR effect occurred for the repetition of stimulus location, but a facilitatory effect occurred if the stimulus remained unchanged or if an overt response was repeated. In Experiments 3 and 4, the participants localized S1 and S2 (Experiment 3) or S2 only (Experiment 4) to the left or right of center. In this case, repeating the same stimulus had no effect: IOR occurred any time stimulus location repeated. These results demonstrate that the expression of IOR is modulated by the repetition of a target object, but only when the task requires the discrimination of that object; when no discrimination is required, IOR is unaffected.     

The importance of irrelevant-dimension variability in the stroop flanker task

Two experiments in which the Stroop flanker task was used were conducted in order to examine the influence of irrelevant dimension invariance on congruency effects. Participants responded manually to a central color patch flanked by a Stroop stimulus. In Experiment 1, invariance in flanker location was found to have no influence on word and color congruency effects. In contrast, invariance of flanker identity led to the disappearance of congruency effects. Experiment 2 indicated that the elimination of a congruency effect was restricted to the dimension that remained constant and did not influence the congruency effect of the other dimension that was presented at the same location. Results suggest that variance is a prerequisite to congruity effects, determining the activation of irrelevant dimensions.     

Attending, ignoring, and repetition: on the relation between negative priming and inhibition of return

A series of spatial localization experiments is reported that addresses the relation between negative priming and inhibition of return. The results of Experiment 1 demonstrate that slowed responses to repeated location stimuli can be obscured by repetition priming effects involving stimulus dimensions other than spatial location. The results of Experiments 2, 3A, and 3B demonstrate that these repetition priming effects may occur only when participants are required to respond to the prime display. Together, these results suggest that differences between attended and ignored repetition effects in selective attention studies of spatial localization do not provide a basis for distinguishing between spatial negative priming and inhibition of return.     

Stroop interference is affected in inhibition of return

In previous research, we have shown that the processing of targets that are presented to locations subject to inhibition of return (IOR) is affected by an inhibitory tagging mechanism. This mechanism acts by disconnecting activated representations of stimuli at inhibited locations from their associated responses. In two experiments, we assessed whether this inhibitory tagging mechanism of visual attention is also applied to task-irrelevant but prepotent dimensions of target stimuli, such as words in the Stroop task. To test this hypothesis, we examined the Stroop effect in an IOR procedure. The results showed that (1) IOR can be found in a color discrimination task, (2) the Stroop interference was reduced (Experiment 1) or eliminated (Experiment 2) when stimuli appeared at cued locations, as compared with cases in which they were presented at uncued locations, and (3) the effect of inhibitory tagging was limited to the shortest stimulus onset asynchrony value, replicating previous findings. These results agree with the idea that inhibitory tagging, occurring in IOR, affects the efficiency with which color words compete for responses in Stroop-like situations.     

Flexibility of attention between stimulus dimensions

Three experiments examined the flexibility of attention to the color and location dimensions of visual stimuli. Displays typically consisted of two curved lines, one a target and the other a distractor. Subjects were precued to the location of the target, and they made a speeded response to that item’s direction of curvature. In Experiment 1, a color difference between the stimuli facilitated selective attention to targets. Experiment 2 demonstrated that this effect was not automatic. Although component color differences were necessary for selective attention, they were not sufficient unless they reliably specified the target. Furthermore, when color was informative but the target was in an unexpected color, performance was markedly impaired. A third experiment, using a response-deadline technique, showed that stimulus color was resolved before stimulus location and that attention can be exclusive to the color dimension. The results were interpreted in terms of a model assuming that stimulus color and location are processed independently. Subjects attend to the dimension resolved most quickly which can reliably specify the target.     

Priming and intrusion errors in RSVP streams with two response dimensions

Loach and Marí-Beffa (Vis Cogn, 10:513-526, 2003) observed that a distractor stimulus, presented immediately after a behaviorally relevant target stimulus, negatively primed a related probe stimulus indicating that the distractor had been inhibited. They argued that "post-target inhibition" may be a mechanism for preventing interference from temporally proximal stimuli; interference that could potentially result in a binding/intrusion error. In order to test this hypothesis, the authors carried out two rapid serial visual presentation (RSVP) experiments in which participants had to report either the identity (Experiment 1) or color (Experiment 2) of a target letter surrounded by distractor letters. In Experiment 1, a close relationship between priming and errors was observed. When a distractor stimulus showed evidence of being inhibited the participant was less likely to commit a binding error. The opposite was true when a distractor stimulus showed evidence of being facilitated. The results of Experiment 2 showed limited evidence of the same relationship.     

Impaired color word processing at an unattended location: Evidence from a Stroop task combined with inhibition of return

A Stroop task with separate color bar and color word stimuli was combined with an inhibition-of-return procedure to examine whether visual attention modulates color word processing. In Experiment 1, the color bar was presented at the cued location and the color word at the uncued location, or vice versa, with a 100- or 1,050-msec stimulus onset asynchrony (SOA) between cue and Stroop stimuli. In Experiment 2, on Stroop trials, the color bar was presented at a central fixated location and the color word at a cued or uncued location above or below the color bar. In both experiments, with a 100-msec SOA, the Stroop effect was numerically larger when the color word was displayed at the cued location than when it was displayed at the uncued location, but with the 1,050-msec SOA, this relation between Stroop effect magnitude and location was reversed. These results provide evidence that processing of the color word in the Stroop task is modulated by the location to which visual attention is directed.     

Effects of similarity of location and temporal intensity pattern of conditioned and unconditioned stimuli on the acquisition of conditioned suppresion in rats.

This article two studies that examined the effect of similarity of location and temporal intensity patterns of the conditioned stimulus (CS) and the unconditioned stimulus (UCS) on the acquision of conditioned suppression. Experiment 1 showed that greater suppression occurs during a stimulus generalization test when the tested stimulus has a location and temporal intensity pattern that is similar to the previously presented UCS. Experiment 2 showed that conditioned suppression is acquired more rapidly if the CS and UCS have similar locations and temporal intensity patterns. These similarity factors were interpreted as forms of event covariation, which aided in associative formation. Several applications of these data are discussed.     

The influence of a distractor during compound preexposure on latent inhibition

Nonreinforced exposure to a nontarget stimulus that was followed by nonreinforced exposure to a target/nontarget simultaneous compound stimulus resulted in enhanced latent inhibition of the target. Conditioning was slower after this treatment than after nonreinforced exposure to the target stimulus alone (Experiment 1). However, a salient auditory stimulus presented immediately after the compound in the second phase reduced levels of latent inhibition, relative to the enhanced latent inhibition produced when no such extracompound stimulus was presented (Experiments 2 and 3). This effect was not noted if the salient auditory cue was presented 10 sec after the termination of the compound stimulus (Experiment 4). In Experiment 5, there was no disruption of simple latent inhibition produced by a salient stimulus. These results are consistent with enhanced latent inhibition's being produced by the formation of within-compound associations, which are disrupted by the salient extracompound stimuli.     

Age differences in response selection for pure and mixed stimulus-response mappings and tasks

Two experiments examined effects of mixed stimulus-response mappings and tasks for older and younger adults. In Experiment 1, participants performed two-choice spatial reaction tasks with blocks of pure and mixed compatible and incompatible mappings. In Experiment 2, a compatible or incompatible mapping was mixed with a Simon task for which the mapping of stimulus color to location was relevant and stimulus location was irrelevant. In both experiments, older adults showed larger mixing costs than younger adults and larger compatibility effects, with the differences particularly pronounced in Experiment 1 when location mappings were mixed. In mixed conditions, when stimulus location was relevant, older adults benefited more than younger adults from complete repetition of the task and stimulus from the preceding trial. When stimulus location was irrelevant, the benefit of complete repetition did not differ reliably between age groups. The results suggest that the age-related deficit associated with mixing mappings and tasks is primarily due to older adults having more difficulty separating task sets that activate conflicting response codes.     

Active inhibition of a distractor word: the distractor precue benefit in the Stroop color-naming task

The current study investigated attentional control through active inhibition of the identity of the distractor. Adapting a Stroop paradigm, the distractor word was presented in advance and made to disappear, followed by the presentation of a Stroop stimulus. Participants were instructed to inhibit the distractor in order to reduce its interference. Experiments 1 and 2 demonstrated that the distractor precue facilitated Stroop color naming by reducing Stroop interference. Experiment 3 demonstrated beneficial effects of the distractor precue when congruent trials were introduced. Experiment 4 showed that the distractor precue benefit was observed when the cue and target were in different forms. Experiment 5 indicated that if the item used as the cue became the target, naming it took longer in order to overcome the inhibitory effect. Experiment 6 demonstrated that the benefit of the distractor precue was not observed when the cue was uninformative. Finally, Experiment 7 demonstrated that active inhibition required working-memory resources to operate. This study suggests that the best explanation for the distractor precue benefit is the active inhibition account.     

Consequences of allocating attention to locations and to other attributes

Simple reaction time to a light target may be lengthened when the light is preceded by a nonin-formative s timulus at the same location. This is known asinhibition of return. Does inhibition of return result if the relation between successive stimuli is defined in terms of color or orientation? Subjects pressed a key when a small square was displayed. In Experiments 1–3, location and color of the square were manipulated; there was inhibition of return based on location, but not on color. In Experiments 4–5, a confounding of color and luminance was eliminated, with no change in results. In Experiments 6–7, the background was composed of vertical stripes and the squares were composed of left- or right-oriented diagonal stripes. There was evidence of inhibition of return based on location, but not on orientation. These data support the idea that location is processed differently from other features.     

The Impact of Stimuli Color in Lexical Decision and Semantic Word Categorization Tasks

In two experiments, we examined the impact of color on cognitive performance by asking participants to categorize stimuli presented in three different colors: red, green, and gray (baseline). Participants were either asked to categorize the meaning of words as related to the concepts of “go” or “stop” (Experiment 1) or to indicate if a neutral verbal stimulus was a word or not (lexical decision task, Experiment 2). Overall, we observed performance facilitation in response to go stimuli presented in green (vs. red or gray) and performance inhibition in response to go stimuli presented in red. The opposite pattern was observed for stop‐related stimuli. Importantly, results also indicated that color might also be used to categorize neutral stimuli. Overall, these findings provide support to the green‐go and red‐stop color associations and test the potential functional autonomy acquired by these colors and the boundary conditions to their effects on stimuli categorization.     

特征和位置信息在价值驱动注意捕获中的作用

本研究采用训练−测试范式考察颜色和位置信息在价值驱动注意捕获中的作用。实验1考察是否存在基于具体位置的价值驱动的注意捕获效应。在训练阶段, 被试对8个位置中两个位置出现的红色目标反应伴随着高奖励反馈, 而对另外两个位置出现的红色目标反应伴随着低奖励反馈, 其它4个位置为中性位置, 没有目标出现。在测试阶段, 一半试次中红色刺激作为分心物出现。结果发现, 只有当分心刺激出现在高奖励位置和两个高奖励位置之间的中性位置时才能够捕获注意; 实验2考察颜色和位置信息在价值驱动注意捕获中的交互作用。在训练阶段, 将颜色特征和位置信息联合起来进行学习。在测试阶段, 和高、低奖励相联结的颜色刺激各在1/3试次中作为分心物出现。结果发现, 只有当高奖励颜色出现在高奖励位置或出现在高奖励位置之间的中性位置时才能够捕获注意。研究结果表明：(1)位置联结的价值驱动的注意捕获效应能够泛化到特定邻近位置上; (2)个体在训练阶段将颜色和位置的联合特征与奖励建立联结, 训练阶段建立的联结不能泛化到部分特征上。价值驱动注意捕获效应的泛化具有选择性。     

Sequential analysis of a Simon task--evidence for an attention-shift account

 We investigated the attention-shift hypothesis of the Simon effect by analysing the effect of repeating relevant colour or irrelevant location of the stimulus in four serial reaction time tasks. In Experiment 1 with short response-stimulus intervals (RSI), we assume that there is no time to engage attention at the fixation cross before the onset of a new stimulus. In agreement with the hypothesis, Experiment 1 reveals no Simon effect when the stimulus location is repeated. In Experiment 2 with long RSI, we observe a Simon effect for location repetitions and alternations. In Experiment 3 with long RSI, we hinder the disengagement of attention by displaying the stimulus after response execution. As expected, the Simon effect is reduced for location repetitions. In Experiment 4 with stimuli additionally presented at the fixation cross, responses are faster if the attention shift towards the centrally presented stimulus corresponds with the location of the required response. Additionally, we argue that binding of the stimulus features into an object or event file better explains the so-called blocking of the automatic response-priming route after a noncorresponding trial. Received: 2 February 2000 / Accepted: 10 November 2000     

Response-effect compatibility in manual choice reaction tasks

This study investigated whether compatibility between responses and their consistent sensorial effects influences performance in manual choice reaction tasks. In Experiment 1 responses to the nonspatial stimulus attribute of color were affected by the correspondence between the location of responses and the location of their visual effects. In Experiment 2, a comparable influence was found with nonspatial responses of varying force and nonspatial response effects of varying auditory intensity. Experiment 3 ruled out the hypothesis that acquired stimulus-effect associations may account for this influence of response-effect compatibility. In sum, the results show that forthcoming response effects influence response selection as if these effects were already sensorially present, suggesting that in line with the classical ideomotor theory, anticipated response effects play a substantial role in response selection.     

Irrelevant auditory attention shifts prime corresponding responses

In this paper we investigate whether an attention shift towards an auditory signal, while performing a two-choice serial reaction time task, primes responses in the direction of the auditory signal. In Experiment 1, subjects had to react to the pitch of the signal, which was randomly presented to the left or right ear. A short (50-ms) and a long (1000-ms) response-stimulus interval (RSI) was used. In Experiment 2 with an RSI of 2000 ms, subjects had to respond to the color of a centrally presented visual stimulus, while a sound was presented to one of the ears. In the short RSI condition of Experiment 1, there was a Simon effect for location alternations only. In the long RSI condition, there was a Simon effect for location repetitions and alternations. Experiment 2 showed a Simon effect in relation to the accessory sound. The results of this study suggest that an attention shift is a sufficient and necessary condition in order to observe a Simon effect. Preparation of this article was supported by a grant from the National Fund for Scientific Research, Flanders, Belgium (FWO-VL G.0009.99)