A Simon effect for stimulus-response duration

A non-spatial variant of the Simon effect for the stimulus-response (S-R) feature of duration is reported. In Experiment 1 subjects were required to press a single response key either briefly or longer in response to the colour of a visual stimulus that varied in its presentation duration. Short keypresses were initiated faster with short than with long stimulus duration whereas the inverse was observed with long keypresses. In Experiment 2 subjects were required to press a left or right key (according to stimulus form) either briefly or longer (according to stimulus colour). The stimuli concurrently varied in their location (left or right) and duration (short or long), which were both task irrelevant. Approximately additive correspondence effects for S-R location and S-R duration were observed. To summarize, the results suggest that the irrelevant stimulus features of location and duration are processed automatically and prime corresponding responses in an independent manner.     

The influence of irrelevant stimulus changes on stimulus and response repetition effects

In this study the influence of irrelevant stimulus changes from one trial to another in a serial reaction time task was investigated. Two experiments were performed in which subjects were required to respond to stimulus colour. Four colours were mapped on two response keys, so that colour and response repetition effects could be dissociated. In Experiment 1, the irrelevant stimulus dimension was location and in Experiment 2 it was shape. Both experiments were performed with a short and a long response-stimulus interval (RSI)-condition. In both experiments, the irrelevant dimension influenced the response repetition effect but not the colour repetition effect. In the reaction times, a response alternation effect was observed only when the irrelevant location of the stimulus changed in the long RSI-condition. The error rates showed a response alternation benefit for both irrelevant dimensions, in the short and the long RSI-condition. The benefit for response alternations is explained in terms of a response bias towards change that is triggered by a changing stimulus feature. We assume that the response bias is stronger for location than for colour and that accuracy is more sensitive to this bias than response latencies.     

Feature binding in visual short-term memory is unaffected by task-irrelevant changes of location,shape, and color

Three experiments used a change detection paradigm across a range of study–test intervals to address the respective contributions of location, shape, and color to the formation of bindings of features in sensory memory and visual short-term memory (VSTM). In Experiment 1, location was designated task irrelevant and was randomized between study and test displays. The task was to detect changes in the bindings between shape and color. In Experiments 2 and 3, shape and color, respectively, were task irrelevant and randomized, with bindings tested between location and color (Experiment 2) and location and shape (Experiment 3). At shorter study–test intervals, randomizing location was most disruptive, followed by shape and then color. At longer intervals, randomizing any task-irrelevant feature had no impact on change detection for bindings between features, and location had no special role. Results suggest that location is crucial for initial perceptual binding but loses that special status once representations are formed in VSTM, which operates according to different principles, than do visual attention and perception.     

Working memory binding of visual object features in older adults

Accurate mental representation of visual stimuli requires retaining not only the individual features but also the correct relationship between them. This associative process of binding is mediated by working memory (WM) mechanisms. The present study re-examined reports of WM-related binding deficits with aging. In Experiment 1, 31 older and 31 younger adults completed a visual change detection task with feature–location relations presented either simultaneously or sequentially; the paradigm was also designed specifically to minimize the impact of lengthy retention intervals, elaborative rehearsal, and processing demands of multi-stimulus probes. In Experiment 2, 38 older and 42 younger adults completed a modified task containing both feature–location relations and feature–feature conjunctions. In Experiment 1 although feature–location binding was more difficult with sequential compared with simultaneous presentation, the effect was independent of age. In Experiment 2 while older adults were overall slower and less accurate than young adults, there were no age-specific deficits in WM binding. Overall, after controlling for methodological factors, there was no evidence of an age-related visual WM binding deficit for surface or location features. However, unlike younger adults, older adults appeared less able to restrict processing of irrelevant features, consistent with reported declines with age in strategic capacities of WM.     

May I have your attention please: Binding of attended but response-irrelevant features

The feature codes of stimuli and responses can be integrated, and if a stimulus is repeated it can retrieve the previously integrated response. Furthermore, even irrelevant features can be integrated and, upon repetition, retrieve the response. Yet the role of attention in feature integration and retrieval is not clearly understood. Some theories assume a central role of attention (e.g., Logan, 1988; Treisman & Gelade, 1980), but other studies have shown no influence of attention on feature binding (e.g., Hommel, 2005). In the present experiments the effect of attention on the integration of two different response-irrelevant features of the same stimulus was examined. In two experiments, participants responded to the color (response feature) of word stimuli, while two irrelevant features of the words (word type and valence) were systematically varied. Participants’ attention was directed to either one or the other of the response-irrelevant features by asking participants to report that feature at the end of the trial. Feature–response binding effects in the color task were observed to be stronger for the attended response-irrelevant feature. These results indicate that feature binding is not only very flexible but also sensitive to the distribution of attention. It is also automatic, in the sense that as long as attention is available, feature binding occurs irrespective of the task-specific demands.     

Transfer of response codes from choice-response to go/no-go tasks

The present study investigated the conditions for observing the Simon effect in go/no-go tasks. The Simon effect denotes faster and more accurate responses when irrelevant stimulus location and response location correspond than when they do not correspond. In four experiments, participants performed both in a choice-response task (CRT) and in a go/no-go task, and we varied the order and the similarity of the tasks. In the CRT, participants pressed a left key to one stimulus colour and a right key to another stimulus colour; in the go/no-go task, participants pressed one (e.g., left) key to one stimulus colour and refrained from responding to the other stimulus colour. As expected, Simon effects were consistently observed in the CRT. In contrast, Simon effects in the go/no-go task were only observed when it followed the CRT and when the mapping of stimulus colours to response locations was preserved between tasks (i.e., in Experiment 4). Results suggest that transfer of a particular S–R rule including response location from the CRT to the go/no-go task was responsible for the Simon effect in the latter task. In general, results are consistent with a response-discrimination account of the Simon effect.     

Feature saliency affects delayed matching of an attended feature

We examined how top-down attentional modulation and bottom-up stimulus saliency interact with feature memory. Experiment 1 used a delayed-matching-to-sample (DMS) task to examine the relative saliency between features by observing the relative accuracy of recognition at different stimulus durations. Feature salience decreased according to the following order: colour, form, and texture. In a modified DMS task (Experiments 2 and 3), participants were required to attend to one of three features and ignore the others. After a delay, they were required to choose which of the two test stimuli matched the reference stimulus on the attended feature, disregarding other task-irrelevant features. The target was either identical to the reference stimulus or mismatched the reference stimulus on one of the irrelevant features. The results showed that colour matching was affected neither by a form change nor by a texture change. Form matching was affected by a colour change, and texture matching was affected by a colour or form change. These results are consistent with the relative saliency hypothesis. Even when all features of an attended object are maintained, a relatively more salient task-irrelevant feature can interfere with the delayed recognition of a less salient feature.     

Configural encoding in visual feature binding

The role of configural encoding in feature binding was assessed using the change detection paradigm. Experiment 1 studied the relevance of location in colour–shape binding with study–test intervals ranging from 0 to 4100 ms. Location was rendered irrelevant by randomising it from study to test display or was kept unchanged from study to test. Results revealed differences between these two conditions at 0 and 200 ms, but not at 1500, 2800, and 4100 ms, suggesting that location was important for feature binding in the initial stages, but performance at longer study–test intervals was impervious to change in locations. Experiment 2 studied the effect of increasing the study-display duration by comparing performance with display durations of 200, 900, and 1500 ms, at the study test intervals of 0 and 2000 ms. Although, there was a general increase in the level of performance with increasing display duration, the interaction effect obtained in Experiment 1 was replicated. Experiments 3 and 4 studied the effect of sequential presentation of stimuli, otherwise retaining the design and procedure of Experiment 2. Different levels of performance in Experiments 2, 3, and 4 revealed the role of configural encoding in the binding process.     

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     

Acquiring conjunctive concepts: When and why does feature frequency affect feature identification?

According to frequency theories of concept attainment, acquisition of rule-governed concepts depends on discriminating relevant from irrelevant stimulus features on the basis of their respective frequencies of occurrence. Depending on the theorist, the critical frequency counts may be based on occurrence in all stimuli or on occurrence in positive instances only. Experiment 1 held frequency in positive instances constant and varied the frequency of irrelevant features in the negative category. High frequency was associated with impaired performance, but only when concept problems started with a negative instance. Experiment 2 demonstrated that some previous findings in the literature that were thought to support frequency theory also depended on problems starting with a negative instance. These findings are not easily reconciled with existing frequency theories. We attribute our results to high intercategory similarity, which is a correlate of high frequency of irrelevant features. In the context of a hypothesis-testing theory, we propose that a negative start stimulus proactively interferes with memory for information in the initial positive instance and that the extent of the interference depends on how similar negative instances are to positive instances.     

Further evidence that object-based correspondence effects are primarily modulated by object location not by grasping affordance

Tipper, Paul and Hayes found object-based correspondence effects for door-handle stimuli for shape judgments but not colour. They reasoned that a grasping affordance is activated when judging dimensions related to a grasping action (shape), but not for other dimensions (colour). Cho and Proctor, however, found the effect with respect to handle position when the bases of the door handles were centred (so handles were positioned left or right; the base-centred condition) but not when the handles were centred (the object-centred condition), suggesting that the effect is driven by object location, not grasping affordance. We conducted an independent replication of Cho and Proctor's design, but with behavioural and event-related potential measures. Participants made shape judgments in Experiment 1 and colour judgments in Experiment 2 on the same door-handle objects. Correspondence effects on response time and errors were obtained in both experiments for the base-centred condition but not the object-centred condition. Effects were absent in the P1 and N1 data, which are consistent with the hypothesis of little binding between visual processing of grasping component and action. These findings question the grasping-affordance view but support a spatial-coding view, suggesting that correspondence effects are modulated primarily by object location.     

Dimensional interactions in language processing: investigating directions and levels of crosstalk

In this article we evaluate current models of language processing by testing speeded classification of stimuli comprising one linguistic and one nonlinguistic dimension. Garner interference obtains if subjects are slower to classify attributes on one dimension when an irrelevant dimension is varied orthogonally than when the irrelevant dimension is held constant. With certain linguistic-nonlinguistic pairings (e.g., Experiment 1: the words high and low spoken either loudly or softly), significant Garner interference obtained when either dimension was classified; this indicated two-directional crosstalk. With other pairings (e.g., Experiment 3: spoken vowels and loudness), only the nonlinguistic dimension (e.g., loudness) displayed interference, suggesting unidirectional crosstalk downstream from a phonemic/graphemic level of analysis. Collectively, these results indicate the interaction can occur either within or across levels of information processing, being directed toward either more advanced or more primitive processes. Although poorly explained by all current models of language processing, our results are strikingly inconsistent with models that posit autonomy among levels of processing.     

Asymmetry of attentional set in rhesus monkeys learning colour and shape discriminations

We trained rhesus monkeys on six visual discrimination problems using stimuli that varied in both shape and colour. For one group of animals shape was always relevant in these six problems, and colour always irrelevant, and for the other animals vice versa. During these “intradimensional shifts” (ID) the problems were learned at equal rates by the two groups, shape-relevant and colour-relevant. We then trained three further problems in which the other dimension was now relevant (“extradimensional shifts”, ED). The animals showed slower learning when shifting from colour-relevant to shape-relevant, but not when shifting from shape-relevant to colour-relevant. These results show that monkeys' ability to selectively attend to a relevant stimulus dimension and to ignore an irrelevant dimension depends on the experimenter's choice of relevant and irrelevant dimensions.     

Intermodal event files: integrating features across vision,audition, taction,and action

Understanding how the human brain integrates features of perceived events calls for the examination of binding processes within and across different modalities and domains. Recent studies of feature-repetition effects have demonstrated interactions between shape, color, and location in the visual modality and between pitch, loudness, and location in the auditory modality: repeating one feature is beneficial if other features are also repeated, but detrimental if not. These partial-repetition costs suggest that co-occurring features are spontaneously bound into temporary event files. Here, we investigated whether these observations can be extended to features from different sensory modalities, combining visual and auditory features in Experiment 1 and auditory and tactile features in Experiment 2. The same types of interactions, as for unimodal feature combinations, were obtained including interactions between stimulus and response features. However, the size of the interactions varied with the particular combination of features, suggesting that the salience of features and the temporal overlap between feature-code activations plays a mediating role.     

Colour correspondence effects between controlled objects and targets

It is increasingly popular to use movement trajectories as a measure of mental processes related to task performance. Often this is accomplished by moving a cursor to a target on a computer screen. However, the relation between features of the cursor and the targets is rarely, if at all, considered. In five experiments, we examined whether moving a cursor to a target was affected by the relation between their colours, even when this relation was task irrelevant. In Experiments 1–3, a mouse-controlled cursor was moved to one of two coloured targets. Results showed colour correspondence effects in latency to initiate a response, duration of movement times, and movement trajectories when the relationship between cursor and target colours was task relevant (Experiment 1) and when only the cursor colour was task relevant (Experiment 2), but not when only the target was task relevant (Experiment 3). Follow-up experiments using single targets showed that colour correspondence effects occurred as long as attention was dedicated to the colour of the cursor, even when neither the cursor nor the target colour was relevant to selecting the correct movement (Experiments 4 and 5). Furthermore, when the relation between cursor and target colours is task irrelevant, colour correspondence effects for response initiation times are uncorrelated with those for movement times and movement trajectories. We interpret the observed correspondence effect in terms of response coding, although attention cueing may also play a role, and suggest that greater consideration of cursor features is needed when examining movement trajectories in choice reaction tasks.     

Asymmetry of attentional set in rhesus monkeys learning colour and shape discriminations

We trained rhesus monkeys on six visual discrimination problems using stimuli that varied in both shape and colour. For one group of animals shape was always relevant in these six problems, and colour always irrelevant, and for the other animals vice versa. During these "intradimensional shifts" (ID) the problems were learned at equal rates by the two groups, shape-relevant and colour-relevant. We then trained three further problems in which the other dimension was now relevant ("extradimensional shifts", ED). The animals showed slower learning when shifting from colour-relevant to shape-relevant, but not when shifting from shape-relevant to colour-relevant. These results show that monkeys' ability to selectively attend to a relevant stimulus dimension and to ignore an irrelevant dimension depends on the experimenter's choice of relevant and irrelevant dimensions.     

Colour correspondence effects between controlled objects and targets

It is increasingly popular to use movement trajectories as a measure of mental processes related to task performance. Often this is accomplished by moving a cursor to a target on a computer screen. However, the relation between features of the cursor and the targets is rarely, if at all, considered. In five experiments, we examined whether moving a cursor to a target was affected by the relation between their colours, even when this relation was task irrelevant. In Experiments 1-3, a mouse-controlled cursor was moved to one of two coloured targets. Results showed colour correspondence effects in latency to initiate a response, duration of movement times, and movement trajectories when the relationship between cursor and target colours was task relevant (Experiment 1) and when only the cursor colour was task relevant (Experiment 2), but not when only the target was task relevant (Experiment 3). Follow-up experiments using single targets showed that colour correspondence effects occurred as long as attention was dedicated to the colour of the cursor, even when neither the cursor nor the target colour was relevant to selecting the correct movement (Experiments 4 and 5). Furthermore, when the relation between cursor and target colours is task irrelevant, colour correspondence effects for response initiation times are uncorrelated with those for movement times and movement trajectories. We interpret the observed correspondence effect in terms of response coding, although attention cueing may also play a role, and suggest that greater consideration of cursor features is needed when examining movement trajectories in choice reaction tasks.     

Haptic integration of object properties: texture, hardness, and planar contour

Planar objects varying in shape, texture, and hardness were classified under haptic exploration. Classes were defined by values on one dimension, or redundantly, by two or three dimensions. Response times and exploratory procedures (Lederman & Klatzky, 1987) were recorded. Experiment 1 showed that a second dimension speeded responses for all combinations (redundancy gain), but a third dimension produced no further effect. In Experiments 2 and 3, classification trials began with two redundant dimensions, and subsequently one was withdrawn (held constant). When texture and hardness varied redundantly, withdrawal of either increased response time--even when subjects were initially instructed to focus on one dimension. Joint exploration for texture and hardness dominated whenever the two varied redundantly and persisted despite withdrawal. Redundancy gains (Experiment 1), but not substantial withdrawal effects (Experiments 2 and 3), were observed for combinations of texture or hardness with planar contour, indicating less integration than between substance dimensions. Compatibility of exploratory procedures appears to constrain dimensional integration.     

S-R compatibility effects due to context-dependent spatial stimulus coding

Responses are faster with spatial S-R correspondence than with noncorrespondence (spatial compatibility effect), even if stimulus location is irrelevant (Simon effect). In two experiments, we sought to determine whether stimuli located above and below a fixation point are coded as left and right (and thus affect the selection of left and right responses) if the visual context suggests such a coding. So, stimuli appeared on the left or right eye of a face’s image that was tilted by 90° to one side or the other (Experiment 1) or varied between upright and 45° or 90° tilting (Experiment 2). Whether stimulus location was relevant (Experiment 1) or not (Experiment 2), responses were faster with correspondence of (face-based) stimulus location and (egocentrically defined) response location, even if stimulus and response locations varied on physically orthogonal dimensions. This suggests that object-based spatial stimulus codes are formed automatically and thus influence the speed of response selection.     

The development of selective attention: holistic perception versus resource allocation

In two experiments, a speeded sorting task was administered to children. In each sorting, the child was instructed to sort a deck of cards according to values on one dimension while the values of a second irrelevant dimension were held constant, were correlated, or were varied orthogonally. Experiment 1 evaluated developmental changes in perceived structure as compared with such changes in the control of attention. Different groups of kindergarten, 2d-, and 5th-grade children performed the task with spatially integrated vs spatially separated dimensions. The results indicate that with spatially integrated dimensions there is a trend from holistic to featural perception and an increase in attentional control with increasing age. Spatially separate dimensions are perceived dimensionally at all ages, but show a trend in attentional development. In Experiment 2, the spatially integrated dimensions of Experiment 1 were made separable by portraying different targets within a configuration in different colors. The theoretical implications of the results are discussed.