What visual information do children and adults consider while switching between tasks? Eye-tracking investigation of cognitive flexibility development.

This study investigated the visual information that children and adults consider while switching or maintaining object-matching rules. Eye movements of 5- and 6-year-old children and adults were collected with two versions of the Advanced Dimensional Change Card Sort, which requires switching between shape- and color-matching rules. In addition to a traditional integrated version with bidimensional objects (e.g., a blue bear), participants were tested on a dissociated version with pairs of unidimensional objects as stimuli (e.g., a noncolored bear beside a blue patch) so that fixations on the relevant and irrelevant dimensions of the stimuli could be distinguished. The fixation times were differentially distributed depending on whether children had to switch or maintain matching rules. Trial type differences in fixation times were primarily observed for the cues and the relevant and irrelevant dimensions of the stimuli, whereas responses options were seldom fixated even by the youngest children. In addition, the shape modality of the stimulus was more fixated than the color modality whether or not shape was relevant. Finally, the fixation patterns were modulated by age. These results suggest that switch costs are more related to selection of the relevant dimension on the stimulus than to response selection and point to age-related differences in strategies underlying flexible behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the relations between seen objects and components of potential actions.

Accounts of visually directed actions usually assume that their planning begins with an intention to act. This article describes three experiments that challenged this view through the use of a stimulus-response compatibility paradigm with photographs of common graspable objects as stimuli. Participants had to decide as fast as possible whether each object was upright or inverted. Experiments 1 and 2 examined the effect of the irrelevant dimension of left-right object orientation on bimanual and unimanual keypress responses. Experiment 3 examined wrist rotation responses to objects requiring either clockwise or anticlockwise wrist rotations when grasped. The results (a) are consistent with the view that seen objects automatically potentiate components of the actions they afford, (b) show that compatibility effects of an irrelevant stimulus dimension can be obtained across a wide variety of naturally occurring stimuli, and (c) support the view that intentions to act operate on already existing motor representations of the possible actions in a visual scene. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Precueing spatial S-R correspondence: Is there regulation of expected response conflict?

Four experiments investigated the ability to prepare for the level of forthcoming stimulus-response correspondence in choice-response tasks. In a Simon task, participants responded to the color of spatially variable stimuli with spatially variable responses. Participants were given advance information about whether a forthcoming stimulus-response event would be spatially corresponding, neutral, or spatially noncorresponding. Reliable cues decreased reaction times (RTs) in the corresponding conditions of 2- and 3-choice tasks, decreased RTs in noncorresponding conditions of a 2-choice task but not in a 3-choice task, and left RTs in neutral conditions unaffected. The pattern of results suggests that participants used reliable cues for responding to the nominally irrelevant stimulus location if the correct response could be inferred from location (attention switching). By contrast, the lack of cueing effects on performance in noncorresponding conditions of 3-choice tasks suggests that participants cannot use cues for changing the attentional weights of processing channels for different stimulus dimensions (gating). In summary, gating may be involved in the regulation of experienced response conflict, but the present results suggest that it is not involved in the regulation of expected (i.e., predicted) response conflict. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hand to mouth: Automatic imitation across effector systems.

The effector dependence of automatic imitation was investigated using a stimulus–response compatibility (SRC) procedure during which participants were required to make an open or closed response with their hand or their mouth. The correct response for each trial was indicated by a pair of letters in Experiments 1 and 2 and by a colored square in Experiment 3. Each of these imperative stimuli was accompanied by task-irrelevant action images depicting a hand or mouth opening or closing. In relation to the response, the irrelevant stimulus was movement compatible or movement incompatible, and effector compatible or effector incompatible. A movement compatibility effect was observed for both hand and mouth responses. These movement compatibility effects were present when the irrelevant stimulus was effector compatible and when it was effector incompatible, but were smaller when the irrelevant stimulus and response effectors were incompatible. Consistent with the associative sequence learning (ASL) model of imitation, these findings indicate that automatic imitation is partially effector dependent and therefore that the effector dependence of intentional imitation reflects, at least in part, the nature of the mechanisms that mediate visuomotor translation for imitation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus-response compatibility for moving stimuli: Perception of affordances or directional coding?

C. F. Michaels (1988) reported a compatibility effect in which responses were fastest at the destination of a moving stimulus; this "destination" compatibility effect was interpreted in terms of catching actions "afforded" by the stimulus motion. The present study evaluated implications of the catching-affordance account and compared them with those of an account based on spatial coding or relative direction. The destination compatibility effect was obtained when the responses were keypresses rather than catching movements of a joystick and regardless of whether the stimulus expanded, contracted, or only changed location. This effect was a function of relative rather than absolute location of the responses. A similar compatibility effect was obtained when destinations were designed by static arrow stimuli. The results are inconsistent with the catching-affordance account and are best explained by the coding of relative direction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition and the SNARC effect with one- and two-digit numbers.

The SNARC (Spatial Numerical Association of Response Codes) effect is the finding that small numbers elicit faster left than right responses and large numbers elicit faster right than left responses. This effect suggests that numbers activate left-right magnitude-laterality codes and that these codes interact with the selection of left-right responses. In the present research, subjects made parity decisions for one-digit numbers (in Experiment 1) and two-digit numbers (in Experiment 2), and we examined the effect of stimulus repetition on the SNARC effect. With single-digit stimuli, responses were faster and the SNARC effect was eliminated when stimuli were identical on successive trials. With two-digit stimuli, responses were faster when the ones digit was repeated, but the SNARC effect was found regardless of whether the digit was repeated or not. We argue that magnitude-laterality codes are activated in the process of accessing number information in memory and that this process can be short circuited if the visual stimulus matches that on the previous trial. Thus, no SNARC effect is found in Experiment 1 when identical stimuli are presented on successive trials. However, this result is not found in Experiment 2 because successive stimuli do not match even if the ones digit is repeated. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Processing of an irrelevant location dimension as a function of the relevant stimulus dimension.

The effect of an irrelevant location dimension on choice reactions to the relevant stimulus dimension was examined. Exp 1 used variations of the spatial Stroop task and the Simon task that differed in whether the relevant dimension (location name or color) was similar to the irrelevant location dimension. Congruity of the stimulus dimensions and stimulus–response (S–R) mapping had additive effects in the Simon task but overadditive effects in the Stroop task. Exps 2–4 showed that each pattern could be obtained for both tasks, suggesting that dimensional similarity is not crucial; overadditivity occurred only when stimulus identification was prolonged. Results can be interpreted in terms of the relative timing of activation for the relevant and irrelevant information, if it is assumed that the activation function for irrelevant location varies across different S–R mappings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial coding and central patterns: Is there something special about the eyes?

In this study we investigated in a Simon-like task whether task-irrelevant spatial information, delivered by centrally presented patterns, interfered with response selection in the same way as laterally presented stimuli. Second, we asked whether such interference was equal for different kinds of stimuli. Participants were required to respond to the colour of two framed squares, two arrows, or two schematic eyes by pressing one of two lateralized response keys. The results consistently show that the Simon effect occurs independently of the nature of the stimulus, as classically reported for lateralized stimuli. Response times were influenced by the direction and frame-relative position of the stimuli, being faster for responses corresponding to the direction indicated by the stimuli than for noncorresponding responses regardless of stimulus types. Contrary to findings with lateralized nondirectional stimuli, such an effect increased with increasing RTs indicating that for centrally presented patterns the extraction of spatial information is time consuming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of stimulus and response variability on S-R correspondence effects.

Six experiments investigated how variability on irrelevant stimulus dimensions and variability on response dimensions contribute to spatial and nonspatial stimulus-response (S-R) correspondence effects. Experiments 1-3 showed that, when stimuli varied in location and number, S-R correspondence effects for location or numerosity occurred when responses varied on these dimensions but not when responses were invariant on these dimensions. These results are consistent with the response-discrimination account, according to which S-R correspondence effects should only arise for a dimension that is used for discriminating between responses in working memory. Experiments 4-6 showed that, when responses varied in location and number, both invariant and variable stimulus number produced correspondence effects in S-R numerosity. In summary, the present results indicate that the usefulness of a particular dimension for response discrimination can be sufficient for producing S-R correspondence effects, whereas variability of a stimulus dimension is not sufficient for producing such effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition effects with categorizable stimulus and response sets.

The repetition effect refers to the finding that reaction times (RTs) are faster on trial n when the stimulus presented and/or the response required is the same as on trial n?–?1 than when it is different. Five experiments examined the importance of stimulus features and response features in obtaining the repetition effect. Exp 1 demonstrated a need for the stimuli to be categorically mapped to responses for a response repetition effect to be observed. Exps 2–5 showed that the repetition effect can be obtained across responding hands when spatial information (Exps 2 and 4) or finger information (Exps 2 and 5) is consistent across hands but not when these sources of information are eliminated (Exp 3). The results are in agreement with expectations developed from salient-features coding and with the inclusive links hypothesis proposed by H. Pashler and G. Baylis (1991). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Simon effect and its reversal in three-choice Hedge and Marsh tasks: Evidence for irrelevant stimulus-response compatibility and stimulus congruity.

In 2-choice A. Hedge and N. W. A. Marsh (1975) tasks or S. Komblum's (1992) Type-5 ensembles, irrelevant stimulus-response compatibility (SRC), logical recoding, display control arrangement correspondence (DCQ, and stimulus congruity are confounded. By using 3 response alternatives and both compatible and incompatible stimulus-response mappings, irrelevant SRC was pitted against logical recoding and both of them were disentangled from DCC and stimulus congruity. By varying response labels on a trial-by-trial basis and using different stimuli and responses, DCC and stimulus congruity were decoupled. Results from 4 experiments showed that neither logical recoding nor DCC contributes to the Simon effect and its reversal. Irrelevant SRC and stimulus congruity are necessary but neither is sufficient to account for the Simon effect and its reversal. A connectionist model of compatibility incorporating both irrelevant SRC and stimulus congruity appears to account for the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer of noncorresponding spatial associations to the auditory Simon task.

Four experiments examined transfer of noncorresponding spatial stimulus-response associations to an auditory Simon task for which stimulus location was irrelevant. Experiment 1 established that, for a horizontal auditory Simon task, transfer of spatial associations occurs after 300 trials of practice with an incompatible mapping of auditory stimuli to keypress responses. Experiments 2-4 examined transfer effects within the auditory modality when the stimuli and responses were varied along vertical and horizontal dimensions. Transfer occurred when the stimuli and responses were arrayed along the same dimension in practice and transfer but not when they were arrayed along orthogonal dimensions. These findings indicate that prior task-defined associations have less influence on the auditory Simon effect than on the visual Simon effect, possibly because of the stronger tendency for an auditory stimulus to activate its corresponding response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity and boundary conditions of automatic response activation in the Simon task.

Three experiments were conducted to determine whether spatial stimulus-response compatibility effects are caused by automatic response activation by stimulus properties or by interference between codes during translation of stimulus into response coordinates. The main evidence against activation has been that in a Simon task with hands crossed, responses are faster at the response location ipsilateral to the stimulus though manipulated by the hand contralateral to the stimulus. The experiments were conducted with hands in standard and in crossed positions and electroencephalogram measures showed coactivation of the motor cortex induced by stimulus position primarily during standard hand positions with visual stimuli. Only in this condition did the Simon effect decay with longer response times. The visual Simon effect appeared to be due to specific mechanisms of visuomotor information transmission that are not responsible for the effects obtained with crossed hands or auditory stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequential analysis of the numerical Stroop effect reveals response suppression.

Automatic processing of irrelevant stimulus dimensions has been demonstrated in a variety of tasks. Previous studies have shown that conflict between relevant and irrelevant dimensions can be reduced when a feature of the irrelevant dimension is repeated. The specific level at which the automatic process is suppressed (e.g., perceptual repetition, response repetition), however, is less understood. In the current experiment we used the numerical Stroop paradigm, in which the processing of irrelevant numerical values of 2 digits interferes with the processing of their physical size, to pinpoint the precise level of the suppression. Using a sequential analysis, we dissociated perceptual repetition from response repetition of the relevant and irrelevant dimension. Our analyses of reaction times, error rates, and diffusion modeling revealed that the congruity effect is significantly reduced or even absent when the response sequence of the irrelevant dimension, rather than the numerical value or the physical size, is repeated. These results suggest that automatic activation of the irrelevant dimension is suppressed at the response level. The current results shed light on the level of interaction between numerical magnitude and physical size as well as the effect of variability of responses and stimuli on automatic processing. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Correction to Kornblum et al. (1999).

Reports an error in "The effects of irrelevant stimuli: 1. The time course of stimulus–stimulus and stimulus–response consistency effects with Stroop-like stimuli, Simon-like tasks, and their factorial combinations" by Sylvan Kornblum, Gregory T. Stevens, Anthony Whipple and Jean Requin (Journal of Experimental Psychology: Human Perception and Performance, 1999[Jun], Vol 25[3], 688-714). A key reference for coauthor Gregory T. Stevens’s PhD dissertation was omitted and appears in the correction. (The following abstract of the original article appeared in record 1999-13929-008.) The effects of Simon- and Stroop-like stimuli are examined in isolation and in factorial combinations with different delays between the presentation of the irrelevant and the relevant stimuli. The effects of irrelevant stimuli have different time courses depending on whether they overlap with the relevant stimulus (stimulus-stimulus overlap, Dimensional Overlap [DO] Type 4) or with the response (stimulus-response overlap, DO Type 3). A new, computational, parallel distributed processing (PDP)-type model, DO'97, is presented that is based on the original DO model (S. Kornblum, 1994; S. Kornblum, T. Hasbroucq, & A. Osman, 1990), and it postulates a nonmonotone irrelevant stimulus activation function in addition to 2 temporally ordered, serial, nonindependent stages: a stimulus processing stage and a response production stage. DO'97 is able to simulate the temporal dynamic characteristics of the processes, with good fits to the empirical data of this study and other published studies, at the level of means, variances, and distributional plots. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporary activation of perceptual–motor associations: A stimulus–response interpretation of automaticity.

Some types of automaticity can be attributed to simple stimulus–response associations (G. D. Logan, 1988). This can be studied with paradigms in which associations to an irrelevant stimulus automatically influence responding to a relevant stimulus. In 1 example, the irrelevant and relevant stimuli were presented successively with the 1st, irrelevant, stimulus masked. Although this stimulus was not phenomenally visible, it influenced responding to the 2nd, visible, stimulus. This influence was substantial only if associations to the 1st stimulus had been activated by recent responding (S. T. Klapp & B. W. Haas, 2005). These associations were not processed deeply; instead, they only relate specific stimuli to specific responses. Whereas these conclusions were demonstrated previously with masking so that participants were not aware of the irrelevant stimulus and thus had no basis to permit control of its influence, the present research demonstrated the same principles when all stimuli were visible. Furthermore, activation of the associations was not subject to substantial intentional control. These findings imply that association-based automaticity occurs independently of, and uninfluenced by, awareness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of irrelevant stimuli: 1. The time course of stimulus–stimulus and stimulus–response consistency effects with Stroop-like stimuli, Simon-like tasks, and their factorial combinations.

[Correction Notice: An erratum for this article was reported in Vol 36(3) of Journal of Experimental Psychology: Human Perception and Performance (see record 2010-10162-008). A key reference for coauthor Gregory T. Stevens’s PhD dissertation was omitted and appears in the correction.] The effects of Simon- and Stroop-like stimuli are examined in isolation and in factorial combinations with different delays between the presentation of the irrelevant and the relevant stimuli. The effects of irrelevant stimuli have different time courses depending on whether they overlap with the relevant stimulus (stimulus-stimulus overlap, Dimensional Overlap [DO] Type 4) or with the response (stimulus-response overlap, DO Type 3). A new, computational, parallel distributed processing (PDP)-type model, DO'97, is presented that is based on the original DO model (S. Kornblum, 1994; S. Kornblum, T. Hasbroucq, & A. Osman, 1990), and it postulates a nonmonotone irrelevant stimulus activation function in addition to 2 temporally ordered, serial, nonindependent stages: a stimulus processing stage and a response production stage. DO'97 is able to simulate the temporal dynamic characteristics of the processes, with good fits to the empirical data of this study and other published studies, at the level of means, variances, and distributional plots. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Asymmetric relationships among perceptions of facial identity, emotion, and facial speech

Effects of variation in an irrelevant stimulus dimension on judgments of faces with respect to a relevant dimension were investigated. Dimensions were identity, emotional expression, and facial speech. The irrelevant dimension was correlated with, constant, or orthogonal to the relevant one. Reaction times (RTs) were predicted to increase over these conditions to the extent that the relevant dimension could not be processed independently of the irrelevant one. RTs for identity judgments were independent of variation in expression or facial speech, but RTs for expression and facial speech judgments were influenced by identity variation. Facial speech perception was affected by identity even when variation in the mouth region was eliminated. Moreover, observers could judge speech faster for personally familiar faces than for unfamiliar faces. The results suggest asymmetric dependencies between different components of face perception. Identity is perceived independently of, but may exert an influence on, expression and facial speech analysis.     

Conflicts during response selection affect response programming: Reactions toward the source of stimulation.

In the Simon effect, participants make a left or right keypress in response to a nonspatial attribute (e.g., color) that is presented on the left or right. Reaction times (RTs) increase when the response activated by the irrelevant stimulus location and the response retrieved by instruction are in conflict. The authors measured RTs and movement parameters (MPs) of pointing responses in a typical Simon task. Their results show that the trajectories veer toward the imperative stimulus. This bias decreased as RTs increased. The authors suggest that the time course of trajectory deviations reflects the resolution of the response conflict over time. Further, time pressure did not affect the size of the Simon effect in MPs or its time course, but strongly reduced the Simon effect in RTs. In contrast, response selection before the onset of a go signal on the left or right did not affect the Simon effect in RTs, but reduced the Simon effect in MPs and reversed the time course. The authors speculate about independent Simon effects associated with response selection and programming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Locus of the single-channel bottleneck in dual-task interference.

Two experiments used the locus-of-cognitive-slack method to determine whether dual-task interference occurs before or after the response selection stage. The experiments used the overlapping tasks paradigm, in which 2 signals, each requiring a different speeded choice response, are presented in rapid succession. In Exp 1, stimulus–response (S–R) compatibility was manipulated by varying whether Task 2 stimuli were mapped onto their responses by a rule or arbitrarily. Compatibility effects were additive with the effects of degree of task overlap, manipulated by varying the stimulus onset asynchrony between the signals. Exp 2 examined 2 additional forms of S–R compatibility: symbolic compatibility (arrows vs letters) and spatial compatibility (the "Simon" effect). Effects of symbolic compatibility were additive with effects of degree of task overlap, whereas the effects of spatial compatibility and degree of task overlap were underadditive. It is argued that only a central-bottleneck model provides a consistent account of these results. The nature of the central bottleneck is considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)