Mixing compatible and incompatible mappings: Elimination, reduction, and enhancement of spatial compatibility effects

Effects of a neutral warning signal under increased temporal uncertainty

Han and Proctor (2022a, Quarterly Journal of Experimental Psychology, 75[4], 754-764) reported that in a visual two-choice task, compared with a no-warning condition, a neutral warning tone caused shorter reaction times (RTs) but at the expense of an increase in error percentages (a speed-accuracy trade-off) at a constant 50-ms foreperiod but shorter RTs without an increase in error percentages at a 200-ms foreperiod. Also, the spatial compatibility of stimulus-response mappings was found to interact with the foreperiod effect on RT. We conducted three experiments to investigate whether these findings can be replicated without the constancy of foreperiod within a trial block. In Experiments 1 and 2, participants performed the same two-choice task as in Han and Proctor's study but with the foreperiod randomly varied among 50, 100, and 200 ms and RT feedback provided after each response. Results showed that as the foreperiod increased, RT decreased while EP increased, demonstrating a consistent speed-accuracy trade-off. Also, the mapping effect was found to be largest at the 100-ms foreperiod. In Experiment 3, RT feedback was not provided, and the warning tone speeded responses without evidence of an increase in error percentage. We conclude that the enhanced information processing at a 200-ms foreperiod depends on constancy of foreperiod within a trial block, whereas the mapping-foreperiod interaction found in Han and Proctor is relatively unaffected by increased temporal uncertainty.

Seeing through the cat's eyes: evidence of a spontaneous perspective taking process using a non-human avatar

In many daily face-to-face interactions, people are able to take the perspective of others, for example, coding right and left based on point-of-view of others. In the present study, we investigated whether observers are able to take the perspective of a non-human figure such as a cat, observing the same effects obtained with human or robot avatars. In both experiments, we used a centrally presented stimulus (i.e. a cat), with its tail lateralized to the left or to the right. Participants had to respond to the side of the tail with a lateralized keypress. In Experiment 1 (spatial perspective taking task), participants were required to explicitly adopt the cat's perspective to respond, whereas in Experiment 2 (SR compatibility task), this was not explicitly required. In both experiments, faster RTs are obtained when the cat is presented back, with a greater difference between front and back views when the tail is on the right; furthermore, there is no temporal modulation of the back-front effect. These common results between the two experiments are interpreted on the basis of the spatial perspective taking processes, elicited voluntarily (Experiment 1) or spontaneously (Experiment 2).

Examination of a Response–Effect Compatibility Task With Continuous Mouse Movements: Free- Versus Forced-Choice Tasks and Sequential Modulations

According to ideomotor theory, we select actions by recalling and anticipating their sensory consequences, that is, their action effects. Compelling evidence for this theory comes from response–effect compatibility (REC) experiments, in which a response produces an effect with which it is either compatible or incompatible. For example, pressing a left/right response key is faster if it is predictably followed by an action effect on the same, compatible side compared with the other, incompatible side, even though the effect itself appears only after response time is measured. Recent studies investigated this effect with continuous responses (i.e., computer mouse movements) and reported an REC effect in a forced-choice but not in a free-choice task. From the keypressing literature, the opposite result pattern or no differences would have been expected. To clarify this issue, we report 3 experiments with mouse movement responses. Experiment 1 used a simpler scenario than in prior studies and found a similar result: The REC effect was evident in a forced- but not in a free-choice task. Also, sequential modulations of the REC effect were exploratorily analyzed and replicated with higher power in Experiment 2. However, Experiment 3 demonstrated that at least part of the REC effect with mouse movements can be attributed to stimulus–response compatibility (SRC), with a much smaller compatibility effect evident with a procedure for which SRC was reduced. We conclude that a sequentially modulated compatibility effect can be observed with mouse movements, but previous studies may have underestimated the contribution from SRC. The results are also discussed in terms of why the compatibility effect was observed in forced- but not free-choice tasks with mouse movement responses.

Mapping effects in choice-response and go/no-go variants of the lexical decision task: A case for polarity correspondence

Previous research has shown that responses to words are faster and more accurate in the go/no-go version of the lexical decision task (LDT) than in the choice-response version. This finding has been attributed to reduced response-selection demands in the go/no-go task. Here, we test an alternative account assuming similar response-selection demands in the two tasks, but an additional impact of polarity correspondence between stimuli and responses in the go/no-go task. Positive and negative polarities have been described as a frequent characteristic of binary stimulus and response dimensions. Only for the go/no-go version of the LDT, an apparent polarity difference between go and no-go responses exists, with go responses having the same polarity as words and no-go responses the same polarity as nonwords. Thus, compared with the choice-response LDT, in the go/no-go LDT, go responses to words should be facilitated by polarity correspondence, and go responses to nonwords should be inhibited by polarity noncorrespondence. In this study, each participant performed a go/no-go LDT and a choice-response LDT. Responses to words were faster and more accurate than responses to nonwords, and-consistent with the alternative account-this difference was larger in the go/no-go LDT than in the choice-response LDT. An analysis of performance by means of sequential-sampling models that take into account a decaying influence of irrelevant stimulus features supported the effect of polarity correspondence in the go/no-go LDT. This analysis suggested an effect in the choice-response LDT as well, though of a smaller size and a faster decay.

Individual Response–Effect Congruencies Modulate Subsequent Stimulus–Response Compatibility Effects

Expectations of the outcomes of our actions can directly influence response behavior. In 2 experiments, we demonstrate that the congruency between a response and its unanticipated effect (R-E congruency) can also influence task performance by moderating the magnitude of stimulus-response (S-R) compatibility effects on a subsequent trial. This is the case when response effects are physical locations that precede a location-based S-R compatibility task and when response effects are spatial words preceding a spatial word-based S-R compatibility task (Experiment 1). However, prior R-E congruency does not influence the subsequent S-R compatibility effect when the stimulus type has changed from location to word or vice versa (Experiment 2). In both experiments, the correspondence between the spatial information of the S-R task stimulus and prior effect also influences the S-R compatibility effect. We discuss how conflict control and event coding may lead to the observed results and why their influence is specific to spatial mode.

Can We Prepare to Negate? Negation as a Reversal Operator

Negation is a critical cognitive operator that is investigated across a wide range of psychological phenomena (e.g., language, eating control, emotion control, stereotype processing). A core function of negation is reversing input information. In the current study, we investigated whether this reversing process benefits from temporal preparation. In Experiment 1, participants were first presented with either the negator "not" or the affirmative counterpart "now", and in a variable delay with the response indicating stimulus "left" or "right". Participants had to respond according to phrase meaning (e.g., "now right" ➔ right response; "not right" ➔ left response). The results showed a persisting negation effect of 150 ms that did not reduce with preparatory time. In Experiment 2, we replicated this study using non-linguistic input information (i.e. crosses, tick-marks and arrows). Again, despite standard temporal preparation effects being present, the reversal process itself did not benefit from preparatory time. In summary, these experiments suggest that capacity demanding reversal processes are not eased if we know that a reversal process is coming up soon. This is particularly interesting, as in the current experiments a very basic binary negation paradigm was implemented. The implications of these results for models of negation processing are discussed.

Visual salience, not the graspable part of a pictured eating utensil, grabs attention

Three experiments used compatible and incompatible mappings of images of eating utensils to test the hypothesis that these images activate affordances for grasping with the corresponding hand when the required response is a key-press. In Experiment 1, stimuli were photographs of a plastic spoon oriented on the horizontal axis, with the handle location varying randomly between left and right. Participants were instructed to respond to the handle or the tip, with a compatible mapping in one trial block and an incompatible mapping in another. A benefit for the compatible mapping was evident when the spoon tip was defined as relevant and a smaller cost when the handle was defined as relevant, suggesting a larger influence of the tip than the handle. In Experiment 2, the stimuli were photographs of bamboo chopsticks, for which the functional end is pointed and the graspable end is squared. East Asian participants familiar with chopsticks showed compatibility effects that did not differ significantly between the two ends. In Experiment 3, the chopstick handles were colored red to make them relatively more distinct than the tips. Both East Asian participants (Experiment 3B) and a more diverse sample (Experiment 3A) showed a benefit of the compatible mapping when the handle was defined as task relevant but not when the functional end was. Altogether, the results provide evidence that left-right location of a visually salient feature is the main factor driving these compatibility effects, rather than the automatic activation of a grasping affordance.

How Do Children Deal With Conflict? A Developmental Study of Sequential Conflict Modulation

This study examined age-related differences in sequential conflict modulation (SCM), elicited in three tasks requiring the inhibition of pre-potent responses; a Simon task, an S-R compatibility (SRC) task and a hybrid Choice-reaction/NoGo task. The primary focus was on age-related changes in performance changes following a conflict trial. A secondary aim was to assess whether SCM follows different developmental trajectories depending on the type of conflict elicited by the tasks. The tasks were presented to three different groups of participants with an age range between 7- to 25-years-one group of participants for each task. For each task, the response-to-stimulus interval (RSI) was manipulated (50 vs. 500 ms) across trial blocks to assess time-dependent changes in conflict modulation. The results showed SCM for all three tasks, although the specific patterns differed between tasks and RSIs. Importantly, the magnitude of SCM decreased with advancing age, but this developmental trend did not survive when considering age-group differences in basic response speed. The current results contribute to the emerging evidence suggesting that patterns of SCM are task specific and were interpreted in terms of multiple bottom-up control mechanisms.

Flowers and spiders in spatial stimulus-response compatibility: does affective valence influence selection of task-sets or selection of responses?

The present study examined the effect of stimulus valence on two levels of selection in the cognitive system, selection of a task-set and selection of a response. In the first experiment, participants performed a spatial compatibility task (pressing left and right keys according to the locations of stimuli) in which stimulus-response mappings were determined by stimulus valence. There was a standard spatial stimulus-response compatibility (SRC) effect for positive stimuli (flowers) and a reversed SRC effect for negative stimuli (spiders), but the same data could be interpreted as showing faster responses when positive and negative stimuli were assigned to compatible and incompatible mappings, respectively, than when the assignment was opposite. Experiment 2 disentangled these interpretations, showing that valence did not influence a spatial SRC effect (Simon effect) when task-set retrieval was unnecessary. Experiments 3 and 4 replaced keypress responses with joystick deflections that afforded approach/avoidance action coding. Stimulus valence modulated the Simon effect (but did not reverse it) when the valence was task-relevant (Experiment 3) as well as when it was task-irrelevant (Experiment 4). Therefore, stimulus valence influences task-set selection and response selection, but the influence on the latter is limited to conditions where responses afford approach/avoidance action coding.

Tactile warning signals for in-vehicle systems

The last few years have seen growing interest in the design of tactile warning signals to direct driver attention to potentially dangerous road situations (e.g. an impending crash) so that they can initiate an avoidance maneuver in a timely manner. In this review, we highlight the potential uses of such warning signals for future collision warning systems and compare them with more traditional visual and auditory warnings. Basic tactile warning signals are capable of promoting driver alertness, which has been demonstrated to be beneficial for forward collision avoidance (when compared to a no warning baseline condition). However, beyond their basic alerting function, directional tactile warning signals are now increasingly being utilized to shift the attention of the driver toward locations of interest, and thus to further facilitate their speeded responses to potential collision events. Currently, many researchers are focusing their efforts on the development of meaningful (iconic) tactile warning signals. For instance, dynamic tactile warnings (varying in their intensity and/or location) can potentially be used to convey meaningful information to drivers. Finally, we highlight the future research that will be needed in order to explore how to present multiple directional warnings using dynamic tactile cues, thus forming an integrated collision avoidance system for future in-vehicle use.

Is automatic imitation based on goal coding or movement coding? A comparison of goal-directed and goal-less actions

A key issue for research on automatic imitation is whether it occurs primarily at the level of movements, that is, by automatically activating a representation of the movement/effector involved in the execution of the observed action, or at the level of goals, that is, by triggering a representation of the action goal, irrespective of how the motor act is physically instantiated. The present study presents two experiments aimed at investigating the contribution of movement coding and goal coding to automatic imitation, by assessing participants' performance in a spatial compatibility task where the observed stimuli were goal-directed and goal-less actions, which have been demonstrated to elicit, respectively, goal and movement coding. We found a significant automatic imitation effect both when the stimuli were goal-less actions and when they were actions directed toward a goal. However, the effect was stronger for the goal-less actions, even after controlling for saliency effects. These results suggest that goal coding contributes to automatic imitation, but to a lesser degree compared to movement coding. The implications of these results for theory and research on automatic imitation are discussed.

Neural systems for preparatory control of imitation

Humans have an automatic tendency to imitate others. Previous studies on how we control these tendencies have focused on reactive mechanisms, where inhibition of imitation is implemented after seeing an action. This work suggests that reactive control of imitation draws on at least partially specialized mechanisms. Here, we examine preparatory imitation control, where advance information allows control processes to be employed before an action is observed. Drawing on dual route models from the spatial compatibility literature, we compare control processes using biological and non-biological stimuli to determine whether preparatory imitation control recruits specialized neural systems that are similar to those observed in reactive imitation control. Results indicate that preparatory control involves anterior prefrontal, dorsolateral prefrontal, posterior parietal and early visual cortices regardless of whether automatic responses are evoked by biological (imitative) or non-biological stimuli. These results indicate both that preparatory control of imitation uses general mechanisms, and that preparatory control of imitation draws on different neural systems from reactive imitation control. Based on the regions involved, we hypothesize that preparatory control is implemented through top-down attentional biasing of visual processing.

To imitate or not: Avoiding imitation involves preparatory inhibition of motor resonance

Stimulus-response compatibility (SRC)-the fact that some stimulus-response pairs are faster than others-is attributed in part to automatic activation of the stimulus-compatible response representation. Cognitive models of SRC propose that automatic response activation can be strategically suppressed if the automatic response is likely to interfere with behavior; in particular, suppression is thought to occur in preparation for incompatible responses and when the required stimulus-response mapping is unknown before stimulus presentation. We test this preparatory suppression hypothesis in the context of imitation, a special form of SRC particularly relevant to human social behavior. Using TMS, we measured muscle-specific corticospinal excitability during action observation (motor resonance) while human participants prepared to perform imitative and counterimitative responses to action videos. Motor resonance was suppressed during preparation to counterimitate and for unknown mappings, compared to preparation to imitate and a baseline measure of motor resonance. These results provide novel neurophysiological evidence that automatic activation of stimulus-compatible responses can be strategically suppressed when the automatic response is likely to interfere with task goals. Insofar as motor resonance measures mirror neuron system activity, these results also suggest that preparatory control of automatic imitative tendencies occurs through modulation of mirror neuron system activity.

Interference between accustomed number-space mappings and unacquainted letter-space mappings in a button press task

OBJECTIVE

We aimed to investigate how ordered mappings (e.g., left-to-right and right-to-left order representations) would interfere with each other.

BACKGROUND

Mental representations of numbers and letters are linked with spatial representation and can be changed intentionally.

METHOD

The experiment consisted of three sessions. In the digit-alone session, two digits randomly selected from [1], [2], and [3] were shown. If the two digits were the same, participants pressed the button corresponding to the digit, and if the digits differed, they pressed the remaining button. The response buttons were ordered [1][2][3] from the left. In the letter-alone session, three different button configurations were prepared: sequential [A][B][C], reversed [C][B][A], or partially reversed [B][A][C]. The same-versus-different rules were basically identical to those in the digit task. In the mixed session, trials of the digit task and those of the letter task were randomly mixed.

RESULTS

We found that two ordinal representations did not interfere with each other when they shared the same direction of order ([1][2][3] vs. [A][B][C]), two ordinal mappings interfered with each other when they had different directions of order ([1][2][3] vs. [C][B] [A]), and an ordinal mapping ([1][2][3]) was affected by a nonordinal mapping ([B][A][C]), but the nonordinal mapping was less affected by the ordinal mapping.

CONCLUSION

The mapping between ordinal information and space can be modulated by top-down processes, and it is prone to interference depending on the nature of another coexisting mapping.

APPLICATION

Our findings may be used in designing response assignments for input devices for multiple functions.

Right inferior frontal gyrus activation as a neural marker of successful lying

There is evidence to suggest that successful lying necessitates cognitive effort. We tested this hypothesis by instructing participants to lie or tell the truth under conditions of high and low working memory (WM) load. The task required participants to register a response on 80 trials of identical structure within a 2 (WM Load: high, low) × 2 (Instruction: truth or lie) repeated-measures design. Participants were less accurate and responded more slowly when WM load was high, and also when they lied. High WM load activated the fronto-parietal WM network including dorsolateral prefrontal cortex (PFC), middle frontal gyrus, precuneus, and intraparietal cortex. Lying activated areas previously shown to underlie deception, including middle and superior frontal gyrus and precuneus. Critically, successful lying in the high vs. low WM load condition was associated with longer response latency, and it activated the right inferior frontal gyrus—a key brain region regulating inhibition. The same pattern of activation in the inferior frontal gyrus was absent when participants told the truth. These findings demonstrate that lying under high cognitive load places a burden on inhibition, and that the right inferior frontal gyrus may provide a neural marker for successful lying.

Effect of prior practice on the stimulus-response compatibility effect in a mixed mapping environment

A stimulus-response compatibility (SRC) effect is obtained when performance is better with compatible mappings than with incompatible mappings. When mappings are mixed within a task, the SRC effect is often eliminated or reversed.The present study examines how 1,600 trials with different practice tasks can affect the response selection process in these mixed mapping environments. Participants were assigned to one of three practice groups: mixed mapping, pure compatible mapping, and pure incompatible mapping. Subsequently, all participants performed an experimental session in which compatible and incompatible trials were mixed.The SRC effect was eliminated in the experimental mixed mapping session, regardless of practice condition. The results suggest that practice does not change the need to suppress the direct response selection route in a mixed mapping task. However, reaction time distributions and sequential analyses were modulated by practice condition, which indicates that the new associations acquired during practice may activate new routes that interact with preexisting ones.

Up or Down: Directional Stimulus-Response Compatibility and Natural Scrolling

The settings of scrolling direction (e.g., whether scrolling up or down to move the display content up) on current computer operating systems are discrepant, which may impair users’ performance and user experience. To evaluate the alternatives, we conducted two experiments. In Experiment 1, we simulated the way people read and scroll on a computer by asking participants to press the up-arrow or down-arrow key to scroll the screen. In Experiment 2, we eliminated the scrolling component by including only a location-judgment task. We examined directional stimulus-response compatibility in the scrolling task and the location-judgment task. Results showed that responses were facilitated when the control direction was compatible with the display content movement direction. This finding is consonant with the Mac OS X Lion operating system, which defines the default scrolling direction as “move content in the direction of finger movement.” We recommend that other systems adopt this directional compatible mapping.

Effects of in-vehicle warning information displays with or without spatial compatibility on driving behaviors and response performance

A driving simulator study was conducted to evaluate the effects of five in-vehicle warning information displays upon drivers' emergent response and decision performance. These displays include visual display, auditory displays with and without spatial compatibility, hybrid displays in both visual and auditory format with and without spatial compatibility. Thirty volunteer drivers were recruited to perform various tasks that involved driving, stimulus-response, divided attention and stress rating. Results show that for displays of single-modality, drivers benefited more when coping with visual display of warning information than auditory display with or without spatial compatibility. However, auditory display with spatial compatibility significantly improved drivers' performance in reacting to the divided attention task and making accurate S-R task decision. Drivers' best performance results were obtained for hybrid display with spatial compatibility. Hybrid displays enabled drivers to respond the fastest and achieve the best accuracy in both S-R and divided attention tasks.

The influence of visual search efficiency on the time-course of identity-based SR-compatibility

Three experiments were conducted to investigate the impact of stimulus-driven control on the time-course of stimulus-response (SR) compatibility. Participants responded to the presence or absence of a singleton arrow that was presented among multiple nontargets. When the singleton arrow was present, observers pressed a button with their right index finger, when it was absent they pressed with their left-index finger. SR-compatibility depended on the relation between the identity of the target and the present response: Even though the identity of the target singleton arrow (whether it was pointing to the right or left) was irrelevant to the task, the direction could be corresponding (right arrow) or noncorresponding (left arrow) with a target present response (the right hand). To examine the time-course of performance target-distractor similarity was varied to increase or decrease visual search efficiency and accordingly response latency. There were three main findings. First, the results of Experiment 1 showed that observers were no faster to respond 'present' when the singleton arrow pointed to the right (corresponding to the right hand) than when it pointed left (noncorresponding to the right hand) in a simple present-absent detection task. Second, only when observers were encouraged to process the identity of the arrow singleton, an effect of an SR-compatibility effect was found which developed over time. Third, the time-course of SR-compatibility was not influenced by visual search efficiency. The results of the present work suggest that visual selection and response selection occur in different stages.

Domain general mechanisms account for imagined transformations of whole body perspective

Three experiments investigated the contribution of domain general processes to imagined transformations of whole body perspective. In a task where participants make left-right judgements about a schematic human figure, reaction times made from the point of view of the figure are longer when the figure does not share the same spatial orientation as the participant and are substantially longer than those made from the participant's own point of view. These phenomena have been attributed to a specialised mechanism for imagined perspective transformations. In the present experiments, the effect of orientation on performance was influenced by factors that affect spatial stimulus-response (S-R) compatibility; it was attenuated with reduced dimensional overlap and reversed by crossed S-R mappings. Performance in a control experiment in which no figure was present suggests that processes moderating S-R mappings may account for the effect of adopting another's point of view. Our findings demonstrate a role for domain general processes in imagined transformations of whole body perspective, imply that egocentric codes for spatial relationships within visually presented bodies are automatically generated, and undermine evidence for a specialised mechanism for imagined perspective transformations.

Working-memory load decreases mappings effects in spatial-compatibility tasks

The paper investigates the role of working memory for the translation of spatial stimuli into spatial responses. Performance is typically superior with compatible mapping between stimulus and response locations than with incompatible mapping (spatial-mapping effect). According to popular dual-route models, the spatial-mapping effect may arise from differences in the effectiveness of S-R translation, and/or from the effects of automatic response activation. Working-memory load should not affect the automatic route, but delay S-R translation in the incompatible condition, increasing the mapping effect under load. These predictions were tested in two dual-task experiments. Participants performed a spatial-compatibility task with compatible or incompatible S-R mapping, while memorizing different amounts of spatial (Experiment 1) or verbal (Experiment 2) information. In both experiments, working-memory load decreased the mapping effect, but did not eliminate it. Results are at odds with the dual-route account. An alternative explanation based on the response-discrimination account (Ansorge and Wühr in J Exp Psychol Hum Percept Perform 30:365-377, 2004) is proposed.

Stimulus–response compatibility for mixed mappings and tasks with unique responses

For two stimulus locations mapped to two keypresses, reaction time is shorter when the mapping is compatible than when it is not (the stimulus–response compatibility, SRC, effect). A similar result, called the Simon effect, occurs when stimulus location is irrelevant, and colour is relevant. When compatibly mapped trials are intermixed with incompatibly mapped trials or Simon task trials, the compatibility effect is eliminated, and the Simon effect is influenced by the location mapping. In five experiments, we examined whether similar mixing effects occur when the two spatial mappings or location-relevant and location-irrelevant tasks use distinct keypresses on the left and right hands. Mixing had considerably less influence on the SRC and Simon effects than it does when the intermixed trial types or tasks share the same responses, even though response time was lengthened to a similar extent. Mixing two tasks for which stimulus location was irrelevant yielded no within-task Simon effect, but the effect was also absent when four stimuli were assigned to two responses on a single hand. The relative lack of influence of mixing on the SRC and Simon effects when the tasks have unique responses implies that suppression of direct activation of the corresponding response occurs primarily when the tasks share responses.

Task-defined associations are mode specific for selection of relevant dimension but mode independent for selection of location mapping

When compatible and incompatible mappings of a location-relevant task are mixed, or a location-relevant task is mixed with a task for which stimulus location is irrelevant, the benefit of the compatible mapping is eliminated for physical locations and enhanced for location words. Two experiments examined the influence of presenting the location information for the mixed conditions in different stimulus modes (physical location or word). Experiment 1 showed that the effects of mixing location-relevant and location-irrelevant tasks on the spatial compatibility and Simon effects are reduced when the location information is presented in different modes for the two tasks. Experiment 2 showed, in contrast, that the mode distinction had little influence on the effects of mixed compatible and incompatible mappings for location-relevant tasks: The compatibility effect was eliminated for physical locations and enhanced for words, as when there is no mode distinction. Thus, when location is relevant for one task and colour for the other, the task-defined associations of locations to responses are mode specific, but when location is relevant for both tasks, the associations are mode independent.

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.

How task errors affect subsequent behavior: evidence from distributional analyses of task-switching effects

Switch costs in task switching are often assumed to reflect the strengthening of task-related associations. Recently, we provided evidence that committing an error leads to the strengthening of the wrong task (Steinhauser & Hübner, 2006). In the present study, we report how error-induced control compensates for the effects of error strengthening. We hypothesized that, although error detection cannot prevent an error from being strengthened, it initiates processes that suppress the negative consequences of error strengthening on subsequent trials. Because error-induced control is known to operate slowly, we predicted that a compensatory effect should be observable only for slow responses. In three task-switching experiments, these predictions were confirmed by distributional analyses. The results extend our understanding of the interplay between procedural learning and executive control.

Influence of Intermixed Emotion-Relevant Trials on the Affective Simon Effect

“Good” and “bad” vocal responses are faster when an irrelevant emotional stimulus feature corresponds with the response than when it does not, a phenomenon known as the affective Simon effect. Two experiments investigated how this effect was influenced by an intermixed emotion-relevant evaluation task. In Experiment 1, four schematic faces (friendly, happy, hostile, sad) were used for the affective Simon task and four different images (bird, heart, gun, ghost) for the evaluation task, whereas in Experiment 2 the schematic faces were used for both tasks. Mixed-compatible emotion-relevant trials increased the affective Simon effect in both experiments, but mixed-incompatible emotion-relevant trials did not influence it. Also, the advantage of the compatible mapping over the incompatible mapping increased in mixed conditions rather than decreased. These results differ from those obtained when visual-manual tasks for which location is relevant and irrelevant are mixed. They confirm that enhancement of the affective Simon effect when the Simon task is mixed with a compatible emotion-relevant task is due to increased salience of the affective valence.

Performance consequences of alternating directional control-response compatibility: evidence from a coal mine shuttle car simulator

OBJECTIVE

To investigate error and reaction time consequences of alternating compatible and incompatible steering arrangements during a simulated obstacle avoidance task.

BACKGROUND

Underground coal mine shuttle cars provide an example of a vehicle in which operators are required to alternate between compatible and incompatible steering configurations.

METHODS

This experiment examines the performance of 48 novice participants in a virtual analogy of an underground coal mine shuttle car. Participants were randomly assigned to a compatible condition, an incompatible condition, an alternating condition in which compatibility alternated within and between hands, or an alternating condition in which compatibility alternated between hands.

RESULTS

Participants made fewer steering direction errors and made correct steering responses more quickly in the compatible condition. Error rate decreased over time in the incompatible condition. A compatibility effect for both errors and reaction time was also found when the control-response relationship alternated; however, performance improvements over time were not consistent. Isolating compatibility to a hand resulted in reduced error rate and faster reaction time than when compatibility alternated within and between hands.

CONCLUSION

The consequences of alternating control-response relationships are higher error rates and slower responses, at least in the early stages of learning.

APPLICATION

This research highlights the importance of ensuring consistently compatible human-machine directional control-response relationships.

Spatial compatibility effects with tool use

OBJECTIVE

We explored constraints in responding to spatially variable stimuli when hand movements are transformed into inverse movements of a tool.

BACKGROUND

Generally, the spatial compatibility between stimuli and responses is a powerful determinant of performance. However, many tasks require the use of simple tools such as first-class levers that transform hand movements into inverted movements of a tool. What types of compatibility effects arise with such tools?

METHOD

Participants moved the tip of a pointer to the left or right according to the color of a stimulus. The pointer was manipulated either directly, so that a hand movement caused a pointer movement in the corresponding direction, or indirectly, so that the hand moved the pointer in the opposite direction.

RESULTS

Responding was faster when the location of stimulus and the movement direction of the tool corresponded than when they did not correspond, independent of the movement direction of the hand. This occurred when stimulus location was task relevant (Experiment 1) as well as when it was task irrelevant (Experiment 2). Furthermore, responding was delayed when the hand and the relevant end of the tool moved in noncorresponding rather than corresponding directions.

CONCLUSION

These results point to two distinct compatibility effects in tool use: one that relates to the transformation of stimuli into goals and one that relates to the transformation of goals into movements.

APPLICATION

Potential applications of this research include the prediction and possibly manipulation of unwanted "fulcrum effects" in laparoscopic surgery and other first-class lever movements.

Effects of precuing horizontal and vertical dimensions on right—left prevalence

When stimuli and responses can be coded along horizontal and vertical dimensions simultaneously, a right-left prevalence effect is often obtained for which the advantage for a compatible mapping is larger on the horizontal dimension than on the vertical dimension. The present study investigated the role of preparatory processes in this right-left prevalence effect using a method in which the relevant dimension was cued at short and long intervals prior to presentation of the target stimulus. In three experiments, the right-left prevalence effect did not vary significantly in magnitude as a function of cue-target interval, suggesting that the effect is due primarily to relative salience of the horizontal and vertical codes, as determined by the task structure, and not to a greater ease of attending to the horizontal dimension.

Development of cognitive control and executive functions from 4 to 13 years: evidence from manipulations of memory, inhibition, and task switching

Predictions concerning development, interrelations, and possible independence of working memory, inhibition, and cognitive flexibility were tested in 325 participants (roughly 30 per age from 4 to 13 years and young adults; 50% female). All were tested on the same computerized battery, designed to manipulate memory and inhibition independently and together, in steady state (single-task blocks) and during task-switching, and to be appropriate over the lifespan and for neuroimaging (fMRI). This is one of the first studies, in children or adults, to explore: (a) how memory requirements interact with spatial compatibility and (b) spatial incompatibility effects both with stimulus-specific rules (Simon task) and with higher-level, conceptual rules. Even the youngest children could hold information in mind, inhibit a dominant response, and combine those as long as the inhibition required was steady-state and the rules remained constant. Cognitive flexibility (switching between rules), even with memory demands minimized, showed a longer developmental progression, with 13-year-olds still not at adult levels. Effects elicited only in Mixed blocks with adults were found in young children even in single-task blocks; while young children could exercise inhibition in steady state it exacted a cost not seen in adults, who (unlike young children) seemed to re-set their default response when inhibition of the same tendency was required throughout a block. The costs associated with manipulations of inhibition were greater in young children while the costs associated with increasing memory demands were greater in adults. Effects seen only in RT in adults were seen primarily in accuracy in young children. Adults slowed down on difficult trials to preserve accuracy; but the youngest children were impulsive; their RT remained more constant but at an accuracy cost on difficult trials. Contrary to our predictions of independence between memory and inhibition, when matched for difficulty RT correlations between these were as high as 0.8, although accuracy correlations were less than half that. Spatial incompatibility effects and global and local switch costs were evident in children and adults, differing only in size. Other effects (e.g., asymmetric switch costs and the interaction of switching rules and switching response-sites) differed fundamentally over age.