The role of environmental contextual cues in sequence learning: evidence from a virtual maze context.

Studies on sequence learning usually focus on single, isolated stimuli that are presented sequentially. For example, in the serial reaction time (RT) task, stimuli are either presented in a predictable sequence or in a random sequence, and better performance with the predictable sequence is taken as evidence for sequence-specific learning. Yet, little is known about the role of environmental context cues in sequence learning. If the target stimuli are embedded in a meaningful context, would this facilitate learning by providing helpful contextual associations or would it hinder learning by adding distracting stimuli? This question was examined in two studies. A pilot study compared sequence learning in a virtual maze with a horizontal vs. vertical maze context, in which arrow stimuli guide spatial lever movement responses that resulted in a corresponding virtual transport on the screen. The results showed only overall somewhat better performance with the vertical maze compared to the horizontal maze, but general practice effects and sequence-specific learning effects were the same for both contexts. The main study compared sequence learning with a maze context to sequence learning of arrows without a maze context. The results showed significantly better learning with maze context than without context. These data suggest that the maze context facilitated sequence learning by inducing a meaningful spatial representation ("mental map") similar to that formed in wayfinding.

Learning a covert sequence of effector movements: limits to its acquisition.

Sequence learning in serial reaction time (SRT) tasks is an established, lab-based experimental paradigm to study acquisition and transfer of skills based on the detection of predictable regularities in stimulus and motor response sequences. Participants learn a sequence of targets and responses to these targets by associating the responses with subsequently presented targets. In the traditional paradigm, however, actions and response targets are directly related. In contrast, the present study asked whether participants would demonstrate acquisition of a sequence of effector movements of the left vs. right hand (e.g., hand sequence learning), whilst the actual targets and associated finger responses are unpredictable. Twenty-seven young adults performed a SRT task to visually presented characters with the index or middle fingers of both hands. While the specific fingers to respond with were randomly selected for each target presentation, both hands followed a covert sequence. We asked whether participants would learn the underlying hand sequence as demonstrated by shortened response latencies and increased accuracy compared to a fully randomized hand sequence. The results show sequence-specific learning effects. However, categorization of hand responses depending on the previous response suggested that learning occurred predominantly for subsequent finger responses of the same hand, which added to general hand-based priming. Nevertheless, a marginally significant effect was observed even for predictable shifts between hands when homologous fingers were involved. Our results thus suggest that humans are able to benefit from predictable within-hand finger shifts but less so for predicted shifts between hands.

Inhibition of cued but not executed task sets depends on cue-task compatibility and practice.

In task switching, processing a task cue is thought to activate the corresponding task representation ("task set"), thereby allowing for advance task preparation. However, the contribution of preparatory processes to the emergence of n-2 repetition costs as index of task set inhibition processes is debated. The present study investigated whether merely preparing for a task activates a corresponding task set, which needs to be inhibited in order to switch to a different task. To this end, we presented so-called task cue-only trials in trial n-2 and assessed subsequent n-2 repetition costs. The results revealed n-2 repetition costs following a task cue-only, but only for compatible cues with a transparent cue-task relation and only at the beginning of the experiment. In contrast, n-2 repetition costs following task execution in trial n-2 were absent. In a second experiment, we sought to rule out that the presence of n-2 repetition costs following a task cue-only and the corresponding absence following task execution were the consequence of a decay of task sets. This second experiment replicated the result pattern of the first experiment, with n-2 repetition costs following a task cue-only being present only at the beginning of the experiment and only for compatible cues. Hence, cue-induced task set inhibition effects depended on cue-task compatibility and practice. Furthermore, merely prepared task sets were more likely inhibited than executed task sets.

Repetition costs in task switching are not equal to cue switching costs: evidence from a cue-independent context.

Recent task-switching studies highlighted the presence of feature binding processes. These studies documented that even a task-irrelevant feature (the context, henceforth) may be bound with the task and the response in each trial. When the context repeated in the following trial, it supposedly retrieved the bound features, causing benefits when the task and the response repeated and costs otherwise (i.e. full repetition benefits). In the present study, we aim to rule out an alternative explanation for such full repetition benefits in task switching. These benefits were observed in studies that used a cue-related context so that full repetition conditions always implied a cue repetition. Therefore, these full repetition benefits may be ascribed to the priming of cue encoding, instead of the binding of the context. In the present study, we implemented a similar context manipulation but used univalent target stimuli and did not present any cue. Hence, the varying context was never cue-related. We still found full repetition benefits but only when the context appeared before the target and not when they appeared simultaneously. Thus, full repetition benefits can be observed in the absence of priming of cue encoding. However, the context must occupy a prominent position (i.e. at the beginning of the trial). These results, therefore, reinforce the hypothesis that full repetition benefits stem from binding processes that take place on a trial-by-trial basis and involve both task-relevant (the task and the response) and task-irrelevant features (the context).

Impact of aging on crossmodal attention switching.

Previous studies on crossmodal visual-auditory attention switching using a spatial discrimination task showed performance costs when the target modality changed relative to when it repeated. The present study (n = 42 for each age group) examined age-related changes in crossmodal attention switching by asking young (age range 19 to 30 years old) and older (age range 64 to 80 years old) participants to respond to unimodal central cues and bimodal lateralized stimuli. The participants' task was to indicate the location of the target in the relevant modality using button presses. Results showed general attention switch costs. Additionally, we found no specific age-related increase of attention switch costs (no difference in performance between switch and repetition of target modality), but age-related increased mixing costs (decreased performance for repetition in modality-mixed condition compared to single target modality). Moreover, spatial distraction produced a crossmodal congruency effect, which was only slightly larger in older adults. Taken together, age-related increased mixing costs suggest a general difficulty with maintaining more than one task, but no specific age-related crossmodal impairment in crossmodal attention switching.

Impact of process interference on memory encoding and retrieval processes in dual-task situations.

Dual-tasks at the memory encoding stage have been shown to decrease recall performance and impair concurrent task performance. In contrast, studies on the effect of dual-tasks at the memory retrieval stage observed mixed results. Which cognitive mechanisms are underlying this dual-task interference is still an unresolved question. In the present study, we investigated the influence of a concurrent reaction-time task on the performance in a long-term memory task in two experiments. In Experiment 1, participants performed an auditory-verbal free recall memory task and a visual-manual spatial Stroop task in a single or dual-task condition, either at the encoding or retrieval stage of the memory task. In Experiment 2, we examined the influence of processing conflicts in a concurrent RT task on memory encoding. Both experiments showed detrimental effects on recall accuracy and concurrent RT task performance in dual-task conditions at the encoding stage. Dual-task conditions at the retrieval stage led to a slowdown in recall latency and impaired concurrent RT task performance, but recall accuracy was maintained. In addition, we observed larger Stroop congruency effects in the dual-task conditions, indicating an increased processing conflict. However, in Experiment 2, we analyzed the effect of the processing conflict in a time-locked manner and could not find a significant influence on success of memory encoding. These findings suggest that processes in both tasks share the same limited capacity and are slowed down due to parallel processing, but we could not find evidence that this is further influenced by task-specific processing conflicts.

Examining the cognitive processes underlying resumption costs in task-interruption contexts: Decay or inhibition of suspended task goals?

To examine whether an ongoing primary task is inhibited when switching to an interruption task, we implemented the n - 2 backward inhibition paradigm into a task-interruption setting. In two experiments, subjects performed two primary tasks (block-wise manipulation) consisting of a predefined sequence of three subtasks. The primary tasks differed regarding whether the last subtask switched or repeated relative to the penultimate subtask, resulting in n - 1 switch subtasks (e.g., ABC) and n - 1 repetition subtasks (e.g., ACC) as the last subtask of the primary task. Occasionally, an interruption task was introduced before the last subtask of a primary task, changing the last subtask of the primary task from a n - 1 switch subtask to a n - 2 switch subtask (e.g., AB → secondary task → C) and from a n - 1 repetition subtask to a n - 2 repetition subtask (e.g., AC → secondary task → C). In two experiments with different degrees of response-set overlap between the interruption task and the subtasks of the primary task, we observed that switching back from the interruption task to the primary task resulted in n - 2 switch costs in the first subtask after the interruption (i.e., worse performance in n - 2 switch subtasks than in n - 2 repetition subtasks). This n - 2 switch cost was replicated in a third experiment in which we used a predefined sequence of four subtasks instead of three subtasks. Our finding of n - 2 switch costs suggest that the last subtask performed before the interruption remains activated when switching to the interruption task.

Voluntary task switching is affected by modality compatibility and preparation.

Cognitive task control can be examined in task-switching studies. Performance costs in task switches are usually smaller with compatible stimulus-response modality mappings (visual-manual and auditory-vocal) than with incompatible mappings (visual-vocal and auditory-manual). Modality compatibility describes the modality match of sensory input and of the anticipated response effect (e.g., vocal responses produce auditory effects, so that auditory stimuli are modality-compatible with vocal responses). Fintor et al. (Psychological Research, 84(2), 380-388, 2020) found that modality compatibility also biased task choice rates in voluntary task switching (VTS). In that study, in each trial participants were presented with a visual or auditory spatial stimulus and were free to choose the response modality (manual vs. vocal). In this free-choice task, participants showed a bias to create more modality-compatible than -incompatible mappings. In the present study, we assessed the generality of Fintor et al.'s (2020) findings, using verbal rather than spatial stimuli, and more complex tasks, featuring an increased number of stimulus-response alternatives. Experiment 1 replicated the task-choice bias to preferentially create modality-compatible mappings. We also found a bias to repeat the response modality just performed, and a bias to repeat entire stimulus-response modality mappings. In Experiment 2, we manipulated the response-stimulus interval (RSI) to examine whether more time for proactive cognitive control would help resolve modality-specific crosstalk in this free-choice paradigm. Long RSIs led to a decreased response-modality repetition bias and mapping repetition bias, but the modality-compatibility bias was unaffected. Together, the findings suggest that modality-specific priming of response modality influences task choice.

Preparing auditory task switching in a task with overlapping and non-overlapping response sets.

We used a variant of cued auditory task switching to investigate task preparation and its relation to response-set overlap. Previous studies found increased interference with overlapping response sets across tasks relative to non-overlapping motor response sets. In the present experiments, participants classified either pitch or loudness of a simple tone as low or high, hence, both tasks were constructed around common underlying integrated semantic categories ranging from low to high. Manual responses overlapped in both category and modality for both tasks in Experiment 1A, whereas each task was related to a specific response category and response modality (manual vs. vocal) in Experiment 1B. Focusing on the manual responses in both experiments, the data showed that non-overlapping response sets (Experiment 1B) resulted in a decreased congruency effect, suggesting reduced response-based crosstalk and thus better task shielding, but at the same time switch costs were increased, suggesting less efficient switching between task sets. Moreover, varying preparation time (cue-stimulus interval, CSI) showed that long CSI led to better performance overall. Our results thus suggest that when non-overlapping response sets share common semantic categories across tasks, there is no general benefit over overlapping response sets.

Disentangling task-selection failures from task-execution failures in task switching: an assessment of different paradigms.

Differentiating errors on the basis of the distinct cognitive mechanisms that may have generated them has provided neuropsychologists with useful diagnostic tools. For example, perseverative errors arising from the inability of the patient to set a new criterion for responding are considered one of the hallmarks of cognitive inflexibility. Similarly, in the task-switching paradigm it is possible to distinguish between task-confusion errors, produced by a failure in task selection, and response-confusion errors, arising when the correct task is selected, but the wrong response is given. Nonetheless, only a few studies so far have exploited the existence of different kinds of errors in multitasking situations to inform theories of cognitive flexibility. In the present study, we set out to use a variety of methodologies employed so far in the literature for disentangling errors due to task-selection failure from errors due to task-execution failure. In three experiments, we assessed the capacity of each method to produce error categories that can be mapped as clearly as possible to the cognitive mechanism(s) underlying them using multinomial processing tree modelling. Subsequently, the distinction between task- and response-confusion errors was used to test their differential impact on inhibitory mechanisms in task switching as measured by N-2 repetition costs. Our results are encouraging regarding the possibility of correctly detecting response- and task-selection failures, thus allowing us to assess their differential impact on N-2 repetition costs.

Assessing the influence of cognitive response conflict on balance control: an event-related approach using response-aligned force-plate time series data.

Process interference or sharing of attentional resources between cognitive tasks and balance control during upright standing has been well documented. Attentional costs increase with greater balancing demands of a balance activity, for example in standing compared to sitting. The traditional approach for analyzing balance control using posturography with a force plate integrates across relative long trial periods of up to several minutes, which blends any balance adjustments and cognitive operations within this period. In the present study, we pursued an event-related approach to assess if single cognitive operations resolving response selection conflict in the Simon task interfere with concurrent balance control in quiet standing. In addition to traditional outcome measures (response latency, error proportions) in the cognitive Simon task, we investigated the effect of spatial congruency on measures of sway control. We expected that conflict resolution in incongruent trials would alter short-term progression of sway control. Our results demonstrated the expected congruency effect on performance in the cognitive Simon task and the mediolateral variability of balance control within 150 ms before the onset of the manual response was reduced to a greater degree in incongruent compared to congruent trials. In addition, mediolateral variability before and after the manual response was generally reduced compared to variability following target presentation, where no effect of congruency was observed. Assuming that response conflict in incongruent conditions requires suppression of the incorrect response tendencies, our results may imply that mechanisms of cognitive conflict resolution may also carry over to intermittent balance control mechanisms in a direction-specific manner.

The role of action effects in motor sequence planning and execution: exploring the influence of temporal and spatial effect anticipation.

Actions we perform every day generate perceivable outcomes with both spatial and temporal features. According to the ideomotor principle, we plan our actions by anticipating the outcomes, but this principle does not directly address how sequential movements are influenced by different outcomes. We examined how sequential action planning is influenced by the anticipation of temporal and spatial features of action outcomes. We further explored the influence of action sequence switching. Participants performed cued sequences of button presses that generated visual effects which were either spatially compatible or incompatible with the sequences, and the spatial effects appeared after a short or long delay. The sequence cues switched or repeated across trials, and the predictability of action sequence switches was varied across groups. The results showed a delay-anticipation effect for sequential action, whereby a shorter anticipated delay between action sequences and their outcomes speeded initiation and execution of the cued action sequences. Delay anticipation was increased by predictable action switching, but it was not strongly modified by the spatial compatibility of the action outcomes. The results extend previous demonstrations of delay anticipation to the context of sequential action. The temporal delay between actions and their outcomes appears to be retrieved for sequential planning and influences both the initiation and the execution of actions.

On the reliability of behavioral measures of cognitive control: retest reliability of task-inhibition effect, task-preparation effect, Stroop-like interference, and conflict adaptation effect.

This study examined the reliability (retest and split-half) of four common behavioral measures of cognitive control. In Experiment 1 (N = 96), we examined N - 2 task repetition costs as a marker of task-level inhibition, and the cue-stimulus interval (CSI) effect as a marker of time-based task preparation. In Experiment 2 (N = 48), we examined a Stroop-like face-name interference effect as a measure of distractor interference control, and the sequential congruency effect ("conflict adaptation effect") as a measure of conflict-triggered adaptation of cognitive control. In both experiments, the measures were assessed in two sessions on the same day, separated by a 10 min-long unrelated filler task. We observed substantial experimental effects with medium to large effect sizes. At the same time, split-half reliabilities were moderate, and retest reliabilities were poor, for most measures, except for the CSI effect. Retest reliability of the Stroop-like effect was improved when considering only trials preceded by congruent trials. Together, the data suggest that these cognitive control measures are well suited for assessing group-level effects of cognitive control. Yet, except for the CSI effect, these measures do not seem suitable for reliably assessing interindividual differences in the strength of cognitive control, and therefore are not suited for correlational approaches. We discuss possible reasons for the discrepancy between robustness at the group level and reliability at the level of interindividual differences.

Dissociating stimulus-response compatibility and modality compatibility in task switching.

Modality compatibility (MC) describes the similarity between the modality of the stimulus and the modality of the anticipated response effect (e.g., auditory effects when speaking). Switching between two incompatible modality mappings (visual-vocal and auditory-manual) typically leads to larger costs than switching between two compatible modality mappings (visual-manual and auditory-vocal). However, it is unclear whether the influence of MC arises before or after task selection or response selection, or affects both processes. We investigated this issue by introducing a factor known to influence response selection, stimulus-response (S-R) compatibility, examining possible interactions with MC. In Experiment 1, stimulus location was task-irrelevant; participants responded manually or vocally to the meaning of visual and auditory colour words presented left or right (Simon task). In Experiment 2, stimulus location was task-relevant; participants responded manually or vocally, indicating the location (left or right) of visual or auditory stimuli, using a spatially compatible versus incompatible mapping rule ("element-level" S-R compatibility). Results revealed independent effects of S-R and modality compatibility in both experiments (n = 40 per experiment). Bayes factors suggested moderate but consistent evidence for the absence of an interaction. Independent effects suggest MC effects arise either before or after response selection, or possibly both. We propose that motor response initiation is associated with anticipatory activation of modality-specific sensory effects (e.g., auditory effects when speaking), which in turn facilitates the correct response in case of modality-compatible mappings (e.g., auditory-vocal) or reactivates, at the task-selection level, the incorrect task in case of modality-incompatible mappings (e.g., visual-vocal).

Are some effector systems harder to switch to? In search of cost asymmetries when switching between manual, vocal, and oculomotor tasks.

In task-switching studies, performance is typically worse in task-switch trials than in task-repetition trials. These switch costs are often asymmetrical, a phenomenon that has been explained by referring to a dominance of one task over the other. Previous studies also indicated that response modalities associated with two tasks may be considered as integral components for defining a task set. However, a systematic assessment of the role of response modalities in task switching is still lacking: Are some response modalities harder to switch to than others? The present study systematically examined switch costs when combining tasks that differ only with respect to their associated effector systems. In Experiment 1, 16 participants switched (in unpredictable sequence) between oculomotor and vocal tasks. In Experiment 2, 72 participants switched (in pairwise combinations) between oculomotor, vocal, and manual tasks. We observed systematic performance costs when switching between response modalities under otherwise constant task features and could thereby replicate previous observations of response modality switch costs. However, we did not observe any substantial switch-cost asymmetries. As previous studies using temporally overlapping dual-task paradigms found substantial prioritization effects (in terms of asymmetric costs) especially for oculomotor tasks, the present results suggest different underlying processes in sequential task switching than in simultaneous multitasking. While more research is needed to further substantiate a lack of response modality switch-cost asymmetries in a broader range of task switching situations, we suggest that task-set representations related to specific response modalities may exhibit rapid decay.

Dual-task interference and response strategies in simulated car driving: impact of first-task characteristics on the psychological refractory period effect.

Presentation of a task T1 typically delays the response to a subsequent task T2, more so with high temporal task overlap than with low temporal overlap. This so-called "psychological refractory period effect" (PRP effect) has been observed even if T1 required not a choice between distinct stimulus-response pairs, but rather between a given stimulus-response pair occurring once or twice. We explored which response strategy participants use for responding to such an unusual type of T1 and how such a T1 interacts with T2 performance. In a driving simulator, participants followed a lead car and had to honk when that car's rear window changed color (T1). In condition "pure", the color always changed once and required a single honk; in condition "mixed", the color changed once and required a single honk on some trials, but on other trials, it changed twice 200 ms apart and required a double honk. Participants also had to brake when the lead car braked (T2). On dual-task trials, T1 preceded T2 with a varying stimulus onset asynchrony (SOA) of 50-1200 ms. Reaction time to the first T1 stimulus was similar in "pure" and "mixed" and it was comparable with the reaction time to the second T1 stimulus. Reaction time to the T2 stimulus increased as SOA decreased from 350 to 50 ms, confirming the existence of a PRP effect. Furthermore, reaction time to the T2 stimulus was similar in "pure" and in "mixed" with one T1 stimulus, but was higher in "mixed" with two T1 stimuli. This pattern of findings is compatible with the view that presentation of the first T1 stimulus triggers a single response, which is amended into a double response, if a second T1 stimulus is displayed. The amendment does not need to wait until central processing of the original response is completed, and it therefore begins with no delay beyond the regular reaction time. Our findings further suggest that the mere possibility of a second T1 stimulus being presented does not increase the PRP effect on T2, probably because response amendments are not equivalent to classical response choices. However, the actual presentation of a second T1 stimulus indeed does increase the PRP effect on T2, probably because amendments start 200 ms later than the original response, and therefore prolong central processing of T1.

Inhibitory mechanisms in motor imagery: disentangling different forms of inhibition using action mode switching.

In motor imagery, probably several inhibitory mechanisms prevent actual movements: global inhibition, effector-specific inhibition, and inhibition retrieved during target processing. We investigated factors that may influence those mechanisms. In an action mode switching paradigm, participants imagined and executed movements from home buttons to target buttons. We analysed sequential effects. Activation (due to execution) or inhibition (due to imagination) in the previous trial should affect performance in the subsequent trial, enabling conclusions about inhibitory mechanisms in motor imagery. In Experiment 1, evidence for global and effector-specific inhibition was observed. Evidence for inhibition retrieved during target processing was inconclusive. Data patterns were similar when start and end of the imagined movements were indicated with an effector that was part of the imagined movement (hand) and with a different effector (feet). In Experiment 2, we ruled out that the use of biological stimuli (left/right hands in Experiment 1) to indicate the effector causes sequential effects attributed to effector-specific inhibition, by using uppercase letters (R, L). As in Experiment 1, evidence for effector-specific inhibition was observed. In conclusion, we could reliably disentangle several inhibitory mechanisms in motor imagery.

Modality compatibility in task switching depends on processing codes and task demands.

Modality compatibility denotes the match between sensory stimulus modality and the sensory modality of the anticipated response effect (for example, vocal responses usually lead to auditory effects, so that auditory-vocal stimulus-response mappings are modality-compatible, whereas visual-vocal mappings are modality incompatible). In task switching studies, it has been found that switching between two modality-incompatible mappings (auditory-manual and visual-vocal) resulted in higher switch costs than switching between two modality-compatible mappings (auditory-vocal and visual-manual). This finding suggests that with modality-incompatible mappings, the anticipation of the effect of each response primes the stimulus modality linked to the competing task, creating task confusion. In Experiment 1, we examined whether modality-compatibility effects in task switching are increased by strengthening the auditory-vocal coupling using spatial-verbal stimuli relative to spatial-location stimuli. In Experiment 2, we aimed at achieving the same goal by requiring temporal stimulus discrimination relative to spatial stimulus localisation. Results suggest that both spatial-verbal stimuli and temporal discrimination can increase modality-specific task interference through a variation of the strength of anticipation in the response-effect coupling. This provides further support for modality specificity of cognitive control processes in task switching.

Evidence for a multicomponent hierarchical representation of dual tasks.

Recent dual-task studies observed worse performance in task-pair switches than in task-pair repetitions and interpreted these task-pair switch costs as evidence that the identity of the two individual tasks performed within a dual task is jointly represented in a single mental representation, termed "task-pair set." In the present study, we conducted two experiments to examine (a) whether task-pair switch costs are due to switching cues or/and task pairs and (b) at which time task-pair sets are activated during dual-task processing. In Experiment 1, we used two cues per task-pair and found typical dual-task interference, indicating that performance in the individual tasks performed within the dual task deteriorates as a function of increased temporal task overlap. Moreover, we observed cue switch costs, possibly reflecting perceptual cue priming. Importantly, there were also task-pair switch costs that occur even when controlling for cue switching. This suggests that task-pair switching per se produces a performance cost that cannot be reduced to costs of cue switching. In Experiment 2, we employed a go/no-go-like manipulation and observed task-pair switch costs after no-go trials where subjects prepared for a task-pair, but did not perform it. This indicates that task-pair sets are activated before performing a dual task. Together, the findings of the present study provide further evidence for a multicomponent hierarchical representation consisting of a task-pair set organized at a hierarchically higher level than the task sets of the individual tasks performed within a dual task.

Modality compatibility biases voluntary choice of response modality in task switching.

The term modality compatibility refers to the similarity between stimulus modality and the modality of response-related sensory consequences (e.g., vocal responses produce auditory effects). The previous results showed smaller task-switching costs when participants switched between modality compatible tasks (auditory-vocal and visual-manual) compared to switching between modality incompatible tasks (auditory-manual and visual-vocal). In the present study using a voluntary task-switching paradigm (VTS), participants chose the response modality (vocal or manual) to indicate the location of either a visual or an auditory stimulus. We examined whether free task choices were biased by modality compatibility, so that modality compatible tasks are preferred in VTS. The choice probability analysis indicated that participants tended to choose the response modality that is compatible to the stimulus modality. However, participants did not show a preference to repeat a stimulus-response (S-R) modality mapping, but to switch between modality compatibility (i.e., from S-R modality compatible mapping to S-R modality incompatible mapping and vice versa). More interestingly, even though participants freely chose the response modality, modality compatibility still influenced task-switching costs, showing larger costs with modality incompatible mappings. The finding that modality compatibility influenced choice behaviour suggests components of both top-down control and bottom-up effects of selecting a response modality for different stimulus modalities.