The visuomotor mental rotation task: visuomotor transformation times are reduced for small and perceptually familiar angles

In the visuomotor mental rotation (VMR) task, participants point to a location that deviates from a visual cue by a predetermined angle. This task elicits longer reaction times (RT) relative to tasks wherein the visual cue is spatially compatible with the movement goal. The authors previously reported that visuomotor transformations are faster and more efficient when VMR responses elicit a degree of dimensional overlap (i.e., 0° and 5°) or when the transformation involves a perceptually familiar angle (i.e., 90° or 180°; K. A. Neely & M. Heath, 2010b). One caveat to this finding is that standard and VMR responses were completed in separate blocks of trials. Thus, between-task differences not only reflect the temporal demands of the visuomotor transformations, but also reflect the temporal cost of response inhibition. The goal of this study was to isolate the time cost of visuomotor transformations in the VMR task. The results demonstrated that visuomotor transformations are more efficient and effective when the response entails a degree of dimensional overlap between target and response (i.e., when the angular disparity between the responses is small) or when the transformation angle is perceptually familiar.     

Crossmodal action selection: Evidence from dual-task compatibility

Response-related mechanisms of multitasking were studied by analyzing simultaneous processing of responses in different modalities (i.e., crossmodal action). Participants responded to a single auditory stimulus with a saccade, a manual response (single-task conditions), or both (dual-task condition). We used a spatially incompatible stimulus-response mapping for one task, but not for the other. Critically, inverting these mappings varied temporal task overlap in dual-task conditions while keeping spatial incompatibility across responses constant. Unlike previous paradigms, temporal task overlap was manipulated without utilizing sequential stimulus presentation, which might induce strategic serial processing. The results revealed dual-task costs, but these were not affected by an increase of temporal task overlap. This finding is evidence for parallel response selection in multitasking. We propose that crossmodal action is processed by a central mapping-selection mechanism in working memory and that the dual-task costs are mainly caused by mapping-related crosstalk.     

The influence of dimensional overlap on location-related priming in the Simon task

Choice reaction times are shorter when stimulus and response locations are compatible than when they are incompatible as in the Simon effect. Recent studies revealed that Simon effects are strongly attenuated when there is temporal overlap with a different high-priority task, accompanied by a decrease of early location-related response priming as reflected in the lateralized readiness potential (LRP). The latter result was obtained in a study excluding overlap of stimulus location with any other dimension in the tasks. Independent evidence suggests that location-related priming might be present in conditions with dimensional overlap. Here we tested this prediction in a dual-task experiment supplemented with recording LRPs. The secondary task was either a standard Simon task where irrelevant stimulus location overlapped with dimensions of the primary task or a Stroop-like Simon task including additional overlap of irrelevant and relevant stimulus attributes. At high temporal overlap, there was no Simon effect nor was there stimulus-related response priming in either condition. Therefore stimulus-triggered response priming seems to be abolished in conditions of limited capacity even if the likelihood of an S–R compatibility effect is maximized.     

Response coding in the Simon task

Recent findings indicate that two distinct mechanisms can contribute to a Simon effect: a visuomotor information transmission on the one hand and a cognitive code interference on the other hand (see for e.g., Wiegand & Wascher, in Journal of Experimental Psychology: Human Perception and Performance 2005a). Furthermore, it was proposed that the occurrence of one or the other mechanism strongly depends on the way responses are coded. Visuomotor information transmission seems to depend on a correspondence between stimulus position and spatial anatomical status of the effector, whereas cognitive code interference is thought to be based on relative response location codes. To further test the spatial anatomic coding hypothesis, three experiments were conducted, in which the Simon effect with unimanual responses was investigated for horizontal (Experiment 1 and 2) and vertical (Experiment 3) stimulus-response (S-R) relations. Based on the finding of a decreasing effect function (indicating the presence of visuomotor information transmission) for horizontal and vertical S-R relations, it was concluded that visuomotor information transmission occurs whenever there is an overlap between the spatial stimulus feature and parameters of the motor representation of the response. Furthermore, the specific motor representation seems to be task dependent, that is, it entails those response parameters that clearly differentiate between the two response alternatives in a given task situation.     

Evidence for the automatic processing of prelexical codes in an orthographic but not a phonological task

The automatic activation of phonological and orthographic information in auditory and visual word processing was examined using a task-set procedure. Participants engaged in a phonological task (i.e., determining whether the letter “a” in a word sounded like /e/ or /æ/) or an orthographic task (i.e., determining whether the sound /s/ in a word was spelled with an “s” or a “c”). Participants were cued regarding which task to perform simultaneously with, or 750 ms before, a clear or degraded target. The stimulus clarity effect (i.e., clear words responded to faster than degraded words) was absorbed into the time that it took participants to identify the task on the basis of the cue in a simultaneous cue–target as compared to a delayed cue–target condition, but only for the orthographic task. These data are consistent with the claim that prelexical processing occurs in a capacity-free manner upon stimulus presentation when participants are trying to extract orthographic codes from words presented in the visual and auditory modalities. Such affirmative data were not obtained when participants attempted to extract phonological codes from words, since here the effects of stimulus clarity and cue delay were additive.     

Cue type affects preparatory influences on task inhibition

The present study investigates the influence of preparation on inhibitory effects in cued task switching. In three experiments, we assessed n − 2 repetition costs as marker of inhibition of the just executed and now irrelevant task by comparing performance in task sequences such as ABA (i.e., n − 2 repetitions, with A, B and C standing for different tasks) to task sequences such as CBA (i.e., n − 2 switches). Specifically, we varied the cue–target interval (CTI) to examine cue-based preparation effects. In addition, we manipulated cue type (i.e., abstract, verbal, and direct cues) across the three experiments. We obtained significant reductions of n − 2 repetition costs with prolonged CTI when using abstract cues (i.e., coloured frames) and task names (i.e., digit), but not when using the task-specific stimulus–response mapping as cue for the upcoming task. These data suggest that cue-based preparation is not a uniform process but depends on the information provided by the cue.     

Are transposition effects specific to letters?

Recent research has consistently shown that pseudowords created by transposing two letters are perceptually similar to their corresponding base words (e.g., jugde–judge). In the framework of the overlap model (Gomez, Ratcliff, & Perea, 2008), this effect is due to a noisy process in the localization of the “objects” (e.g., letters, kana syllables). In the present study, we examine whether this effect is specific to letter strings or whether it also occurs with other “objects” (namely, digits, symbols, and pseudoletters). To that end, we conducted a series of five masked priming experiments using the same–different task. Results showed robust effects of transposition for all objects, except for pseudoletters. This is consistent with the view that locations of familiar objects (i.e., letters, numbers, and symbols) can be best understood as distributions along a dimension rather than as precise points.     

Time course of the Simon effect in pointing movements for horizontal, vertical, and acoustic stimuli: evidence for a common mechanism

In the Simon effect, responses to a non-spatial attribute are faster when the irrelevant spatial position of the stimulus corresponds to the position of the response. It was suggested that there are two distinct mechanisms involved in the Simon effect. In the visuomotor Simon effect, the stimulus transiently activates the corresponding response which results in a decaying Simon effect function (i.e., the Simon effect decreases in slower reaction time [RT]-bins). In contrast, the cognitive Simon effect arises from a conflict between stimulus and response codes and is associated with a stable Simon effect function (i.e., the Simon effect is the same in fast and slow RT-bins). We recorded RTs and motor parameters of pointing movements in a Simon paradigm. Consistent with the previous research, the time course of the Simon effect in RTs was stable with vertical visual and horizontal acoustic stimuli (cognitive Simon tasks), but decreased with horizontal visual stimuli (visuomotor Simon task). In contrast, the Simon effect in motor parameters decreased across RT-bins in all conditions, supporting the idea that only a single, common mechanism underlies the Simon effect.     

Effects of relevant and irrelevant color singletons on inhibition of return and attentional capture

We tested whether color singletons lead to saccadic and manual inhibition of return (IOR; i.e., slower responses at cued locations) and whether IOR depended on the relevance of the color singletons. The target display was preceded by a nonpredictive cue display. In three experiments, half of the cues were response-relevant, because participants had to perform a discrimination task at the cued location. With the exception of Experiment 2, none of the cue colors matched the target color. We observed saccadic IOR after color singletons, which was greater for slow than for fast responses. Furthermore, when the relevant cue color matched the target color, we observed attentional capture (i.e., faster responses at cued locations) with rapid responses, but IOR with slower responses, which provides evidence for attentional deallocation. When the cue display was completely response-irrelevant in two additional experiments, we did not find evidence for IOR. Instead, we found attentional capture when the cue color matched the target color. Also, attentional capture was greater for rapid responses and with short cue–target intervals. Thus, IOR emerges when cues are relevant and do not match the target color, whereas attentional capture emerges with relevant and irrelevant cues that match the target color.     

Arrow-elicited cueing effects at short intervals: Rapid attentional orienting or cue-target stimulus conflict?

The observation of cueing effects (faster responses for cued than uncued targets) rapidly following centrally-presented arrows has led to the suggestion that arrows trigger rapid automatic shifts of spatial attention. However, these effects have primarily been observed during easy target-detection tasks when both cue and target remain on the screen until the behavioral response. We manipulated stimulus duration and task difficulty in an attention-cueing experiment to explore non-attentional explanations for rapid cueing effects. Contrary to attention-based predictions, short-interval cueing effects were observed only for long-duration cue and target stimuli, occurred even when the cue and target were presented simultaneously, and were driven by slowing of the uncued-target responses, rather than any facilitation for cued targets. We propose that, under these long-duration, short-interval conditions, the processing of the cue and target interact more extensively in the brain, and that when the cue and target convey incongruent spatial information (i.e., on invalidly cued trials) it leads to conflict-related slowing of responses.     

Exploring temporal dissipation of attention settings in auditory task switching

Using a cued auditory task-switching variant of dichotic listening, we varied the response–cue interval (RCI) to examine temporal dissipation effects. On each trial, participants were presented with two different number words, one spoken by a female speaker and another by a male speaker (dichotic listening), that served as competing targets for a numerical judgment. The gender of the task-relevant speaker was indicated by a visual task cue prior to each trial. Experiment 1A used two different cues for each task (i.e., gender) and showed only small cue repetition benefits (same cue vs. alternate cue) but large auditory switch costs (alternate cue vs. task switch). A replication without immediate cue repetitions (Experiment 1B) showed very similar switch costs, suggesting that immediate cue repetitions play a negligible role for the size of auditory task switch costs. Moreover, switch costs were reduced when the (entirely task-irrelevant) location of the task-relevant speaker changed, relative to when it was unchanged, suggesting an episodic feature-binding component in our dichotic-listening task. Importantly, both experiments showed no effect of RCI on auditory switch costs. Because statistical power for this null effect was reasonably high across experiments (n?=?50), this finding suggests that auditory attention settings do not dissipate quickly over time.     

Verbal response-effect compatibility

Ideomotor theory states that motor responses are activated by an anticipation of their sensory effects. We assumed that anticipated effects would produce response-effect (R-E) compatibility when there is dimensional overlap of effects and responses. In a four-choice task, visual digit stimuli called for verbal responses (color names). Each response produced a written response-effect on the screen. In different groups, the response-effect was a colored color word (e.g., blue in blue), a white color word, or a colored nonword (Xs in blue). In different blocks, the predictable effects were either incompatible (e.g., response "blue" --> effect: green) or compatible with the response. We found faster responses with compatible than with incompatible R-E mappings. The compatibility effect was strongest with colored words, intermediate with white words, and smallest with colored nonwords. We conclude that effect anticipation influences response selection on both a perceptual level (related to the word's color) and a conceptual level (related to the word's meaning).     

Effect on of familiarity and category contrast stimulus and response priming

In a letter-symbol classification task, flanking incompatible symbols slowed response latencies to letter targets, whereas incompatible letter flankers did not slow the classification of symbol targets. The conditions surrounding this asymmetry in response competition were investigated in five experiments. The results showed that: (1) the asymmetry was not related to the familiarity of the symbol targets or to the prime-target interval; (2)when the classification involved familiar and unfamiliar symbols, the asymmetry remained (i.e., there was less interference associated with the unfamiliar symbol targets), but there was now significant response competition associated with both symbol categories; and (3) with a mixed-category task (i.e., letters and symbols assigned to both responses), the symbol targets continued to be less interfered with by both letter and symbol incompatible flankers. These findings were interpreted as suggesting that response competition can be influenced by both classification decision rules and cohesiveness of exemplars comprising a category.     

Effect of familiarity and category contrast on stimulus and response priming

In a letter-symbol classification task, flanking incompatible symbols slowed response latencies to letter targets, whereas incompatible letter flankers did not slow the classification of symbol targets. The conditions surrounding this asymmetry in response competition were investigated in five experiments. The results showed that: (1) the asymmetry was not related to the familiarity of the symbol targets or to the prime-target interval; (2) when the classification involved familiar and unfamiliar symbols, the asymmetry remained (i.e., there was less interference associated with the unfamiliar symbol targets), but there was now significant response competition associated with both symbol categories; and (3) with a mixed-category task (i.e., letters and symbols assigned to both responses), the symbol targets continued to be less interfered with by both letter and symbol incompatible flankers. These findings were interpreted as suggesting that response competition can be influenced by both classification decision rules and cohesiveness of exemplars comprising a category.     

Compatibility of precuing and of S-R mapping in choice reactions

This study investigates information processing elicited by precuing a subset of alternatives in a choice reaction task. The aim was to study the influence of some task variables on the effectiveness of precuing, in order to determine the locus of differential precuing effects, in either central decisional processing or in motor programming. Partial advance information (PAI) was given 300 msec in advance of the action signal and it indicated the subset from which the action signal would be chosen. Thus, precuing reduced the number of alternatives. The resulting decrease of reaction time (RT) was assessed under various levels of SR compatibility, response specificity and cue compatibility. Cue compatibility refers to the naturalness of the (spatial) relation between the cue signals and the stimulus-response pairs. This study shows that (a) precuing effectiveness is strongly affected by cue compatibility, and (b) cue compatibility should be viewed as a twofold concept: it refers to the naturalness of the relation of the cue signal, either with action signals or with responses.Experiment 1 compared a naming and a pointing task. Although in both tasks the cue signal was compatible with the cued action signals, the naming task had a lower level of SR compatibility and also a lower level of compatibility between the cue signal and responses. Precuing was highly effective when pointing towards the action signal, but hardly effective when naming ordinal positions. Experiments 2–4, using only a pointing task, showed a decrease of the precuing effect with a decrease of either type of cue compatibility, although cue compatibility with action signals was the strongest factor. Low SR compatibility further decreased the size of the precuing effect caused by low compatibility between cue and action signals. Differential precuing effects did not result from differences in response specificity (i.e., the lack of similarity among the cued responses). It is concluded that precuing and both types of cue compatibility affect the stage of response decision, while no evidence was found for effects on motor programming. Implications are discussed for movement precuing studies that rely on differential precuing effects to discover properties of motor programming.     

Implicit Transfer of Reversed Temporal Structure in Visuomotor Sequence Learning

Some spatio‐temporal structures are easier to transfer implicitly in sequential learning. In this study, we investigated whether the consistent reversal of triads of learned components would support the implicit transfer of their temporal structure in visuomotor sequence learning. A triad comprised three sequential button presses ([1][2][3]) and seven consecutive triads comprised a sequence. Participants learned sequences by trial and error, until they could complete it 20 times without error. Then, they learned another sequence, in which each triad was reversed ([3][2][1]), partially reversed ([2][1][3]), or switched so as not to overlap with the other conditions ([2][3][1] or [3][1][2]). Even when the participants did not notice the alternation rule, the consistent reversal of the temporal structure of each triad led to better implicit transfer; this was confirmed in a subsequent experiment. These results suggest that the implicit transfer of the temporal structure of a learned sequence can be influenced by both the structure and consistency of the change.     

Temporal averaging across multiple response options: insight into the mechanisms underlying integration

Rats trained on a dual-duration, dual-modality peak-interval procedure (e.g., tone = 10 s/light = 20 s) often show unimodal response distributions with peaks that fall in between the anchor durations when both cues are presented as a simultaneous compound. Two hypotheses can explain this finding. According to the averaging hypothesis, rats integrate the anchor durations into an average during compound trials, with each duration being weighted by its respective reinforcement probability. According to the simultaneous temporal processing hypothesis, rats time both durations veridically and simultaneously during compound trials and respond continuously across both durations, thereby producing a unimodal response distribution with a peak falling in between the anchor durations. In the present compounding experiment, rats were trained to associate a tone and light with two different durations (e.g., 5 and 20 s, respectively). However, in contrast to previous experiments, each cue was also associated with a distinct response requirement (e.g., left nosepoke for tone/right nosepoke for light). On the majority of compound trials, responding on a given nosepoke fell close to its respective duration, but was shifted in the direction of the other cue’s duration, suggesting rats timed an average of the two durations. However, more weight appeared to be given to the duration associated with the manipulandum on which the rat responded, rather than the duration associated with a higher reinforcement probability as predicted by the averaging hypothesis. Group differences were also observed, with rats trained to associate the tone and light with the short and long durations, respectively, being more likely to show these shifts than the counterbalanced modality–duration group (i.e., light-short/tone-long). This parallels group differences observed in past studies and suggest that cue weighting in response to stimulus compounds is influenced by the modality–duration relationship of the anchor cues. The current results suggest that temporal averaging is a more flexible process than previously theorized and provide novel insight into the mechanisms that affect cue weighting.     

Motor execution affects action prediction

Previous studies provided evidence of the claim that the prediction of occluded action involves real-time simulation. We report two experiments that aimed to study how real-time simulation is affected by simultaneous action execution under conditions of full, partial or no overlap between observed and executed actions. This overlap was analysed by comparing the body sides and the movement kinematics involved in the observed and the executed action. While performing actions, participants observed point-light (PL) actions that were interrupted by an occluder, followed by a test pose. The task was to judge whether the test pose depicted a continuation of the occluded action in the same depth angle. Using a paradigm proposed by Graf et al., we independently manipulated the duration of the occluder and the temporal advance of the test pose relative to occlusion onset (occluder time and pose time, respectively). This paradigm allows the assessment of real-time simulation, based on prediction performance across different occluder time/pose time combinations (i.e., improved task performance with decreasing time distance between occluder time and pose time is taken to reflect real-time simulation). The PL actor could be perceived as from the front or back, as indicated by task instructions. In Experiment 1 (front view instructions), evidence of action simulation was obtained for partial overlap (i.e., observed and performed action corresponded either in body side or movement kinematics), but not for full or no overlap conditions. The same pattern was obtained in Experiment 2 (back view instructions), ruling out a spatial compatibility explanation for the real-time pattern observed. Our results suggest that motor processes affect action prediction and real-time simulation. The strength of their impact varies as a function of the overlap between observed and executed actions.     

Sensory generalization and learning about novel colours by poultry chicks

Previous research has shown semantic influence from irrelevant peripheral cues on the spatial allocation of covert visual attention. The present study explored whether the task set determines the extent of such semantic influence. A spatial cueing paradigm with strict eye movement control was used, where cues were either first names (male or female) or emotionally charged words (positive or negative) followed by a face target. Participants discriminated either the gender (male or female) or the emotion (positive or negative) of the face. When there was high information overlap between cue and task set, responses were faster when the cue and target value were semantically congruent than when they were incongruent. It was concluded that the semantically related cues primed a task-influencing response independently of spatial attention allocation processes, showing that semantic influences from brief peripheral cues depend on the degree of information overlap between cue and task set.     

Reduced response readiness delays stop signal inhibition

This study examines the effect of response readiness on the stopping of motor responses. Thirteen subjects performed a primary task requiring a speeded choice reaction on go trials and response inhibition on nogo trials. An occasional cue informed subjects that a nogo trial was imminent but left them uncertain about the number of go trials separating the cue and the upcoming nogo trial. This setup was meant to create test episodes of reduced response readiness (i.e., trial sequences initiated by the cue and terminated by the nogo signal) and control episodes, in which subjects were ready to execute a speeded choice reaction (i.e., trial sequences consisting only of go trials). During both episodes, a visual stop signal could occasionally and unpredictably follow go signal onset, instructing subjects to withhold their response to the go signal. Choice reactions on go trials were delayed during test episodes relative to control episodes. Most importantly, stop reactions were delayed, not facilitated, during test episodes compared to control episodes. These findings were taken to suggest that reduced readiness gives rise to more forceful responses that are then more difficult to inhibit.