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Switching between competing tasks is supported by active inhibition of the preceding task. The level of task stimulus processing at which interference between competing tasks must occur for inhibition to be recruited is still unclear. Here, we investigated whether inhibition is recruited by task conflict occurring at an early or late (semantic) stage of task stimulus processing by dissociating the task stimulus format from its meaning. In two experiments, participants performed three different numerical judgment tasks on numerical stimuli that could be presented as digits or number words (e.g., "6" or "six") in a cued task-switching procedure. The effects of the change of stimulus format for the inhibition of the previous task were investigated and assessed by the N-2 task repetition cost, an index of the extent to which task representations are inhibited. The N-2 task repetition cost observed in the same stimulus format condition disappeared when target stimuli on task N-1 were presented in a different format from stimuli of task N-2 and N. This occurred both when the format changed from digits to number words stimuli (Experiment 1) as well as when it changed from number words to digits stimuli (Experiment 2). Results indicated that task set inhibition is recruited very early during the stimulus processing stage. They also provided evidence that task inhibition is not tied to task preparation processes but operates as a reactive, rather than proactive mechanism of conflict resolution. [ABSTRACT FROM AUTHOR]

Body re-sizing illusions can profoundly alter perception of our own body. We investigated whether creating the illusion of a muscled and fit-looking back (Strong) influenced perceived back size, body ownership, and attitudes towards self-capacity during a lifting task. Twenty-four healthy male volunteers performed a standardised lifting task while viewing real-time (delay < 20 ms) video of their own back through a head-mounted display under four different conditions (Normal size, Strong, Reshaped, Large; order randomised). The MIRAGE-mediated reality system was used to modify the shape, size, and morphology of the back. Participants were poor at recognizing the correct appearance of their back, for both implicit (perceived width of shoulders and hips) and explicit (questionnaire) measures of back size. Visual distortions of body shape (Reshaped condition) altered implicit back size measures. However, viewing a muscled back (Strong condition) did not result in a sense of agency or ownership and did not update implicit perception of the back. No conditions improved perceptions/attitudes of self-capacity (perceived back strength, perceived lifting confidence, and perceived back fitness). The results lend support for the importance of the embodiment of bodily changes to induce changes in perception. Further work is warranted to determine whether increased exposure to illusory changes would alter perceptions and attitudes towards self-capacity or whether different mechanisms are involved. [ABSTRACT FROM AUTHOR]

The sustained attention to response task (SART) has been used for over 20 years to assess participants' response times and inability to withhold to No-Go stimuli (commission errors). While there is debate in the literature regarding what causes commissions errors in the SART, there is agreement the SART is subject to a speed-accuracy trade-off (SATO). Researchers have demonstrated that performance on the SART can be influenced by directive instructions to participants to prioritize either speed or accuracy during the task. In the present study, we investigated whether real-time performance feedback and whether feedback emphasis (emphasizing speed or accuracy) affected participants' response times and accuracy. We found performance feedback per se had no impact on performance, but performance emphasis did affect performance, apparently shifting the SATO. This finding provides further evidence that the commission errors in the SART are not indicative of sustained attention or vigilance as those terms are commonly used in the literature, but more likely assess response strategy and motor control (or lack of motor control). These findings have implications for the psychological assessment literature, as well as applied areas where SART findings have been utilized such as shoot/no-shoot decision making. [ABSTRACT FROM AUTHOR]

This study aimed to investigate whether the N2 or P3 component in the count/no-count task reflects response inhibition. The participants were asked to count/withhold counting the number of O/X letters in the count/no-count task, and to calculate the sum of all digits (i.e., 1/0) in the digital accumulation task. Therefore, four conditions were obtained in this study: count, no-count, Add 1, and Add 0. In the count and Add 1 conditions, the counting/calculation number need to be updated. In both no-count and Add 0 conditions, the memory of counting/calculation number need not to be updated; a No-go (withhold) instruction was given in the no-count condition, but a Go instruction was given in the Add 0 condition. Results showed that an enhanced fronto-central N2 was evoked in the no-count than in the Add 0 condition, indicating that a stronger response conflict or stronger inhibition might be triggered in the No-count condition. The frontocentral P3 showed no differences between no-count and Add 0 conditions, however, an enhanced centro-parietal P3 component was observed for the count relative to the no-count condition and for the Add 1 relative to the Add 0 condition, indicating that a greater amount of attentional resources might be consumed during memory updating process. Taken together, in the count/no-count task, the fronto-central N2 might reflect response inhibition or conflict and the parietal P3 might reflect attentional resource allocation but not response inhibition. [ABSTRACT FROM AUTHOR]

A common marker for inhibition processes in task switching are n − 2 repetition costs. The present study aimed at elucidating effects of no-go trials on n − 2 repetition costs. In contrast to the previous studies, no-go trials were associated with only one of the three tasks in the present two experiments. High n − 2 repetition costs occurred if the no-go task had to be executed in trial n − 2, irrespective of whether a response had to be withheld or not. In contrast, no n − 2 repetition costs were visible if the other two tasks were relevant in n − 2. Whereas this n − 2 effect was unaffected by whether participants could reliably exclude a no-go trial or not, effects of no-gos in trial n were determined by this knowledge. The results differ from effects of no-go trials that are not bound to a specific task. It is assumed that the present no-go variation exerted its effect not on the response level, but on the level of task sets, resulting in enhanced salience of the no-go task that leads to higher activation and, as a consequence, to stronger inhibition. The dissociation of the effects on no-gos in trials n − 2 and n as a function of foreknowledge suggests that the balance between activation and inhibition is shifted not only for single trials and tasks, but for the whole task space. [ABSTRACT FROM AUTHOR]

In previous studies investigating the space–time compatibility effect, the experimental task always invites explicit spatial or temporal processing or both. In this study, we kept space and time irrelevant to the task. In a go/no-go task, participants (N = 50) were asked to either press a single button when they found the target or refrain from responding when there was no target in a search array. We manipulated the duration of the target-alone presentation that preceded a 7 × 7 search array consisting of either target plus distractors or distractors alone. The results revealed faster responses to shorter durations when the target appeared in the upper relative to the lower space. A similar effect also appeared along the diagonal axis with faster responses to shorter durations in upper-left relative to lower-right space. In contrast, no such difference was found along the horizontal axis. We hypothesize that vertical and diagonal space–time associations arise from the grounding of mental representation of time in physical experiences. [ABSTRACT FROM AUTHOR]

This study presents two experiments that explored consolidation of implicit sequence learning based on two dependent variables—reaction time (RT) and correct anticipations to clarify the role of sleep, and whether the manual component is necessary for consolidation processes. Experiment 1 (n = 37) explored the performance of adults using an ocular variant of the serial reaction time task (O-SRT) with manual activation (MA), and Experiment 2 (n = 37) used the ocular activation (OA) version of the task. Each experiment consisted of a Day and a Night group that performed two sessions of the O-SRT with an intervening 12-h offline period (morning/evening in Day group, evening/following morning in Night group). Night offline had an advantage only when manual response was required and when correct anticipations (i.e., accuracy) but not RT (i.e., speed) were measured. We associated this finding with the dual-learning processes required in the MA O-SRT that led to increased sequence specific learning overnight. When using the OA O-SRT, both groups demonstrated similar rates after offline in RT and correct anticipations. We interpreted this finding to reflect stabilization, which confirmed our hypothesis. As expected, all the groups demonstrated reduced performance when another sequence was introduced, thus reflecting sequence-specific learning. This study used a powerful procedure that allows measurement of implicit sequence learning in several ways: by evaluating two different measures (RT, correct anticipations) and by isolating different aspects of the task (i.e., with/without the manual learning component, more/less general skill learning), which are known to affect learning and consolidation. [ABSTRACT FROM AUTHOR]

Insight accompanied by an 'aha!' experience has a mnemonic effect. Previous studies of insight have often focused on the mnemonic effect of insight on veridical memories, while the effect of insight on false memories is not known. More understanding of the mnemonic effect of insight on false memories could have implications for the mechanism of insightful mnemonic effects. The present research examined whether insight has a mnemonic effect on false memories. Participants were asked to perform Chinese verbal compound remote associate (CRA) tasks and then complete the Deese–Roediger–McDermott (DRM) task, the critical lure of which was also the solution to the Chinese CRA problem. Compared to non-insight, insight was associated with a lower critical lures rate in Experiment 1 and with lower critical lures and unrelated words rates in Experiment 2 when the presentation of DRM list words was random. Giving a warning before DRM tasks could reduce the critical lures rate of non-insight but had little effect on insightful solutions in Experiment 3. These findings indicate that insight can reduce false memories. [ABSTRACT FROM AUTHOR]

Actions can be identified at a range of levels, from higher level, outcome-related descriptions to lower level, movement-related descriptions. But how do these levels of identification influence the experience of control (agency) over a task? We addressed the relation between the level of action identification and agency using a hierarchical task modeled from typing. Participants memorized letter sequences and reported them by moving a cursor to targets that contained letters. To manipulate lower level (aiming) difficulty, the targets were either large or small. To manipulate higher level (memory) difficulty, the letter sequences were either constant or random within a block. We found effects of higher and lower level difficulty on agency and action identification. Moreover, we found interactive effects of higher and lower level difficulty on performance. We discuss these findings in terms of contributions to the study of agency, and some differences from the results of previous studies of action identification. [ABSTRACT FROM AUTHOR]

It has been proposed that motivating participants to perform well on a cognitive task ought to lead to decreases in rates of intentional, but not unintentional, task-unrelated thought (TUT; a commonly studied variety of mind wandering). However, at odds with this prediction, research has found that increasing motivation results in decreases in both intentional and unintentional TUTs. One possible explanation for this surprising finding is that standard assessments of TUT may inadvertently conflate TUTs with another variety of mind wandering: unconstrained thought. If so, then deconfounding task-unrelated and unconstrained varieties of mind wandering might produce the predicted effect of a decrease in intentional, but not unintentional, TUT when motivation is increased. To explore this possibility, in the present study, participants completed a sustained-attention task after receiving standard instructions (normal-motivation condition) or instructions informing them that they could leave the study early if they achieved a certain level of performance (motivated condition). Throughout the task, we assessed rates of TUT (both intentional and unintentional) and unconstrained thoughts. Consistent with prior work, the results indicated that motivated participants reported being on-task significantly more frequently than non-motivated participants. However, unlike previous work, we found that when deconfounding TUTs and unconstrained thoughts, participants in the motivation condition reported significantly fewer bouts of intentional TUT than those in the non-motivation condition, but no differences in rates of unintentional TUT were observed between groups. These results suggest that (a) motivation specifically targets intentional TUT and (b) standard assessments of TUT conflate task-relatedness and thought constraint. [ABSTRACT FROM AUTHOR]

How do we compare the difficulty of different kinds of tasks, and how we do sequence tasks of different kinds when the basis for the ordering is the tasks' difficulty levels? The ability to do these things requires a common currency, but the identity of that currency, if it exists, is unknown. We hypothesized that people may believe that the time that attention is paid to tasks enables people to compare and sequence tasks of different kinds. To evaluate this hypothesis, we tested three groups of participants. One group estimated the proportion of time that performance of a task requires attention—what we called attention time proportions or ATPs. We obtained ATPs for tasks that were "more intellectual" (counting) and others that were "more physical" (locomotion). Two additional groups made 2-alternative-forced-choice decisions about the relative ease and preferred sequencing of all possible pairs of tasks for which ATPs were independently obtained. We found that ATPs predicted judgments of task difficulty and preferred task order. [ABSTRACT FROM AUTHOR]

In most of our daily activities and in team sports, we interact with other individuals and do not act in isolation. Using a social variant of the standard two-choice Simon task, this study aims to test if competitive/cooperative processing modes (i.e., metacontrol states) change the degree of bodily self-other integration between two persons in joint action. In addition, and more exploratory the study tested if this effect depends on a shared group experience with the partner. Two participants shared a visual Simon task, so that each person basically performed complementary parts of the task, which transfers the paradigm into a go/no-go Simon task for each person. Before running this joint Simon task, we set both participants either in a competitive or a cooperative control state by means of a dyadic game, a manipulation aimed at testing possible goal transfer across tasks. We found significant joint Simon effects for participants who were in a competitive state and for participants who were in a cooperative state. The joint Simon effect for participants being in a competitive state was significantly smaller than for participants being in a cooperative state. When experiencing the goal induction together with the partner, the joint Simon effect was significantly decreased as when the induction was performed alone. Both effects (metacontrol state induction and shared experience) seem to be statistically independent of each other. In line with predictions of metacontrol state theory, our study indicated that abstract cognitive goal states can be transferred from one task to another task, able to affect the degree of bodily self-other integration across different task situations. [ABSTRACT FROM AUTHOR]

The ubiquitous availability of technological aids requires individuals to constantly decide between either externalizing cognitive processes into these aids (i.e. cognitive offloading) or relying on their own internal cognitive resources. With the present research, we investigated the influence of metacognitive beliefs on individuals' offloading behavior in an experimental setup (N = 159). We manipulated participants' metacognitive beliefs about their memory abilities by providing fake performance feedback: below-average feedback, above-average feedback, or no feedback (control-group). We then measured offloading behavior, using a pattern copying task in which participants copied a color pattern from a model window into a workspace window. While solving this task, participants could rely either more on an internal memory strategy or more on an offloading strategy. Fake performance feedback affected the participants' metacognitive evaluations about their memory abilities (below-group < control-group < above-group). Although fake performance feedback did not affect actual offloading behavior, the participants receiving below-average performance feedback reported that they had relied more on an offloading strategy than those participants receiving above-average performance feedback. Furthermore, the participants in the below-group reported lower general memory abilities than the other groups at the end of the experiment. We conclude that while fake performance feedback strongly influenced metacognitive beliefs, this did not transfer into a change of strategy selection, thus not influencing offloading behavior. We propose to consider not only metacognitive beliefs but also metacognitive experiences as potential determinants of cognitive offloading. [ABSTRACT FROM AUTHOR]

Recently, it was demonstrated that even basic numerical cognition such as the processing of number magnitude is under cognitive control. However, evidence so far primarily came from adaptation effects to stimulus characteristics (e.g., relative frequency of specific stimulus categories). Expanding this approach, we evaluated a possible influence of more active exertion of cognitive control on basic number processing in task switching. Participants had to perform a magnitude comparison task while we manipulated the order of compatible and incompatible input–output modalities (i.e., auditory/vocal input–visual/manual output vs. auditory/visual input–manual/vocal output, respectively) on the trial level, differentiating repeat vs. switch trials. Results indicated that the numerical distance effect but not the problem size effect was increased after a switch in input–output modality compatibility. In sum, these findings substantiate that basic number processing is under cognitive control by providing first evidence that it is influenced by the active exertion of cognitive control as required in task switching. [ABSTRACT FROM AUTHOR]

In a word valence judgment task, positive words (e.g., excellence) are judged faster when presented at the top (congruent position) than at the bottom of the screen (incongruent position), whereas the opposite pattern occurs for negative words (e.g., disaster). This spatial-valence metaphoric congruency effect reflects top-positive/bottom-negative metaphoric association and may be attributed to at least three possible mechanisms: spreading activation between spatial and valence concepts (activation account), epistemic function that a conceptual metaphor serves to reduce the uncertainty associated with valence concepts (epistemic account), and/or the extent to which spatial-valence metaphoric association is relevant to task demand (relevance account). In three experiments, we manipulated congruency proportion, target eccentricity, and valence strength in a word valence judgment task to test these three possible accounts. Results showed that the metaphoric congruency effect was larger when a high (vs. equal) proportion of targets appears in congruent, relative to incongruent, position, and for targets with strong (vs. weak) valence. However, the effect in reaction time measure was not modulated by whether the target appeared in the position being near vs. far away from the center of the screen. The overall findings are better accommodated by the relevance account. The implications of the current findings on other theoretical accounts, such as Conceptual Metaphor Theory and polarity correspondence account, are also discussed. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Task conflict is a type of conflict that emerges when a stimulus triggers two or more competing tasks. In the Stroop task, task conflict occurs between the relevant color-naming task and irrelevant word reading task and can be observed mainly on congruent trials, which only involve task conflict and are devoid of additional conflict types. We hypothesized that task conflict also manifests in the affordances task between the relevant task (e.g., classifying manipulatable objects), and the automatic task afforded by the object (e.g., grasping the object), and is mostly evident on congruent trials. Using an individual differences design we assessed the relationship between control mechanisms operating on Stroop congruent and affordances congruent trials under conditions of high and low cognitive control requirements. We hypothesized that task control is employed in both tasks. One-hundred and twenty-three participants performed an affordances task and two blocks of a Stroop task, each requiring a different level of task control (high vs. low). In a hierarchical regression model, we found a significant and specific correlation between affordances congruent and Stroop congruent conditions only in the high-control block, designed to greatly engage participants' task control, thus linking the task control mechanism in both tasks. These results indicate that task control underlies diverse modalities of response (visuomotor and linguistic), independently of other conflict types. We suggest that the affordances task may serve as a supplementary tool for the assessment of task control in the lab. [ABSTRACT FROM AUTHOR]

People respond to small numbers faster with the left hand and respond to large numbers faster with the right hand, a phenomenon known as the Spatial-Numerical Association of Response Codes (SNARC) effect. Whether the SNARC effect originates from culturally determined long-term experience or the task-set-influenced temporary associations among spaces, locations, and numerical magnitudes in working memory (WM) is still controversial. In the present study, we used a trisection paradigm in which numbers were divided into three categories (small: 1, 2; middle: 4, 5, 6; and large: 8, 9) to explore whether the central executive control can modulate the SNARC effect. Participants were serially presented with a cue and a target number. The cue denoted a task rule, which informed participants to compare the target number with either 3 or 7. The cue was either switched or repeated across trials. We found that the SNARC effects were observed in the cue-switching condition. In the cue-repeat condition, the SNARC effect disappeared. These findings suggest that the SNARC effect is modulated by set-shifting-related central executive control in WM, supporting the view that the SNARC effect is WM-dependent. [ABSTRACT FROM AUTHOR]

This study investigated the relationship between numerical and spatial processing and reading direction, conducting conceptual replications of the Shaki et al. (Psychonomic Bulletin & Review 16(2): 328–331, 2009) parity task and the Mathieu et al. (Cognition 146: 229–239, 2016, Experiment 1) simple addition (e.g., 3 + 2) and subtraction (e.g., 3 − 2) task. Twenty-four left-to-right readers (LTR) and 24 right-to-left readers (RTL) were tested. The response time (RT) analysis of the parity task presented a robust spatial-numerical association of response codes (SNARC) effect (left-side response advantage for smaller numbers and right-side advantage for larger numbers) for LTR but not RTL readers. In the arithmetic task, the three problem elements (e.g., 3 + 4) were presented sequentially with the second operand displaced slightly to the left or right of fixation. RTL but not LTR readers presented a RT advantage for subtraction relative to addition with a right-shifted second operand compared to it being left-shifted. This is consistent with a spatial bias linked to native reading direction. For both reading-direction groups, effects of the left vs. right side manipulation in the arithmetic or parity task did not correspond to parallel effects in the other task. The results imply that the parity-based SNARC effects and side-related effects in cognitive arithmetic are not equivalent measures of space-related processes in cognitive number processing and likely reflect distinct mechanisms. [ABSTRACT FROM AUTHOR]

Why are some tasks more difficult to learn than others? Hoffman et al. (Accelerated expertise: training for high proficiency in a complex world. Psychology Press, New York, 2014) hypothesized that certain task characteristics—termed "dimensions of difficulty"—hindered learning and performance. Previously, we tested two dimensions: consistent vs. variably mapped and static vs. dynamic. Here, we test three more dimensions of difficulty: sequential vs. simultaneous, discrete vs. continuous, and separable vs. interactive. In each study, we manipulate a single task feature (dimension of difficulty) while holding all others constant. Tasks with continuous (rather than discrete) features slowed participants' performance but did not impair learning. Learning and performance were unimpaired in tasks with interactive (rather than largely separable) processes. By contrast, we found strong evidence that simultaneous tasks (i.e., those that demand multitasking) inhibit learning, slow performance, and increase task errors. Importantly, this occurred in the absence of perceptual and mechanical bottlenecks present in most other studies of multitasking. We also are the first to examine simultaneity on learning a new task while controlling for other dimensions of difficulty. We discuss the potential impact of these results on current theory and application to real-world domains. [ABSTRACT FROM AUTHOR]

The Simon effect refers to the fact that, even though stimulus position is task-irrelevant, responses to a task-relevant stimulus dimension are faster and more accurate when the stimulus and response spatially correspond than when they do not. Although the Simon effect is a very robust phenomenon, it is modulated by practice or transfer from previous tasks. Practice refers to the modulation of the Simon effect as a function of number of trials. Transfer refers to the modulation of the Simon effect as a function of preceding tasks. The aim of the present study is to disentangle the role of practice and transfer in modulating the Simon effect and to investigate whether such modulation can be extended to a different response modality. Three experiments were conducted, which included three sessions: the Baseline session, the Inducer session and the Diagnostic session. The task performed in the Baseline and the Diagnostic sessions were comprised of location-irrelevant trials (i.e., they were Simon tasks). The task performed in the Inducer session required performing location-relevant trials (i.e., it was a spatial compatibility task with a compatible or an incompatible stimulus–response mapping). In the first and third experiments, participants were required to respond manually in all sessions. In the second experiment, the task performed in the Inducer session required manual response, while in the Baseline and Diagnostic sessions the tasks required ocular response. Results showed a reduced-Diagnostic Simon effect after both compatible and incompatible mapping in the Inducer session, regardless of whether response modality was the same or different. These results support the notion that the practice effect prevails over the transfer effect. [ABSTRACT FROM AUTHOR]

According to an influential concept, humans acquire spatial knowledge about their environment in three distinct stages: landmark knowledge is acquired first, then route knowledge, and finally survey knowledge. The stage concept has been challenged by studies which observed that in a wayfinding paradigm, route, and survey knowledge emerge at the same time and; therefore, were seemingly acquired in parallel. However, this experimental evidence is not conclusive because the above studies suffered from a ceiling effect. The present study was designed to overcome the ceiling effect by increasing the complexity of the wayfinding task. We asked 60 young participants to find their way through an urban environment rendered in virtual reality, and assessed their landmark, route, and survey knowledge after each of ten trials. We found that all three types of knowledge gradually increased from the first to the last trial. We further found that correlations between the three types of knowledge increased from trial to trial. This outcome disagrees profoundly with the stage concept, but is compatible with the parallel concept. Specifically, it is in accordance with the view that landmark, route, and survey knowledge are acquired by multiple overlapping and interacting processes: those processes may start out more or less independently in the first trial but, due to common constraints or synergies, may gradually increase their cooperation during subsequent trials. [ABSTRACT FROM AUTHOR]

The present study investigated how response mode determines the specificity of control responsible for the congruency sequence effect (CSE), especially when conflict arises from spatial dimensions. Horizontal and vertical Simon tasks were presented in turn, while response mode (Experiment 1) or task-relevant stimulus dimension (Experiment 2) was manipulated. All responses were made by aimed movements to make the relative salience of the horizontal and vertical dimensions equivalent regardless of response mode. The confound-minimized CSEs were significant only when the two tasks shared the same response mode, which did not vary as a function of task-relevant stimulus dimension. This result suggests that response mode determines the scope of control, as it reconfigures the representations of the task-irrelevant spatial dimensions (i.e., the horizontal and vertical dimensions), which is corroborated by distributional analyses. This response mode-specific control was also consistently found for the horizontal and vertical arrow versions of flanker-compatibility tasks in Experiment 3, in which conflict does not directly arise from the response dimension. Furthermore, the current findings revealed that the CSEs were more evident in movement times than in initiation times, which provides new insight on how control inhibits the response activated by a task-irrelevant stimulus dimension, especially at a motor level. [ABSTRACT FROM AUTHOR]

Research has supported two distinct forms of motor skill consolidation that can occur between practice sessions: (1) off-line learning, and (2) memory stabilization. Off-line learning describes performance improvement between practice sessions that is above the gain observed at the end of practice, while memory stabilization describes a gain in performance that is maintained between practice sessions. This study used a Lissajous plot to provide concurrent feedback to train participants to produce a 90° relative phase between the index fingers (flexion/extension motion). Significant improvements in performance emerged after ten trials (5 min) of practice. At the end of training, participants were divided into two delay interval groups before retesting, 2-h and 6-h. The retesting session started with participants performing an interference task (10 trials, 5 min) that required training on a 45° relative phase between the fingers with concurrent feedback from the Lissajous plot. When training with the interference task was completed participants were retested with the 90° relative phase without the Lissajous plot feedback. In the retest of the 90° pattern, a performance loss was found in the 2-h delay group, whereas the 6-h delay group maintained the end of practice performance level. Maintenance of the same level of performance without the Lissajous plot represents memory stabilization of the initially trained 90° pattern. The findings are discussed within the context of current positions regarding procedural consolidation and the coordination dynamics framework wherein action and perception are linked through the informational nature of relative phase. [ABSTRACT FROM AUTHOR]

Even after a long time of research on dual-tasking, the question whether the two tasks are always processed serially (response selection bottleneck models, RSB) or also in parallel (capacity-sharing models) is still going on. The first models postulate that the central processing stages of two tasks cannot overlap, producing a central processing bottleneck in Task 2. The second class of models posits that cognitive resources are shared between the central processing stages of two tasks, allowing for parallel processing. In a series of three experiments, we aimed at inducing parallel vs. serial processing by manipulating the relative frequency of short vs. long SOAs (Experiments 1 and 2) and including no-go trials in Task 2 (Experiment 3). Beyond the conventional response time (RT) analyses, we employed drift–diffusion model analyses to differentiate between parallel and serial processing. Even though our findings were rather consistent across the three experiments, they neither support unambiguously the assumptions derived from the RSB model nor those derived from capacity-sharing models. SOA frequency might lead to an adaptation to frequent time patterns. Overall, our diffusion model results and mean RTs seem to be better explained by participant's time expectancies. [ABSTRACT FROM AUTHOR]

The aim was to examine theories of bilingual inhibitory control superiority in the visual domain. In an ambiguous figure task, the ability to reverse (switch) interpretations (e.g., duck-rabbit) was examined in 3–5-year-olds bilinguals and monolinguals (N = 67). Bilingualism was no performance predictor in conceptual tasks (Droodle task, false belief task, ambiguous figures production task) that did not pose inhibitory demands. Bilinguals outperformed monolinguals in the ability to reverse, suggesting superior inhibitory capacity per se. Once reversal was experienced there was no difference in the time it took to reverse or reversal frequency between bilinguals and monolinguals. Bayesian analyses confirmed statistical result patterns. Findings support the established view of bilinguals' superior domain-general inhibitory control. This might be brought to bear by attending the environment differently. [ABSTRACT FROM AUTHOR]

The phonological Stroop task, in which the participant names the color of written distractors, is being used increasingly to study the phonological encoding process in speech production. A brief review of experimental paradigms used to study the phonological encoding process indicated that currently it is not known whether the onset overlap benefit (faster color naming when the distractor shares the onset segment with the color name) in a phonological Stroop task is due to phonology or orthography. The present paper investigated this question using a picture variant of the phonological Stroop task. Participants named a small set of line drawings of animals (e.g., camel) with a pseudoword distractor printed on it. Picture naming was facilitated when the distractor shared the onset segment with the picture name regardless of orthographic overlap (CUST–camel = KUST–camel < NUST–camel). We conclude that the picture variant of the phonological Stroop task is a useful tool to study the phonological encoding process, free of orthographic influence. [ABSTRACT FROM AUTHOR]

It has been suggested that the interference in the Stroop task arises due to both information conflict (color vs. word meaning) and task conflict (respond to the color vs. read the word). Interestingly, the task conflict (faster responses in the congruent condition compared to the neutral condition) is influenced by the readability of the stimulus. However, behavioral results indicate the influence of the contribution of readability to the task conflict appears only when vocal responses are required. We conducted a Stroop experiment with four readability levels of neutrals. Participants were required to respond manually, and both their response times and pupil dilation were measured. Our results showed the slowest responses for incongruent trials and the fastest responses for congruent trials. However, no differences in responses were found between the readability levels of the neutrals. In contrast, pupil dilation showed the largest dilation in the incongruent trials and smallest dilation in the neutral trials. In addition, the differences between congruent and neutral trials were influenced by the readability of the stimulus. Specifically, unreadable neutral stimuli showed meaningful differences early on, which also remained for longer time compared with readable neutral stimuli. These results are important and can help in specifying new requirements regarding the theory and modeling of the Stroop task; in particular, studies that want to control the neutrality of their neutral trials should take the readability into account. [ABSTRACT FROM AUTHOR]

"Power of instructions" originally referred to automatic response activation associated with instructed rules, but previous examination of the power of instructed rules in actual task implementation has been limited. Typical tasks involve both explicit aspects (e.g., instructed stimulus–response mapping rules) and implied, yet easily inferred aspects (e.g., be ready, attend to error beeps) and it is unknown if inferred aspects also become readily executable like their explicitly instructed counterparts. In each mini-block of our paradigm we introduced a novel two-choice task. In the instructions phase, one stimulus was explicitly mapped to a response; whereas the other stimulus' response mapping had to be inferred. Results show that, in most cases, explicitly instructed rules were implemented more efficiently than inferred rules, but this advantage was observed only in the first trial following instructions (though not in the first implementation of the rules), which suggests that the entire task set was implemented in the first trial. Theoretical implications are discussed. [ABSTRACT FROM AUTHOR]

Task performance improves when the required tasks are predicted by the preceding time intervals, suggesting that participants form time-based task expectancies. In the present study, we pursued the question whether temporal predictability of tasks can also influence task choice. For this purpose, we conducted three experiments using a hybrid task-switching paradigm (with two tasks) combining forced-choice and free-choice trials. Each trial was preceded by either a short (500 ms) or a long (1500 ms) foreperiod. In forced-choice trials, the instructed task was predicted by the length of the foreperiod (Exp. 1A and 1B: 100% foreperiod-task contingencies; Exp. 2: 80% foreperiod-task contingencies). In the remaining trials, participants were free to choose which task to perform. In all three experiments, we found that participants' task choice was influenced by the foreperiod-task contingencies implemented in forced-choice trials. Specifically, participants were overall biased to choose tasks compatible with these contingencies; these compatible choice rates were larger for the short compared to the long foreperiod. Our findings suggest that learned time-based task expectancies influence subjects' voluntary task choice and that an initially present task bias toward the "short" task is not always overcome at the long foreperiod. We discuss potential underlying mechanisms against the background of voluntary task switching and interval timing. [ABSTRACT FROM AUTHOR]

Recent investigation of individual differences in multitasking revealed evidence for individual preferences for modes of task processing (serial vs. overlapping) in a task switching with preview (TSWP) paradigm and different strategies of response organization (blocking, switching, and response grouping) in a free concurrent dual-tasking (FCDT) paradigm. However, this research on individual differences at the levels of cognitive task processing and behavioral response organization has been pursued separately, thus far, by testing independent samples of participants. In the current study, we investigated whether these two levels of task coordination were linked intra-individually. As individuals preferring an overlapping task processing mode can generate time gains particularly at task switches, we predicted that they prefer a switching strategy of response organization. In contrast, individuals preferring a serial processing mode are expected to prefer a blocking strategy to reduce dual-task demands. These predictions were confirmed in an experiment based on n = 70 participants. Indeed, most serial processors preferred a blocking strategy, whereas overlapping processors predominantly preferred to switch between the tasks. This finding suggests a strong correspondence between individual preferences emerging in both aspects of task coordination, which might reflect a common basic difference in the preferred style of cognitive control (flexible vs. persistent). Moreover, in case the preferred modes of task processing and strategies of response organization did not correspond to each other, the overall multitasking efficiency was comparably low. Thus, the distinction between the preferences for both aspects of multitasking seems to be an important aspect of understanding multitasking performance and should be considered in future studies. [ABSTRACT FROM AUTHOR]

The present study investigated participants' ability to introspect about the effect of between-task crosstalk in dual tasks. In two experiments, participants performed a compatibility-based backward crosstalk dual task, and additionally provided estimates of their RTs (introspective reaction times, IRTs) after each trial (Experiment 1) or after each pair of prime and test trials (Experiment 2). In both experiments, the objective performance showed the typical backward crosstalk effect and its sequential modulation depending on compatibility in the previous trial. Very similar patterns were observed in IRTs, despite the typical unawareness of the PRP effect. In sum, these results demonstrate the reliability of between-task crosstalk in dual tasks and that people's introspection about the temporal processing demands in this complex dual-task situation is intriguingly accurate and severely limited at the same time. [ABSTRACT FROM AUTHOR]

Motor sequencing models suggest that when with extensive practice sequence representations have developed, stimuli indicating the individual sequence elements may no longer be used for sequence execution. However, it is not clear whether participants can at all refrain from processing these stimuli. Two experiments were performed in which participants practiced two 7-keypress sequences by responding to isoluminant key-specific stimuli. In the mixed condition of the ensuing test phase, the stimuli were displayed only occasionally, and the question was whether this would make participants stop processing these stimuli. In Experiment 1, the benefit of displaying stimuli was assessed after substantial practice, while Experiment 2 examined development of this benefit across practice. The results of Experiment 1 showed that participants rely a little less on these stimuli when they are displayed only occasionally, but Experiment 2 revealed that participants quickly developed high awareness, and that they ignored these stimuli already after limited practice. These findings confirm that participants can choose to ignore these isoluminant stimuli but tend to use them when they are displayed. These and other findings show in some detail how various cognitive systems interact to produce familiar keying sequences. [ABSTRACT FROM AUTHOR]

The Simon effect, that is the advantage of the spatial correspondence between stimulus and response locations when stimulus location is task irrelevant, occurs even when the task is performed by two participants, each performing a go/no-go task. This effect, known as the joint Simon effect, does not emerge when participants sit outside each other's peripersonal space, thus suggesting that the presence of an active confederate in peripersonal space might provide a reference for response coding. The present study investigated whether this finding is due to the distance separating the participants and/or to the distance separating each participant and the other agent's response. In two experiments, pairs of participants performed a social detection task sitting outside each other's arm reach, with response keys located close to the participants or outside arm reach. When the response key was located outside the participant's arm reach, he/she could reach it by means of a tool. In Experiment 1, by means of a tool, participants could reach their response key only, while in Experiment 2, they could reach also their co-agent's response key. The joint Simon effect did not emerge when participants could not reach the co-actor's response, while it emerged when they could potentially reach the other participant's response using the tool, but only when turn taking was required. These results may be taken as evidence that the possibility to reach and act upon the co-actor's response key may be at the bases of compatibility effects observed in joint action contexts requiring complementary responses. [ABSTRACT FROM AUTHOR]

There is still a need to analyze the factors that enhance navigation accuracy. This study aims to examine how success in environment learning relates to task goals and WM. A total of 90 undergraduates (46 females) learned a route from a virtual navigation experience after being given a goal that involved tracing the route (a route-based goal) or finding a shortcut (a survey-based goal). The two groups thus formed were each divided into three subgroups according to the dual-task paradigm: one only navigated (control condition); the other two did so while simultaneously performing a visuo-spatial or verbal secondary task. Afterwards, participants traced the previously seen route and found a shortcut. Several visuo-spatial and verbal WM tasks were also administered. The results showed that participants given a route-based goal performed better in the route-tracing task; and those given a survey-based goal were better at finding shortcuts. An influence of WM was also shown: higher WM (visuo-spatial and verbal) ability significantly reduced the number of route-tracing errors made while performing a secondary visuo-spatial task, regardless of the goal, whereas no such effects emerged for shortcut finding. These results offer new insight on how task goals and WM support successful navigation. [ABSTRACT FROM AUTHOR]

The impact of cognitive control demands on long-term memory is mixed, with some conflicts leading to better, others leading to worse subsequent memory. The current study was designed to investigate how different types of cognitive control demands modulate the effects on memory. At study, participants had to switch between two classification tasks and later, free recall performance was assessed. The stimuli consisted of two interleaved words, one word had to be categorized and the other word had to be ignored. In four experiments, the congruency between target and ignored words was manipulated by changing the distractor category. This allowed us to investigate the impact of different types of conflict (i.e., task switching, perceptual load, response-category conflict, stimulus-category conflict). The results revealed that task switching impaired memory in all experiments. In Experiment 1, higher perceptual load also impaired memory. Experiments 2–4 showed that the co-activation of two words which required different responses (i.e., response-category conflict) enhanced memory performance but only when the conflict stimuli were presented in pure blocks. Overall, memory performance seems to depend on attentional policies. Withdrawing attention from target encoding results in lower memory performance. In contrast, focusing attention on the target results in enhanced memory performance. [ABSTRACT FROM AUTHOR]

Dual-task performance typically leads to performance impairments in comparison to single tasks (i.e., dual-task costs). The literature discusses the contribution to these dual-task costs due to (1) bottleneck limitations in the dual-component tasks and (2) executive control processes regulating access to this bottleneck. Previous studies investigated the characteristics of executive control processes primarily triggered by external stimulus information. In the present study, however, we investigated the existence as well as the characteristics of internally triggered and driven endogenous control processes to regulate bottleneck access. In detail, we presented dual-task blocks with varying task orders and informed participants in advance about repetitions of the same task order as well as switches between different task orders (i.e., task-order repetitions and switches were predictable). Experiment 1 demonstrated that task-order information and an increased preparation time generally increase the efficiency for endogenous task-order control and improves preparation for task-order switches. This finding is basically consistent with the assumption of the existence of endogenous control processes. Experiment 2, however, did not provide evidence that this endogenous control is related with working-memory maintenance mechanisms. Experiment 3 showed that endogenous control does not only fully complete task-order preparation but also requires exogenous, stimulus-driven components. [ABSTRACT FROM AUTHOR]

Behaviour occurs not as isolated incidents, but within an ongoing sequence of events. The task-switching paradigm provides a useful way to investigate the impact of different events upon subsequent performance. An implication of two-stage task-switching models is that preparing a task without performing it might affect task readiness only to a limited extent. However, recent research has surprisingly shown larger switch costs following preparation ("cue-only" trials) than following performance ("completed" trials). We set out to conduct a rigorous comparison of the size of switch costs following cue-only versus completed trials. In Experiments 1 and 2, we controlled the timing between critical trial events. This had the effect of roughly equating, but not reversing, the relative size of switch costs. In Experiment 3, we restructured the paradigm to equate the predictability of cue and target events. Switch costs following cue-only trials were now smaller than those following completed trials. These studies confirm that task preparation alone is sufficient to drive subsequent switch costs. They also indicate that task performance might increase the size of these costs, consistent with two-stage task-switching models. Switch costs appear to be affected by both the timing and predictability of trial events. [ABSTRACT FROM AUTHOR]

Dual-tasking often requires prioritizing one task over the other. For example, in the psychological refractory period (PRP) paradigm, participants are instructed to initially respond to Task 1 (T1) and only then to Task 2 (T2). Furthermore, in the prioritized processing paradigm (PP), participants are instructed to perform T2 only if T1 was a no-go trial—requiring even more prioritization. The present study investigated the limits of task prioritization. Two experiments compared performance in the PRP paradigm and the PP paradigm. To manipulate task prioritization, tasks were rewarded differently (e.g., high reward for T1, low reward for T2, and vice versa). We hypothesized (a) that performance will improve for the highly rewarded task (Experiments 1 and 2) and (b) that there are stronger reward effects for T1 in the PRP than in the PP paradigm (Experiment 2). Results showed an influence of reward on task prioritization: For T1, high reward (compared to low reward) caused a speed-up of responses that did not differ between the two paradigms. However, for T2, reward influenced response speed selectively in the PP paradigm, but not in the PRP paradigm. Based on paradigm-specific response demands, we propose that the coordination of two motor responses plays a crucial role in prioritizing tasks and might limit the flexibility of the allocation of preparatory capacity. [ABSTRACT FROM AUTHOR]

The strength model of self-control proposes that all acts of self-control are energized by one global limited resource that becomes temporarily depleted by a primary self-control task, leading to impaired self-control performance in secondary self-control tasks. However, failed replications have cast doubt on the existence of this so-called ego depletion effect. Here, we investigated between-task (i.e., variation in self-control tasks) and within-task variation (i.e., task duration) as possible explanations for the conflicting literature on ego depletion effects. In a high-powered experiment (N = 709 participants), we used two established self-control tasks (Stroop task, transcription task) to test how variations in the duration of primary and secondary self-control tasks (2, 4, 8, or 16 min per task) affect the occurrence of an ego depletion effect (i.e., impaired performance in the secondary task). In line with the ego depletion hypothesis, subjects perceived longer lasting secondary tasks as more self-control demanding. Contrary to the ego depletion hypothesis, however, performance did neither suffer from prior self-control exertion, nor as a function of task duration. If anything, performance tended to improve when the primary self-control task lasted longer. These effects did not differ between the two self-control tasks, suggesting that the observed null findings were independent of task type. [ABSTRACT FROM AUTHOR]

Timing is essential for various behaviors and relative to vision, audition is considered to be specialized for temporal processing. The present study conducted a sensorimotor timing task that required tapping in synchrony with a temporally regular sequence and a perceptual timing task that required detecting a timing deviation among a temporally regular sequence. The sequence was composed of auditory tones, visual flashes, or a visual bouncing ball. In the sensorimotor task, sensorimotor timing performance (synchronization stability) of the bouncing ball was much greater than that of flashes and was comparable to that of tones. In the perceptual task, where perceptual timing performance of the bouncing ball was greater than that of flashes, it was poorer than that of tones. These results suggest the facilitation of both perceptual and sensorimotor processing of temporal information by the bouncing ball. Given such facilitation of temporal processing, however, audition is still superior over vision in perceptual detection of timing. [ABSTRACT FROM AUTHOR]

The Stroop-matching task is a variation of the Stroop task in which participants have to compare a Stroop stimulus attribute (color or word) to a second stimulus. The Stroop-matching response conflict (SMRC) represents an interference related to the processes involved in selection/execution of manual responses. In the present study, we developed a variation of the Stroop-matching task in which the Stroop stimuli were matched to graspable objects (a cup) with intact or broken handles laterally oriented (Experiment 1) or to colored bars laterally presented (Experiment 2). It allowed testing the presence of the correspondence effect for lateralized handles and bars and its possible influence on SMRC. Two different intervals (100 and 800 ms) were also included to investigate time modulations in behavioral performance (reaction time and accuracy). Fifty-five volunteers participated in the study. In both experiments, significant SMRC was found, but no interaction occurred between SMRC and correspondence effect, supporting that the hypothesis of different and relatively independent psychological mechanisms is at the basis of each effect. Because significant facilitation for ipsilateral motor responses (correspondence effect) occurred for graspable objects but not for lateralized bars, the attentional shift/spatial-coding view was not able to completely explain our data, and therefore, the grasping affordance hypothesis remained as the most plausible explanation. The time course of facilitation observed in the first experiment and by others indicates the importance of further studies to better understand the time dynamic of facilitation/inhibition of motor responses induced by graspable objects. [ABSTRACT FROM AUTHOR]

Motor imagery requires the covert execution of a movement without any overt motor output. Previous studies indicated that motor imagery results in the prolonged inhibition of motor commands. In the present study, we investigated whether motor imagery also leads to the inhibition of more abstract task representations. To do so, we investigated the effect of motor imagery on n − 2 repetition costs, which offer an index of the extent to which task representations are inhibited. Participants switched among three tasks and among two response modes: overt and covert responding (i.e., motor imagery). N – 2 repetition costs were present when the current trial required an overt response but absent when the current trial required a covert response. Furthermore, n − 2 repetition costs were more pronounced when trial n − 1 required a covert response rather than an overt response. This pattern of results suggests that motor imagery also leads to the inhibition of abstract task representations. We discuss our findings in view of current conceptualizations of motor imagery and argue that the inhibitory mechanism entailed by motor imagery targets more than motor commands alone. Finally, we also relate our findings to the mechanisms underlying the inhibition of task representations. [ABSTRACT FROM AUTHOR]

The Simon effect represents a phenomenon in which the location of the stimuli affects the speed and accuracy of the response, despite being irrelevant for the task demands. This is believed to be due to an automatic activation of a response corresponding to the location of the stimuli, which conflicts with the controlled decision process based on relevant stimuli features. Previously, differences in the nature of the Simon effect (i.e., the pattern of change of the effect across the distribution of response times) between visual and somatosensory stimuli were reported. We hypothesize that the temporal dynamics of visual and somatosensory automatic and controlled processes vary, thus driving the reported behavioral differences. While most studies have used response times to study the underlying mechanisms involved, in this study we had participants reach out to touch the targets and recorded their arm movements using a motion capture system. Importantly, the participants started their movements before a final decision was made. In this way, we could analyze the movements to gain insights into the competition between the automatic and controlled processes. We used this technique to describe the results in terms of a model assuming automatic activation due to location-based evidence, followed by inhibition. We found that for the somatosensory Simon effect, the decay of the automatic process is significantly slower than for the visual Simon effect, suggesting quantitative differences in this automatic process between the visual and somatosensory modalities. [ABSTRACT FROM AUTHOR]

The proximity of hand position alters the processing of visual stimuli. Stimuli presented close (proximal) to hands receive an enhanced allocation of visual attention compared to stimuli presented far (distal) from hands. In the present dual-task study we studied the consequences of this preferential processing when the stimulus for Task 1 (S1) and the stimulus for Task 2 (S2) were presented together and were assigned to specific response hands (R1 and R2) located proximal (at the monitor) versus distal (in the lap) to the stimuli. In two experiments, we tested whether stimulus–hand proximity affected the extent of between-task interference (i.e., influence of additional Task 2 processing on primary Task 1 processing). In Experiment 1, results showed that stimulus–hand proximity reduced the amount of between-task interference compared to the distal stimulus–hand condition. Extending these findings, in Experiment 2 a further reduction of between-task interference was obtained when a single hand was located at the monitor instead of two hands. These results are inconsistent with the assumption of a generally increased attentional processing benefit for multiple stimuli within hand space. Instead, these findings speak for a hand-specific processing benefit that supports more separate processing of two tasks. Together these findings demonstrate that stimulus–hand proximity affects the quality of multiple task performance, which is discussed in the context of both, basic and applied cognitive research. [ABSTRACT FROM AUTHOR]

Does cognitive control operate globally (across task sets) or locally (within a task set)? Recently, two of the current co-authors (Hazeltine and Schumacher 2016; Schumacher and Hazeltine 2016) proposed that humans represent tasks as task files: hierarchically structured, compartmentalized subsets of our current goals and motivations, task instructions, and relevant stimuli and responses that are selected during task performance according to associated contextual rules. Here, we hypothesize that these task representations bound the implementation of cognitive control at distinct levels of this hierarchical structure. To investigate how task structure influences the implementation of control processes, we conducted a pair of experiments that utilized a precuing procedure. To manipulate task structure, we gave participants mappings in which two stimulus sets were either mapped so that each set was separated by response hand or both sets were interleaved across hands. In Experiment 1, participants responded to sets of images distinguished by their semantic category; in Experiment 2, they responded to sets based on different perceptual features (viz., location or color). During each experiment, precues could give information about the stimulus category or response hand for the upcoming target. The results indicate that participants with separated mappings represented the task hierarchically, while those with interleaved mappings did not. This pattern was consistent across experiments, despite the differences in the way that each set of stimuli influenced representation of the low-level task features. These findings suggest that task structure can be represented hierarchically, and that this structure supports distinct cognitive control processes at different hierarchical levels. [ABSTRACT FROM AUTHOR]

Recent studies in the field of task switching have shown that humans can base expectancies for tasks on temporal cues. When tasks are predictable based on the duration of the preceding pre-target interval, humans implicitly adapt to this predictability, indicated by better performance in trials with validly compared to invalidly predicted tasks. Yet, it is not clear which internal timing mechanisms are involved. Previous research has suggested that intervals from the sub- and supra-second range are processed by distinct cognitive timing systems. As earlier studies on temporally predictable task switching have used predictive intervals stemming from both ranges, it was not yet clear if the time-based expectancy effect was driven by just one of the two internal timing systems. The present study used clearly sub-second intervals (10 ms and 500 ms) in Experiment 1, while clearly supra-second intervals (1500 ms and 3000 ms) were used in Experiment 2. Substantial adaptation effects were observed in both experiments, showing that sub- as well as supra-second timing systems are involved in time-based expectancies for tasks. The present findings offer important implications for our theoretical understanding of the internal timing mechanisms involved in time-based task expectancy. [ABSTRACT FROM AUTHOR]

In their Perception–Action Model (PAM), Goodale and Milner (1992) proposed functionally independent and encapsulated processing of visual information for action and perception. In this context, they postulated that visual input for action is processed in an automatized and analytic manner, which renders visuomotor behaviour immune to perceptual interferences or multitasking costs due to sharing of cognitive resources. Here, we investigate the well-known Garner Interference effect under dual- and single-task conditions in its classic perceptual form as well as in grasping. Garner Interference arises when stimuli are classified along a relevant dimension (e.g., their length), while another irrelevant dimension (e.g., their width) has to be ignored. In the present study, participants were presented with differently sized rectangular objects and either grasped them or classified them as long or short via button presses. We found classical Garner Interference effects in perception as expressed in prolonged reaction times when variations occurred also in the irrelevant object dimension. While reaction times during grasping were not susceptible to Garner Interference, effects were observed in a number of measures that reflect grasping accuracy (i.e., poorer adjustment of grip aperture to object size, prolonged adjustment times, and increased variability of the maximum hand opening when irrelevant object dimensions were varied). In addition, multitasking costs occurred in both perception and action tasks. Thus, our findings challenge the assumption of automaticity in visuomotor behaviour as proposed by the PAM. [ABSTRACT FROM AUTHOR]

Infants and toddlers engage in instrumental helping, that is, help others in achieving an action-based goal. The underlying psychological mechanisms are unclear and hotly debated. The present study examined whether young children's helping is affected by others' need. To this end, 1.5- and 3.5-year-old children (n = 101) were simultaneously confronted with a needy and a non-needy other in a variety of helping tasks. The results show that the 3.5-year-old, but not the 1.5-year-old children preferentially helped the needy person. This suggests developmental changes in the psychological mechanisms underlying early instrumental helping. The results are explained by a developmental account according to which helping only gradually becomes an other-oriented and need-based behavior in the first years of life. Article highlights: We examined the nature of young children's instrumental helping. 1.5- and 3.5-year-olds were confronted with a needy and non-needy other in several classical helping situations. 3.5-, but not 1.5-year-old children helped more the needy than the non-needy other. The psychological mechanisms underlying young children's helping change during the first years of life. [ABSTRACT FROM AUTHOR]

Prospective memory (PM) involves remembering intended actions in the future, such as posting a letter when seeing a post box (event-based PM) or making a phone call at 2:00 pm (time-based PM). Studies on aging and PM have often reported negative age effects in the laboratory, but positive age effects in naturalistic tasks outside the laboratory (the so-called age–PM-paradox). The present study re-examined this pattern of the paradox by studying, for the first time, age differences in time- and event-based PM in lab-based, experimenter-generated naturalistic and self-assigned real-life PM tasks within the same sample of young and older adults. Results showed that differential age effects in and outside the laboratory were qualified by the type of PM cue. While age-related deficits were obtained for laboratory event-based tasks, no age effect was obtained for naturalistic event-based PM. Age benefits in the field were only observed for naturalistic time-based tasks, but not for participants' own self-assigned time-based tasks. These findings indicate that the age benefits for naturalistic PM tasks may have been overestimated due to the dominant use of experimenter-generated naturalistic time-based PM tasks in previous studies. Therefore, the precise pattern of the age–PM-paradox may need redefining as mostly consisting of negative age effects in lab-based PM tasks and mostly the absence of negative age effects (rather than age benefits) in naturalistic and self-assigned tasks outside the laboratory. [ABSTRACT FROM AUTHOR]