State anticipation and task serialization attenuate embodied decision biases when deciding while moving.

We examined whether and how embodied decision biases-related to motor costs (MC) as well as cognitive crosstalk (CC) due to the body state-are influenced by extended deliberation time. Participants performed a tracking task while concurrently making reward-based decisions, with rewards being presented with varying preview time. In Experiment 1 (N = 58), we observed a reduced CC bias with extended preview time. Partially, this was due to participants slightly adapting tracking to serialize it in relation to decision making. However, the influence of MC was only marginal and not subject to anticipatory state adjustments. In Experiment 2 (N = 67), we examined whether participants integrated the immediate state at reward presentation or anticipated state when a decision could be implemented when adapting their tracking and decision behavior. Results were most compatible with the anticipated state being integrated. We conclude that humans anticipate the body state when a decision must be implemented and consider the corresponding motor and cognitive demands when adapting their decision behavior. However, anticipatory state adaptations targeting the influence of MC with extended preview time were absent, suggesting that anticipatory adaptations are starkly limited in low-practice tasks compared to more overlearned behavior like walking. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Where scrollbars are clicked, and why.

Scrolling is a widely used mean to interact with visual displays, usually to move content to a certain target location on the display. Understanding how user scroll might identify potentially suboptimal use and allows to infer users' intentions. In the present study, we examined where users click on a scrollbar depending on the intended scrolling action. In two online experiments, click positions were systematically adapted to the intended scrolling action. Click position selection could not be explained as strict optimization of the distance traveled with the cursor, memory load, or motor-cognitive factors. By contrast, for identical scrolling actions click positions strongly depended on the context and on previous scrolls. The behavior of our participants closely resembled behavior observed for manipulation of other physical devices and suggested a simple heuristic of movement planning. The results have implications for modeling human-computer interaction and may contribute to predicting user behavior.

Dual-tasking modulates movement speed but not value-based choices during walking.

Value-based decision-making often occurs in multitasking scenarios relying on both cognitive and motor processes. Yet, laboratory experiments often isolate these processes, thereby neglecting potential interactions. This isolated approach reveals a dichotomy: the cognitive process by which reward influences decision-making is capacity-limited, whereas the influence of motor cost is free of such constraints. If true, dual-tasking should predominantly impair reward processing but not affect the impact of motor costs. To test this hypothesis, we designed a decision-making task in which participants made choices to walk toward targets for rewards while navigating past an obstacle. The motor cost to reach these rewards varied in real-time. Participants either solely performed the decision-making task, or additionally performed a secondary pitch-recall task. Results revealed that while both reward and motor costs influenced decision-making, the secondary task did not affect these factors. Instead, dual-tasking slowed down participants' walking, thereby reducing the overall reward rate. Hence, contrary to the prediction that the added cognitive demand would affect the weighing of reward or motor cost differentially, these processes seem to be maintained at the expense of slowing down the motor system. This slowdown may be indicative of interference at the locomotor level, thereby underpinning motor-cognitive interactions during decision-making.

Ideonamic: An integrative computational dynamic model of ideomotor learning and effect-based action control.

According to ideomotor theory, actions are represented, controlled, and retrieved in terms of the perceptual effects that these actions experientially engender. When agents perform a motor action, they observe its subsequent perceptual effects and establish action-effect associations. When they want to achieve this effect at a later time, they use the action-effect associations to preactivate the action by internally activating the effect representation. Ideomotor theory has received extensive support in recent years. To capture this particular effect-based view on action control and goal-directed behavior, we developed IDEONAMIC, an integrative computational model based on dynamic field theory that represents the specific components of the action control process as dynamic neural fields. We show that IDEONAMIC applies conveniently to different types of experimental ideomotor settings, simulates key findings, generates novel predictions from the dynamics of data, and allows reapproaching the underlying cognitive mechanisms from a computational point of view. We encourage the application of IDEONAMIC to more types of ideomotor settings to gain insights into effect-based action control. The model is available at https://osf.io/hbc6n. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Embodied decision biases: individually stable across different tasks?

In everyday life, action and decision-making often run in parallel. Action-based models argue that action and decision-making strongly interact and, more specifically, that action can bias decision-making. This embodied decision bias is thought to originate from changes in motor costs and/or cognitive crosstalk. Recent research confirmed embodied decision biases for different tasks including walking and manual movements. Yet, whether such biases generalize within individuals across different tasks remains to be determined. To test this, we used two different decision-making tasks that have independently been shown to reliably produce embodied decision biases. In a within-participant design, participants performed two tasks in a counterbalanced fashion: (i) a walking paradigm for which it is known that motor costs systematically influence reward decisions, and (ii) a manual movement task in which motor costs and cognitive crosstalk have been shown to impact reward decisions. In both tasks, we successfully replicated the predicted embodied decision biases. However, there was no evidence that the strength of the biases correlated between tasks. Hence, our findings do not confirm that embodied decision biases transfer between tasks. Future research is needed to examine whether this lack of transfer may be due to different causes underlying the impact of motor costs on decisions and the impact of cognitive crosstalk or task-specific differences.

Embodied decisions during walking.

Research on embodied decision-making only recently started to examine whether and how concurrent actions influence value-based decisions. For instance, during walking humans preferably make decisions that align with a turn toward the side of their current swing leg, sometimes resulting in unfavorable choices (e.g., less reward). It is suggested that concurrent movements influence decision-making by coincidental changes in motor costs. If this is true, systematic manipulations of motor costs should bias decisions. To test this, participants had to accumulate rewards (i.e., points) by walking and turning toward left and right targets displaying rewards across three experiments. In experiments 1a and 1b, we manipulated the turning cost based on the current swing leg by applying different symmetric turning magnitudes (i.e., same angles for left and right targets). In experiment 2, we manipulated the turning cost by administering asymmetric turning magnitudes (i.e., different angles for left and right targets). Finally, in experiment 3, we increased the cost of walking by adding ankle weights. Altogether, the experiments support the claim that differences in motor costs influenced participants' decisions: experiments 1a and 1b revealed that the swing leg effect and stepping behavior were moderated by turning magnitude. In experiment 2, participants showed a preference for less costly, smaller turning magnitudes. Experiment 3 replicated the swing leg effect when motor costs were increased by means of ankle weights. In conclusion, these findings provide further evidence that value-based decisions during ongoing actions seem to be influenced by dynamically changing motor costs, thereby supporting the concept of "embodied decision-making."NEW & NOTEWORTHY Motor processes of concurrent movements have been shown to influence embodied decision-making. It is hypothesized that this is driven by coincidental changes in motor costs. We tested this claim by systematically manipulating motor costs of choice options during walking. In three experiments we show how variations in motor cost (e.g., turning angle or stepping constraints) bias decision-making, thereby supporting the concept of "embodied decision-making."

Deciding while moving: Cognitive interference biases value-based decisions.

When people act, they repeatedly have to make value-based decisions about the further course of actions. For example, when driving on the highway, they must decide whether to overtake other cars by changing lanes to arrive at their destination quicker; concurrently, they are required to stay on their momentary lane by controlling the steering wheel. Embodied choice models predict that concurrent action execution modulates value-based decisions. Here, we examined whether value-based decisions are influenced by a change of action costs and/or cognitive interference between concurrent actions and decision making. In a novel, computerized multilane tracking task paradigm, participants (N = 50) controlled a cursor moving on one of three horizontal lanes. During tracking (concurrent action), participants had to switch to other lanes to avoid obstacles or collect rewards (value-based decisions). The action costs associated with a lane switch depended on the cursor position relative to the currently tracked lane, and this relationship varied between conditions. Results showed that value-based lane switching decisions were biased by the cursor state. While this influence was partly attributed to minimizing action costs, a considerable part of the influence could be attributed to cognitive interference. Our findings provide further evidence for embodied choice models, showing that both cognitive interference as well as action costs bias value-based decisions.

The observer's perspective determines which cues are used when interpreting pointing gestures.

Though ubiquitous in human communication, pointing gestures are often misunderstood. This study addressed how the observer's perspective affects pointing perception. More specifically, we tested the hypothesis that two different visual cues-namely (a) the vector defined by the pointer's arm or finger and (b) the pointer's index finger position in the observer's visual field-determine pointing perception and that their relative influence depends on the observer's perspective. In three experiments, participants judged the location at which a virtual or real pointer was pointing from different viewpoints. The experiments show that the observer perspective has a considerable effect on pointing perception. The more the observer's gaze direction is aligned with the pointing arm, the more observers rely on the position of the pointing finger in their visual field and the less they rely on its direction. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Body dynamics of gait affect value-based decisions.

Choosing among different options typically entails weighing their anticipated costs and benefits. Previous research has predominantly focused on situations, where the costs and benefits of choices are known before an action is effectuated. Yet many decisions in daily life are made on the fly, for instance, making a snack choice while walking through the grocery store. Notably, the costs of actions change dynamically while moving. Therefore, in this study we examined whether the concurrent action dynamics of gait form part of and affect value-based decisions. In three experiments, participants had to decide which lateral (left vs. right) target (associated with different rewards) they would go to, while they were already walking. Results showed that the target choice was biased by the alternating stepping behavior, even at the expense of receiving less reward. These findings provide evidence that whole-body action dynamics affect value-based decisions.

Impact of proprioception on the perceived size and distance of external objects in a virtual action task.

Previous research has revealed changes in the perception of objects due to changes of object-oriented actions. In present study, we varied the arm and finger postures in the context of a virtual reaching and grasping task and tested whether this manipulation can simultaneously affect the perceived size and distance of external objects. Participants manually controlled visual cursors, aiming at reaching and enclosing a distant target object, and judged the size and distance of this object. We observed that a visual-proprioceptive discrepancy introduced during the reaching part of the action simultaneously affected the judgments of target distance and of target size (Experiment 1). A related variation applied to the grasping part of the action affected the judgments of size, but not of distance of the target (Experiment 2). These results indicate that perceptual effects observed in the context of actions can directly arise through sensory integration of multimodal redundant signals and indirectly through perceptual constancy mechanisms.

Perspective determines the production and interpretation of pointing gestures.

Pointing is a ubiquitous means of communication. Nevertheless, observers systematically misinterpret the location indicated by pointers. We examined whether these misunderstandings result from the typically different viewpoints of pointers and observers. Participants either pointed themselves or interpreted points while assuming the pointer's or a typical observer perspective in a virtual reality environment. The perspective had a strong effect on the relationship between pointing gestures and referents, whereas the task had only a minor influence. This suggests that misunderstandings between pointers and observers primarily result from their typically different viewpoints.

Precise movements in awkward postures: A direct test of the precision hypothesis of the end-state comfort effect.

When humans manipulate an object, they prefer to grasp the object in a way that allows to terminate the manipulation in a comfortable posture. The reasons for this end-state comfort effect have remained elusive so far. One explanation assumes that comfortable end-states are not preferred per se, but rather because they come with increased movement precision, which is typically required by the end of an object manipulation. Five experiments were conducted to test this hypothesis and yielded 3 main results. First, grasps that increase control over an object are preferred irrespective of the resulting arm postures. Second, differences in the controllability associated with comfortable and uncomfortable postures are sufficient to elicit the end-state comfort effect. Third, grasps that optimize control are preferred even when this implies adopting uncomfortable end-states. Altogether, these findings directly support the hypothesis that the end-state comfort emerges because it maximizes the control over the manipulated object at the end of object manipulations. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Free-choice saccades and their underlying determinants: Explorations of high-level voluntary oculomotor control.

Models of eye-movement control distinguish between different control levels, ranging from automatic (bottom-up, stimulus-driven selection) and automatized (based on well-learned routines) to voluntary (top-down, goal-driven selection, e.g., based on instructions). However, one type of voluntary control has yet only been examined in the manual and not in the oculomotor domain, namely free-choice selection among arbitrary targets, that is, targets that are of equal interest from both a bottom-up and top-down processing perspective. Here, we ask which features of targets (identity- or location-related) are used to determine such oculomotor free-choice behavior. In two experiments, participants executed a saccade to one of four peripheral targets in three different choice conditions: unconstrained free choice, constrained free choice based on target identity (color), and constrained free choice based on target location. The analysis of choice frequencies revealed that unconstrained free-choice selection closely resembled constrained choice based on target location. The results suggest that free-choice oculomotor control is mainly guided by spatial (location-based) target characteristics. We explain these results by assuming that participants tend to avoid less parsimonious recoding of target-identity representations into spatial codes, the latter being a necessary prerequisite to configure oculomotor commands.

Emergence of anticipatory actions in a novel task.

Humans normally adapt earlier segments of multistep motor actions in such a way that the execution of later segments is facilitated. For example, the kinematics of grasping movements are adapted to the requirements of the intended subsequent object manipulations. Here we studied which factors foster adaptation of earlier action segments to later ones in a novel task for which no prior experience existed. Participants executed a two-step isometric force production task, in which the force produced in the first segment determined the difficulty of the second segment. Adaptation of the first segment to the second one benefited from explicit knowledge of the dependency between both segments but not from extensive prior experience with the second segment. These observations show that adaptation of motor actions to subsequent actions demands the construction of a task representation that allows to plan the first action segment with respect to its successor. How specifically the first segment is tailored to the second one does not depend on prior experience with the second segment but depends on experience from performing the interdependent two-step action sequence.

Flexible coupling of covert spatial attention and motor planning based on learned spatial contingencies.

The present study tested whether the coupling of covert attentional shifts and motor planning of pointing movements can be modulated by learning. Participants performed two tasks. As a primary movement task, they executed a pointing movement to a movement target (MT) location. As a secondary visual attention task, they identified a discrimination target (DT) that was presented shortly before initiation of the pointing movement. These DTs either occurred at the same or at different locations with the MT. A common finding in such and similar settings is the enhanced visual target identification when locations of MT and DT coincide. However, it is not known which factors govern the flexibility of spatial attention-action coupling. Here, we tested the influence of previously learned spatial contingencies between MT and DT on the coupling of covert attention and motor planning. These contingencies were manipulated in three groups (always same locations, always opposite locations, non-contingent locations) in a training session. Results indicated that in a subsequent test phase, previously learned contingencies enhanced visual identification accordingly, even when targets for the movement task and the visual task were presented at opposite sides. These results corroborate previous findings of a rather flexible interaction of attention and motor planning, and demonstrate how one can learn to control attention by means of motor planning.

Intentional binding is unrelated to action intention.

The present study examined the role of voluntary motor commands in the subjective temporal attraction between an action and its sensory consequence termed as intentional binding. Participants either pressed a key voluntarily or involuntarily while seeing a rotating clock hand. The key press was followed by a short beep tone in some blocks of trials. Then, the position of the clock hand at action or tone occurrence was judged. Trials in which key presses and tones occurred separately provided baseline measures. A direct comparison of baseline uncorrected estimates between both action conditions indicated less binding for involuntary than for voluntary movements as reported by previous studies. However, this effect disappeared after a baseline correction and when we controlled for the temporal predictability of critical events. These results cast substantial doubts on a close link between action intention and intentional binding, but instead highlight the role of causal inference and multisensory integration processes. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Grasp planning for object manipulation without simulation of the object manipulation action.

When an object is grasped, the grasp is usually adapted to upcoming object manipulations. We tested the hypothesis that grasp planning for object manipulation is based on simulations of body movements that could implement intended object manipulations. The simulation of body movements requires to map the desired object movement onto body movements at some stage of the planning process. Hence, manipulating this mapping should affect simulations and ultimately grasp selections. This hypothesis was tested in five experiments, in which participants grasped a circular knob and used it to rotate a pointer to various targets. In Experiments 1-3, we selectively manipulated the pointer-to-hand-rotation mapping with a "virtual rotation" procedure. During these virtual rotations, participants were exposed to an altered mapping between their hand movements and movements of the pointer. However, the exposure did not affect grasp selections in a subsequent test block. In Experiment 4, we verified that our manipulations of the mapping were sufficient to evoke substantial changes in grasp selections. In Experiment 5, we verified that adaptations in the virtual rotation procedure carried over to the test blocks, in which grasp selections were probed. In summary, participants adapted their grasps to different intended pointer rotations on a trial-to-trial bases, thus showing the end-state comfort effect. However, grasp selections were unaffected by the acquired mapping between pointer and hand movements. This suggests that anticipations of the body movements associated with specific object manipulation play no crucial role during grasp planning. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

This Is How To Be a Rule Breaker.

Violating rules comes with cognitive conflict for the rule-breaker. Here, we probed for means to reduce the behavioral effects of this conflict by studying the combined impact of recency and frequency of rule violations. We found that violating a rule facilitated the initiation of a subsequent rule violation, while notable costs relative to rule-based responding remained in measures of response execution. Such costs during response execution vanished, however, when frequency and recency of rule violation worked in concert. That is, it is possible to overcome the costs of rule violation when (a) having violated this particular rule frequently and (b) having violated this particular rule very recently. Moreover, we demonstrated that recent rule violations reduce the costs of cognitive conflict in an unrelated interference task (Simon task). Based on these findings, we present a revised model of the cognitive processes underlying deliberate rule violations.

How to point and to interpret pointing gestures? Instructions can reduce pointer-observer misunderstandings.

In everyday communication, people often point. However, a pointing act is often misinterpreted as indicating a different spatial referent position than intended by the pointer. It has been suggested that this happens because pointers put the tip of the index finger close to the line joining the eye to the referent. However, the person interpreting the pointing act extrapolates the vector defined by the arm and index finger. As this line crosses the eye-referent line, it suggests a different referent position than the one that was meant. In this paper, we test this hypothesis by manipulating the geometry underlying the production and interpretation of pointing gestures. In Experiment 1, we compared naïve pointer-observed dyads with dyads in which the discrepancy between the vectors defining the production and interpretation of pointing acts has been reduced. As predicted, this reduced pointer-observer misunderstandings compared to the naïve control group. In Experiment 2, we tested whether pointers elevate their arms steeper than necessary to orient it toward the referent, because they visually steer their index finger tips onto the referents in their visual field. Misunderstandings between pointers and observers were smaller when pointers pointed without visual feedback. In sum, the results support the hypothesis that misunderstandings between (naïve) pointers and observers result from different spatial rules describing the production and interpretation of pointing gestures. Furthermore, we suggest that instructions that reduce the discrepancy between these spatial rules can improve communicating with pointing gestures.

Preschool children adapt grasping movements to upcoming object manipulations: Evidence from a dial rotation task.

In adults, the motor plans for object-directed grasping movements reflects the anticipated requirements of intended future object manipulations. This prospective mode of planning has been termed second-order planning. Surprisingly, second-order planning is thought to be fully developed only by 10 years of age, when children master seemingly more complex motor skills. In this study, we tested the hypothesis that already 5- and 6-year-old children consistently use second-order planning but that this ability does not become apparent in tasks that are traditionally used to probe it. We asked 5- and 6-year-olds and adults to grasp and rotate a circular dial in a clockwise or counterclockwise direction. Although children's grasp selections were less consistent on an intra- and inter-individual level than adults' grasp selections, all children adjusted their grasps to the upcoming dial rotations. By contrast, in an also administered bar rotation task, only a subset of children adjusted their grasps to different bar rotations, thereby replicating previous results. The results indicate that 5- and 6-year-olds consistently use second-order planning in a dial rotation task, although this ability does not become apparent in bar rotation tasks.