Labor division in collaborative visual search: a review.

When looking for a certain object or person, individuals often engage in collaborative visual search, i.e., they search together by coordinating their behavior. For instance, when parents are looking for their child on a busy playground, they might search collaboratively by dividing the search area. This type of labor division in collaborative visual search could be beneficial not only in daily life, but also in professional life (e.g., at airport security screening, lifeguarding, or diagnostic radiology). To better understand the mechanisms underlying this type of collaborative behavior, as well as its benefits and costs, researchers have studied visual search scenarios in the laboratory. The aim of this review article is to provide a brief overview of the results of these studies. Are individuals faster if they search together compared to alone? And if so, should they simply search in parallel, or will they benefit from agreeing on a specific labor division? How should they divide the search space, and how to communicate this division? Should a consensus be reached (target present or absent?) before ending the search? We address these and further key questions, focusing on the aspect of labor division. In conclusion, we integrate the reviewed findings into an applied context, point out which questions still remain, and put forward suggestions for future research. We hope that this review can serve not only as a theoretical foundation for basic research but also as a practical inspiration for applied research and development.

Advanced clinical parameters: A complementary hydroxyurea adherence evaluation in sickle cell anemia treatment.

OBJECTIVES: Given the complex pathology of sickle cell anemia (SCA) and low adherence to hydroxyurea (HU) treatment, there is a need to seek parameters that identify recent changes in patient status. The advanced clinical parameters (ACPs) allow an early analysis of hematopoiesis. We aimed to draw the demographic profile of non-adherent SCA patients and to verify the use of ACPs as a measure of HU treatment adherence. METHOD: In a cross-sectional study, we divided 83 SCA subjects treated with HU into Children (<12 years old) and adolescents/adults (≥12 years old). Their hemogram with the ACPs, electronic medical charts and pharmacy claim data were analyzed. RESULTS: Non-adherent ≥12 years old patients had significantly increased WBC, absolute neutrophil, lymphocyte, monocyte, and basophil counts, RBC, RET, RDW, and PLT, and significantly decreased MCV and MCH. Subjects in the adolescent/adult group with IG† ≥0.035 cells/mm3 had the RR for non-adherence increased by 4.6 times (p = .014), and the systemic immune inflammation index (SII) of non-adherent patients was also significantly higher (p = .042). CONCLUSION: IG† presents clinical utility in early identification of non-adherence to HU, especially when combined with other parameters, suggesting the evaluation of ACPs in laboratory routine, as they can be easily implemented.

When eyes beat lips: speaker gaze affects audiovisual integration in the McGurk illusion.

Eye contact is a dynamic social signal that captures attention and plays a critical role in human communication. In particular, direct gaze often accompanies communicative acts in an ostensive function: a speaker directs her gaze towards the addressee to highlight the fact that this message is being intentionally communicated to her. The addressee, in turn, integrates the speaker's auditory and visual speech signals (i.e., her vocal sounds and lip movements) into a unitary percept. It is an open question whether the speaker's gaze affects how the addressee integrates the speaker's multisensory speech signals. We investigated this question using the classic McGurk illusion, an illusory percept created by presenting mismatching auditory (vocal sounds) and visual information (speaker's lip movements). Specifically, we manipulated whether the speaker (a) moved his eyelids up/down (i.e., open/closed his eyes) prior to speaking or did not show any eye motion, and (b) spoke with open or closed eyes. When the speaker's eyes moved (i.e., opened or closed) before an utterance, and when the speaker spoke with closed eyes, the McGurk illusion was weakened (i.e., addressees reported significantly fewer illusory percepts). In line with previous research, this suggests that motion (opening or closing), as well as the closed state of the speaker's eyes, captured addressees' attention, thereby reducing the influence of the speaker's lip movements on the addressees' audiovisual integration process. Our findings reaffirm the power of speaker gaze to guide attention, showing that its dynamics can modulate low-level processes such as the integration of multisensory speech signals.

A bonus task boosts people's willingness to offload cognition to an algorithm.

With the increased sophistication of technology, humans have the possibility to offload a variety of tasks to algorithms. Here, we investigated whether the extent to which people are willing to offload an attentionally demanding task to an algorithm is modulated by the availability of a bonus task and by the knowledge about the algorithm's capacity. Participants performed a multiple object tracking (MOT) task which required them to visually track targets on a screen. Participants could offload an unlimited number of targets to a "computer partner". If participants decided to offload the entire task to the computer, they could instead perform a bonus task which resulted in additional financial gain-however, this gain was conditional on a high performance accuracy in the MOT task. Thus, participants should only offload the entire task if they trusted the computer to perform accurately. We found that participants were significantly more willing to completely offload the task if they were informed beforehand that the computer's accuracy was flawless (Experiment 1 vs. 2). Participants' offloading behavior was not significantly affected by whether the bonus task was incentivized or not (Experiment 2 vs. 3). These results combined with those from our previous study (Wahn et al. in PLoS ONE 18:e0286102, 2023), which did not include a bonus task but was identical otherwise, show that the human willingness to offload an attentionally demanding task to an algorithm is considerably boosted by the availability of a bonus task-even if not incentivized-and by the knowledge about the algorithm's capacity.

Communicative modulations of early action components support the prediction of distal goals.

The successful unfolding of many social interactions relies on our capacity to predict other people's action goals, whether these are proximal (i.e., immediate) or distal (i.e., upcoming). The present set of studies asks whether observers can predict the distal goal of two-step action sequences when presented with communicative modulations of the first movement component of the sequence. We conducted three online experiments in which we presented participants with animations of a box moving to a first target location before moving onwards to a final, either near or far, target location. The second movement component and the target locations were occluded. After observing the first movement, participants were asked to select the most likely final target location, i.e., the distal goal of the sequence. Experiment 1 showed that participants relied on the velocity modulations of the first movement to infer the distal goal. The results of Experiment 2 indicated that such predictions of distal goals are possible even when the second movement in the sequence does not contain any velocity information, thus suggesting that the information present in the first movement plays the major role in the process of linking movements to their distal goals. However, Experiment 3 showed that under some circumstances the second movement can also contribute to how observers predict a distal goal. We discuss these results in terms of the underlying simulation processes that enable observers to predict a distal goal from the observation of proximal communicative modulations.

Attention allocation in complementary joint action: How joint goals affect spatial orienting.

When acting jointly, individuals often attend and respond to the same object or spatial location in complementary ways (e.g., when passing a mug, one person grasps its handle with a precision grip; the other receives it with a whole-hand grip). At the same time, the spatial relation between individuals' actions affects attentional orienting: one is slower to attend and respond to locations another person previously acted upon than to alternate locations ("social inhibition of return", social IOR). Achieving joint goals (e.g., passing a mug), however, often requires complementary return responses to a co-actor's previous location. This raises the question of whether attentional orienting, and hence the social IOR, is affected by the (joint) goal our actions are directed at. The present study addresses this question. Participants responded to cued locations on a computer screen, taking turns with a virtual co-actor. They pursued either an individual goal or performed complementary actions with the co-actor, in pursuit of a joint goal. Four experiments showed that the social IOR was significantly modulated when participant and co-actor pursued a joint goal. This suggests that attentional orienting is affected not only by the spatial but also by the social relation between two agents' actions. Our findings thus extend research on interpersonal perception-action effects, showing that the way another agent's perceived action shapes our own depends on whether we share a joint goal with that agent.

Smaller preferred interpersonal distance for joint versus parallel action.

During social interaction, humans prefer to keep a certain distance between themselves and other individuals. This preferred 'interpersonal distance' (IPD) is known to be sensitive to social context, and in the present study we aimed to further investigate the extent to which IPD is affected by the specific type of social interaction. In particular, we focused on the contrast between joint actions, where two or more individuals coordinate their actions in space and time to achieve a shared goal, and parallel actions, where individuals act alongside each other but individually. We predicted that joint action would be associated with a smaller preferred IPD compared to parallel action. Additionally, given that this research took place in the midst of the COVID-19 pandemic, we aimed to assess whether IPD preferences are affected by individuals' concerns about infection in general, as well as COVID-19 in particular. We predicted that higher individual concerns would be associated with greater preferred IPD. To test these hypotheses, we asked participants to imagine different social scenarios (involving either joint or parallel actions alongside a stranger) and indicate, on a visual scale, their preferred IPD. The results of two experiments (n = 211, n = 212) showed that participants preferred a shorter distance when they imagined acting jointly compared to when they imagined acting in parallel. Moreover, participants who reported higher discomfort for potential pathogen contact and who were more aware of the COVID-19 context in which the study took place preferred a larger IPD in general. Our results provide further evidence that different types of social interaction shape IPD preference. We discuss potential reasons for this phenomenon and highlight remaining questions for future research.

Understanding others' distal goals from proximal communicative actions.

Many social interactions require individuals to coordinate their actions and to inform each other about their goals. Often these goals concern an immediate (i.e., proximal) action, as when people give each other a brief handshake, but they sometimes also refer to a future (i.e. distal) action, as when football players perform a passing sequence. The present study investigates whether observers can derive information about such distal goals by relying on kinematic modulations of an actor's instrumental actions. In Experiment 1 participants were presented with animations of a box being moved at different velocities towards an apparent endpoint. The distal goal, however, was for the object to be moved past this endpoint, to one of two occluded target locations. Participants then selected the location which they considered the likely distal goal of the action. As predicted, participants were able to detect differences in movement velocity and, based on these differences, systematically mapped the movements to the two distal goal locations. Adding a distal goal led to more variation in the way participants mapped the observed movements onto different target locations. The results of Experiments 2 and 3 indicated that this cannot be explained by difficulties in perceptual discrimination. Rather, the increased variability likely reflects differences in interpreting the underlying connection between proximal communicative actions and distal goals. The present findings extend previous research on sensorimotor communication by demonstrating that communicative action modulations are not restricted to predicting proximal goals but can also be used to infer more distal goals.

Offloading under cognitive load: Humans are willing to offload parts of an attentionally demanding task to an algorithm.

In the near future, humans will increasingly be required to offload tasks to artificial systems to facilitate daily as well as professional activities. Yet, research has shown that humans are often averse to offloading tasks to algorithms (so-called "algorithmic aversion"). In the present study, we asked whether this aversion is also present when humans act under high cognitive load. Participants performed an attentionally demanding task (a multiple object tracking (MOT) task), which required them to track a subset of moving targets among distractors on a computer screen. Participants first performed the MOT task alone (Solo condition) and were then given the option to offload an unlimited number of targets to a computer partner (Joint condition). We found that participants significantly offloaded some (but not all) targets to the computer partner, thereby improving their individual tracking accuracy (Experiment 1). A similar tendency for offloading was observed when participants were informed beforehand that the computer partner's tracking accuracy was flawless (Experiment 2). The present findings show that humans are willing to (partially) offload task demands to an algorithm to reduce their own cognitive load. We suggest that the cognitive load of a task is an important factor to consider when evaluating human tendencies for offloading cognition onto artificial systems.

Clinical validation of a semi-automated segmentation algorithm for target volume definition on planning CT and CBCT in stereotactic body radiotherapy (SBRT) for peripheral lung lesions.

INTRODUCTION: Stereotactic body radiotherapy (SBRT) is an ablative method for lung malignancies. Here, the definition of the gross target volume (GTV) is subject to interobserver variation. In this study, we aimed to evaluate the interobserver variability during SBRT and its dosimetric impact, as well as to introduce a semi-automated delineation tool for both planning computer tomography (P-CT) and cone beam CT (CBCT) to help to standardise GTV delineation and adaptive volume-change registration. METHODS: The interobserver variation of GTV manual contours from five physicians was analysed in 15 patients after lung SBRT on free breathing (FB) P-CT (n = 15) and CBCT (n = 90) before and after each fraction. The dosimetric impact from interobserver variations of GTV based on the original treatment plan was analysed. Next, the accuracy of an in-house easy-to-use semi-automated-segmentation algorithm for pulmonary lesions was compared with gold standard contours in FB P-CT and CBCT, as well as 4D P-CT of additional 10 patients. RESULTS: The interobserver variability in manual contours resulted in violations of dose coverage of the planning target volume (PTV), which, in turn, resulted in compromised tumour control probability in contours from four physicians. The validation of the semi-automated delineation algorithm using thorax phantom led to a highly reliable accuracy in defining GTVs. Comparing the unsupervised auto-contours with the gold standard delineation revealed high equal high concordance for FB P-CT, 4D P-CT and CBCT, with a DSC of 0.83, 0.76 and 0.8, respectively. The supervised use of the semi-automated delineation tool improved its accuracy, with DSCs of 0.86, 0.86 and 0.8 for FB P-CT, 4D P-CT and CBCT, respectively. The use of the algorithm was associated with a significantly shorter working time. The semi-automated delineation tool can accurately register volume changes in CBCTs. CONCLUSION: The segmentation algorithm provides a reliable, standardised and time-saving alternative for manual delineation in lung SBRT in P-CT and CBCT.

Crossmodal correspondences as common ground for joint action.

When performing joint actions, people rely on common ground - shared information that provides the required basis for mutual understanding. Common ground can be based on people's interaction history or on knowledge and expectations people share, e.g., because they belong to the same culture or social class. Here, we suggest that people rely on yet another form of common ground, one that originates in their similarities in multisensory processing. Specifically, we focus on 'crossmodal correspondences' - nonarbitrary associations that people make between stimulus features in different sensory modalities, e.g., between stimuli in the auditory and the visual modality such as high-pitched sounds and small objects. Going beyond previous research that focused on investigating crossmodal correspondences in individuals, we propose that people can use these correspondences for communicating and coordinating with others. Initial support for our proposal comes from a communication game played in a public space (an art gallery) by pairs of visitors. We observed that pairs created nonverbal communication systems by spontaneously relying on 'crossmodal common ground'. Based on these results, we conclude that crossmodal correspondences not only occur within individuals but that they can also be actively used in joint action to facilitate the coordination between individuals.

A lifestyle intervention during pregnancy to reduce obesity in early childhood: the study protocol of ADEBAR - a randomized controlled trial.

BACKGROUND: The prevalence of obesity in childhood is increasing worldwide and may be affected by genetic factors and the lifestyle (exercise, nutrition behavior) of expectant parents. Lifestyle factors affect adipokines, namely leptin, resistin, and adiponectin as well as cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), which are involved in the regulation of maternal metabolic homeostasis, glucose metabolism, and the development of insulin resistance, metabolic syndrome, gestational diabetes mellitus, and hypertension. However, studies focusing on the effect of exercise or a combination of parental exercise and nutrition on the above-mentioned markers in newborns (venous cord blood) and especially on the long-term development of infants' weight gain are lacking. The study will investigate the effects of a multimodal intervention (regular exercise, diet) on parental and childhood adipocytokines (leptin, resistin, adiponectin, TNF-α, IL-6, BDNF). The effect of a lifestyle-related change in "fetal environmental conditions" on the long-term weight development of the child up to the age of two will also be assessed. METHODS/DESIGN: A randomized multi-center controlled trial will be conducted in Germany, comparing supervised aerobic and resistance training 2x/week (13th to 36th weeks of gestation) and nutritional counseling (6th to 36th weeks of gestation) during pregnancy with usual care. Thirty women (pre-pregnancy Body Mass Index ≥25 kg/m2, 6th-10th week of gestation) will be included in each group. Maternal anthropometric and physical measurements as well as blood sampling will occur at the 6th-10th, 13th-14th, 21st-24th, and 36th week of gestation, at delivery as well as 8 weeks and 24 months postpartum. Neonatal measurements and umbilical blood sampling will be performed at birth. Maternal and infants' weight development will be assessed every 6 months till 24 months postpartum. A difference in childhood BMI of 1 kg/m2 at the age of two years between both groups will be assumed. A power size of 80% using a significance level of 0.05 and an effect size of 1.0 is presumed. DISCUSSION: A better understanding of how lifestyle-related changes in the fetal environment might influence infants' outcome after two years of life could have a profound impact on the prevention and development of infants' obesity. TRIAL REGISTRATION: The trial is registered at the German Clinical Trial Register (DRKS00007702); Registered on 10th of August 2016; retrospectively registered https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00007702.

Impact of endurance exercise and probiotic supplementation on the intestinal microbiota: a cross-over pilot study.

BACKGROUND: The human microbiota has a broad range of functions contributing to metabolic processes and the activities of our immune system. Its influence on health, well-being and chronic diseases are discussed in various studies. The intestinal microbiota and the mucosal integrity are influenced by diet, environment and other lifestyle factors, including physical activity. There are correlations between cardiorespiratory fitness and important markers of intestinal health. However, data linking endurance exercise to microbiota composition are sparse. Many endurance athletes take probiotics to reduce gastrointestinal symptoms linked to exercise or immunosuppression, but the longitudinal data is insufficient.This randomised, controlled cross-over pilot study will examine the impact of specific endurance training and probiotic supplementation on the intestinal microbiota and mucosa in healthy, athletic students. OBJECTIVE: The aim of this pilot study is to elucidate the impact of physical activity on the intestinal microbiota and mucosa with regard to the effects of a probiotic supplementation. METHODS: In this pilot study, thirty non-specifically trained student athletes will participate in an intervention consisting of a two-week rest (baseline) period, a four-week exercise programme and a four-week probiotic intervention using SymbioLactComp®. The exercise programme consists of three 60-min running workouts per week at 70-85% of the peak heart rate (HRpeak). Primary endpoint of this pilot study is the feasibility and practicality of the intervention as well as a sample size estimation. Furthermore, anthropometric measurements and information on nutrition and lifestyle will be obtained. The peak oxygen uptake (VO2peak) and peak heart rate (HRpeak) (determined during a shuttle run test) as well as selected blood and saliva parameters (haemogram, cytokines) will be evaluated. Changes to the intestinal microbiota will be analysed by stool diagnostics (KyberKompaktPRO®, KyberPlus®). The potential changes may include microbiota composition, bacterial metabolites and mucosa- and immune markers. CONCLUSION: Results will be used for the design of a main randomised controlled trial with a larger collective based on feasibility, validity and sample size estimation as well as the potential effects of endurance exercise on intestinal microbiota and mucosa. Evidence-based information of an exercise-altered microbiota could be of importance for the prevention and therapy of intestinal or immune disorders. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00011108. Retrospectively registered on 28 November 2016.

Co-actors represent the order of each other's actions.

Previous research has shown that people represent each other's tasks and actions when acting together. However, less is known about how co-actors represent each other's action sequences. Here, we asked whether co-actors represent the order of each other's actions within an action sequence, or whether they merely represent the intended end state of a joint action together with their own contribution. In the present study, two co-actors concurrently performed action sequences composed of two actions. We predicted that if co-actors represent the order of each other's actions, they should experience interference when the order of their actions differs. Supporting this prediction, the results of six experiments consistently showed that co-actors moved more slowly when performing the same actions in a different order compared to performing the same actions in the same order. In line with findings from bimanual movement tasks, our results indicate that interference can arise due to differences in movement parameters and due to differences in the perceptual characteristics of movement goals. The present findings extend previous research on co-representation, providing evidence that people represent not only the elements of another's task, but also their temporal structure.

Let's Move It Together: A Review of Group Benefits in Joint Object Control.

In daily life, humans frequently engage in object-directed joint actions, be it carrying a table together or jointly pulling a rope. When two or more individuals control an object together, they may distribute control by performing complementary actions, e.g., when two people hold a table at opposite ends. Alternatively, several individuals may execute control in a redundant manner by performing the same actions, e.g., when jointly pulling a rope in the same direction. Previous research has investigated whether dyads can outperform individuals in tasks where control is either distributed or redundant. The aim of the present review is to integrate findings for these two types of joint control to determine common principles and explain differing results. In sum, we find that when control is distributed, individuals tend to outperform dyads or attain similar performance levels. For redundant control, conversely, dyads have been shown to outperform individuals. We suggest that these differences can be explained by the possibility to freely divide control: Having the option to exercise control redundantly allows co-actors to coordinate individual contributions in line with individual capabilities, enabling them to maximize the benefit of the available skills in the group. In contrast, this freedom to adopt and adapt customized coordination strategies is not available when the distribution of control is determined from the outset.

When Height Carries Weight: Communicating Hidden Object Properties for Joint Action.

In the absence of pre-established communicative conventions, people create novel communication systems to successfully coordinate their actions toward a joint goal. In this study, we address two types of such novel communication systems: sensorimotor communication, where the kinematics of instrumental actions are systematically modulated, versus symbolic communication. We ask which of the two systems co-actors preferentially create when aiming to communicate about hidden object properties such as weight. The results of three experiments consistently show that actors who knew the weight of an object transmitted this weight information to their uninformed co-actors by systematically modulating their instrumental actions, grasping objects of particular weights at particular heights. This preference for sensorimotor communication was reduced in a fourth experiment where co-actors could communicate with weight-related symbols. Our findings demonstrate that the use of sensorimotor communication extends beyond the communication of spatial locations to non-spatial, hidden object properties.

Modulating action duration to establish nonconventional communication.

In many joint actions, knowledge about the precise task to be performed is distributed asymmetrically such that one person has information that another person lacks. In such situations, interpersonal coordination can be achieved if the knowledgeable person modulates basic parameters of her goal-directed actions in a way that provides relevant information to the co-actor with incomplete task knowledge. Whereas such sensorimotor communication has frequently been shown for spatial parameters like movement amplitude, little is known about how co-actors use temporal parameters of their actions to establish communication. The current study investigated whether systematic modulations of action duration provide a sufficient basis for communication. The results of 3 experiments demonstrate that knowledgeable actors spontaneously and systematically adjusted the duration of their actions to communicate task-relevant information if the naïve co-actor could not access this information in other ways. The clearer the communicative signal was the higher was the benefit for the co-actor's performance. Moreover, we provide evidence that knowledgeable actors have a preference to separate instrumental from communicative aspects of their action. Together, our findings suggest that generating and perceiving systematic deviations from the predicted duration of a goal-directed action can establish nonconventionalized forms of communication during joint action. (PsycINFO Database Record

Co-representation of others' task constraints in joint action.

Previous research has demonstrated that humans tend to represent each other's tasks even if no interpersonal coordination is required. The present study asked whether coactors in a joint action rely on task co-representation to achieve temporal coordination even if this implies increased movement effort for an unconstrained actor. Pairs of participants performed reaching movements back and forth between two targets, with the aim of synchronizing their landing times. One of the participants needed to move over an obstacle while the other had no obstacle. The results of four experiments showed that the participant without obstacle moved as if an obstacle was obstructing her way. Further amplifying the demands on interpersonal coordination led to a significant increase of this effect, indicating that unconstrained actors represented their coactor's task constraint and adjusted their own actions accordingly, particularly under high coordination demands. The findings also showed that unconstrained actors represented the object property constraining their coactor's movement rather than parameters of this movement. We conclude that joint action partners rely on task co-representation to achieve temporal coordination in a task with asymmetric task constraints. (PsycINFO Database Record

Training impulsive choices for healthy and sustainable food.

Many people find it hard to change their dietary choices. Food choice often occurs impulsively, without deliberation, and it has been unclear whether impulsive food choice can be experimentally created. Across 3 exploratory and 2 confirmatory preregistered experiments we examined whether impulsive food choice can be trained. Participants were cued to make motor responses upon the presentation of, among others, healthy and sustainable food items. They subsequently selected these food items more often for actual consumption when they needed to make their choices impulsively as a result of time pressure. This effect disappeared when participants were asked to think about their choices, merely received more time to make their choices, or when choosing required attention to alternatives. Participants preferred high to low valued food items under time pressure and without time pressure, suggesting that the impulsive choices reflect valid preferences. These findings demonstrate that it is possible to train impulsive choices for food items while leaving deliberative choices for these items unaffected, and connect research on attention training to dual-process theories of decision making. The present research suggests that attention training may lead to behavioral change only when people behave impulsively. (PsycINFO Database Record

The role of shared visual information for joint action coordination.

Previous research has identified a number of coordination processes that enable people to perform joint actions. But what determines which coordination processes joint action partners rely on in a given situation? The present study tested whether varying the shared visual information available to co-actors can trigger a shift in coordination processes. Pairs of participants performed a movement task that required them to synchronously arrive at a target from separate starting locations. When participants in a pair received only auditory feedback about the time their partner reached the target they held their movement duration constant to facilitate coordination. When they received additional visual information about each other's movements they switched to a fundamentally different coordination process, exaggerating the curvature of their movements to communicate their arrival time. These findings indicate that the availability of shared perceptual information is a major factor in determining how individuals coordinate their actions to obtain joint outcomes.