Planning maximally smooth hand movements constrained to nonplanar workspaces

The article characterizes hand paths and speed profiles for movements performed in a nonplanar, 2-dimensional workspace (a hemisphere of constant curvature). The authors assessed endpoint kinematics (i.e., paths and speeds) under the minimum-jerk model assumptions and calculated minimal amplitude paths (geodesics) and the corresponding speed profiles. The authors also calculated hand speeds using the 2/3 power law. They then compared modeled results with the empirical observations. In all, 10 participants moved their hands forward and backward from a common starting position toward 3 targets located within a hemispheric workspace of small or large curvature. Comparisons of modeled observed differences using 2-way RM-ANOVAs showed that movement direction had no clear influence on hand kinetics (p < .05). Workspace curvature affected the hand paths, which seldom followed geodesic lines. Constraining the paths to different curvatures did not affect the hand speed profiles. Minimum-jerk speed profiles closely matched the observations and were superior to those predicted by 2/3 power law (p < .001). The authors conclude that speed and path cannot be unambiguously linked under the minimum-jerk assumption when individuals move the hand in a nonplanar 2-dimensional workspace. In such a case, the hands do not follow geodesic paths, but they preserve the speed profile, regardless of the geometric features of the workspace.     

Threaded cognition: an integrated theory of concurrent multitasking

The authors propose the idea of threaded cognition, an integrated theory of concurrent multitasking--that is, performing 2 or more tasks at once. Threaded cognition posits that streams of thought can be represented as threads of processing coordinated by a serial procedural resource and executed across other available resources (e.g., perceptual and motor resources). The theory specifies a parsimonious mechanism that allows for concurrent execution, resource acquisition, and resolution of resource conflicts, without the need for specialized executive processes. By instantiating this mechanism as a computational model, threaded cognition provides explicit predictions of how multitasking behavior can result in interference, or lack thereof, for a given set of tasks. The authors illustrate the theory in model simulations of several representative domains ranging from simple laboratory tasks such as dual-choice tasks to complex real-world domains such as driving and driver distraction.     

On the nature of nonverbal working memory fractionation: a case of selective spatial short-term memory deficit in a child

Several lines of research on adult subjects demonstrate a visual/spatial fractionation of nonverbal working memory (WM), while behavioral studies on normal children support the idea of a static/dynamic distinction. In the present paper, we report a child (Z.M.) who failed on nonverbal WM tasks. To verify the nature of his defect, we carried out two experiments: in Experiment 1, Z.M. failed on spatial WM tasks but not on visual WM tasks and was not affected by the static/dynamic format of stimulus presentation; in Experiment 2, this visual/spatial dissociation was extended to the imagery domain. These results are best accounted for within the visual/spatial fractionation of WM and confirmed the role of WM in mental imagery. Clinical and rehabilitative implications of the present findings are also discussed.     

Action-dependent perceptual invariants: from ecological to sensorimotor approaches

Ecological and sensorimotor theories of perception build on the notion of action-dependent invariants as the basic structures underlying perceptual capacities. In this paper we contrast the assumptions these theories make on the nature of perceptual information modulated by action. By focusing on the question, how movement specifies perceptual information, we show that ecological and sensorimotor theories endorse substantially different views about the role of action in perception. In particular we argue that ecological invariants are characterized with reference to transformations produced in the sensory array by movement: such invariants are transformation-specific but do not imply motor-specificity. In contrast, sensorimotor theories assume that perceptual invariants are intrinsically tied to specific movements. We show that this difference leads to different empirical predictions and we submit that the distinction between motor equivalence and motor-specificity needs further clarification in order to provide a more constrained account of action/perception relations.     

Cheating on college examinations

The aim of this study was to investigate the influence of contexts on cheating attitudes and behavior among Brazilian undergraduates. Participants were 77 Previous Choice Engineering and 70 Late Choice Engineering students. Previous Choice students enter the desired field chosen by examination, whereas Late Choice students' grades during the two first college years give them preference to choose the field. Their self-reported attitudes and behaviors were compared with those of 82 chemistry undergraduates from two universities (UNI-C and USP-C). The Late Choice students reported significant negative opinion about cheating, whereas Previous Choice students, especially women, reported significant favorable opinion. Furthermore, Previous Choice students reported colleagues more frequently gave them answers on examinations than Late Choice students. The two university groups in chemistry had intermediate scores. Deterrents of cheating strongly embedded in the student culture were found among Late Choice engineering undergraduates which may be explained by social learning theory.     

Perceptions of the Targets and Sources of COVID-19 Threat are Structured by Group Memberships and Responses are Influenced by Identification with Humankind

The purpose of this study was to investigate which social groups are perceived as a threat target and which are perceived as a threat source during the COVID-19 outbreak. In a German sample (N = 1454) we examined perceptions of social groups ranging from those that are psychologically close and smaller (family, friends, neighbors) to those that are more distal and larger (people living in Germany, humankind). We hypothesized that psychologically closer groups would be perceived as less affected by COVID-19 as well as less threatening than more psychologically distal groups. Based on social identity theorizing, we also hypothesized that stronger identification with humankind would change these patterns. Furthermore, we explored how these threat perceptions relate to adherence to COVID-19 health guidelines. In line with our hypotheses, latent random-slope modelling revealed that psychologically distal and larger groups were perceived as more affected by COVID-19 and as more threatening than psychologically closer and smaller groups. Including identification with humankind as a predictor into the threat target model resulted in a steeper increase in threat target perception patterns, whereas identification with humankind did not predict differences in threat source perceptions. Additionally, an increase in threat source perceptions across social groups was associated with more adherence to health guidelines, whereas an increase in threat target perceptions was not. We fully replicated these findings in a subgroup from the original sample (N = 989) four weeks later. We argue that societal recovery from this and other crises will be supported by an inclusive approach informed by a sense of our common identity as human beings.     

Human rights studied as social representations in a cross‐national context

A questionnaire study using the 30 Articles of the Universal Declaration of Human Rights was conducted in 35 countries (N=6791 students). The basic assumption was that human rights can be studied as social representations following the model of Doise, Clémence, & Lorenzi‐Cioldi (1993). The existence of a shared meaning system concerning the 30 articles in different countries was demonstrated. Individual attitudes toward the whole set of rights were proven to be highly consistent. However, individuals differed systematically in beliefs about their own and the government's efficacy in having human rights respected. An individual‐level and a pancultural analysis (Kenny & La Voie, 1985; Leung & Bond, 1989) converged in the definition of four groups of respondents: advocates (most favorable responses towards human rights), sceptics (less favorable responses), personalists (high personal involvement and scepticism about governmental efficacy) and governmentalists (low personal involvement and strong belief in governmental efficacy). Analyses of anchoring started either from assessing individual positionings or from maximizing between‐country differences. Individual‐level analyses show that positionings are anchored in value choices as well as in perception and experience of social conflicts. Pancultural analyses confirm the importance of national context concerning the attitudes of scepticism or advocacy, personalism and governmentalism. Copyright © 1999 John Wiley & Sons, Ltd.     

Cross-cultural effects of parent warmth and control on aggression and rule-breaking from ages 8 to 13

We investigated whether bidirectional associations between parental warmth and behavioral control and child aggression and rule-breaking behavior emerged in 12 cultural groups. Study participants included 1,298 children (M = 8.29 years, standard deviation [SD] = 0.66, 51% girls) from Shanghai, China (n = 121); Medellín, Colombia (n = 108); Naples (n = 100) and Rome (n = 103), Italy; Zarqa, Jordan (n = 114); Kisumu, Kenya (n = 100); Manila, Philippines (n = 120); Trollhättan/Vänersborg, Sweden (n = 101); Chiang Mai, Thailand (n = 120); and Durham, NC, United States (n = 111 White, n = 103 Black, n = 97 Latino) followed over 5 years (i.e., ages 8–13). Warmth and control were measured using the Parental Acceptance-Rejection/Control Questionnaire, child aggression and rule-breaking were measured using the Achenbach System of Empirically-Based Assessment. Multiple-group structural equation modeling was conducted. Associations between parent warmth and subsequent rule-breaking behavior were found to be more common across ontogeny and demonstrate greater variability across different cultures than associations between warmth and subsequent aggressive behavior. In contrast, the evocative effects of child aggressive behavior on subsequent parent warmth and behavioral control were more common, especially before age 10, than those of rule-breaking behavior. Considering the type of externalizing behavior, developmental time point, and cultural context is essential to understanding how parenting and child behavior reciprocally affect one another.     

Kinship does not affect litter defence in pairs of communally nesting female house mice

Communal litter defence by sister and nonsister female mice can provide a valuable experimental paradigm to test whether females invest preferentially in kin. Since females within sister and nonsister pairs have different coefficients of relatedness with the young, the cumulative litter has more fitness value for related than for unrelated partners. Sister and nonsister paired females that gave birth simultaneously (n = 18), or at least within 7 days from each other (n = 12), were tested for maternal aggression on post partum day 7, or 10 days after the first delivery, respectively. Sister (n = 14) and nonsister pairs (n = 16) did not differ in cumulative values of post partum aggression or in the extent to which aggression was balanced within the pair. The aggressive behavior of each female was not correlated with her relative proportion of pups in the litter. Rather, the combined scores of aggression within the pairs were found to be positively correlated with the cumulative litter size. The analysis of mouse litter defence behavior shows that, under conditions of communal nesting, kinship does not seem to affect parental investment in the young significantly. Rather, the cumulative litter size could be used by paired females as a major indicator for parental investment allocation.     

Gruesomeness conveys formidability: Perpetrators of gratuitously grisly acts are conceptualized as larger,stronger, and more likely to win

While associated with extreme terrorist organizations in modern times, extensive accounts of grisly acts of violence exist in the archeological, historical, and ethnographic records. Though reasons for this dramatic form of violence are multifaceted and diverse, one possibility is that violence beyond what is required to win a conflict is a method by which violent actors communicate to others that they are formidable opponents. The formidability representation hypothesis predicts that formidability is cognitively represented using the dimensions of envisioned bodily size and strength. We tested the informational ramifications of gruesome acts using two vignette studies depicting individuals who either did or did not grievously damage the corpse of a deceased foe. Participants rated the individual's height, bodily size, and strength, as well as his aggressiveness, motivation, and the capacity to vanquish opponents in future conflicts. Results indicate that, as predicted, committing gruesome acts of violence enhances perceptions of formidability as measured both by envisioned bodily size and strength and expectations regarding the outcomes of agonistic conflicts. Moreover, the gruesome actor was perceived as more aggressive and more motivated to overcome his enemies, and this mediated the increase in conceptualized size and strength. These results both provide further evidence for the formidability representation hypothesis and support the thesis that overtly grisly violence is tactically employed, in part, because it conveys information about the perpetrator's formidability.