Evidence for the specificity of control motivations in worldview defense: Distinguishing compensatory control from uncertainty management and terror management processes

Research inspired by the compensatory control model (CCM) shows that people compensate for personal control threats by bolstering aspects of the cultural worldview that afford external control. According to the CCM these effects stem from the motivation to maintain perceived order, but it is alternatively possible that they represent indirect efforts to bolster distally related psychological structures described by uncertainty management theory (self-relevant certainty) and terror management theory (death-transcendence). To assess whether compensatory control processes play a unique role in worldview defense, we hypothesized that personal control threats would increase affirmation of cultural constructs that specifically bolster order more so than constructs that bolster distally related structures. The results of 5 studies provide converging support for this hypothesis in the context of attitudes toward diverse cultural constructs (Study 1: national culture; Studies 2 and 3: consumer products;  and : political candidates). Also supporting hypotheses, uncertainty salience and mortality salience elicited greater affirmation of identity- and immortality-conferring targets, respectively, compared to order-conferring constructs. Discussion focuses on the value of different perspectives on existential motivation for predicting specific forms of worldview defense.     

Effects of vision and cognitive load on anticipatory and compensatory postural control

This study assessed the effects of vision and cognitive load on anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) in response to an externally triggered postural perturbation. A ball-hitting test was repeated under different visual conditions (eyes open, EO; eyes closed, EC) and cognitive loads (no load, 3-subtraction task, time-limited 3-subtraction task). Data were collected separately for I) surface electromyography from the right side of the biceps brachii (BIC) and erector spinae (ES) to detect the latency and response intensity (RI); and II) displacement of the centre of pressure (ΔCOP) to detect the standard deviation (ΔCOP_SD) and maximum value (ΔCOP_max) in the anterior-posterior direction. Compared with the results under the EC condition, the ES latency was shorter and the RI of the BIC was lower under the EO condition. Accordingly, the ΔCOP_SD and ΔCOP_max were increased in the APAs phase and decreased in the CPAs phase. Cognitive load had no effect on APAs and CPAs or on ΔCOP in the APAs phase. However, ΔCOP_max was decreased in the CPAs phase during the EC condition. In conclusion, vision played an important role in APAs and CPAs for muscle activation and ΔCOP. Cognitive load had no effect on neuromuscular APAs or CPAs except when the postural perturbation occurred when visually unexpected.     

Effect of body configuration at step contact on balance recovery from sideways perturbations

Compensatory stepping is an important protective mechanism to prevent falling. To recover from sideways perturbations side steps are generally more advantageous than cross-over steps. However, there is lack of understanding of the characteristics of compensatory side steps following sideways perturbations that separate successful recoveries (i.e., no falls) from falls, the most clinically relevant outcome following a balance perturbation. We aimed to identify the critical determinants for successful side stepping after large sideways balance perturbations. Twelve healthy young adults were subjected to large leftward perturbations at varying intensities on a translating sheet. For recovery attempts started with a side step, we determined body configuration variables (frontal-plane leg and trunk angle) at first step contact, as well as spatiotemporal step variables (onset, length, duration, velocity). A logistic regression analysis was conducted to determine the predictive ability of body configuration and spatiotemporal variables on the probability of success (no fall vs. fall); perturbation intensity (peak jerk of translating sheet) and a random effect for individual were also included in the model. In the final model, leg angle and peak jerk were retained as predictors of successful balance recovery and these variables correctly classified the recovery outcome in 86% of the trials. This final ‘body configuration’ model yielded a −2 log likelihood of −36.3, whereas the best fitting model with only spatiotemporal variables yielded a −2 log likelihood of −45.8 (indicating a poorer fit). The leg angle at a given perturbation intensity appears to be a valid measure of reactive side step quality. The relative ease of measuring this leg angle at step contact makes it a candidate outcome for reactive stepping assessments in clinical practice.     

Hands Support and Postural Oscillation During Sit-to-Stand Movement in Children With Cerebral Palsy and Typical Children

The authors aimed to compare the weight bearing on hands during sit-to-stand (STS) movement in children with cerebral palsy (CP) and typical children (TC), verify its effect on postural oscillation, and analyze the relationship between weight bearing on hands and postural oscillation. Twenty children with CP (Gross Motor Function Classification System levels I and II) and 35 TC performed STS with and without anterior hands support. Mann-Whitney test compared weight bearing between groups. Wilcoxon test investigated differences in postural oscillation between the conditions with and without anterior hand support for both groups. The Spearman correlation tested the relationship between weight-bearing and postural oscillation during the hand support condition. Children with CP bore more weight on hands than TC to perform STS. The hand support reduced postural oscillation during the second phase of STS in both groups. In the CP group, greater weight bearing was related with lower postural oscillation in the beginning of STS. Although children with CP were able to perform STS without support, they bore more weight on their hands to perform the task than TC. Moreover, children with CP and TC use mechanical and somatosensory information to modulate their postural control during STS in different ways.     

姿势－认知双任务研究述评

姿势与认知的双任务研究将两个分离的主题联系起来,成为一个新的正在扩展的领域。大量实验证据揭示了认知在平衡控制中的作用,表明了姿势与认知普遍关联的事实;较多的临床研究初步揭示了有特定类型神经病理的老年人在认知影响下其动作控制问题的机制。姿势-认知双任务研究为老年人跌倒预防和干预训练提供了重要借鉴,为理解儿童注意问题及其学习环境建设提供了新的视角,并提示后继的研究者应对姿势控制与认知发展的关系予以关注     

Compensating for Innovation: Extreme Product Incongruity Encourages Consumers to Affirm Unrelated Consumption Schemas

New products are often extremely incongruent with expectations. The inability to make sense of these products elevates anxiety and leads to negative evaluations. Although scholars have predominantly focused on combating the negative response to extreme incongruity, we propose that extreme incongruity may have implications that extend beyond the category. We base our predictions on the concept of fluid compensation, which suggests that when people struggle to make sense of something, they will nonconsciously reinforce highly accessible schemas in unrelated domains. Four studies confirm that extreme incongruity encourages fluid compensation, such that it elevates preference for dominant brands (study 1), green consumption (studies 2 and 4), and ethnocentric products (study 3). We isolate the causal role of anxiety using moderation tasks and biometric feedback. Furthermore, we demonstrate that compensation has an immediate dampening effect on arousal intensity. Thus, if consumers can compensate before explicitly evaluating an extremely incongruent product, their evaluations tend not to be negative. Taken together, we document that extreme innovations encourage compensation, and in compensating, consumers can become more receptive to extreme innovations.     

Perturbations of Human Posture

Leg muscle EMG responses and cerebral evoked potentials (CP), elicited by perturbations of stance while on a treadmill with split belts, were analyzed in order to study the relationship between compensatory leg muscle responses and afferent input to supraspinal centers. Various conditions of perturbation were used to establish the extent to which compensatory EMG responses and CPs show congruent behavior. Four different treadmill acceleration rates were applied in three different conditions (unilateral perturbation, directed forward or backward; bilateral perturbation, directed forward or backward; and opposing bilateral perturbation). EMG responses and CPs showed parallel increases in amplitude with increasing displacement velocity. The EMG responses showed distinct differences, predominantly in the response amplitude, between the different perturbation conditions, whereas the CPs were affected only to a minor degree. Tibialis anterior EMG responses were more closely related to the CP following forward perturbation than the corresponding gastrocnemius responses were to the CP following backward perturbation.

We conclude that the EMG responses are more closely related than the CPs to displacement parameters and suggest that this is due to the further spinal processing of the afferent input needed to generate an appropriate EMG response. The closer relationship between the tibialis anterior response and CP may reflect a predominant central representation and control of tibialis anterior activation in the regulation of posture. The functional implications of these findings are discussed.     

Anticipatory Postural Adjustments for Altering Direction During Walking

The authors examined how individuals adapt their gait and regulate their body configuration before altering direction during walking. Eight young adults were asked to change direction during walking with different turning angles (0deg;, 45deg;, 90deg;), pivot foot (left, right), and walking speeds (normal and fast). The authors used video and force platform systems to determine participants' whole-body center of mass and the center of pressure during the step before they changed direction. The results showed that anticipatory postural adjustments occurred during the prior step and occurred earlier for the fast walking speed. Anticipatory postural adjustments were affected by all 3 variables (turn angle, pivot foot, and speed). Participants leaned backward and sideward on the prior step in anticipation of the turn. Those findings indicate that the motor system uses central control mechanisms to predict the required anticipatory adjustments and organizes the body configuration on the basis of the movement goal.     

Postural Asymmetries in Response to Holding Evenly and Unevenly Distributed Loads During Self-Selected Stance

The authors examined postural asymmetries during quiet stance and while holding evenly or unevenly distributed loads. Right-hand dominant subjects preferentially loaded their right lower limb when holding no load or a load evenly distributed in both hands, but no differences in center of pressure (CoP) were observed between the left and right limbs. However, longer CoP displacement was observed under the preferentially loaded limb, which may reflect a functional asymmetry that allows quick movement of one limb in response to a potential perturbation. When a load was held only in the nondominant hand, sample entropy decreased in the left (loaded) limb but increased in the right (unloaded) limb, suggesting the unloaded foot compensated for a loss of control flexibility in the loaded foot.