Concurrent Directional Adaptation of Reactive Saccades and Hand Movements to Target Displacements of Different Size

When eye and hand movements are concurrently aimed at double-step targets that call for equal and opposite changes of response direction (–10° for the eyes, +10° for the hand), adaptive recalibration of both motor systems is strongly attenuated; instead, hand but not eye movements are changed by corrective strategies (V. Grigorova et al., 2013a). The authors introduce a complementary paradigm, where double-step targets call for a –10° change of eye and a ?30° change for hand movements. If compared to control subjects adapting only the eyes or only the hand, adaptive improvements were comparable for the eyes but were twice as large for the hand; in contrast, eye and hand aftereffects were comparable to those in control subjects. The authors concluded that concurrent exposure of eyes and hand to steps of the same direction but different size facilitated hand strategies, but didn't affect recalibration. This finding together with previous one (V. Grigorova et al., 2013a), suggests that concurrent adaptation of eyes and hand reveals different mechanisms of recalibration for step sign and step size, which are shared by reactive saccades and hand movements. However, hand mostly benefits from strategies provoked by the difference in target step sign and size.     

Temporal structure coding with and without awareness

In order to interpret a constantly changing environment, visual events far apart in space and time must be integrated into a unified percept. While spatial properties of invisible signals are known to be encoded without awareness, the fate of temporal properties remains largely unknown. Here, we probed temporal integration for two distinct motion stimuli that were either visible or rendered invisible using continuous flash suppression. We found that when invisible, both the direction of apparent motion and the gender of point-light walkers were processed only when defined across short time periods (i.e., respectively 100 ms and 1000 ms). This limitation was not observed under full visibility. These similar findings at two different hierarchical levels of processing suggest that temporal integration windows shrink in the absence of perceptual awareness. We discuss this phenomenon as a key prediction of the global neuronal workspace and the information integration theories of consciousness.     

Is social inhibition of return due to action co-representation?

When two individuals alternate reaching responses to visual targets presented on a shared workspace, one individual is slower to respond to targets occupying the same position as their partner’s previous response. This phenomenon is thought to be due to processes that inhibit the initiation of a movement to a location recently acted upon. However, two distinct forms of the inhibition account have been posited, one based on inhibition of an action, the other based on inhibition of an action and location. Furthermore, an additional recent explanation suggests the phenomenon is due to mechanisms that give rise to action congruency effects. Thus the three different theories differ in the degree to which action co-representation plays a role in the effect. The aim of the present work was to examine these competing accounts. Three experiments demonstrated that when identical actions are made, the effect is modulated by the configuration of the visual stimuli acted upon and the perceptual demands of the task. In addition, when the co-actors perform different actions to the same target, the effect is still observed. These findings support the hypothesis that this particular joint action phenomenon is generated via social cues that induce location-based inhibition of return rather than being due to shared motor co-representations.     

基于伪装原理研究无意识视觉运动加工的方法

研究提出一种新的连续闪烁抑制(CFS)范式, 利用透明度混合(alpha blending)原理, 使目标刺激的颜色与相应位置的掩蔽刺激的颜色时刻保持一致。研究随机招募了8名被试, 向其优势眼呈现Mondrian图像序列, 非优势眼呈现固定速率运动的多个正方形。结果表明目标为多运动点动态刺激时, 该范式依然具备掩蔽作用, 且当目标刺激与相应位置的掩蔽刺激的颜色完全一致时, 掩蔽效果最好, 证明这种新范式比传统CFS范式对动态刺激的掩蔽作用更好。相比以往修改CFS掩蔽刺激的思路, 该范式为研究无意识视觉运动加工提供了新方法, 且适用性更广。     

Developmental changes in children's understanding of horizontal projectile motion

This study investigated 5‐ to 13‐year‐old children's performance in solving horizontal projectile motion problems, in which they predicted the trajectory of a carried object released from a carrier in three different contexts. The results revealed that 5‐ and 8‐year‐olds' trajectory predictions were easily distracted by salient contextual features (e.g. the relative spatial locations between objects), whereas a proportion of 11‐ and 13‐year‐olds' performance suggested the engagement of the impetus concept in trajectory prediction. The impetus concept is a typical misconception of inertial motion that assumes that motion is caused by force. Children's performance across ages suggested that their naïve knowledge of projectile motion was neither well‐developed and coherent nor completely fragmented. Instead, this study presented the dynamic process in which children with age gradually overcame the influences of contextual features and consistently used the impetus concept across motion problems.     

From body motion to cheers: Speakers’ body movements as predictors of applause

Appearance cues and brief displays of behavior are related to people’s personality, to their performance at work and to the outcomes of elections. Thus, people present themselves to others on different communication channels, while their interaction partners form first impressions on the basis of the displayed cues. In the current study we examined whether people are able to read information from politicians’ body motion. For a rating experiment we translated short video clips of politicians giving a speech into animated stick-figures and had these animations rated on trustworthiness, dominance, competence and the Big Five personality dimensions. Afterwards we correlated the ratings with the applause and the hecklings that the speakers received throughout their entire speech. This revealed that speakers whose body movements were perceived as high on dominance, as high on extraversion and as low on agreeableness received more applause. Although the results obtained need support from additional studies they indicate that body motion is an informative cue in real life settings.     

Emotion comprehension and attachment: A conversational intervention with school-aged children

IntroductionAs part of the flourishing line of enquiry into children's emotion understanding, we report the results of a conversation-based intervention study aimed at improving participants’ emotion comprehension, and exploring the intervention effect as a function of attachment security.MethodThe study was conducted at school with the participation of 98 second-grade children (mean age: 7 years, 7 months; SD: 3.4 months). Participants were assigned to experimental and control groups that were balanced with respect to attachment security and insecurity as evaluated using the Separation Anxiety Test (SAT). The experimental group was exposed to a conversational intervention, in which short story readings with emotional content were used to stimulate discussion on the nature, causes and regulation of emotion. The children in the control group listened to the same stories, but did not take part in the conversational activity. Children from both groups were individually pre- and post-tested on measures of emotional lexicon (ELT) and emotion comprehension (TEC).ResultsThe training was found to have a significant effect on the emotion comprehension of the children allocated to the experimental group. In addition, non-secure children displayed higher gains in emotion comprehension than secure participants. The implications of the findings for educational and school contexts are discussed.     

Body movements of male and female speakers and their influence on perceptions of personality

Men and women score differently on some personality traits and people’s behavior reflects who they are. Therefore, males and females could be expected to express themselves differently on a behavioral level. To test this idea we turned the public performances of speakers (20 female and 20 male) into stick figure movies. Students of the University of Vienna (n = 150) rated these movies on scales measuring the Big Five personality traits. The participants experienced difficulties in ascribing the correct sex to the stick figures. Nevertheless, stick figures representing male speakers received higher ratings for extraversion and emotional stability than stick figure animations of female speakers. In addition, gender stereotypes seemed to influence the participants’ ratings. Agreeableness, for instance, was preferably classified as female trait. In conclusion, our results suggest that body motion conveys social information, that men and women present themselves differently, and that people’s judgments are influenced by gender stereotypes.     

Biological motion task performance predicts superior temporal sulcus activity

Numerous studies implicate superior temporal sulcus (STS) in the perception of human movement. More recent theories hold that STS is also involved in the understanding of human movement. However, almost no studies to date have associated STS function with observable variability in action understanding. The present study directly associated STS activity with performance on a challenging task requiring the interpretation of human movement. During functional MRI scanning, fourteen adults were asked to identify the direction (left or right) in which either a point-light walking figure or spinning wheel were moving. The task was made challenging by perturbing the dot trajectories to a level (determined via pretesting) where each participant achieved 72% accuracy. The walking figure condition was associated with increased activity in a constellation of social information processing and biological motion areas, including STS, MT+/V5, right pars opercularis (inferior frontal gyrus), fusiform gyrus, and amygdala. Correctly answered walking figure trials were uniquely associated with increased activity in two right hemisphere STS clusters and right amygdala. Present findings provide some of the strongest evidence to date that STS plays a critical role in the successful interpretation of human movement.