Effects of feedback from active and passive body parts on spatial and temporal parameters in sensorimotor synchronization

Previous research on sensorimotor synchronization has manipulated the somatosensory information received from the tapping finger to investigate how feedback from an active effector affects temporal coordination. The current study explored the role of feedback from passive body parts in the regulation of spatiotemporal motor control parameters by employing a task that required finger tapping on one’s own skin at anatomical locations of varying tactile sensitivity. A motion capture system recorded participants’ movements as they synchronized with an auditory pacing signal by tapping with the right index finger on either their left index fingertip (Finger/Finger) or forearm (Finger/Forearm). Results indicated that tap timing was more variable, and movement amplitude was larger and more variable, when tapping on the finger than when tapping on the less sensitive forearm. Finger/Finger tapping may be impaired relative to Finger/Forearm tapping due to ambiguity arising through overlap in neural activity associated with tactile feedback from the active and the passive limb in the former. To compensate, the control system may strengthen the assignment of tap-related feedback to the active finger by generating correlated noise in movement kinematics and tap dynamics.     

The effect of positive events at work on after-work fatigue: they matter most in face of adversity

There is evidence that daily negative events at work enhance fatigue. In contrast, positive events may trigger processes that increase, but also processes that decrease, energetic resources. Accordingly, results regarding a main effect of positive events on fatigue have been mixed. However, a clearer pattern between positive events and fatigue can be expected under adverse circumstances (i.e., accumulation of negative events, high chronic stressors). Positive events may facilitate coping and accelerate recovery processes and, thus, reduce resource drain due to daily negative events and chronic stressors. Predicting fatigue in a diary study with 76 employees, we investigated interactions between daily positive events and (a) daily negative events and (b) chronic social stressors. Multilevel modeling revealed that negative but not positive events were associated with increased end-of-work fatigue. However, positive events interacted with negative events and with chronic social stressors. As expected, positive events were negatively associated with fatigue only on days with many negative events, but not so on days with few negative events. Analogously, positive events were negatively associated with fatigue only among employees with high, compared with low, chronic social stressors. We conclude that the beneficial short-term effects of positive events on energetic resources are largely confined to adverse circumstances.     

Implementation intentions as goal primes: Boosting self‐control in tempting environments

People often forget their long‐term strivings because their environment confronts them with attractive temptations. Previous research suggests that self‐control failures can be prevented by reminding people of their higher‐order goal. Therefore, we hypothesized that using implementation intentions as a tool to directly re‐activate people's higher‐order goal in tempting situations would effectively enhance self‐control. We tested this in the domain of dieting behavior. Results demonstrated that this specific planning strategy activated the dieting goal for unsuccessful dieters when exposed to tempting food cues (Study 1) and reduced their consumption of calorically dense food across 2 weeks (Study 2) compared to those in control conditions. This suggests that preparing people to think of their higher‐order goal when tempted can be used to protect ongoing goal striving. Appealing to higher‐order goals potentially makes implementation intentions flexible instruments of self‐regulation as this should trigger motivated behavior to reach goals and initiate various goal‐instrumental actions. Copyright © 2011 John Wiley & Sons, Ltd.     

Perception and production of object-related grasping in 6-month-olds

In this study, 6-month-olds’ perception of an object-related human grasping action was compared with their level of grasping performance using a within-participants design. In the action perception task, infants were presented with the video of an actor’s grasping movement toward an occluded target object. Subsequently, an expected and an unexpected final state of this grasping movement were presented simultaneously, and infants’ looking times were measured. In the action production task, infants were presented with three graspable objects. Infants’ grasping behavior was coded to be either palmar or thumb-opposite grasping. Results indicate that infants who were already able to perform a thumb-opposite grasp differentiated between the two final states in the action perception task by looking longer toward the unexpected final state. In contrast, infants who showed only palmar grasps looked equally long toward both final states. This finding supports the assumption that action perception and action control are already closely related in infants as young as 6 months.     

Reversing 30?years of discussion: why causal decision theorists should one-box

The paper will show how one may rationalize one-boxing in Newcomb??s problem and drinking the toxin in the Toxin puzzle within the confines of causal decision theory by ascending to so-called reflexive decision models which reflect how actions are caused by decision situations (beliefs, desires, and intentions) represented by ordinary unreflexive decision models.     

Intentionality and Presence: On the Intrinsic Of-ness of Consciousness from a Transcendental-Phenomenological Perspective

This paper discusses the nature of consciousness?? intrinsic intentionality from a transcendental-phenomenological viewpoint. In recent philosophy of mind the essentially intentional character of consciousness has become obscured because the latter is predominantly understood in terms of ??qualia?? or the ??what-it-is-like-ness?? of mental states and it is hard to see why such subjective ??feels??, of all things, could bestow states with objective reference. As the paper attempts to demonstrate, this is an inadequate understanding of consciousness, which should instead be defined in terms of presence. Consciousness essentially takes place as presence-of, i.e., consists in something coming to appearance. This presence-of is not only a fundamental, irreducible phenomenon, but also in a radical sense un-naturalisable. Naturalism only knows ??nature??, as the world of objects, and the question of intentionality then seems to be how certain inner-worldly objects can be ??representations?? of other inner-worldly objects. In fact, no object is ever intrinsically ??about?? anything. This is exclusively the nature of subjectivity qua consciousness, which is not an object alongside other objects but rather exists as the manifestation of objects.     

Identifying individuality and variability in team tactics by means of statistical shape analysis and multilayer perceptrons

Offensive and defensive systems of play represent important aspects of team sports. They include the players' positions at certain situations during a match, i.e., when players have to be on specific positions on the court. Patterns of play emerge based on the formations of the players on the court. Recognition of these patterns is important to react adequately and to adjust own strategies to the opponent. Furthermore, the ability to apply variable patterns of play seems to be promising since they make it harder for the opponent to adjust. The purpose of this study is to identify different team tactical patterns in volleyball and to analyze differences in variability. Overall 120 standard situations of six national teams in women's volleyball are analyzed during a world championship tournament. Twenty situations from each national team are chosen, including the base defence position (start configuration) and the two players block with middle back deep (end configuration). The shapes of the defence formations at the start and end configurations during the defence of each national team as well as the variability of these defence formations are statistically analyzed. Furthermore these shapes data are used to train multilayer perceptrons in order to test whether artificial neural networks can recognize the teams by their tactical patterns. Results show significant differences between the national teams in both the base defence position at the start and the two players block with middle back deep at the end of the standard defence situation. Furthermore, the national teams show significant differences in variability of the defence systems and start-positions are more variable than the end-positions. Multilayer perceptrons are able to recognize the teams at an average of 98.5%. It is concluded that defence systems in team sports are highly individual at a competitive level and variable even in standard situations. Artificial neural networks can be used to recognize teams by the shapes of the players' configurations. These findings support the concept that tactics and strategy have to be adapted for the team and need to be flexible in order to be successful.     

Before, during and after you disappear: aspects of timing and dynamic updating of the real-time action simulation of human motions

The detailed dynamics of action simulation was investigated using the occluder paradigm: a point light actor (PLA) was shown, then briefly occluded from view, during which period action simulation was generated. Following occlusion, the PLA reappeared, either a progression of the motion as it should be post-occlusion or temporally shifted earlier/later. Participants made judgements on whether the reappearing PLA was too early or too late to be a correct continuation (Experiments 1 and 3) or whether it was a veridical continuation or not (Experiment 2). Over three experiments we asked how action simulation is affected by motion information before, during and after occlusion. Reducing motion presented before occlusion retained the accuracy of action simulation judgements. Presenting 4 frames (67 ms) of PLA motion during the occluder duration dynamically updates or altogether regenerates the action simulation. Reducing the duration of the test motion after the occluder decreases judgement precision, which we interpret as a limitation in the process of postdictive motion judgments. Overall, this is further evidence that the action simulation process is remarkably adapted to making human motion predictions.