Anarchic-hand syndrome: ERP reflections of lost control over the right hemisphere

In patients with the callosal type of anarchic-hand syndrome, the left hand often does not act as intended and counteracts the right hand. Reports are scarce about the underlying neurophysiological mechanisms. We report the case G.H. who developed the syndrome after infarction of the left arteria pericallosa. It has been suggested that the syndrome arises out of lacking inhibition from the dominant left hemisphere on the right hemisphere. Yet, in tests of spatial intelligence G.H. performed much better with his “anarchic” left hand than with his dominant right hand, similar to observations commonly reported in split-brain patients. Left-right manual choice responses and event-related EEG potentials to laterally presented stimuli were measured. Asymmetries were evident in G.H.’s behavior and EEG potentials, different from age-matched healthy participants (n = 11). His right-hand responses were fast and unaffected by incompatibility with stimulus location, whereas his left-hand responses were variable and accompanied by a large negative central-midline EEG potential, probably reflecting efforts in initiating the response. G.H.’s visual N1 component peaked earlier and was larger at the right than the left side of the scalp, and the P3 component was distinctly reduced at the right side. Both features occurred independent of side of stimulus presentation and side of responding hand. The effort indicated by the midline negativity and the asymmetrically reduced P3 might directly reflect G.H.’s lack of control on his right hemisphere’s processing. The faster visual processing of the right hemisphere suggested by the N1 asymmetry might contribute to “anarchic” processing, making the right hemisphere process stimuli before control impulses exert their effect. These neurophysiological results tend to support the split-brain account which assumes that the syndrome arises by the lack of communication between hemispheres that act according to their respective competences.     

Rubber hand illusion, empathy, and schizotypal experiences in terms of self-other representations

When participants observed a rubber hand being touched, their sense of touch was activated (rubber hand illusion: RHI). While this illusion might be caused by multi-modal integration, it may also be related to empathic function, which enables us to simulate the observed information. We examined individual differences in the RHI, including empathic and schizotypal personality traits, as previous research had suggested that schizophrenic patients would be more subject to the RHI. The results indicated that people who experience a stronger RHI might have stronger empathic and schizotypal personalites simultaneously. We discussed these relationships in terms of self-other representations.     

Body ownership and beyond: Connections between cognitive neuroscience and linguistic typology

During the past few decades, two disciplines that rarely come together—namely, cognitive neuroscience and linguistic typology—have been generating remarkably similar results regarding the representational domain of personal possessions. Research in cognitive neuroscience indicates that although the core self is grounded in body ownership, the extended self encompasses a variety of noncorporeal possessions, especially those that play a key role in defining one’s identity. And research in linguistic typology indicates that many languages around the world contain a distinct grammatical construction for encoding what is commonly called “inalienable” possession—a category of owned objects that almost always includes body parts, but that also tends to include several other kinds of personally relevant entities. Both of these independent lines of investigation are summarized, and a number of interdisciplinary connections between them are discussed.     

The distorted hand metric representation serves both perception and action

ABSTRACT

The representation of our body location is achieved by integrating sensorimotor inputs with information about our body size. Previous studies have shown that the metric representation of our hand, also called the body model, is distorted, namely overestimated in width and underestimated in length, although we are able to perform accurate fine movements. Considering the known dissociation between action-oriented and perception-oriented body representations, we asked whether the body model mainly serves body perception or whether it is also involved in movements. Twenty-one healthy adults were administered with the Localization Task (LT) which required the participants to localise the perceived position of their unseen hand by means of a stick held by their other hand, and the Proprioceptive Matching Task (PMT) which required the participants to match their perceived hand position with a visual target. LT and PMT maps were compared with the actual hand sizes. We found that the PMT map exhibited similar body model distortions, confirming that the body model is involved in motor programming. Furthermore, we observed that a partial adjustment of the distortions occurs in a motor condition.     

Heuristics as beliefs and as behaviors: the adaptiveness of the "hot hand"

and analyzed reasoning by asking: what are the reasoner's goals? This emphasizes the adaptiveness of behavior rather than whether a belief is normative. Belief in the "hot hand" in basketball suggests that players experiencing streaks should be given more shots, but this has been seen as a fallacy due to failure to find dependencies between players' shots. Based on their findings, I demonstrate by Markov modeling and simulation that streaks are valid allocation cues for deciding who to give shots to, because this behavior achieves the team goal of scoring more. Empirically I show that this adaptive heuristic is supported by the fallacious belief in dependency, more so as skill level increases. I extend the theoretical analysis to identify general conditions under which following streaks should be beneficial. Overall, this approach illustrates the advantages of analyzing reasoning in terms of adaptiveness.     

The effects of noncontingent access to food on the rate of object mouthing across three settings

Object mouthing is associated with several potential deleterious side effects. In the current investigation, we modified the use of noncontingent access to competing items (food) and evaluated the effects of the treatment on object mouthing across three settings. Results demonstrated reductions in mouthing associated with the modified treatment.     

EFFECTS OF INTERMITTENT PUNISHMENT ON SELF-INJURIOUS BEHAVIOR: AN EVALUATION OF SCHEDULE THINNING

Although the use of punishment often raises ethical issues, such procedures may be needed when the reinforcers that maintain behavior cannot be identified or controlled, or when competing reinforcers cannot be found. Results of several studies on the effects of intermittent schedules of punishment suggest that therapists must use fairly rich schedules of punishment to suppress problem behavior. However, residential caretakers, teachers, and parents often have difficulty implementing programs that require constant monitoring of the client's behavior. In this study, we examined the feasibility of gradually thinning the delivery of punishment from a continuous schedule to an intermittent schedule during the course of treatment for self-injurious behavior (SIB). Results of functional analyses for 5 individuals who had been diagnosed with profound mental retardation indicated that their SIB was not maintained by social consequences. Treatment with continuous schedules of time-out (for 1 participant) or contingent restraint (for the other 4 participants) produced substantial reductions in SIB. When they were exposed to intermittent schedules of punishment (fixed-interval [FI] 120 s or FI 300 s), SIB for all but 1 of the participants increased to levels similar to those observed during baseline. For these 4 participants, the schedule of punishment was gradually thinned from continuous to FI 120 s or FI 300 s. For 2 participants, SIB remained low across the schedule changes, demonstrating the utility of thinning from continuous to intermittent schedules of punishment. Results for the other 2 participants showed that intermittent punishment was ineffective, despite repeated attempts to thin the schedule.     

定量运动负荷和个性特征对动觉准确性和动作稳定性的影响

目的在于了解个性特征和定量运动负荷与同射箭运动员技术水平密切相关的肘关节动觉方位准确性和手动作稳定性的关系。研究结果表明：个性特征对肘关节动觉方位准确性和手动作稳定性的影响不显著;定量运动负荷可以使肘关节动觉方位准确性明显提高,而手动作稳定性变化不显著。本研究初步证明了韩国射箭训练中利用跑步等手段使运动员处于较高心率之下进行射准练习的方法是实用有效的。     

A person-oriented approach to hand hygiene behaviour: Emotional empathy fosters hand hygiene practice

Objectives: Adopting a social-psychological approach, this research examines whether emotional empathy, an affective reaction regarding another’s well-being, fosters hand hygiene as this affects other’s health-related well-being extensively.

Design: Three studies tested this notion: (a) a cross-sectional study involving a sample of health care workers at a German hospital, (b) an experiment testing the causal effect of empathy on hand hygiene behaviour and (c) an 11-week prospective study testing whether an empathy induction affected disinfectant usage frequency in two different wards of a hospital.

Main outcome measures: Self-reported hand hygiene behaviour based on day reconstruction method was measured in Study 1, actual hand sanitation behaviour was observed in Study 2 and disinfectant usage frequency in two different hospital wards was assessed in Study 3.

Results: Study 1 reveals an association of empathy with hand hygiene cross-sectionally, Study 2 documents the causal effect of empathy on increased hand sanitation. Study 3 shows an empathy induction increases hand sanitiser usage in the hospital.

Conclusions: Increasing emotional empathy promotes hand hygiene behaviour, also in hospitals. Besides providing new impulses for the design of effective interventions, these findings bear theoretical significance as they document the explanatory power of empathy regarding a distal explanandum (hand hygiene).     

情绪效价、唤醒度和有无评价影响手部动作

研究探讨情绪正-负效价、唤醒度水平(高、中、低)以及有意识评价对推拉动作的影响。分3个实验进行, 收集反应时(RT)和手部动作指标等。实验1使用正-负效价下高、中、低唤醒水平的图片进行评价并执行推-拉动作任务; 实验2使用中性图片和灰色空白图片完成相同任务; 实验3在不进行效价评估情况下完成推-拉动作。结果表明(1)情绪效价对反应时, 运动时间和到达峰速时间等有显著影响：向上拖动图片时, 消极图片拖得更快; 向下拖动时, 则积极图片更快。(2)情绪唤醒度调节情绪效价对推-拉动作的作用：唤醒度越高, 情绪效价尤其是负性情绪对推-拉动作的作用越大; 反之, 则作用越小。(3)无评价条件下, 情绪效价对推-拉动作无显著影响; 即情绪对动作的影响需要有意识评价的参与。这些结果说明情绪对推拉动作影响可能发生在早期, 不仅影响动作计划, 而且影响到随后动作的执行, 而高唤醒度和有意识评价增强了这种影响。