Single-Joint Movements in Parkinson's Disease: A Pulse-Width and Pulse-Height Theory Review

The process by which the brain controls single-joint movements (SJM) is still not well understood. Some studies have defined rules describing the duration and magnitude of the agonist and antagonist muscles. Therefore, the purpose of this study was to analyze scientific publications about the electromyographic characteristics of SJM performed by patients with Parkinson's disease. A bibliographical review of the years 1989–2015 was performed using keywords such as electromyography, upper limb, and Parkinson's disease. After applying the inclusion criteria, 8 articles were included for analysis. The literature indicates that despite the lack of studies, it is possible to assume that considering the SJM, those with Parkinson's disease only control the magnitude of electromyography activation, being consistent only with the pulse-height theory control.     

Motor Cortex Plasticity in Children With Spastic Cerebral Palsy: A Systematic Review

A review of the literature was performed to answer the following questions: Does motor cortex excitability correlate with motor function? Do motor cortex excitability and cortex activation change after a rehabilitation program that results in improvements in motor outcomes? Can the 10–20 electroencephalography (EEG) system be used to locate the primary motor cortex when employing transcranial direct current stimulation? Is there a bihemispheric imbalance in individuals with cerebral palsy similar to what is observed in stroke survivors? the authors found there is an adaptation in the geometry of motor areas and the cortical representation of movement is variable following a brain lesion. The 10–20 EEG system may not be the best option for locating the primary motor cortex and positioning electrodes for noninvasive brain stimulation in children with cerebral palsy.     

An Integrative Model of the Impact of Exposure to Idealized Female Images on Adolescent Girls’ Body Satisfaction1

This research examined a model describing the interrelationships between individual characteristics and the extent of change in body dissatisfaction following exposure to idealized female images. Three samples of middle adolescent girls (2 Australian, n = 118, and n = 63; 1 Italian, n = 88) completed self‐report assessments. Several days later, they viewed idealized female images, and body satisfaction was assessed immediately prior to and following exposure. Across all 3 samples, structural equation modeling supported a model in which body comparison tendency mediated the role of psychological functioning and internalization of the thin ideal on changes in body satisfaction following image exposure. Internalization of the thin ideal partially mediated the path between psychological functioning and body comparison tendency.     

Resilience and vagal tone predict cardiac recovery from acute social stress

Previous studies showed that heart period decreases during and recovers after an acute stress. We investigated if individual predispositions and emotional priming influence heart period recovery after a speech stress task. Psychometric scales and resting cardiac vagal tone were used to measure individual traits. The presentation of a sequence of either pleasant or unpleasant pictures, as emotional primers, preceded the speech stress. Heart period was measured throughout the experiment. Stress induced tachycardia irrespective of emotional priming or traits. In the recovery period, participants with higher resting cardiac vagal tone or presenting higher resilience significantly reduced the heart acceleration. Furthermore, these traits interacted synergistically in the promotion of the recovery of heart period. Pleasant priming also improved recovery for participants with lower negative affect. In conclusion, the stress recovery measured through heart period seemed dependent upon individual predispositions and emotional priming. These findings further strengthen previous observations on the association between greater cardiac vagal tone and the ability to regulate emotion.     

The ideal elf: identity exploration in World of Warcraft.

In this study, we examine the identity exploration possibilities presented by online multiplayer games in which players use graphics tools and character-creation software to construct an avatar, or character. We predicted World of Warcraft players would create their main character more similar to their ideal self than the players themselves were. Our results support this idea; a sample of players rated their character as having more favorable attributes that were more favorable than their own self-rated attributes. This trend was stronger among those with lower psychological well-being, who rated themselves comparatively lower than they rated their character. Our results suggest that the game world allows players the freedom to create successful virtual selves regardless of the constraints of their actual situation.     

Effect of anosmia on the behavior of standard non-aggressive male mice opponents during agonistic encounters

This study assessed whether the differences observed in a previous experiment [Martinez M, Salvador A, Simon VM (1994): Aggressive Behavior 20:441–451] in the behavior of isolated male mice over several agonistic encounters in which they confronted either an “anosmic” or an “intact” non-aggressive “standard opponent” were due to the differences in the behavior of the opponents themselves. Ethologically-inspired analysis was used to assess the behavior of the opponents during the first agonistic encounter. Anosmic opponents spent less time in social investigation and defense and more time in immobility than intact ones. These results suggest that the differences in the behavior of the opponents could be one of the causes of the differences observed in the behavior of the aggressive males confronting them. However, more research is needed to study if other variables, such as the production of odors, are also affected by the state (deprived or intact) of the olfactory sense. These findings provide additional support for the view that the type of opponent used in studies on intermale aggression is of paramount importance.Aggr. Behav. 23:179–181, 1997.© 1997 Wiley-Liss, Inc.     

Age-Related Changes in Smoothness of Gait of Healthy Children and Early Adolescents

Abstract

In this study, we acquired and processed trunk accelerations during level walking in 85 children aged 8-13?years to calculate spatio-temporal parameters and Harmonic Ratio (HR), which is a metrics representative of gait smoothness and step-to-step symmetry. The results show that while spatio-temporal parameters remain unchanged once normalized considering individuals’ anthropometry, significantly higher values of HR for both the antero-posterior and vertical directions were found in participants aged 12–13 with respect to those of 8–9. This indicates an improvement of gait symmetry, which suggests that the gait maturation process is still ongoing for the age ranges tested here.