On the atomic structure of an asymmetrical near Σ = 27 grain boundary in copper

The atomic structure of an asymmetrical near Σ = 27 {525} tilt grain boundary (GB) in copper is determined by coupling high-resolution transmission electron microscopy and molecular dynamics simulation. The average GB plane is parallel to {414} in crystal (1) and {343} in crystal (2). The detailed GB structure shows that it is composed of facets always parallel to {101} and {111} in crystals (1) and (2), respectively. The atomic structure of one facet is described using the structural units model. Each facet is displaced with respect to its neighbours by a pure step, giving rise to the asymmetry of the GB plane orientation. The energy of this asymmetrical GB is significantly lower than that of both the {525} symmetrical and the {11,1,11}/{111} asymmetrical Σ = 27 GBs. One GB region displays another atomic structure with a dislocation that accounts for the misfit between interatomic distances in the {414} and {343} GB planes.     

Hand–foot motor priming in the presence of temporary inability to use hands

To verify if the link between observed hand actions and executed foot actions found in aplasics is essentially induced by the constant use of foot substituting the hand, we investigated if the vision of a grasping hand is able to prime a foot response in normals. Participants were required to detect the time-to-contact of a hand grasping an object either with a suitable or a less suitable movement, an experimental paradigm known to induce a priming effect. Participants responded either with the hand or the foot, while having free or bound hands. Results showed that for hand responses motor priming effect was stronger when the hands were free, whereas for foot responses it was stronger when the hands were bound. These data are interpreted as a further evidence that a difficulty to move affects specific cognitive functions and that the vision of a grasping hand may prime a foot response.     

Neuropsychological Sequelae of Subthalamic Nucleus Deep Brain Stimulation in Parkinson's Disease: A Critical Review

Neuropsychologists are increasingly involved in surgical candidacy evaluations and postoperative neurobehavioral assessments of patients with movement disorders, most notably those with disease (PD). We review here the initial studies regarding neuropsychological outcomes of deep brain stimulation (DBS) within the subthalamic nucleus (STN) for treatment of PD. Overall, these initial investigations provide preliminary support for the cognitive and neurobehavioral safety of STN DBS. Improvements in self-reported symptoms of depression and diminished verbal fluency were the most common findings, whereas changes in global cognitive abilities, memory, attention, and frontal/executive functions were inconsistent and most often described as nominal and/or transient. The generalizability of this literature is hindered by several methodological limitations, including small samples and the absence of appropriate control participants. The clinical and theoretical implications of these initial studies are highlighted and recommendations are offered to guide future research.     

Integration of spatial maps in pigeons

The integration of spatial maps in pigeons was investigated using a spatial analog to sensory preconditioning. The pigeons were tested in an open-field arena in which they had to locate hidden food among a 4×4 grid of gravel-filled cups. In phase 1, the pigeons were exposed to a consistent spatial relationship (vector) between landmark L (a red L-shaped block of wood), landmark T (a blue T-shaped block of wood) and the hidden food goal. In phase 2, the pigeons were then exposed to landmark T with a different spatial vector to the hidden food goal. Following phase 2, pigeons were tested with trials on which they were presented with only landmark L to examine the potential integration of the phase 1 and 2 vectors via their shared common elements. When these test trials were preceded by phase 1 and phase 2 reminder trials, pigeons searched for the goal most often at a location consistent with their integration of the LT phase 1 and Tphase 2 goal vectors. This result indicates that integration of spatial vectors acquired during phases 1 and 2 allowed the pigeons to compute a novel Lgoal vector. This suggests that spatial maps may be enlarged by successively integrating additional spatial information through the linkage of common elements.     

Electrical Stimulation, Endorphins, and the Practice of Clinical Psychology

Recent studies have demonstrated an alternative to drug treatment for patients presenting with anxiety disorders. This new technique involves electrical stimulation of the peripheral nervous system to induce chemical changes in the brain that can support and promote healing. This method was developed in part from studies of ancient Chinese acupuncture, but it is noninvasive and does not require needles, and it does not depend on prescientific rituals or metaphysical theories. Endorphins, natural neuropeptides active in basal brain structures, act upon anxiolytic receptors. Solid evidence from fMRI and neurochemical studies show that a simple office procedure involving electrical stimulation can stimulate the expression of endorphins in the brain. Patients have demonstrated symptom relief from this simple adjunctive treatment with a concomitant reduction in dependency on psychotropic medications.     

Proposal of a common terminology for the neuropsychological rehabilitation

The literature on neuropsychological intervention (NI) uses a variety of terms to refer to equivalent constructs, making it difficult to compare intervention programmes and their outcomes. The purpose of this work is to propose a unified terminological framework for describing NI programmes. The terminological framework was developed based on a previous proposal for common terminology by Johnstone and Stonnington (Rehabilitation of neuropsychological disorders: A practical guide for rehabilitation professionals. Psychology Press, 2011) and driven by Cognitive Psychology concepts. The terminological framework was organized into two sections: (a) NI, which includes types of NI, methods and approaches, instructional methods, and strategies; and (b) neurocognitive functions, which include temporal and spatial orientation, sensation, perception, visuo-constructional abilities, attention, memory, language, reasoning of several sorts (e.g., abstract reasoning, and numerical reasoning), and executive functions. Most NI tasks target a main neurocognitive function, but there are underlying neurocognitive functions that may impair performance in the former. Since it is difficult to create a task that is solely focused on one neurocognitive function, the proposed terminology should not be viewed as a taxonomy, but rather as dimensional, with the same task allowing to work different functions, in varying grades. Adopting this terminological framework will allow to define the targeted neurocognitive functions more accurately and simplify the comparison between NI programmes and their outcomes. Future research should focus on describing the main techniques/strategies for each neurocognitive function and non-cognitive interventions.     

NEGATIVE REINFORCEMENT IN APPLIED BEHAVIOR ANALYSIS: AN EMERGING TECHNOLOGY

Although the effects of negative reinforcement on human behavior have been studied for a number of years, a comprehensive body of applied research does not exist at this time. This article describes three aspeas of negative reinforcement as it relates to applied behavior analysis: behavior acquired or maintained through negative reinforcement, the treatment of negatively reinforced behavior, and negative reinforcement as therapy. A consideration of research currently being done in these areas suggests the emergence of an applied technology on negative reinforcement.     

CLINICAL EVALUATION OF THE SELF-INJURIOUS BEHAVIOR INHIBITING SYSTEM (SIBIS)

Five cases involving the treatment of longstanding, severe, and previously unmanageable self-injurious behavior are presented. In each case, the behavior was forceful contact with the head or face, and treatment consisted of mild and brief contingent electrical stimulation, delivered automatically or by a therapist, via the Self-Injurious Behavior Inhibiting System. Results of reversal and/or multiple baseline designs, in which sessions ranged in duration from 10 min to all day across a variety of settings, showed that the effects of the system were immediate and produced almost complete elimination of the self-injurious behavior. Controlled and anecdotal follow-up data for four of the five cases suggest continuing benefits and the absence of detrimental side effects associated with treatment. Potential applications of the device, as well as extensions and limitations, are discussed.     

Stimulation-induced behavioral inhibition: A new model for understanding physical violence

Physical violence is widely considered to result from action carried out with the intention of causing injury; that is, from aggression. However, the “hypothesis” of aggression is inapplicable in all but a few instances as well as inappropriate for many destructive rage-associated responses directed at inanimate objects. This paper outlines a new perspective on physical violence, reinterpreting many behaviors hitherto labeled aggressive as stimulation-seeking behaviors (SSBs) above an arbitrary level of intensity. It is further proposed that: 1) physical violence is a by-product of SSB, driven, in part by brain catecholaminergic (CA) systems, and the direct result of exchanges of energy that exceed the body's tolerance threshold; 2) allegedly discrete categories of motor-motivational behavior represent overlapping bands of intensity on a continuous spectrum of SSB; and 3) the sensory input derived from SSB is fed back into the central nervous system where it activates, brain serotonergic and/or cholinergic systems, which in turn inhibit CA systems, resulting in a general state of behavioral quiescence. In addition to accounting for a number of previously unexplained observations, the model suggests that physical violence could be prevented by providing groups at high risk with extensive opportunities for therapeutic sensory stimulation to substitute for that derived from excessive SSB. For people at especially high risk, portable devices could be developed that would allow the user to self-administer desired levels of sensory stimulation at moments of intense anger, thereby preventing potentially dangerous outbursts of SSB prior to the onset of the behavior.     

Differential effects of massage and heelstick procedures on transcutaneous oxygen tension in preterm neonates

The present study investigated the differential effects of heelsticks and tactile-kinesthetic massage on transcutaneous oxygen tension (TcPO₂) in preterm infants. The sample was comprised of 37 stabilized preterm neonates from the Neonatal Intensive Care Unit. During the heelstick procedure, TcPO₂ significantly declined an average of 14 mmHg. When compared to the tactile-kinesthetic massage, TcPO₂ levels during the heelstick (M = 39.8) were significantly lower than during the stimulation (M = 72.8). Mean TcPO₂ levels remained clinically safe during the four massage sessions evaluated. The TcPO₂ levels during kinesthetic stimulation were somewhat more varied, and movement and pressurization of the TcPO₂ electrode were investigated as possible artifactual explanations for this phenomenon. Overall, the findings indicate that social forms of touch such as tactile-kinesthetic massage do not appear to have a medically compromising effect on TcPO₂ in the preterm neonate. These findings are evaluated in relation to the “minimal touch” policy, and implications for future handling of the stabilized preterm neonate are discussed.