Modulation of pain ratings by expectation and uncertainty: Behavioral characteristics and anticipatory neural correlates.

Expectations about the magnitude of impending pain exert a substantial effect on subsequent perception. However, the neural mechanisms that underlie the predictive processes that modulate pain are poorly understood. In a combined behavioral and high-density electrophysiological study we measured anticipatory neural responses to heat stimuli to determine how predictions of pain intensity, and certainty about those predictions, modulate brain activity and subjective pain ratings. Prior to receiving randomized laser heat stimuli at different intensities (low, medium or high) subjects (n=15) viewed cues that either accurately informed them of forthcoming intensity (certain expectation) or not (uncertain expectation). Pain ratings were biased towards prior expectations of either high or low intensity. Anticipatory neural responses increased with expectations of painful vs. non-painful heat intensity, suggesting the presence of neural responses that represent predicted heat stimulus intensity. These anticipatory responses also correlated with the amplitude of the Laser-Evoked Potential (LEP) response to painful stimuli when the intensity was predictable. Source analysis (LORETA) revealed that uncertainty about expected heat intensity involves an anticipatory cortical network commonly associated with attention (left dorsolateral prefrontal, posterior cingulate and bilateral inferior parietal cortices). Relative certainty, however, involves cortical areas previously associated with semantic and prospective memory (left inferior frontal and inferior temporal cortex, and right anterior prefrontal cortex). This suggests that biasing of pain reports and LEPs by expectation involves temporally precise activity in specific cortical networks.

Exploring the use of sensors to measure behavioral interactions: an experimental evaluation of using hand trajectories.

Humans appear to be sensitive to relative small changes in their surroundings. These changes are often initially perceived as irrelevant, but they can cause significant changes in behavior. However, how exactly people's behavior changes is often hard to quantify. A reliable and valid tool is needed in order to address such a question, ideally measuring an important point of interaction, such as the hand. Wearable-body-sensor systems can be used to obtain valuable, behavioral information. These systems are particularly useful for assessing functional interactions that occur between the endpoints of the upper limbs and our surroundings. A new method is explored that consists of computing hand position using a wearable sensor system and validating it against a gold standard reference measurement (optical tracking device). Initial outcomes related well to the gold standard measurements (r = 0.81) showing an acceptable average root mean square error of 0.09 meters. Subsequently, the use of this approach was further investigated by measuring differences in motor behavior, in response to a changing environment. Three subjects were asked to perform a water pouring task with three slightly different containers. Wavelet analysis was introduced to assess how motor consistency was affected by these small environmental changes. Results showed that the behavioral motor adjustments to a variable environment could be assessed by applying wavelet coherence techniques. Applying these procedures in everyday life, combined with correct research methodologies, can assist in quantifying how environmental changes can cause alterations in our motor behavior.

The user-value of rural electrification: An analysis and adoption of existing models and theories

User-value is a determining factor for product acceptance in product design. Research on rural electrification to date, however, does not draw sufficient attention to the importance of user-value with regard to the overall success of a project. This is evident from the analysis of project reports and applicable indicators from agencies active in the sector. Learning from the design, psychology and sociology literatures, it is important that rural electrification projects incorporate the value perception of the end-user and extend their success beyond the commonly used criteria of financial value, the appropriateness of the technology, capacity building and technology uptake. Creating value for the end-user is particularly important for project acceptance and the sustainability of a scheme once it has been handed over to the local community. In this research paper, existing theories and models of value-theory are transposed and applied to community operated rural electrification schemes and a user-value framework is developed. Furthermore, the importance of value to the end-user is clarified. Current literature on product design reveals that user-value has different properties, many of which are applicable to rural electrification. Five value pillars and their sub-categories important for the users of rural electrification projects are identified, namely: functional; social significance; epistemic; emotional; and cultural values. These pillars provide the main structure for the conceptual framework developed in this research paper. It is proposed that by targeting the values of the end-user, the key factors of user-value applicable to rural electrification projects will be identified and the sustainability of the project will be better ensured. © 2014 The Authors.

Self-stabilization and behavioral diversity of embodied adaptive locomotion

Locomotion is of fundamental importance in understanding adaptive behavior. In this paper we present two case studies of robot locomotion that demonstrate how higher level of behavioral diversity can be achieved while observing the principle of cheap design. More precisely, it is shown that, by exploiting the dynamics of the system-environment interaction, very simple controllers can be designed which is essential to achieve rapid locomotion. Special consideration must be given to the choice of body materials. We conclude with some speculation about the importance of locomotion for understanding cognition. © Springer-Verlag Berlin Heidelberg 2004.

An Accurate and Fast Behavioral Model for PLL Frequency Synthesizer Phase Noise/Spurs Prediction

This paper presents a behavior model for PLL Frequency Synthesizer. All the noise sources are modeled with noise voltages or currents in time-domain. An accurate VCO noise model is introduced, including both thermal noise and 1/f noise. The behavioral model can be co-simulated with transistor level circuits with fast speed and provides more accurate phase noise and spurs prediction. Comparison shows that simulation results match very well with measurement results.

CONTINUUM-THEORIES OF OPTICAL PHONONS AND POLARITONS IN SUPERLATTICES - A BRIEF CRITIQUE - COMMENT

The so-called hydrodynamic (HD) model on optical-phonon modes in superlattices is critically examined. Contrary to the HD model, a comparison between TM polaritons and the Fuchs-Kliewer-type interface modes has shown that the Fuchs-Kliewer interface modes do possess Frohlich potentials.

The generalized second law of thermodynamics in generalized gravity theories

We investigate the generalized second law of thermodynamics (GSL) in generalized theories of gravity. We examine the total entropy evolution with time including the horizon entropy, the non-equilibrium entropy production, and the entropy of all matter, field and energy components. We derive a universal condition to protect the generalized second law and study its validity in different gravity theories. In Einstein gravity (even in the phantom-dominated universe with a Schwarzschild black hole), Lovelock gravity and braneworld gravity, we show that the condition to keep the GSL can always be satisfied. In f ( R) gravity and scalar-tensor gravity, the condition to protect the GSL can also hold because the temperature should be positive, gravity is always attractive and the effective Newton constant should be an approximate constant satisfying the experimental bounds.

Dynamical horizon entropy and equilibrium thermodynamics of generalized gravity theories

We study the relation between the thermodynamics and field equations of generalized gravity theories on the dynamical trapping horizon with sphere symmetry. We assume the entropy of a dynamical horizon as the Noether charge associated with the Kodama vector and point out that it satisfies the second law when a Gibbs equation holds. We generalize two kinds of Gibbs equations to Gauss-Bonnet gravity on any trapping horizon. Based on the quasilocal gravitational energy found recently for f(R) gravity and scalar-tensor gravity in some special cases, we also build up the Gibbs equations, where the nonequilibrium entropy production, which is usually invoked to balance the energy conservation, is just absorbed into the modified Wald entropy in the Friedmann-Robertson-Walker spacetime with slowly varying horizon. Moreover, the equilibrium thermodynamic identity remains valid for f(R) gravity in a static spacetime. Our work provides an alternative treatment to reinterpret the nonequilibrium correction and supports the idea that the horizon thermodynamics is universal for generalized gravity theories.

Behavioral responses of tilapia (Oreochromis niloticus) to acute fluctuations in dissolved oxygen levels as monitored by computer vision

Behavioral and ventilatory parameters have the possibility of predicting the stress state of fish in vivo and in situ. This paper presents a new image-processing algorithm for quantifying the average swimming speed of a fish school in an aquarium. This method is based on the alteration in projected area caused by the movement of individual fish during frame sequences captured at given time intervals. The image enhancement method increases the contrast between fish and background, and is thus suitable for use in turbid aquaculture water. Behavioral parameters (swimming activity and distribution parameters) and changes in ventilation frequency (VF) of tilapia (Oreochromis niloticus) responded to acute fluctuations in dissolved oxygen (DO) which were monitored continuously in the course of normoxia, falling DO level, maintenance of hypoxia (three levels of 1.5, 0.8 and 0.3 mg l(-1)) and subsequent recovery to normoxia. These parameters responded sensitively to acute variations in DO level; they displayed significant changes (P < 0.05) during severe hypoxia (0.8 and 0.3 mg l(-1) level) compared with normoxic condition, but there was no significant difference under conditions of mild hypoxia (1.5 mg l(-1) level). There was no significant difference in VF between two levels of severe hypoxia 0.8 and 0.3 mg l(-1) level during the low DO condition. The activity and distribution parameters displayed distinguishable differences between the 0.8 and 0.3 mg l(-1) levels. The behavioral parameters are thus capable of distinguishing between different degrees of severe hypoxia, though there were relatively large fluctuations. (c) 2006 Elsevier B.V. All rights reserved.

社会困境中的行为决策――社会身份与地位的影响

Social dilemmas are defined as such situations in which short-term individual and long-term collective interests are at odds (Hardin, 1968; Messick & Brewer, 1983). Severe social problems lead more and more researchers to pay attention to the issue of social dilemmas. Until now, research has widely examined the factors influencing cooperation in social dilemmas, and provided solutions to social dilemmas. In the need of theory development, previous research generally simplified the situation of realistic social dilemmas. Therefore, few studies have explored the issue of cooperation in social dilemmas in an intergroup situation. On the other hand, there has been little empirical attention for such issues in countries outside of United States and Western Europe. To meet this gap, the present study grounded itself in social identity theories and examined the effect of unequal group status on behavioral decision making in social dilemmas. To this end, the study designed three experiments to examine how individuals with different group status response psychologically and behaviorally to cooperation in intragroup and intergroup social dilemmas. In experiment 1, the study examined how independent and interdependent self- construals affect cooperative behavior in an intragroup social dilemma. The results showed that when individuals were primed with interdependent (as opposed to independent) self-construal, they consistently contributed highly, regardless of context manipulation. In contrast, those primed with independent self-construal contributed less in the investment game but only when placed in a context where group members were encouraged to think about their individual (versus shared) fate. Results supported the idea that independent self-construal in a low interdependent context produces the most competitive behavior and that this effect was partially mediated by the feeling of interaction within a group. In experiment 2, the study examined how the effect of group status on different level of cooperation in a nested social dilemma was moderated by individual status, and what roles ingroup and superordinate identifications played in the above effect. Results found that individuals in higher status groups tended to allocate more to private account and less to subgroup account compared to those in lower status group; individuals in higher status groups allocated more to higher level accounts than to private account, whereas those in lower status acted in a reverse way. The results indicated that group status (compared to individual status) exerted a positive influence on behavioral decision making in social dilemmas, with higher group status contributing more to subgroup as well as collective interests. Results also found that the effect of group status and/or individual status on cooperation in social dilemmas was moderated by sex. As for individual status, results showed that the effect of individual status on subgroup interest was significantly moderated only by the combination of higher ingroup identification and lower superordinate identification. In experiment 3, the study explored how group stability and cognitive categorization interactively influenced the relationship between group status and behavioral decision making in a social dilemma. Results did not support the prediction that group status and stability interactively affected behavioral decision-making in social dilemmas. However, it was found that this relationship was moderated by which level individuals categorized themselves at. When categorization at the individual level was salient, individuals in high status group contributed more to subgroup account than those in low status group if they perceived a stable status hierarchy; whereas they contributed more to private account and less to collective account if they perceived that the status was instable. On the other hand, when categorization at the subgroup level was salient, individuals in high status group contributed less to collective account than those in low status group if they perceived that the status was stable; whereas they contributed less to private account and more to subgroup account if they perceived an instable status relation. In summary, the present study suggests that cooperation with ingroup forms the basis of social harmony, and higher status for everyone in any given group is a necessary for social development. On the other hand, individuals in higher status group tend to be more selfish once they realize that their current status hierarchy is unstable. However, activating their collective identity will to some degree increase the level of their cooperation with the collective. The study thus provides psychological explanations on how to construct group harmony and management suggestions on how to solve social conflicts.