Dynamics of Lennard-Jones clusters: A characterization of the activation-relaxation technique

The potential energy surface (PES) of Lennard-Jones clusters is investigated using the activation-relaxation technique (ART). This method defines events in the configurational energy landscape as a two-step process: (a) a configuration is first activated from a local minimum to a nearby saddle-point and (b) is then relaxed to a new minimum. Although ART has been applied with success to a wide range of materials such as a-Si, a-SiO2 and binary Lennard-Jones glasses, questions remain regarding the biases of the technique. We address some of these questions in a detailed study of ART-generated events in Lennard-Jones (LJ) clusters, a system for which much is already known. In particular, we study the distribution of saddle-points, the pathways between configurations, and the reversibility of paths. We find that ART can identify all trajectories with a first-order saddle point leaving a given minimum, is fully reversible, and samples events following the Boltzmann weight at the saddle point.Comment: 8 pages, 7 figures in postscrip

Communicator Style as an Effect Determinant of Attraction

This research reports the results of three independent studies which investigate the relationship between attraction and communicator style (the way a person communicates). Study 1 compares the communicator styles of "best liked" and "least liked" friends. The "best liked" friend's style differed significantly from that of the "least liked" friend, scoring higher on attraction, communicator image, open, attentive relaxed. and dramatic/animated. In study 2, four specific styles were studied in relation to attraction. The dominant/open style was seen by subjects as the most attractive; the not-dominant/not-relaxed style was seen as least attractive. In study 3, teachers rated students representing the four styles investigated in study 2 on a nine-item attraction measure entailing physical, personality, and liking dimensions. Again, the dominant/open style emerged as most attractive. The three studies provide strong evidence that communicator style is an important effect determinant of attraction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66866/2/10.1177_009365027700400302.pd

Neural pathways of embarrassment and their modulation by social anxiety

While being in the center of attention and exposed to other's evaluations humans are prone to experience embarrassment. To characterize the neural underpinnings of such aversive moments, we induced genuine experiences of embarrassment during person–group interactions in a functional neuroimaging study. Using a mock-up scenario with three confederates, we examined how the presence of an audience affected physiological and neural responses and the reported emotional experiences of failures and achievements. The results indicated that publicity induced activations in mentalizing areas and failures led to activations in arousal processing systems. Mentalizing activity as well as attention towards the audience were increased in socially anxious participants. The converging integration of information from mentalizing areas and arousal processing systems within the ventral anterior insula and amygdala forms the neural pathways of embarrassment. Targeting these neural markers of embarrassment in the (para-)limbic system provides new perspectives for developing treatment strategies for social anxiety disorders