La Universidad de las Islas Baleares ante la Ley de Reforma universitaria

Abstract not availabl

Cooperation and the Emergence of Role Differentiation in the Dynamics of Social Networks

By means of extensive computer simulations, the authors consider the entangled coevolution of actions and social structure in a new version of a spatial Prisoner's Dilemma model that naturally gives way to a process of social differentiation. Diverse social roles emerge from the dynamics of the system: leaders are individuals getting a large payoff who are imitated by a considerable fraction of the population, conformists are unsatisfied cooperative agents that keep cooperating, and exploiters are defectors with a payoff larger than the average one obtained by cooperators. The dynamics generate a social network that can have the topology of a small world network. The network has a strong hierarchical structure in which the leaders play an essential role in sustaining a highly cooperative stable regime. But disruptions affecting leaders produce social crises described as dynamical cascades that propagate through the network.Comment: (15 pages, 7 figures

Aesthetic appreciation: event-related field and time-frequency analyses

Improvements in neuroimaging methods have afforded significant advances in our knowledge of the cognitive and neural foundations of aesthetic appreciation. We used magnetoencephalography (MEG) to register brain activity while participants decided about the beauty of visual stimuli. The data were analyzed with event-related field (ERF) and Time-Frequency (TF) procedures. ERFs revealed no significant differences between brain activity related with stimuli rated as “beautiful” and “not beautiful.” TF analysis showed clear differences between both conditions 400 ms after stimulus onset. Oscillatory power was greater for stimuli rated as “beautiful” than those regarded as “not beautiful” in the four frequency bands (theta, alpha, beta, and gamma). These results are interpreted in the frame of synchronization studies

The world can look better: enhancing beauty experience with brain stimulation

Aesthetic appreciation is part of our everyday life: it is a subjective judgment we make when looking at a painting, a landscape, or--in fact--at another person. Neuroimaging and electrophysiological evidence suggests that the left dorsolateral prefrontal cortex (DLPFC) plays a critical role in aesthetic judgments. Here, we show that the experience of beauty can be artificially enhanced with brain stimulation. Specifically, we show that aesthetic appreciation of representational paintings and photographs can be increased by applying anodal (excitatory) transcranial direct current stimulation on the left DLPFC. Our results thus show that beauty is in the brain of the beholder, and offer a novel view on the neural networks underlying aesthetic appreciation

Lateral Orbitofrontal Cortex Involvement in Initial Negative Aesthetic Impression Formation

It is well established that aesthetic appreciation is related with activity in several different brain regions. The identification of the neural correlates of beauty or liking ratings has been the focus of most prior studies. Not much attention has been directed towards the fact that humans are surrounded by objects that lead them to experience aesthetic indifference or leave them with a negative aesthetic impression. Here we explore the neural substrate of such experiences. Given the neuroimaging techniques that have been used, little is known about the temporal features of such brain activity. By means of magnetoencephalography we registered the moment at which brain activity differed while participants viewed images they considered to be beautiful or not. Results show that the first differential activity appears between 300 and 400 ms after stimulus onset. During this period activity in right lateral orbitofrontal cortex (lOFC) was greater while participants rated visual stimuli as not beautiful than when they rated them as beautiful. We argue that this activity is associated with an initial negative aesthetic impression formation, driven by the relative hedonic value of stimuli regarded as not beautiful. Additionally, our results contribute to the understanding of the nature of the functional roles of the lOFC