Narrative dynamics in social groups: A discrete choice model.

Individuals follow different rules for action: they react swiftly, grasping the short-term advantages in sight, or they waste cognitive resources to complete otherwise easy tasks, but they are able to plan ahead future complex decisions. Scholars from different disciplines studied the conditions under which either decision rule may enhance the fitness of its adopters, with a focus on the environmental features. However, we here propose that a crucial feature of the evolution of populations and their decision rules is rather inter-group interactions. Indeed, we study what happens when two groups support different decision rules, encapsulated in narratives, and their populations interact with each other. In particular, we assume that the payoff of each rule depends on the share of both social groups which adopt such rules. We then describe the most salient dynamics scenarios and identify the conditions which lead to chaotic dynamics and multistability regimes.

An unusual finding in nerve root compression at L5 caused by herniated disc.

The authors describe the severe changes observed in the L5 nerve root in a patient aged 46 years with lumbar disc herniation at L4-L5. The lesions observed in the nerve root made it unrecognisable, thus we could not be certain that we were actually dealing with a nerve root until it was confirmed by histological examination. The severe macroscopic and microscopic changes observed had resulted in complete loss of function in the nerve root, so its removal did not cause any changes in the neurological, clinical or electromyographic pictures.

Recognizing people seen in events via dynamic "mug shots".

This study examined effects of an event and dynamic mug shots on facial recognition. Witnesses saw either a film of a liquor store holdup staged by six perpetrators, slides of the same targets, or freeze-framed views from the filmed event. Slides of different facial views of targets among 12 foils, or dynamic 180 degrees mug shots of the same men, or multiple static views were administered 24 hr later in yes-no recognition tests. Recognition (d') was poorer for the same men seen in the event than in slides, but better for dynamic than for static mug shots. Nondynamic event characteristics were responsible for poor recognition of people seen in events, whereas dynamic aspects of facial transformations, not multiple views, seemed responsible for the superiority of dynamic mug shots. The implications of these results for issues of ecological validity of traditional face recognition methodology and for static feature models vs. dynamic transformation models of face recognition are discussed.