Treatment of painful peripheral neuroma by vein implantation

Painful neuromas form on cutaneous nerves as a result of,trauma, pressure, stretch or entrapment. Since the earliest descriptions of neuromas, proposed treatments have been met with poor results and controversy. The myriad of treatments described include: simple division of an affected nerve, implantation into muscle or bone, silicon sleeves and caps, repeated injection of steroids, end-to-side neurorrhaphy, medication and vein caps to name a few. Due to encouraging recent reports of treatment of painful neuromas by vein implantation, the authors describe a simple technique to achieve this surgical goal. As veins are readily accessible due to their proximity in the neurovascular bundle, they serve as a ready source for grafting. The advantages include minimisation of trauma to bone and muscle as compared with previous treatment techniques and the relative ease of the method. (C) 2003 Elsevier Science Ltd. All rights reserved

Optimistic biases in observational learning of value

Action-outcome contingencies can be learnt either by active trial-and-error, or vicariously, by observing the outcomes of actions performed by others. The extant literature is ambiguous as to which of these modes of learning is more effective, as controlled comparisons of operant and observational learning are rare. Here, we contrasted human operant and observational value learning, assessing implicit and explicit measures of learning from positive and negative reinforcement. Compared to direct operant learning, we show observational learning is associated with an optimistic over-valuation of low-value options, a pattern apparent both in participants’ choice preferences and their explicit post-hoc estimates of value. Learning of higher value options showed no such bias. We suggest that such a bias can be explained as a tendency for optimistic underestimation of the chance of experiencing negative events, an optimism repressed when information is gathered through direct operant learning