Neural Computation in Medicine: Perspectives and Prospects

In 1998, over 400 pape r on ar ificial neu rx networ s (ANNs) wer e published in the context of medicine, but why is ther e this inter est in ANNs? And how do ANNs compar e with tr aditional statistical methods? We pr opose some answer to these questions, and go on to consider the `black box' issue. Finally, we br iefly look at two dir ections in which ANNs ar e likely to develop, namely the use of Bayesian statistics and knowledgedata fusion. 1 Cognitive and data modelling In the wake of publication of the back-propagation algorithm in 1986, the number of ANN-oriented articlesfc tured in the Medline database has grownf rom 2 in 1990 to 473 in 1998. But why is there this interest in ANNs within medicine? The design of ANNs was originally motivated by the phenomena of learning and recognition, and the desire to model these cognitive processes. The cognitive-modelling branch of ANN research is still active, and it is relevant to medicine in providing models of psychological and cerebr..

A matter of space and time: How frequent is convergence in lithic technology in the African archaeological record over the last 300 kyr?

Stone artefacts are frequently used to identify and trace human populations in the Paleolithic. Convergence in lithic technology has the potential to confound such interpretations, implying connections between unrelated groups. To further the general theoretical debate on this issue, we first delineate the concepts of independent innovation, diffusion and migration and provide archaeological expectations for each of these processes that can create similarities in material culture. As an empirical test case, we then assess how these different mechanisms play out in both space and time for lithic technology across several scales of the African Stone Age record within the last 300 thousand years (kyr). Our findings show that convergence is neither the exception nor the norm, but a scale-dependent phenomenon that occurs more often for complex artefacts than is generally acknowledged and in many different spatio-temporal contexts of the African record that can crosscut the MSA/LSA boundary. Studies using similarly-looking stone tools to recognize past populations and track human dispersals in the Stone Age thus always need to test for the potential of independent innovation and not assume migration or diffusion a priori