[Navigation and robotics of the lateral skull base]

Computer-aided microscopic surgery of the lateral skull base is a rare intervention in daily practice. It is often a delicate and difficult minimally invasive intervention, since orientation between the petrous bone and the petrous bone apex is often challenging. In the case of aural atresia or tumors the normal anatomical landmarks are often absent, making orientation more difficult. Navigation support, together with imaging techniques such as CT, MR and angiography, enable the surgeon in such cases to perform the operation more accurately and, in some cases, also in a shorter time. However, there are no internationally standardised indications for navigated surgery on the lateral skull base. Miniaturised robotic systems are still in the initial validation phase.

Intelligence and the psychological refractory period: A lateralized readiness potential study

The psychological refractory period (PRP) refers to a delay of response times (RT) to the second of two stimuli when these stimuli are presented in rapid succession. If this limitation of rapidly processing the second stimulus contributes to the well-known differences in speed of information processing between individuals with higher and lower mental ability, individuals with lower mental ability should exhibit a more pronounced PRP effect than individuals with higher mental ability. Previous studies on this question, however, yielded inconsistent results. In the present study, we assessed mental ability-related differences in the PRP by measuring lateralized readiness potentials (LRPs) to separate premotor and motor aspects of speed of information processing in 95 individuals with higher and 95 individuals with lower mental ability. Although individuals with higher mental ability processed information faster than individuals with lower mental ability as indicated by shorter RTs and shorter premotor LRP latencies, the PRP effect was equally pronounced in both groups. These findings suggest that the processes underlying the PRP effect do not contribute to mental ability-related differences in speed of information processing. Rather, these differences seem to occur at an earlier stage of information processing such as stimulus encoding, stimulus analysis, or stimulus evaluation.

Skolemization for Substructural Logics

The usual Skolemization procedure, which removes strong quantifiers by introducing new function symbols, is in general unsound for first-order substructural logics defined based on classes of complete residuated lattices. However, it is shown here (following similar ideas of Baaz and Iemhoff for first-order intermediate logics in [1]) that first-order substructural logics with a semantics satisfying certain witnessing conditions admit a “parallel” Skolemization procedure where a strong quantifier is removed by introducing a finite disjunction or conjunction (as appropriate) of formulas with multiple new function symbols. These logics typically lack equivalent prenex forms. Also, semantic consequence does not in general reduce to satisfiability. The Skolemization theorems presented here therefore take various forms, applying to the left or right of the consequence relation, and to all formulas or only prenex formulas.