The "mirror box" illusion: effect of visual information on bimanual coordination in children with spastic hemiparetic cerebral palsy

The study examined symmetrical bimanual coordination of children with spastic hemiparetic cerebral palsy (SHCP) and a typically developing (TD) control group under conditions of visual feedback created by placing a glass screen, opaque screen or a mirror (“mirror box”) between the arms. The “mirror box” creates a visual illusion, which gives rise to a visual perception of a zero lag, symmetric movement between the two arms. Children with SHCP exhibited a similar mean coordination pattern as the TD control group, but had greater movement variability between the arms. Furthermore, movement variability in children with SHCP was significantly greater in the screen condition compared with the glass and mirror condition, which were similar to each other. The effects of the availability of visual feedback in individuals with hemiparesis are discussed with reference to central and peripheral mechanisms

Collision velocities between offshore supply vessels and fixed platforms

SIGLELD:6026.982(NMI-R--126). / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Voluntary disclosure of information in a setting in which endowment of information has productive value

This paper introduces a model capturing managers' disclosure policies in settings in which disclosure is rewarded by the financial market because disclosure implies that managers are endowed with information and endowment of information may potentially improve the firm's productive efficiency. It provides sufficient condition for a threshold disclosure equilibrium to obtain and compares disclosure policies in a setting in which endowment of information improves the firm's productive efficiency with disclosure policies in a setting in which endowment of information has no impact on the firm's productive efficiency. Managers' disclosure policies are shown to depend crucially on whether the endowment of information is exogenous or endogenous. When the endowment of information is exogenous, an increase in the usefulness of information in improving the firm's productive efficiency leads to a decrease in the disclosure threshold and hence an increase in the amount of information disclosed. In contrast, when the endowment of information is endogenous, an increase in the usefulness of information in improving the firm's productive efficiency has no effect on the disclosure threshold but leads to a decrease in the probability with which information is acquired and hence a decrease in the amount of information disclosed. As, in the threshold disclosure equilibrium, the net present value of information acquisition arising from any increase in production efficiency is negative, an increase in the usefulness of information in improving the firm's productive efficiency thus reduces the inefficiency caused by information acquisition. Copyright 2006 The Authors Journal compilation (c) 2006 Blackwell Publishing Ltd.