John Dee and the 'Sidney Group' : cosmopolitics and Protestant 'activism' in the 1570s

The life and thought of John Dee (1527-1608) have in recent years received considerable attention from historians. His nineteenth-century reputation as a deluded (and deluding) crank has been dispelled and he is seen now as the proponent of an immensely complex system of philosophy which made important contributions to the development of mathematics, astronomy, architecture, navigation and applied science. Many claims have been made for the profundity of the influence exerted by Dee and his ideas, both in his own lifetime and after his death, and a great effort has been made to define his 'world picture' by reference to such formulae as 'Neoplatonism', 'Hermeticism', and 'Rosicrucianism', but while these are valid and significant in all sorts of ways, there has been no clear apprehension of the main focus of his system. The predominant impression of Dee is of an enormously erudite, but intellectually insular man, pursuing a tremendously diffuse range of studies which, while they have important implications for the history of science and ideas, do not appear to be organised into a consistent, internally - coherent system, directly relevant to the contemporary world. It is such an incorrect picture of Dee that I wish to rectify

The hippocampus pre-orders movements for skilled action sequences

Plasticity in the subcortical motor basal ganglia-thalamo-cerebellar network plays a key role in the acquisition and control of long-term memory for new procedural skills, from the formation of population trajectories controlling trained motor skills in the striatum to the adaptation of sensorimotor maps in the cerebellum. However, recent findings demonstrate the involvement of a wider cortical and subcortical brain network in the consolidation and control of well-trained actions, including an area traditionally associated with declarative memory - the hippocampus. Here, we probe which role these subcortical areas play in skilled motor sequence control, from sequence feature selection during planning to their integration during sequence execution. An fMRI dataset collected after participants learnt to produce four finger sequences entirely from memory with high accuracy over several days was examined for both changes in BOLD activity and their informational content in subcortical regions of interest. Although there was a widespread activity increase in effector-related striatal, thalamic and cerebellar regions, the associated activity did not contain information on the motor sequence identity. In contrast, hippocampal activity increased during planning and predicted the order of the upcoming sequence of movements. Our findings show that the hippocampus pre-orders movements for skilled action sequences, thus contributing to the higher-order control of skilled movements. These findings challenge the traditional taxonomy of episodic and procedural memory and carries implications for the rehabilitation of individuals with neurodegenerative disorders