Mixing matters

Fidelity matters: the birth of entanglement in the mixing of Gaussian states.

We address the interaction of two Gaussian states through bilinear exchange Hamiltonians and analyze the correlations exhibited by the resulting bipartite systems. We demonstrate that entanglement arises if and only if the fidelity between the two input Gaussian states falls under a threshold value depending only on their purities, first moments, and the strength of the coupling. Our result cla...

Philosophy matters in brain matters

PURPOSE Although most neuroscientists and physicians would argue against Cartesian dualism, Descartes's version of the psyche/soma divide, which has been controversial since he proposed it in the seventeenth century, continues to haunt contemporary neurological diagnoses through terms such as functional, organic, and psychogenic. Drawing on my own experiences as a person with medically unexplai...

Matters of sex: sex matters.

Despite the popular concept that heart disease preferentially affects the male population, in every year for the past 16 years, cardiovascular disease has killed more women than men.1 Unfortunately, a disparity still exists between men and women in the diagnosis and aggressive treatment of heart disease. The perception that women are relatively protected is reflected by the fact that women are ...

Politics Matters: A Response to Recent Commentaries

Context Matters

Midbrain dopamine neurons are thought to encode the difference between predicted and actual reward on conditioning tasks. Successful models assumed a simple form of prediction that depended only on currently available information. In this issue of Neuron, Nakahara and colleagues record from dopamine neurons in alert monkeys and show that the neurons can encode predictions that are not so restri...