Anti-planetward auroral electron beams at Saturn.

Strong discrete aurorae on Earth are excited by electrons, which are accelerated along magnetic field lines towards the planet. Surprisingly, electrons accelerated in the opposite direction have been recently observed. The mechanisms and significance of this anti-earthward acceleration are highly uncertain because only earthward acceleration was traditionally considered, and observations remain limited. It is also unclear whether upward acceleration of the electrons is a necessary part of the auroral process or simply a special feature of Earth's complex space environment. Here we report anti-planetward acceleration of electron beams in Saturn's magnetosphere along field lines that statistically map into regions of aurora. The energy spectrum of these beams is qualitatively similar to the ones observed at Earth, and the energy fluxes in the observed beams are comparable with the energies required to excite Saturn's aurora. These beams, along with the observations at Earth and the barely understood electron beams in Jupiter's magnetosphere, demonstrate that anti-planetward acceleration is a universal feature of aurorae. The energy contained in the beams shows that upward acceleration is an essential part of the overall auroral process.

Affect and cognition in dreams: a critique of the cognitive role in adaptive dream functioning and support for associative models.

Dream affect and cognition are examined in a 4-month longitudinal study of depressed, recently divorced subjects. Several measures of cognition in dream reports were used to determine whether remitting subjects were more likely to utilize certain cognitive strategies than nonremitters. No differences were found in the cognition between those who were remitting and nonremitting subjects. Levels of cognition in dreaming were directly related to the emotional intensity of the dreams across all subjects. In subjects with higher depression scores (Beck Depression Inventory > 20), depression levels were inversely related to both dream affect and cognition. It is argued that cognition plays a secondary role in dream production. A modification of David Foulkes's model of dreaming is proposed, in which emotional intensity drives associative processes, which in turn require more elaborate cognitive devices to relate diverse activated mnemonic units.