Doldrums Doldrums The doldrums is a colloquial expression derived from historical maritime usage, which refers to those parts of the Atlantic Ocean and the Pacific Ocean affected by a low-pressure area around the equator where the prevailing winds are calm. The doldrums are also noted for calm periods when the winds disappear altogether, trapping sailing ships for periods of days or weeks. The term appears to have arisen in the eighteenth century, when trans-equator sailing voyages became more common. Since this zone is where two trade winds meet, it is also called the Intertropical Convergence Zone. They roughly lie between latitudes
Convergence-divergence zone Convergence-divergence zone The theory of convergence-divergence zones was proposed by Antonio Damasio, in 1989, to explain the neural mechanisms of recollection. It also helps to explain other forms of consciousness: creative imagination, thought, the formation of beliefs and motivations ... It is based on two key assumptions: imagination is a simulation of perception, brain registrations of memories are self-excitatory neural networks (neurons can activate each other). A convergence-divergence zone (CDZ) is a neural network which receives convergent projections from the sites whose activity is to be recorded, and which returns divergent projections to the same sites. When an experiment is