“Thinking about Not-Thinking”: Neural Correlates of Conceptual Processing during Zen Meditation

Recent neuroimaging studies have identified a set of brain regions that are metabolically active during wakeful rest and consistently deactivate in a variety the performance of demanding tasks. This “default network” has been functionally linked to the stream of thoughts occurring automatically in the absence of goal-directed activity and which constitutes an aspect of mental behavior specifically addressed by many meditative practices. Zen meditation, in particular, is traditionally associated with a mental state of full awareness but reduced conceptual content, to be attained via a disciplined regulation of attention and bodily posture. Using fMRI and a simplified meditative condition interspersed with a lexical decision task, we investigated the neural correlates of conceptual processing during meditation in regular Zen practitioners and matched control subjects. While behavioral performance did not differ between groups, Zen practitioners displayed a reduced duration of the neural response linked to conceptual processing in regions of the default network, suggesting that meditative training may foster the ability to control the automatic cascade of semantic associations triggered by a stimulus and, by extension, to voluntarily regulate the flow of spontaneous mentation

Behavioral artifacts: what is an artifact? Or who does it?

Abstract not availabl

Molecular ruby under pressure

Abstract The intensely luminescent chromium(III) complexes [Cr(ddpd)2]3+ and [Cr(H2tpda)2]3+ show surprising pressure-induced red shifts of up to ?15?cm?1?kbar?1 for their sharp spin-flip emission bands (ddpd=N,N?-dimethyl-N,N?-dipyridine-2-yl-pyridine-2,6-diamine; H2tpda=2,6-bis(2-pyridylamino)pyridine). These shifts surpass that of the established standard, ruby Al2O3:Cr3+, by a factor of 20. Beyond the common application in the crystalline state, the very high quantum yield of [Cr(ddpd)2]3+ enables optical pressure sensing in aqueous and methanolic solution. These unique features of the molecular rubies [Cr(ddpd)2]3+ and [Cr(H2tpda)2]3+ pave the way for highly sensitive optical pressure determination and unprecedented molecule-based pressure sensing with a single type of emitter