Short communication Anxious apprehension increases coupling of delta and beta oscillations
Recent findings showing that anxiety is associated with enhanced coupling of EEG rhythms imply higher information exchange between populations of neurons associated with different oscillatory systems. In this study, influence of uncertainty on alpha–delta anticorrelation and delta–beta coupling was studied in 39 subjects (27 females) aged 19 to 30 years who also filled out the State Trait Anxiety Inventory. A measure of alpha–delta anticorrelation showed trait-like properties being uniformly higher in high trait anxiety subjects independent of experimental manipulation. Contrariwise, delta–beta coupling appeared only in anxiogenic situation both in high and low anxiety subjects. © 2006 Elsevier B.V. All rights reserved.
Selected mapping (SLM) and partial transmit sequence ::: (PTS) are well-known techniques for peak-power reduction ::: in orthogonal frequency-division multiplexing (OFDM). We ::: derive a simplified maximum likelihood (ML) decoder for SLM ::: and PTS that operates without side information. This decoder ::: exploits the fact that the modulation symbols belong to a given ::: constellation and that the multiple signals generated by the PTS or ::: SLM processes are widely different in a Hamming distance sense. ::: Pairwise error probability (PEP) analysis suggests how SLM and ::: PTS vectors should be chosen. The decoder performs well over ::: additive white Gaussian noise (AWGN) channels, fading channels, ::: and amplifier nonlinearities.