GRID lifetime measurements in ⁵⁹, ⁶¹, ⁶³Ni following thermal neutron capture

The GRID-method has been used to measure the life-times of ten excited states in Ni-59, Ni-61, Ni-63 following thermal neutron capture in Ni targets of natural isotopic composition. Four of the lifetimes have been determined for the first time, the other six lifetimes can be compared with the results of conventional DSA-measurements following charged particle induced reactions. Cascade feeding effects have been included in the analysis. Level energies and electromagnetic properties of negative parity states in Ni-59 have been compared with the results of shell model calculations in 3p 0h and 4p 1h model spaces. Statistical model estimates of the lifetimes as function of excitation energy and spin are also given

An oscillatory correlation model of auditory streaming

We present a neurocomputational model for auditory streaming, which is a prominent phenomenon of auditory scene analysis. The proposed model represents auditory scene analysis by oscillatory correlation, where a perceptual stream corresponds to a synchronized assembly of neural oscillators and different streams correspond to desynchronized oscillator assemblies. The underlying neural architecture is a two-dimensional network of relaxation oscillators with lateral excitation and global inhibition, where one dimension represents time and another dimension frequency. By employing dynamic connections along the frequency dimension and a random element in global inhibition, the proposed model produces a temporal coherence boundary and a fissure boundary that closely match those from the psychophysical data of auditory streaming. Several issues are discussed, including how to represent physical time and how to relate shifting synchronization to auditory attention