Gain functions for spectral noise suppression have been derived in literature for some error criteria and statistical models. These gain functions are only optimal when the statistical model is correct and the speech and noise spectral variances are known. Unfortunately, the speech distributions are unknown and can at best be determined conditionally on the estimated spectral variance. We show ...

Dopaminergic modulation of prefrontal cortical activity is known to affect cognitive functions like working memory. Little consensus on the role of dopamine modulation has been achieved, however, in part because quantities directly relating to the neuronal substrate of working memory are difficult to measure. Here we show that dopamine increases the gain of the frequency-current relationship of...

In this work, we propose a novel approach called “Normalized Gain Function (NGF) method” to design low/medium power single stage ultra wide band microwave amplifiers based on linear S parameters of the active device. Normalized Gain Function TNGF is defined as the ratio of T and |S21|, desired shape or frequency response of the gain function of the amplifier to be designed and the shape of the ...

Prolonged stimulation by temporally modulated sinusoidal gratings causes a decrease in the contrast sensitivity and response of neurons in the visual cortex. We have studied the dynamic aspects of this contrast gain control mechanism, and how its temporal properties affect the determination of neural contrast response functions. In addition, we have considered the possibility that a single mech...