Frequency sensitivity of signal detection in scale-free networks

It has been recently reported that scale-free topology favors the detection of a weak signal because of the higher amplification at the hub node than that at other nodes [Phys. Ref. E 78 (2008) 046111]. We investigate the corresponding synchronization behaviors and find that the favorite detection depends not only on the coupling and noise strengths but also on the frequency of the external signal. We reveal theoretically and numerically that the amplification effect of the hub node will decrease monotonously with the external frequency, which is useful to understand the high sensitivity of animal visual and auditory systems to weak external signals.