Auditory STRFs
The example STRF here is for an auditory neuron from the area CM of a male zebra finch, when played conspecific birdsong. The colour of this plot shows the effect of sound on this neuron: this neuron tends to be excited by sound from about 2.5 kHz to 7 kHz heard by the animal 12 ms ago, but it is inhibited by sound in the same frequency range from about 18 ms ago.
This STRF was generated with STRFPAK: free software (registration required) to help estimate STRFs.
Read more about this topic: Spatio Temporal Receptive Field