Selective Attention Increases Both Gain and Feature Selectivity of the Human Auditory Cortex
Figure 2
Illustration of the hypothesized effects of selective attention.
Top: The bell-shaped curve represents the presumed single-neuron RFs during baseline (“Ignore”), and the proposed attention-dependent changes in the RFs (increased gain vs. narrowing of RFs vs. both effects). Here, the noise suppresses responsiveness of the neuron to the 1-kHz tone as a function of the overlap with the receptive field of the neuron. Thus, the red-coloured area below the bell-shaped curve indicates how likely the neuron will respond to the 1-kHz probe sound. In the white noise condition, only neurons optimally tuned to the tone respond [61]. Below: Hypothesized effects at the level of neuronal population responses as a function of notch width. The curves are only suggestive, based on a simple simulation (see Methods for details). Still, it should be noted with “gain only” mechanism, the amplitude reduction curve is assumed to stay identical between the stimuli endpoints, only scaled differently, while the other mechanisms would result in modulation of the basic shape of the amplitude reduction function as well.