Skip to main content
. Author manuscript; available in PMC: 2009 Nov 26.
Published in final edited form as: Neuron. 2008 Nov 26;60(4):698–708. doi: 10.1016/j.neuron.2008.09.013

Figure 1.

Figure 1

Effects of AGFa microstimulation on OT auditory responses at aligned AGFa-OT sites. A) Mean firing rate for the OT site plotted as a function of stimulus ITD for trials with (red) and without (black) AGFa microstimulation. Error bars represent s.e.m. Black arrowhead: best ITDno stim = −21 μs; red arrowhead: best ITDstim = −23 μs; red arrow: best ITD of the AGFa stimulation site = −32 μs. B) Mean firing rate and best-fit sound level response functions with (red) and without (black) AGFa microstimulation. Responses are to sounds with best ITD and best ILD values for this site. Error bars represent s.e.m. Parameters of the fitted curves with and without microstimulation (S and NS, respectively) are indicated in the upper left. C) Effects of AGFa microstimulation on the fits of sound level response functions to the response data. For each of the 4 sound level response function parameters (rmax, m, c50, and n; see Experimental Procedures), the change between parameters with and without AGFa microstimulation was converted to a modulation index (see Experimental Procedures). Each panel plots the distribution of modulation indices across the population. Arrows mark the mean modulation index. The distribution of indices was significantly different from zero for only c50 (asterisk). D) Top: Population ABL curves measured with (red circles and line) and without (black circles and line) AGFa microstimulation. Ordinate shows normalized response; abscissa shows stimulus ABL normalized to the threshold ABL without AGFa stimulation (plotted as ABL = 0 dB). In most cases, error bars are smaller than the symbol. Bottom: Difference in the normalized sound level response functions measured with versus without AGFa microstimulation plotted as a function of sound level. Responses to sounds that were 5 dB below threshold to 25 dB above were significantly increased by AGFa microstimulation. E) Distribution of the changes in response threshold with AGFa microstimulation (see Experimental Procedures). Distribution is shifted toward negative values indicating that responses could be driven by lower sound levels with AGFa microstimulation. The median value of the distribution is −1.45 dB.