Fig. 13.
Detection of a stimulus and detection of modulation. Left, percent of cells in A1 (open) and ML (shaded) that detect the stimulus (compared against spontaneous firing). Cells that failed to detect the presence of a stimulus with both spike count and vector strength are labeled as Not Sensitive. Cells that could detect the presence of a stimulus (relative to spontaneous) with spike counts, but not with vector strength are labeled SC Only. Cells that could detect the presence of a stimulus (relative to spontaneous activity) with vector strength, but not with spike counts are labeled VSPP Only. Cells that had responses that significantly differed from the spontaneous firing rate for both spike counts and vector strength are labeled as VSPP + SC. For each category, an A1/ML comparison was made using a z test for the difference of independent proportions (P value noted above bars). Right, same as left, except the comparison was made against the response to the unmodulated stimulus and represents detection of amplitude modulation at 100% depth. A1, primary auditory cortex; ML, middle lateral auditory cortex; SC, spike count; VSPP: phase-projected vector strength.