Figure 12. PET images showing sites at which there was a statistically significant increase in CBF in response to a 2 kHz tone burst. Sites of significant activation have been projected onto the surface of a brain. Threshold for a significant increase in blood flow was set at a Z score of 2.33 which corresponds to an omnibus p > 0.01. Z range from 2.33 to 4.33; lighter colors indicate higher Z score. Relationship between Z-scores and grayscale intensity is shown on the left side of panel 12A. (A) Activation sites in 6 normal hearing subjects. SPM contrast: controls (2 kHz - rest). (B) Comparison of patients (n = 3) with normal controls. SPM contrast: patients (2 kHz - rest) - controls (2 kHz - rest).