FIG 2. Ratio of total left hemispheric activation in response to passive text listening between the scanner noise conditions of 12 sections (6 Hz) and 4 sections (2 Hz). There is no change in activation between the 2 background noise conditions in women (n = 6), but a significant (P < .01) increase in left hemispheric activation in men (n = 6) as the rate of scanner noise is increased, compared with that of women. All 6 men showed a 20% or greater increase in activation with the more rapid rate of scanner noise. Also noted is the increased variance among the men.