An intriguing finding was the significant difference between the groups in the amplitude of the CNV (anterior region CNV: t[157]=2.4, p=.02; posterior region CNV: t[157]=1.9, p=.06) recorded while patients awaited the passage of a 2-s time estimation interval. Group-averaged event-related potential wave-forms from three representative midline electrode sites are shown in Figure 1. As shown in the figure, obese patients exhibited a greater (more negative) rise in CNV amplitude, particularly over the frontal scalp, toward the conclusion of the interval. Analyses of median reaction times during the time estimation task yielded a result consistent with the CNV result: A greater percentage of patients in the obese group overestimated the passage of the 2-s time estimation interval and responded prematurely (χ2=3.8, p=.05).
