Table 1.

List of quantitative behavioral variables derived from long-term observations of fluid licking behavior evaluated in this study

Number of inter-lick-intervals (ILIs)	Intervals within a range from 40 – 180 ms. This range included the primary ILI distribution. All longer intervals were excluded from all analyses based on ILI counts (Boughter and others 2007).
Mean ILI duration	Mean of the ILI distribution
Coefficient of variation of the ILI distribution	A measure of the variability. The distribution standard deviation divided by the mean.
Fano Factor of the ILI distribution	A measure of variability. The distribution variance divided by the mean.
Number of visits to the water spout	A visit consisted of two or more licks with an ILI within the 40 – 180 ms range. By definition visits had to be preceded by a 1 min interval without licks.
Mean log(inter visit interval duration), log(IVI)	Mean of the log10(IVI) distribution
Coef. of Var. of the log(IVI) distribution	A measure of the variability. The distribution standard deviation divided by the mean.
Fano Factor of the log(IVI) distribution	A measure of variability. The distribution variance divided by the mean.
Mean number of licks per visit	Average of the counts of all licks in all visit
Coef. of Var. of licks per vist	A measure of the variability. The distribution standard deviation divided by the mean.
Fano Factor of licks per visit	A measure of variability. The distribution variance divided by the mean.
Mean number of licks per burst	A burst is defined as an uninterrupted sequence of licks with no interval exceeding 500 ms duration. This allows for “missed” licks which occur occasionally when the mouse extends the tongue but does not touch the water spout. This results in a double-long interval which shows up in the ILI distribution as a small second peak centered at twice the mean ILI (Boughter and others 2007).
Coef. of Var. of licks per burst	A measure of variability. The distribution standard deviation divided by the mean.
Fano Factor of licks per burst	A measure of variability. The distribution variance divided by the mean.
Mean number of bursts per visit	Average count of the number of bursts in all visits.
Coef. of Var. of bursts per vist	A measure of the variability. The distribution standard deviation divided by the mean.
Fano Factor of bursts per visit	A measure of variability. The distribution variance divided by the mean.