A signal-to-noise statistic (d´) was used to quantify the degree to which each neurons activity changed in response to the task stimuli compared to pre-task (baseline) activity as well as chance (surrogate testing); binned (100 ms) spike trains were not transformed or normalized in any way before these analyses. Individual neurons were evaluated for the degree of responsiveness using d´ (Barr et al., 2010; Gale and Perkel, 2010). Specifically, d´ was calculated by dividing the absolute values of the mean difference between firing rate during the baseline epoch and the rest of trial by the square root of the sum of their squared deviations. To evaluate the significance of the d´ values, surrogate data were created by taking each neurons spike train and randomly shuffling it 500 times; d´ was then determined for each of the 500 randomly shuffled spike trains and these values were used to compute a 95% confidence interval of the null distribution for each neuron. To evaluate differences in d´ on drinking versus non-drinking trials, a two-way ANOVA was conducted with responsiveness group (drinking significant, non-drinking
