Analysis of individual within-group activation revealed highly significant activation of the right hippocampus [ t (14) = 3.74, p = 0.003] and right parahippocampal gyrus [ t (14) = 3.51, p = 0.006] and significant activation of the left hippocampus [ t (14) = 3.21, p = 0.021]and left parahippocampal gyrus [ t (14) = 3.14, p = 0.014] in controls, again for the main effect of task.
A negative correlation between amount of grams of ketamine taken per day and hippocampal activation approached significance following Bonferroni correction ( r = −0.696, p = 0.025).
fMRI data Contrast 1: Navigation from memory Analysis of the individual ROIs between groups revealed significantly greater activation of the right hippocampus [ t (24) = 2.77, p = 0.03], as shown in Figure 4 A, and the left parahippocampal gyrus [ t (24) = 2.81, p = 0.03], Figure 4 B, in the control group compared to the ketamine group for navigation from memory compared to walking to a visible object, with similar findings approaching significance in the right parahippocampal gyrus [ t (24) = 2.42, p = 0.07] and left caudate [ t (24) = 2.35, p = 0.08] (See Figure 4 ).