Primary Aim 1: To determine if LY500307 demonstrates cortical target engagement as assessed by fMRI/N-back in frontal-parietal regions. Secondary measures of target engagement are fMRI episodic memory, Pseudo-Continuous Arterial Spin Labeling, Mismatch Negativity/evoked response potentials, Auditory Steady State Response, Auditory P300 and Quantitative EEG (QEEG).