Sensory neuroprostheses aim to restore sight or hearing through electrical microstimulation viaimplanted neural interfaces. Although there has been significant progress recently, there are stillgaps in our understanding of how to precisely target and activate specific neurons usingintracortical microstimulation. The application of advanced stimulation strategies such as currentsteering and dynamic stimulation might improve control over neuronal activity and keep thenumber of implanted electrodes reasonable. In this study, we developed flexible multi-shankprobes containing iridium-oxide microelectrodes to assess the effects of advanced electricalmicrostimulation patterns on cortical activity obtained using in vivo calcium imaging. The probeswere inserted into layer 2/3 of the primary visual cortex (V1) of Thy1-GCaMP6 transgenic mice,including both anesthetized and awake, head-fixed animals. Electrical stimulation patterns weregenerated by a custom high-channel-count neural stimulator. To image calcium activity, weused a two-photon laser scanning microscope (laser wavelength: 820-920 nm; raster scanningat 31 Hz) with a 20x water immersion objective (field of view: 550 μm × 550 μm). We tested adiverse set of stimulation parameters (e.g., amplitude, frequency, pulse duration) and patterns(e.g., current steering), then evaluated the observed spatial and temporal activation patterns ofneurons. Processing of calcium imaging datasets was performed using Suite2p. Here, we reportthe preliminary findings of these in vivo experiments. Our future plans involve exploring theinfluence of advanced stimulation patterns on the activity of V1 and higher order visual cortex,and identifying stimulation strategies that may improve the resolution of state-of-the-art visualcortical prostheses.