To study how animals use sensory information to make decisions, we have developed a rodent model of auditory discrimination. We previously found that a subset of neurons in auditory cortex, those that project to the auditory striatum, play a central role in propagating information beyond the cortex. In my talk I will discuss recent experiments indicating that plasticity at corticostriatal synapses plays an essential role in the acquisition of the association between the sound and the action in this task. At the end of the talk, time permitting, I will also provide a brief summary of an unrelated project to develop a technique ("BOINC") for converting connectomics into form amenable to high-throughput DNA sequencing. If successful, BOINC has to potential to provide the wiring diagram of the mouse cortex for about $10K.