Researchers from the California Institute of Technology recently studied that effect by giving 99 study participants 15 minutes of transcranial direct current stimulation, or TDCS, an electrode-based, non-invasive way of juicing the brain. (A company is also marketing TDCS as a very sketchy means of getting better at video games.) The participants got an fMRI scan before and after the brain shock, and were shown faces while in the fMRI machine. After the zapping, the participants rated the faces as more attractive. The fMRI, meanwhile, showed increases in activity in the patients' prefrontal area and midbrain, as well as a higher output of dopamine.