Some experiments have shown the neural correlates of peoples' brand preferences. Samuel M. McClure used fMRI to show the dorsolateral prefrontal cortex, hippocampus and midbrain were more active when people knowingly drank Coca-Cola as opposed to when they drank unlabeled Coke. Other studies have shown the brain activity that characterizes men's preference for sports cars, and even differences between Democrats and Republicans in their reaction to campaign commercials with images of the 9/11 attacks. Neuromarketing companies have seized on these studies as a better tool to poll user preferences than the conventional survey technique. One such company was BrightHouse, now shut down. Another is Oxford, UK-based Neurosense, which advises clients how they could potentially use fMRI as part of their marketing business activity. A third is Sales Brain in California.