Lowdown: Neuro research

Nick Hirst

Purveyors of neuro research claim that their methodologies offer a direct line to our inner emotional lives. But how much can we really depend upon technology and science that's in its infancy?

Neuro research tends to use a small range of core methodologies. Two brain scanning approaches attract the most attention. Functional magnetic resonance imaging (or fMRI) detects the activity of neurons indirectly, by measuring levels of blood oxygen in the brain. fMRI machines are huge, noisy and expensive, so many commercial research companies use less intrusive electroencephalograms (EEGs) instead. Subjects wear a cap covered in electrodes, which measure changes in the brain's electrical field. Rather than lying in a noisy metal tube, you can sit on a comfy sofa and watch TV. Both methodologies have their strengths and weaknesses: EEG can measure changes in time more precisely (making it good for speed-of-response implicit studies, for example), but fMRI is better at seeing where activity is happening.