• Research showed that after social isolation, subjects' brain scans showed more activity in the midbrain when shown pictures of social cues.
• When subjects were hungry but had not been socially isolated, they showed a similar reaction to food cues, but not social ones. This shows that the drive for social contact and for things like food seems to be represented in a similar way.

Objectively measuring loneliness in the brain, as opposed to asking people how they feel, could give clarity on, for example, the connection between loneliness and depression. It could also shed some light on addiction.

The ability to measure loneliness may make it far easier to d...