These brain manifestations were centred on what is called the default network: a set of brain regions involved in inner thoughts such as reminiscing, future planning, imagining and thinking about others. Loneliness also correlated with differences in the fornix: a bundle of nerve fibres that carries signals from the hippocampus to the default network. We use the default network when remembering the past, envisioning the future or thinking about a hypothetical present. Understanding how loneliness manifests itself in the brain could be key to preventing neurological disease and developing better treatments. The Montreal Neurological Institute is a McGill University research and teaching institute.
