Ageing is associated with a progressive loss of both physical and mental functions as well as with the development of ageing-related diseases such as Parkinson’s Disease, cancer, dementia, and Alzheimer’s Disease. Increasing evidence suggests that various meditative approaches including mindfulness techniques could be used to reduce specific health problems while promoting healthy ageing. However, a significant hurdle for major research advances in this field remains – i.e., no consensus exists on what a reliable, meaningful and scientifically useful definition of awareness, consciousness or self-consciousness is. It is thus relatively complicated, specifically for neuroscientists, to investigate objectively a brain function for which no unique definition, neurological correlates nor quantitative assessment methods have been widely accepted yet. This mini-review aims at introducing a new definition based on a multifactorial-dependent concept called 3TC (Time-, Training-, Task(s)-, and Concentration-dependent). As consciousness depends on several factors, the assembly of underlying neuronal networks and related neural correlates at any given moment is expected to change also. This concept aims at providing researchers with a single inclusive definition, to ease comparison between studies, stimulate biomedical research and promote the development of innovative ageing disease-modifying therapies.