In the past decade or so, mainly due to advances in brain imaging technology such as magnetic resonance imaging, or MRI, neuroscientists have started to look inside the living human brain of all ages, and to track changes in brain structure and brain function, so we use structural MRI if you'd like to take a snapshot, a photograph, at really high resolution of the inside of the living human brain, and we can ask questions like, how much gray matter does the brain contain, and how does that change with age?
Na última década, grazas aos avances nas técnicas de neuroimaxe cerebral como a resonancia magnética ou RM, os neurocientíficos  comezaron a explorar en vivo cerebros de todas as idades e a seguir os cambios na estrutura  e na función cerebral. Cando queremos facer  unha foto de alta resolución do cerebro humano vivo, usamos a RM e así podemos facer preguntas como: canta materia gris contén o cerebro e como cambia coa idade?