July 1, 2014
Many people are familiar with how a simple trigger, a scent, a familiar face, a colour, a piece of music, a photograph can bring back a "flood" of disparate memories all at once. There are mathematical theories called global similarity models that attempt to explain this phenomenon. Now, a functional magnetic resonance study (fMRI) on memory and categorization has put this mathematical model on a firm neurobiological footing for the first time.
Psychologist Tyler Davis of Texas Tech's Neuroimaging Institute is a specialist in neurobiological approaches to learning and memory, he and his colleagues are delving into global similarity models of memory. One might assume that when you see a familiar face or visit a favourite restaurant that only the most similar or recent memories are activated for comparison. Global similarity models, the feeling of familiarity for a particular stimulus suggests that we pull in a range of memories all at once.