Researchers from the Salk Institute performed multiple analyses of synapses in the human brain and determined that its memory capacity is around 10 times stronger than previously thought.

The memory capacity of the human brain is likely ten times greater than previous estimates suggested, according to researchers at the Salk Institute. 
This conclusion centers around new findings about the synapses which are important junctions where neural branches interact. While using advanced technology to analyze them on a nanomolecular level, it was determined that around 26 size categories can exist, not just a few as previously believed.
Terry Sejnowski, co-author of the paper,