The big differences is the type of signal. The heart sends a single definable signal. The brain's neurons send a eruption of white noise that can be interpreted over time.
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.