Neurons communicate with each other via electrical events called 'action potentials' and chemical neurotransmitters. At the junction between two neurons (synapse), an action potential causes neuron A to release a chemical neurotransmitter.
Griffin says that photographers “tap into something” when connecting to the viewer. This something is the viewer’s imagination. I think I have learned this because photography is being able to express what you want to express by capturing images that require you to use the techniques you know and the imagination of the viewers. In photography, you are creating an artifact that involves the viewer.