The actual tapping in EFT does have a significance from the neurological point of view –

When a person is anxious and engages in a task that is completely different from the anxiety state… like tapping, his anxiety automatically lowers… this procedure is similar to reciprocal inhibition. (Joseph Wolpe)

So tapping along with the verbal/ non verbal acknowledgement of problem acts as a deterrent to the anxiety. It also forms new neural associations in the brain.

I like David Feinstein’s research in this area as it concurs with my understanding.

When we have anxiety due to an issue, we trigger that anxiety by thinking about that issue, and basically light up that area in our brain… those neural connections; The Alarm response is triggered. Then by repeated tapping we reduce and eliminate the alarm response so that the “memory” no longer evokes the same alarm response.

Alarm Stage – In this state our brain feels as if we are in danger and reacts by making certain changes in the body – the digestion becomes slow (as the blood flow is to directed to the body extremities like arms and legs to prepare for flight or flight), you  start perspiring, heart rate increases and many such changes take place.

If you have had trauma in your life then just by remembering it, you can trigger the alarm stage. And all the symptoms and feelings can come flooding back.  In Panic attack, the person feels completely at the mercy of these bodily symptoms and is unable to Switch off the alarm response. This cycle can be broken by EFT.

Read more on GAS (general Adaptation Syndrome) and How stress affects our body – http://emofreetherapy.com/eftandstress.aspx

Reference – http://www.eftfree.net/energy-psychology/