Puppies that are exposed to early training have an increased capacity to learn new information later in life.  

Plenty of dogs get no training until they are adults and still turn out to be nice dogs. Do we really need to train puppies? 

Most of the puppy training articles that will appear here will address one of the following questions.  What do we present,  When do we present it and How do we present it. This  piece is directed to When we present it. 

The following is from a paper titled "Cognitive Neurorehabilitation"
Edited by Donald T. Stuss, Gordon Winocur and Ina H. Robertson
Cambridge University Press 1999
ISBN 0 521 58102 8 hb 
Written by Brian Kolb, Robin Gibb

I have cited the work as completely as I know how.

This paper/book is about what happens in the brain during the processes of recover from brain injury in people. There are some very interesting points made and research projects mentioned that apply to puppy training that I want to point out.

On page 10 they state two assumptions: the first is not relevant to puppy training but the second is very important and it is this

"Structural changes in the brain underlie behavioral changes."

Page 12 they make two points: the first we all sot of know the second is the one I want to look at. 

1.Neurons in the normal brain change their morphology during development and ageing. 

2. Neurons in the normal brain show specific changes in response to specific environmental experiences.

Theses are the two principal types of changes in the normal brain, changes during brain development and experience-dependant changes.  

Normal Developmental Changes in the brain

The authors go into detail about brain development, covering dendrites, synapses, axon terminals and more. I don’t pretend to understand what it’s all about.

I think of it like a tree the early brain has trunk, as it develops it branches out and the branches branch out and those branches branch out and so on.

When mammals are born their brains are not fully developed. As the brain develops it becomes more and more finely complicated with a higher number of synapses and dendrites.

 Scott and Fuller say that the puppy brain is turned on at 49 days.

Experience-Dependant changes in the brain. Pg.10

Here is where it gets interesting. The authors show that rats raised in enriched environments have a large increase in dendrite length, spine density and changes that suggest a substantial increase in the number of synapses as opposed to rats raised in empty cages. What the heck does that mean?  Rats that are raised in the enriched environments have more fully developed brains than other rats.  

And they exposed rats of different ages to the enriched environment and found that rats that weren’t exposed until they were juvenile showed different changes then the rats that had very early exposure.

They say of the differences: "This capacity presumably reflects the increased potential for these animals (the rats that were exposed to an enriched environment early in life) to learn new information later."   Pg 14

The rats that were exposed very early in their development had the most profound changes and these changes are positive from a trainer’s point of view.

The animal that is exposed to an enriched environment very early in it’s development has an increased potential to learn new information later in life.

Here "early" means the period between 7 and 14 weeks. My take away is to start training early for smarter puppies.