Saturday, July 28, 2012

INTERPRETING THRESHOLDS


NOTE TO MY REGULAR READERS:
Those of you who follow my blogs will have noticed that there has been a long delay since the last blog I posted on March 2nd of this year.  On March 20th, I fell off my horse and sustained a concussion.  One of the things I have not been able to do very well has been to read and write, so I have not been blogging.  Here is my first writing effort since my fall; I hope you enjoy!  I don't promise to be back as often as I have been for a while, but I take it as a good sign that I was able to put this together today.  Thanks for reading.

INTERPRETING THRESHOLDS

A threshold is the limit at which a stimulus causes a response.  When a single mosquito flies past you, most people don’t take note or get concerned; they are below threshold for mosquitoes.  If the mosquito lands upon you and starts to sting you, most people become aware of the mosquito; you could then say that they are at threshold for mosquitoes.  If a swarm of mosquitoes were buzzing towards you, and some were already stinging you, and you were swatting them and trying to get away, then you could say that you were over threshold.  


When working with dogs with behaviour problems, we look at the things that concern the individual dog, and we ask “at what point do these things become a problem for the dog?”  It is tempting to look at the things that dogs are concerned about and classify them according to if you think they should be of concern to the dog or not, but this isn’t helpful.  Looking at each dog and determining what their individual threshold is for a variety of stimuli helps trainers to determine at what point they need to change their training plan.


Thresholds and arousal are closely linked.  Going back to the mosquito example, most people are pretty relaxed about a single mosquito flying around.  When a mosquito lands on us, we become a tiny amount more aware or aroused about that mosquito.  And if we are swarmed by mosquitoes, we become vigilant and aroused, ready to act quickly if needed.  By making the link between arousal and thresholds, we can easily determine at what point we can move the dog’s threshold. 


When a dog is below threshold, they can habituate or just become gradually accustomed to the stimulus.  This is useful information if you want your dog to learn to tolerate a stimulus that you can easily control and present below threshold, but often, we cannot control the target stimulus that readily.


When a dog is at threshold, we can use Classical Conditioning to pair the target stimulus with something that the dog likes a lot.  If for instance, the dog is concerned about men wearing hats and you can present a man with a hat at a distance, so that the dog is aware of the man in the hat but not upset by him, then you could give the dog treats so that he associates men in hats with treats.  You need to repeat this until the dog is well below threshold in order to be successful, and sometimes this takes a great number of sessions.


When a dog is over threshold, he cannot learn at all.  He is aroused and overwhelmed.  Being aroused and overwhelmed can come in two flavours-he may be extremely happy or he may be really frightened.  The dog who is presented with a Frisbee and who barks and lunges and bounces around is as aroused as the dog who is presented with the frightening man in the hat and who stands and shivers.  Either way, his arousal level needs to come down before he can even begin to think, much less learn new things.