noun, Psychology. 1. Also called operant conditioning, instrumental conditioning. a process of changing behavior by rewarding or punishing a subject each time an action is performed until the subject associates the action with pleasure or distress.
Pertussis is caused by the bacterium Bordetella pertussis. It is an airborne disease which spreads easily through the coughs and sneezes of an infected person. People are infectious to others from the start of symptoms until about three weeks into the coughing fits.
Pertussis is a very contagious disease, characterized by severe coughing, caused by the bacterium Bordetella pertussis.Among vaccine-preventable diseases, pertussis is one of the most commonly occurring ones in the United States.ertussis is a very contagious disease, characterized by severe coughing, caused by the bacterium Bordetella pertussis.