Geraniums have been popular garden perennials for a long time, and have lots of devotees. Consequently, there are lots of good sources of information on the internet. A good start is provided by the Open Directory Project's geranium category. For a primer on erodiums, this page from the UK gives a good overview.
Stimulus control is the phenomenon of a stimulus increasing the probability of a behavior (operant response) because of a history of that behavior being differentially reinforced in the presence of the stimulus.
Get rights and content. The meaning of the term noxious stimulus is discussed. The principal meaning of stimulus with which we are concerned is an external or internal physical change that induces afferent input in the nervous system, with or without sensory experience or a behavioral response.