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.
Report Abuse. a stimulus is any substance that can trigger a response. effector organs can either be voluntarily or invountarily controlled. these are the organs that execute the response of the body or the central nervous system to a certain stimulus.sker's rating. Report Abuse. Affector organs are organs that send signals to other organs, much like a leader issuing orders. Effector organs are those that recieve the signals and produce an effect, much like workers who recieve commands and provide the actual results.