Abstract
Classically conditioned eyeblink and nictitating membrane responses in 14 albino rabbits, using electrical stimulation of lateral geniculate nucleus as cs and peripheral shock as ucs. After differential conditioning with a cs+ of .20-ma intensity and cs- of .30, .40, and .50 ma., percentages of crs increased as a function of cs intensity above the cs+ until after 21-28 sessions. In contrast, when differential conditioning was employed in a 2-stimulus procedure emphasizing the discriminability of stimuli, stimulus control was obtained even when the cs- was of greater intensity than the cs+. When cs+ and cs- intensities were gradually made more alike, ss showed differential conditioning until cs-intensity differences were .10 ma. Or less. Results are discussed in terms of a neural theory of stimulus control. (24 ref.)
