"The present experiment was conducted in order to analyze in a more systematic fashion, without speculative embellishments, previously reported observations on the increased frequency of generalized verbal responses at high levels of drive. The corresponding bar-pressing rates of six white rats under positive (reinforced) and negative (nonreinforced) stimulation have been compared at seven levels of hunger. With the exception of a single deviant value, the two rates remain closely proportional; one is a linear function of the other. It is concluded that the increase in rate is general, and that a stimulus discrimination, as measured by the relative rates of response, is not affected by changes in drive." (PsycINFO Database Record (c) 2006 APA, all rights reserved)