"potentiation of habituation" is observed when tests of spontaneous recovery are given repeatedly. in this phenomenon, the decrease in responding that follows spontaneous recovery becomes more rapid with each test of spontaneous recovery. also noted was that an increase in the frequency of stimulus presentation (i.e., shorter interstimulus interval) will increase the rate of habituation. furthermore, continued exposure to the stimulus after the habituated response has plateaued (i.e., show no further decrement) may have additional effects on subsequent tests of behavior such as delaying spontaneous recovery. the concepts of stimulus generalization and stimulus discrimination will be observed. habituation to an original stimulus will also occur to other stimuli that are similar to the original stimulus ("stimulus generalization"). the more similar the new stimulus is to the original stimulus, the greater the habituation that will be observed. when a subject shows habituation to a new stimulus that is similar to the original stimulus but not to a stimulus that is different from the original stimulus, then the subject is showing "stimulus discrimination". (for example, if one was habituated to the taste of lemon, their responding would increase significantly when presented with the taste of lime). stimulus discrimination can be used to rule out sensory adaptation and fatigue as an alternative explanation of the habituation process.