Trained 72 male and female Long-Evans hooded rats on a series of 3 2-choice discrimination problems. The study replicated M. J. Robbins and D. R. Meyer's (see record 1970-11961-001) study which concluded that retrograde amnesias for long-term habits can be produced by single ECS treatments and are under motivational control. The 1st and 3rd problems of a given series were learned under similar incentive/motivational conditions, while the 2nd problem was learned under a different incentive/motivational condition. When they had mastered their 3rd problem, experimental Ss were given a single ECS. This produced amnesia for the 1st but not the 2nd habit. Control Ss subjected to sham ECS procedures showed excellent retention of both habits. Running-time data indicate that the effect is uninterpretable in terms of ECS merely serving as a punishment. (PsycINFO Database Record (c) 2006 APA, all rights reserved)