VARIATIONS IN RETROGRADE AMNESIA WITH PARAMETERS OF ELECTROCONVULSIVE SHOCK AND TIME OF TESTING

ECS OF 35 OR 100 MA. FOR .2 OR .5 SEC. WAS ADMINISTERED TO MALE RATS 3.1-3000 SEC. AFTER A SINGLE STEP-DOWN PASSIVE AVOIDANCE TRIAL. LENGTH OF RETROGRADE AMNESIA (RA) MEASURED 24 HR. LATER VARIED WITH ECS CURRENT, BUT NOT WITH ECS DURATION: 35-MA ECS CAUSED RA OF 30 SEC., WHEREAS 100-MA ECS CAUSED RA OF 50 MIN. A FURTHER RETEST 48 HR. AFTER LEARNING REVEALED INCREASED RETENTION; THE GRADIENT OF RA, WHICH WAS LOGARITHMIC 24 HR. AFTER LEARNING, APPROXIMATED A STEP FUNCTION WITH A DISCONTINUITY BETWEEN 3 AND 30 SEC.; AVERSIVENESS OF A SINGLE ECS, WHICH WAS NEGLIGIBLE AT 24 HR., HAD BECOME SIGNIFICANT. (17 REF.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1968 American Psychological Association.