TIME-DEPENDENT CHANGES IN INACCESSIBLE MEMORY

The present experiment examined whether forgetting of contextual attri butes-the loss of discriminability of background stimulus features ove r time-also occurs when a memory remains inaccessible (amnestic) durin g the retention interval. To examine this issue, rats received an acut e hypothermia treatment that caused reversible anterograde amnesia for a passive-avoidance task and were tested I or 7 days later in either the same or a different context. At the short retention interval, the subjects discriminated between the contexts, as evidenced by the findi ng that reversal of amnesia occurred only in the training context. How ever, at the 7-day interval, recovery of the avoidance response was in duced in either context, reflecting the forgetting of differentiating characteristics. These findings indicate that inaccessible memory rema ins susceptible to processes of modification and distortion that typic ally influence intact memories.