The images that we remember twenty minutes after seeing an ad, the ones in short-term memory, are not necessarily the ones we remember the next day, or weeks, or months after seeing an ad.

Memories decay over time, though not all memories decay at the same rate. For researchers interested in using short-term ad testing data to predict the longer-term brand memories that are measured in ad tracking studies, we need to better understand the linkages between short term memory and long term memory.

We conducted an experiment measuring frame-by-frame memory of a set of TV ads after different time periods of forgetting. For five highly attention-getting commercials, commercial memory was measured after 20 minutes, after one day and after one week.

Not surprisingly, the longer the amount of time consumers had to forget, the less of each commercial they remembered.  While 77% of the images from these ads were remembered after twenty minutes, after a full day only 62% of the images were remembered. After a week, consumers could recognize only 52% of the images.

Of course, averages can be misleading because not all the images from an ad are forgotten at the same rate.

As we looked across the five commercials in our experiment, we found similar patterns: the rhythmic peaks and valleys shape of the memory map that we saw after twenty minutes preserved its structure nearly intact over longer time periods.

There was a key difference. There were slightly fewer peak images remembered over longer time frames. After twenty minutes, these commercials generated an average of five peak memories,but only four peak memories remained after a week. In other words, some peak memories were relatively permanent, while others were transient.

When we looked more closely,  anotherresponse to these moments in the ads revealed the difference. Permanent peak memories were much more likely to generate strong feelings than the transient peaks.

Looking, the imagery from commercials we remember the longest are not just those that stand out in our conscious minds immediately after watching, like those moments in a movie that play back in our minds as we walk out of the theater. Long lasting memories are also those for which we have the strongest feelings.

Please contact Sonya Duran ( for more information