There are two, fundamentally different ways of directly retrieving advertising and brand memories from the mind.  One uses words, the other uses pictures. Subliminal or unconscious memories are not, by definition, accessible with self-report research. They must be inferred from indirect evidence.

Of the two types of memories that can be accessed, the visual is primary.
Babies first experience the world, and form memories, through vision. Talking in words comes much later. As Aristotle observed, “The mind never thinks without an image.”
Visual memory is the “mind’s eye.” Neuroscientists call memories “representations” on the neural circuits of the brain. They also call them “images.”

It was by an accident of technology, or more specifically the limitations of collecting (telephone) and manipulating data (numbers and text), that earlier generations of market researchers started with verbal methods of retrieving memories.

However, collecting memories in day-after-recall tests, communication checks and tracking studies was a messy business of coding verbatims to try to “prove” what was remembered from advertising. Distinctions needed to be made between “top-of-mind” or “unaided” recall and “aided” remembrance. It is the distinction between being able to call up the right word when you want to speak it and recognizing a little-used word when you read it.

Among psychologists, visual recognition as a test of memory has a long history. However, most academic research into memory is based on exposure and recognition of an unconnected series of letters, shapes or photographs—usually involving timed effects.

For research into advertising and brand memories, we are more interested in images that are connected by narrative, in a logical or temporal structure. What matters is the study of a stream of images in a movie, a television commercial, a web video or even a dynamic and moving digital ad. Brand memories are formed in the rapid current, rhythmic waves and complex eddies in the flow of imagery.

Fortunately, for over a century, still photographs have proven to be a useful tool for freezing time and catching the emotional moment in the stream of everyday day living, for storing personalized memories in family albums and now for Facebook. They also turn out to be quite useful for studying how branded memories are created in the flow of advertising.