Jackendoff expands further than just David Marr's model, by stating that the perceived object is the result of a multitude of thoughts competing in our subconscious, producing our conscious thoughts. In his own words, "The distinctions of form present in each modality of awareness are caused by/supported by/projected from a structure of intermediate level for that modality that is part of the matched set of short-term memory representations designated by the selection function and enriched by attentional processing." Jackendoff provides a selection process for the production of thoughts similar to Darwin's evolution theory and Edelman's theory for mind development.

Basically, Jackendoff proposes that what we actually see is a result of the competition between all the possible images to which we could be paying attention; a certain object or small set of objects are given an extra weight in this competition by our paying extra attention to them. To illustrate, there are many things on my floor at the moment, including clothes, several books and papers, and some trash. Right now, however, I am focusing entirely on one notebook. This does not in itself require a great deal of attention, and I could be easily distracted, say by a large cockroach crawling across my floor.

If I were instead to be reading one of the papers lying on my floor, this would require more concentration, and I would be less likely to be distracted, until the cockroach approached closer and diverted my attention. This is because the letters on the paper are given more weight in the competition for attention than the blank cover of my notebook would be in the same situation. Jackendoff proposes that we are actually not conscious of those objects which are less vivid, including the trash, clothes, and lurking cockroach, until we give attention to them. Of course, this competition is complicated by other factors besides vision. Someone who walked into my room and spoke to me would immediately gain my attention, despite my back being turned towards him.