The cognitive process: the stage of investigating consciousness When practicing insight meditation and when observing mental formations arising  then sometimes shortly after another mental formation arises caused by the first mental formation. 

An example could be a memory that arises then shortly after another memory arises that is closely related to the first one. The second memory is clearly caused by the first one since its similar in appearance and "acts" like a continuation of the first memory.

This picture is from Comprehensive Manual of Abhidhamma by Ven. Bhikkhu Bodhi. The picture can be found in the chapter "Compendium of the cognitive process", at p. 155. It shows the different stages in the process of cognition.


I was wondering about at what stage in the cognitive process it happens that an object is compared/coupled to previous experiences?

My best guess is that it might be in the stage of "investigating consciousness".

Lanka
Many people try to read too much into the "17 thought moment sensing process". Please see page 164 of Bhikkhu Bodhi's "Comprehensive Manual of Abhidhamma" which gives Ledi Sayadaw's explanation.

Basically, in the case of eye-door, the "17 thought moment sensing process" captures a small patch of colour. This is followed by gazillions of mind-door processes that glue the entire field of vision together, grasp shapes, recognize shapes, grasp the name, recognize the name, etc. The comparing the object to past experiences comes much later after lots of thinking has been done. In other words, in the case of the eye-door, the "17 thought moment sensing process" brings a small patch of colour into the mind. That's it. All the subsequent analysis is done by gazillions of mind-door processes.

If you want the "bigger picture", the best place to start is the Madhupiṇḍika Sutta (MN 18), "Dependent on eye &amp; forms, eye-consciousness arises. The meeting of the three is contact. With contact as a requisite condition, there is feeling. What one feels, one perceives (labels in the mind). What one perceives, one thinks about. What one thinks about, one objectifies. Based on what a person objectifies, the perceptions &amp; categories of objectification assail him/her with regard to past, present, &amp; future forms cognizable via the eye."

In this sutta, the "compared / coupled to past experiences" that you are asking about happens at the final stage.