Figure 1. Conceptualizing Item and Process Memory.

The ambigram DOG is useful for describing the distinction between the concepts of “item” and “process” memory. The circles represent a network of neurons and green indicates the active subset of neurons, which generate an activity pattern to represent information. In the case of item memory, two distinct patterns would each represent the notions of “dog” and “god.” These patterns would be different from the networks that represent the individual letters, for example, another pattern of coactivity would represent the letter “D.” The neurons may be active for multiple representations, but a unique combination of active and inactive neurons defines the pattern for each representation. In the case of process memory, the activity patterns that represent the letters “D,”“O,” and “G” would be the same for both the notions “god” and “dog” but the letter-specific patterns would activate in one temporal sequence to represent “dog” and the reverse sequence to represent “god.” Whichever activation sequence is more likely will bias representation to “dog” or “god.”