The Representation and Processing of Order Information in Memory.

Abstract

The goal of this dissertation was to characterize different types of order representations in memory as well as the processes involved in accessing this order information. Study 1 was conducted to investigate the representation of order information for everyday routines, like ‘going to a restaurant’ and ‘shopping for groceries’. Participants decided whether actions from a given routine were in the correct order. By manipulating the distance between actions it was shown that variables, such as routine familiarity, influenced the processes involved in accessing this order information. Study 2 focused on order information for well-learned sequences, using numbers and months as stimuli. Participants decided whether three numbers, or months, were in the correct. It was shown that the processes involved in accessing this order information differ from those known to be involved in typical magnitude comparison tasks. Study 3 was an fMRI version of the order task with numbers taken from the 2nd study. The goal of this third study was to compare a magnitude task showing distance effects with an order-judgment task that yields reverse-distance effects. Taken together, these studies reveal that different processes are involved in accessing order information in memory; specifically, scanning, estimation, and long-term memory checking mechanisms. Additionally, this work reveals that the intraparietal sulcus, which has typically been implicated in the processing of magnitude information for numbers, is similarly activated by a task that focuses on order information for numbers.