Neurocognitive Systems Related to Real-World Prospective Memory

Abstract

BackgroundProspective memory (PM) denotes the ability to remember to perform actions in the future. It has been argued that standard laboratory paradigms fail to capture core aspects of PM.Methodology/Principal FindingsWe combined functional MRI, virtual reality, eye-tracking and verbal reports to explore the dynamic allocation of neurocognitive processes during a naturalistic PM task where individuals performed errands in a realistic model of their residential town. Based on eye movement data and verbal reports, we modeled PM as an iterative loop of five sustained and transient phases: intention maintenance before target detection (TD), TD, intention maintenance after TD, action, and switching, the latter representing the activation of a new intention in mind. The fMRI analyses revealed continuous engagement of a top-down fronto-parietal network throughout the entire task, likely subserving goal maintenance in mind. In addition, a shift was observed from a perceptual (occipital) system while searching for places to go, to a mnemonic (temporo-parietal, fronto-hippocampal) system for remembering what actions to perform after TD. Updating of the top-down fronto-parietal network occurred at both TD and switching, the latter likely also being characterized by frontopolar activity.Conclusion/SignificanceTaken together, these findings show how brain systems complementary interact during real-world PM, and support a more complete model of PM that can be applied to naturalistic PM tasks and that we named PROspective MEmory DYnamic (PROMEDY) model because of its dynamics on both multi-phase iteration and the interactions of distinct neurocognitive networks.

Abnormal regional homogeneity and its correlations with personality in first-episode, treatment-naive somatization disorder

“…In task-related fMRI, the right AG is stirred up by the conflict tasks, while the left AG is activated especially in a sentence comprehension task (Ye and Zhou, 2009). The left AG may act as a memory buffer for intention maintenance (Kalpouzos et al, 2010), and may play a role in the verbal coding of numbers (Dehaene et al, 2003) and the arithmetic operations (Ischebeck et al, 2009). Consistent with the previous findings, our results suggest that left-sided affected asymmetry may be a characteristic for patients with SD.…”

Working Memory: Maintenance, Updating, and the Realization of Intentions

“…Functional imaging studies contribute converging evidence by showing that rostro-prefrontal regions code for the nature of future processing (Sakai and Passingham 2003) and that frontopolar regions show a sustained activation profile throughout a taskeven when no stimuli are present (Marklund et al 2007b; see also Velanova et al 2003;Dosenbach et al 2007). Also, frontopolar regions have been implicated in prospective memory (Burgess et al 2003) and in forming new intentions (Kalpouzos et al 2010). Collectively, these kinds of findings link the rostrofrontal cortex to prospective coding of the cognitive context in a given situation.…”

“…When the realization of an intention is much delayed and/or interfered with by various distracting events, long-term memory processes will be critical for reactivating the relevant frontal goal representations based on sensorimotor cues (Rainer et al 1999;cf. Miller and Cohen 2001;Kalpouzos et al 2010). …”

Location-based prospective memory

“…For example, Kalpouzos et al (2010) created a virtual representation of the participants' own town (Umeå, Sweden). They used a joystick to travel along different routes and did four or five event-based prospective memory tasks per route (e.g., throw a candy wrapper in the trashcan).…”