TY - JOUR

T1 - Creating external reminders for delayed intentions

T2 - dissociable influence on "task-positive" and "task-negative" brain networks

AU - Landsiedel, Julia

AU - Gilbert, Sam J

N1 - Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - Studies of prospective memory and other paradigms requiring participants to remember delayed intentions typically reveal a distinction between lateral and medial rostral prefrontal cortex, whereby the experimental condition yields increased signal in the former region and decreased signal in the latter. These regions comprise nodes of larger "task-positive" and "task-negative" networks that often show opposite patterns of signal change in response to diverse cognitive demands. However, it is not clear to what extent activity in these networks is A) inverse but equivalent, or B) functionally dissociable. In order to address this question, participants performed an "intention-offloading" task while undergoing fMRI. On each trial they remembered a delayed intention, which they had the opportunity to fulfill after a brief filled delay. In one condition they were required to set an external reminder of this intention, while in the other they acted without any external memory aid. Results indicated a clear functional dissociation between the two networks. Compared with a control task with no delayed intention, there was a highly significant reduction in task-negative deactivation when participants used an external memory aid. However, there was no reduction in task-positive activation. These results are consistent with previous evidence that medial rostral prefrontal cortex plays a prominent role in representing the content of delayed intentions, accompanied by a reduction in BOLD signal and potentially increased theta-band oscillatory activity. This role is no longer required once an external reminder has been created. By contrast, lateral rostral prefrontal cortex may play a content-free role, unaffected by the offloading of content into the external environment.

AB - Studies of prospective memory and other paradigms requiring participants to remember delayed intentions typically reveal a distinction between lateral and medial rostral prefrontal cortex, whereby the experimental condition yields increased signal in the former region and decreased signal in the latter. These regions comprise nodes of larger "task-positive" and "task-negative" networks that often show opposite patterns of signal change in response to diverse cognitive demands. However, it is not clear to what extent activity in these networks is A) inverse but equivalent, or B) functionally dissociable. In order to address this question, participants performed an "intention-offloading" task while undergoing fMRI. On each trial they remembered a delayed intention, which they had the opportunity to fulfill after a brief filled delay. In one condition they were required to set an external reminder of this intention, while in the other they acted without any external memory aid. Results indicated a clear functional dissociation between the two networks. Compared with a control task with no delayed intention, there was a highly significant reduction in task-negative deactivation when participants used an external memory aid. However, there was no reduction in task-positive activation. These results are consistent with previous evidence that medial rostral prefrontal cortex plays a prominent role in representing the content of delayed intentions, accompanied by a reduction in BOLD signal and potentially increased theta-band oscillatory activity. This role is no longer required once an external reminder has been created. By contrast, lateral rostral prefrontal cortex may play a content-free role, unaffected by the offloading of content into the external environment.

KW - Adult

KW - Brain/physiology

KW - Brain Mapping

KW - Female

KW - Humans

KW - Intention

KW - Magnetic Resonance Imaging

KW - Male

KW - Memory, Episodic

KW - Mental Recall/physiology

KW - Nerve Net/physiology

KW - Reminder Systems

KW - Young Adult

U2 - 10.1016/j.neuroimage.2014.10.021

DO - 10.1016/j.neuroimage.2014.10.021

M3 - Article

C2 - 25451474

VL - 104

SP - 231

EP - 240

JO - Neuroimage

JF - Neuroimage

SN - 1053-8119

ER -