
Specialization in the default mode: Task‐induced brain deactivations dissociate between visual working memory and attention
Author(s) -
Mayer Jutta S.,
Roebroeck Alard,
Maurer Konrad,
Linden David E.J.
Publication year - 2010
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.20850
Subject(s) - default mode network , working memory , neuroscience , prefrontal cortex , psychology , cognition , task positive network , posterior parietal cortex , task (project management) , functional magnetic resonance imaging , functional specialization , human brain , cognitive psychology , management , economics
The idea of an organized mode of brain function that is present as default state and suspended during goal‐directed behaviors has recently gained much interest in the study of human brain function. The default mode hypothesis is based on the repeated observation that certain brain areas show task‐induced deactivations across a wide range of cognitive tasks. In this event‐related functional resonance imaging study we tested the default mode hypothesis by comparing common and selective patterns of BOLD deactivation in response to the demands on visual attention and working memory (WM) that were independently modulated within one task. The results revealed task‐induced deactivations within regions of the default mode network (DMN) with a segregation of areas that were additively deactivated by an increase in the demands on both attention and WM, and areas that were selectively deactivated by either high attentional demand or WM load. Attention‐selective deactivations appeared in the left ventrolateral and medial prefrontal cortex and the left lateral temporal cortex. Conversely, WM‐selective deactivations were found predominantly in the right hemisphere including the medial‐parietal, the lateral temporo‐parietal, and the medial prefrontal cortex. Moreover, during WM encoding deactivated regions showed task‐specific functional connectivity. These findings demonstrate that task‐induced deactivations within parts of the DMN depend on the specific characteristics of the attention and WM components of the task. The DMN can thus be subdivided into a set of brain regions that deactivate indiscriminately in response to cognitive demand (“the core DMN”) and a part whose deactivation depends on the specific task. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.