Spatio-temporal components of preparation in task-switching: A combined EEG and MEG approach
-
1
University of Newcastle, Australia
-
2
Macquarie University, Australia
Background
The cued-trials task switching paradigm is used to decompose the cognitive mechanisms required to flexibly adjust to changes in our environment. Two different types of performance decrements are observed in these studies: a) mixing cost, which refers to the reduction in performance that is observed for repeat trials within a mixed-task block (i.e. mixed repeat trials) relative to repeat trials within a single-task block (i.e. all repeat trials), and b) switch cost, which refers to the reduction in performance on switch relative to mixed repeat trials within an intermixed task block. At least part of these costs is attributable to differences in preparation occurring within the cue to target interval. Cue-locked ERPs have provided evidence for temporally distinct preparatory components underlying mixing and switch cost, respectively. In addition, fMRI evidence suggests that these processes are associated with distinct neural generators. However, sources derived from fMRI cannot be reliably linked to timepoints within the timecourse of a trial. We used a combined EEG-MEG approach that allows us to more precisely map neural sources of these preparatory components.
Methods
EEG and MEG data was recorded simultaneously from 17 participants. Both datasets were analysed in BESA v6.0. Time windows for source analysis were selected based on periods of maximal differentiation between conditions in event-related potentials (ERPs). Frontal and parietal regional sources were seeded based on regions identified in fMRI studies.
Results
Reaction time was slower on switch relative to mixed repeat trials, and for mixed repeat relative to all repeat trials. ERP waveforms at parietal electrodes showed an early mixing positivity that partially overlapped with a later switch positivity. MEG source waveforms showed distinct patterns of activation within the time windows of the mixing positivity and switch positivity at frontal and parietal sources.
Discussion
We found distinct activation profiles in a fronto-parietal network that corresponded to an early preparatory task-set updating process and a later switch preparation process. These findings provide converging evidence for temporally and spatially dissociable preparation processes in cued-trials task switching.
Keywords:
task switching,
MEG,
ERP,
cognitive control,
source modeling
Conference:
ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013.
Presentation Type:
Poster
Topic:
Executive Processes
Citation:
Mansfield
E,
Provost
A,
Johnson
BW,
Tesan
G,
Thienel
R and
Karayanidis
F
(2013). Spatio-temporal components of preparation in task-switching: A combined EEG and MEG approach.
Conference Abstract:
ACNS-2013 Australasian Cognitive Neuroscience Society Conference.
doi: 10.3389/conf.fnhum.2013.212.00095
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
25 Sep 2013;
Published Online:
25 Nov 2013.
*
Correspondence:
Ms. Elise Mansfield, University of Newcastle, Newcastle, Australia, elise.mansfield@newcastle.edu.au