Simultaneous EEG–fMRI reveals a temporal cascade of task-related and default-mode activations during a simple target detection task
| Autor: | Truman R. Brown, Michael Carapezza, Jordan Muraskin, Paul Sajda, Robin I. Goldman, Jennifer M. Walz |
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| Rok vydání: | 2014 |
| Předmět: |
Adult
Male Time Factors Cognitive Neuroscience Precuneus Neuroimaging Stimulus (physiology) Electroencephalography EEG-fMRI Multimodal Imaging behavioral disciplines and activities Article Young Adult Task Performance and Analysis medicine Humans Attention Oddball paradigm Default mode network Communication Blood-oxygen-level dependent medicine.diagnostic_test business.industry Brain Magnetic Resonance Imaging medicine.anatomical_structure Neurology Posterior cingulate Female Psychology business Neuroscience psychological phenomena and processes |
| Zdroj: | NeuroImage. 102:229-239 |
| ISSN: | 1053-8119 |
| DOI: | 10.1016/j.neuroimage.2013.08.014 |
| Popis: | Focused attention continuously and inevitably fluctuates, and to completely understand the mechanisms responsible for these modulations it is necessary to localize the brain regions involved. During a simple visual oddball task, neural responses measured by electroencephalography (EEG) modulate primarily with attention, but source localization of the correlates is a challenge. In this study we use single-trial analysis of simultaneously-acquired scalp EEG and functional magnetic resonance image (fMRI) data to investigate the blood oxygen level dependent (BOLD) correlates of modulations in task-related attention, and we unravel the temporal cascade of these transient activations. We hypothesize that activity in brain regions associated with various task-related cognitive processes modulates with attention, and that their involvements occur transiently in a specific order. We analyze the fMRI BOLD signal by first regressing out the variance linked to observed stimulus and behavioral events. We then correlate the residual variance with the trial-to-trial variation of EEG discriminating components for identical stimuli, estimated at a sequence of times during a trial. Post-stimulus and early in the trial, we find activations in right-lateralized frontal regions and lateral occipital cortex, areas that are often linked to task-dependent processes, such as attentional orienting, and decision certainty. After the behavioral response we see correlates in areas often associated with the default-mode network and introspective processing, including precuneus, angular gyri, and posterior cingulate cortex. Our results demonstrate that during simple tasks both task-dependent and default-mode networks are transiently engaged, with a distinct temporal ordering and millisecond timescale. |
| Databáze: | OpenAIRE |
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