title: Cognitive manipulation of brain electric microstates.
abstract: EEG studies of wakeful rest have shown that there are brief periods in which global electrical brain activity on the scalp remains semi-stable (so-called microstates). Topographical analyses of this activity have revealed that much of the variance is explained by four distinct microstates that occur in a repetitive sequence. A recent fMRI study showed that these four microstates correlated with four known functional systems, each of which is activated by specific cognitive functions and sensory inputs. The present study used high density EEG to examine the degree to which spatial and temporal properties of microstates may be altered by manipulating cognitive task (a serial subtraction task vs. wakeful rest) and the availability of visual information (eyes open vs. eyes closed conditions). The hypothesis was that parameters of microstate D would be altered during the serial subtraction task because it is correlated with regions that are part of the dorsal attention functional system. It was also expected that the sequence of microstates would preferentially transition from all other microstates to microstate D during the task as compared to rest. Finally, it was hypothesized that the eyes open condition would significantly increase one or more microstate parameters associated with microstate B, which is associated with the visual system. Topographical analyses indicated that the duration, coverage, and occurrence of microstate D were significantly higher during the cognitive task compared to wakeful rest; in addition, microstate C, which is associated with regions that are part of the default mode and cognitive control systems, was very sensitive to the task manipulation, showing significantly decreased duration, coverage, and occurrence during the task condition compared to rest. Moreover, microstate B was altered by manipulations of visual input, with increased occurrence and coverage in the eyes open condition. In addition, during the eyes open condition microstates A and D had significantly shorter durations, while C had increased occurrence. Microstate D had decreased coverage in the eyes open condition. Finally, at least 15 microstates (identified via k-means clustering) were required to explain a similar amount of variance of EEG activity as previously published values. These results support important aspects of our hypotheses and demonstrate that cognitive manipulation of microstates is possible, but the relationships between microstates and their corresponding functional systems are complex. Moreover, there may be more than four primary microstates.
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, 1101 East 10th Street, Bloomington, IN 47405, USA. Electronic address: seitzman@wustl.edu.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Seitzman
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, 1101 East 10th Street, Bloomington, IN 47405, USA. Electronic address: malene.abell@gmail.com.
authors.forename: Malene
authors.initials: M
authors.lastname: Abell
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, 1101 East 10th Street, Bloomington, IN 47405, USA. Electronic address: samcbart@indiana.edu.
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Bartley
authors.affiliation: University Behavioral Health Care, Rutgers University, 671 Hoes Ln W, Piscataway Township, NJ 08854, USA. Electronic address: ericksma@indiana.edu.
authors.forename: Molly A
authors.initials: MA
authors.lastname: Erickson
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, 1101 East 10th Street, Bloomington, IN 47405, USA; Department of Psychiatry, Indiana University School of Medicine, 340 West 10th Street, Suite 6200, Indianapolis, IN 46202, USA; Larue D. Carter Memorial Hospital, 2601 Cold Spring Rd, Indianapolis, IN 46222, USA. Electronic address: arhoskin@indiana.edu.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Bolbecker
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, 1101 East 10th Street, Bloomington, IN 47405, USA; Department of Psychiatry, Indiana University School of Medicine, 340 West 10th Street, Suite 6200, Indianapolis, IN 46202, USA; Larue D. Carter Memorial Hospital, 2601 Cold Spring Rd, Indianapolis, IN 46222, USA. Electronic address: whetrick@indiana.edu.
authors.forename: William P
authors.initials: WP
authors.lastname: Hetrick
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D001921:Brain / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult
keywords: Cognition; EEG; Functional systems; Microstates; Resting-state