Frontal midline theta rhythm and gamma power changes during focused attention on mental calculation: an MEG beamformer analysis

Abstract

Frontal midline theta rhythm (Fmθ) appears widely distributed over medial prefrontal areas in EEG recordings, indicating focused attention. Although mental calculation is often used as an attention-demanding task, little has been reported on calculation-related activation in Fmθ experiments. In this study we used spatially filtered MEG and permutation analysis to precisely localize cortical generators of the magnetic counterpart of Fmθ, as well as other sources of oscillatory activity associated with mental calculation processing (i.e., arithmetic subtraction). Our results confirmed and extended earlier EEG/MEG studies indicating that Fmθ during mental calculation is generated in the dorsal anterior cingulate and adjacent medial prefrontal cortex. Mental subtraction was also associated with gamma event-related synchronization, as an index of activation, in right parietal regions subserving basic numerical processing and number-based spatial attention. Gamma event-related desynchronization appeared in the right lateral prefrontal cortex, likely representing a mechanism to interrupt neural activity that can interfere with the ongoing cognitive task.

Cognitive loading via mental arithmetic modulates effects of blink‐related oscillations on precuneus and ventral attention network regions

“…These effects are consistent with the task-related increase in sensorspace gamma and theta power observed in our study (Table 3), and are also consistent with the increased gamma and theta power previously reported for mental arithmetic tasks (Fitzgibbon et al, 2004;Ishii et al, 2014). Additionally, further contrasts were also performed to examine the presence of task-related cortical effects in the absence of blink activity (Supporting Information, Table 3).…”

The roles of cortical oscillations in sustained attention

“…Consistent with this hypothesis, magnetoencephalography (MEG) [43] and intracranial EEG studies [36] have localised fm-theta oscillations to dorsomedial prefrontal and anterior cingulate cortices -key hubs of the executive control and cingulo-opercular networks, respectively. Furthermore, theta oscillations in superficial layers of mPFC have recently been suggested to support cognitive monitoring and control processes by promoting integration of thalamocortical inputs and the detection of conflict between current and intended behaviours [44].…”

7,8-Dihydroxyflavone reduces sleep during dark phase and suppresses orexin A but not orexin B in mice

“…While Alpha activity is associated with quiet wake (Honda et al , 1997, Wright et al , 1995, Beta and Gamma activity are primarily associated with attention or other cognitive activities (Gross and Gotman, 1999, Ishii et al , 2014, Moratti et al , 2014, Suazo et al , 2014. Indirect evidence suggests that BDNF facilitates hippocampal Gamma oscillations (composed primarily in active wake) by attenuating signaling through 5-HT3 receptors (Huang and Morozov, 2011), supporting the association between BDNF and cognitive activity.…”