QPPLab: A generally applicable software package for detecting, analyzing, and visualizing large-scale quasiperiodic spatiotemporal patterns (QPPs) of brain activity.

Unlabelled: One prominent brain dynamic process detected in functional neuroimaging data is large-scale quasi-periodic patterns (QPPs) which display spatiotemporal propagations along brain cortical gradients. QPP associates with the infraslow neural activity related to attention and arousal fluctuations and has been identified in both resting and task-evoked brains across various species. Several QPP detection and analysis tools were developed for distinct applications with study-specific parameter methods.

Comparison of Resting-State Functional MRI Methods for Characterizing Brain Dynamics.

Resting-state functional MRI (fMRI) exhibits time-varying patterns of functional connectivity. Several different analysis approaches have been developed for examining these resting-state dynamics including sliding window connectivity (SWC), phase synchrony (PS), co-activation pattern (CAP), and quasi-periodic patterns (QPP). Each of these approaches can be used to generate patterns of activity or inter-areal coordination which vary across time.

Functional Connectivity of the Brain Across Rodents and Humans.

Resting-state functional magnetic resonance imaging (rs-fMRI), which measures the spontaneous fluctuations in the blood oxygen level-dependent (BOLD) signal, is increasingly utilized for the investigation of the brain's physiological and pathological functional activity. Rodents, as a typical animal model in neuroscience, play an important role in the studies that examine the neuronal processes that underpin the spontaneous fluctuations in the BOLD signal and the functional connectivity that results. Translating this knowledge from rodents to humans requires a basic knowledge of the similarities and differences across species in terms of both the BOLD signal fluctuations and the resulting functional connectivity.

Propagating patterns of intrinsic activity along macroscale gradients coordinate functional connections across the whole brain.

The intrinsic activity of the human brain, observed with resting-state fMRI (rsfMRI) and functional connectivity, exhibits macroscale spatial organization such as functional networks and gradients. Dynamic analysis techniques have shown that functional connectivity is a mere summary of time-varying patterns with distinct spatial and temporal characteristics. A better understanding of these patterns might provide insight into aspects of the brain's intrinsic activity that cannot be inferred by functional connectivity or the spatial maps derived from it, such as functional networks and gradients.

Relationship Between Basic Properties of BOLD Fluctuations and Calculated Metrics of Complexity in the Human Connectome Project.

Resting state functional MRI (rs-fMRI) creates a rich four-dimensional data set that can be analyzed in a variety of ways. As more researchers come to view the brain as a complex dynamical system, tools are increasingly being drawn from other fields to characterize the complexity of the brain's activity. However, given that the signal measured with rs-fMRI arises from the hemodynamic response to neural activity, the extent to which complexity metrics reflect neural complexity as compared to signal properties related to image quality remains unknown.

Quasi-periodic patterns of intrinsic brain activity in individuals and their relationship to global signal.

Quasiperiodic patterns (QPPs) as reported by Majeed et al., 2011 are prominent features of the brain's intrinsic activity that involve important large-scale networks (default mode, DMN; task positive, TPN) and are likely to be major contributors to widely used measures of functional connectivity. We examined the variability of these patterns in 470 individuals from the Human Connectome Project resting state functional MRI dataset.

Quantitative and comparative assessment of learning in a tongue-operated computer input device--part II: navigation tasks.

Tongue drive system (TDS) is a novel tongue-operated assistive technology (AT) for the mobility impaired, to empower them to access computers and drive powered wheelchairs (PWC) using their free voluntary tongue motion. We have evaluated the TDS performance in five sessions over 5-8 weeks to study the learning process in different tasks of computer access and PWC navigation on nine able-bodied subjects who already had tongue piercing and used our magnetic tongue studs throughout the trial. Computer access tasks included on-screen maze navigation and issuing random commands to measure the TDS information transfer rate.

Preliminary assessment of Tongue Drive System in medium term usage for computer access and wheelchair control.

Tongue Drive System (TDS) is a wireless, wearable assistive technology that enables individuals with severe motor impairments access computers, drive wheelchairs, and control their environments using tongue motion. In this paper, we have evaluated the TDS performance as a computer input device using ISO9241-9 standard tasks for pointing and selecting, based on the well known Fitts' Law, and as a powered wheelchair controller through an obstacle course navigation task. Nine able-bodied subjects who already had tongue piercing participated in this trial over 5 sessions during 5 weeks, allowing us to study the TDS learning process and its current limiting factors.

Quantitative and comparative assessment of learning in a tongue-operated computer input device.

Tongue drive system (TDS) is a wireless, wearable assistive technology that enables individuals with severe motor impairments to access computers, drive wheelchairs, and control their environments using tongue motion. In this paper, we have evaluated the TDS performance as a computer input device in four tasks, commonly known as horizontal, vertical, center-out, and multidirectional rapid tapping, based on Fitts' law and ISO9241-9 Standard. Nine able-bodied subjects, who already had tongue piercing, participated in this trial over five sessions during 5 weeks, allowing us to study the TDS learning process and its current limiting factors.

Using Fitts's law for evaluating Tongue Drive System as a pointing device for computer access.

In this paper, the results of a 2-D center-out task in a Fitts's law experiment have been presented for measuring the performance of the Tongue Drive System (TDS). Although the end-user population for TDS is individuals with tetraplegia, in this study, we recruited 6 able-bodied subjects in 3 sessions, conducted in 3 consecutive days. They performed the same task with their right hand using a standard mouse for achieving a baseline as well as a standard keypad with their right index finger.

Postnatal changes of steroid receptor coactivator-1 immunoreactivity in rat cerebellar cortex.

Steroid receptor coactivator-1 (SRC-1) interacts with nuclear hormone receptors (NRs) to mediate their action in a ligand-dependent manner. Among such ligands, thyroid hormone (TH) is particularly crucial for brain development. The expression of many TH target genes is regulated by TH only for a limited critical period, although TH receptor (TR) expression is not greatly altered after such period.