Electrophysiological Low-Frequency Coherence and Cross-Frequency Coupling Contribute to BOLD Connectivity

SummaryBrain networks are commonly defined using correlations between blood oxygen level-dependent (BOLD) signals in different brain areas. Although evidence suggests that gamma-band (30–100 Hz) neural activity contributes to local BOLD signals, the neural basis of interareal BOLD correlations is unclear. We first defined a visual network in monkeys based on converging evidence from interareal BOLD correlations during a fixation task, task-free state, and anesthesia, and then simultaneously recorded local field potentials (LFPs) from the same four network areas in the task-free state. Low-frequency oscillations (<20 Hz), and not gamma activity, predominantly contributed to interareal BOLD correlations. The low-frequency oscillations also influenced local processing by modulating gamma activity within individual areas. We suggest that such cross-frequency coupling links local BOLD signals to BOLD correlations across distributed networks

The Grizzly, April 21, 1997

Dr. Martha Groom to Speak on Communities and Ecosystems • Summer Research Fellows Announced • Housing Changes • Debate on Quality of Majors • Opinion: To Students With Constructive Criticism, Write On!; One\u27s Right to Life and Death; Membership has its Privileges; Operation Understanding; More Money = Better Education? • Final Exam Schedule • Collegeville Headstart Benefits from Bears Game Haircuts • Softball Sweeps Western Maryland • Women\u27s Lacrosse Wins Two in Conference • Baseball Swept • Golf Team Sets New Course Records • Women\u27s Tennis at 3-3https://digitalcommons.ursinus.edu/grizzlynews/1403/thumbnail.jp

The Grizzly, October 1, 1997

Berman Museum Exhibit Features Work of Sidney Quinn • Pfahler Renovations Continue • New Economics Faculty Introduced • Two Faculty Additions in English • Works From the New English Faculty • Opinion: Sculpture Cheesed; Conspiracy Theories, the Media, and Open-Minded Inquiry; A Quick Lesson in EcBa 100; The Things You Might Not Know About Ursinus • Domenick Scudera Directs proTheater\u27s Fall Production of Brecht on Brecht • Biloxi Blues: At Ease and in Top Form • Despite Shaky Start, Guenther\u27s Bears Optimistic • Women\u27s Soccer on a Roll • Men\u27s Soccer off to a Slow Starthttps://digitalcommons.ursinus.edu/grizzlynews/1405/thumbnail.jp

The Grizzly, April 28, 1997

Student Art Exhibit Opens at Berman • Student Research Conference Held at Ursinus • Spirit Week at Ursinus • Opinion: Some Final Thoughts; More Inaccuracies Uncovered; The Ceremony of Innocence; Is Servitude the American Way? • Letter: SERV Denied Drill • Letters from Great Britain • Understanding One Another: Students to Present Projects on Identity and Diversity • Medieval Sports Fest Celebrates Tenth Year • Spring Service Success • A World of Learning at Musser and Beyond • Softball Splits Doubleheader • Golf Team Wins Four Matches • Women\u27s Tennis Jumps Record to 5-3 • Women\u27s Lacrosse Downs Haverford • Baseball Team Pounded by College of New Jerseyhttps://digitalcommons.ursinus.edu/grizzlynews/1404/thumbnail.jp

The Lantern Vol. 62, No. 1, December 1994

• Hollow • A Little Knowledge is Dangerous • My Old Block • Life • The Natural Born Fool • Oracle • Formation of a Triangle • Marie on the Beach • The Tweed Derby • Tripping • In Vitro • The Character • Coming Home for Christmas • Unkempt • Too Much • Reimertanti-Ode • Seeds • Secrethttps://digitalcommons.ursinus.edu/lantern/1145/thumbnail.jp

The Grizzly, March 24, 1997

Alternative Spring Break Unites Students, Charity • Author Ntozake Shange Reads, Lectures in Olin • New Chair of Campus Ministries Committee • Wicks House to Open in Fall • Ursinus is Ranked Among Best Science Schools • Opinion: Some Advice to Mr. Leahy; All Good Things; Liberal Arts Education Part II, Awareness Weeks; Letters from Great Britain; Let\u27s Get it Straight; A Tree or not a Tree, That is the Question • Something Old, Something New, Something Borrowed, Something Blur • The Tempest: Wayfaring Weather • Lady Bears Lose ECAC Championship • Baseball Starts Season at 4-7 Pace • Women\u27s Lacrosse Wins Year\u27s First Contest • Men\u27s Tennis Falls to Moravian • Rhodenbaugh and Minnich Honored as SAAC Chairs • Softball Off to 10-4 Start • Torsone an All-American • Gymnastics Team Places 8th at Nationals • Women\u27s Tennis Wins • USA Wrestling Lineup Announcedhttps://digitalcommons.ursinus.edu/grizzlynews/1400/thumbnail.jp

Perceptual Load-Dependent Neural Correlates of Distractor Interference Inhibition

The load theory of selective attention hypothesizes that distractor interference is suppressed after perceptual processing (i.e., in the later stage of central processing) at low perceptual load of the central task, but in the early stage of perceptual processing at high perceptual load. Consistently, studies on the neural correlates of attention have found a smaller distractor-related activation in the sensory cortex at high relative to low perceptual load. However, it is not clear whether the distractor-related activation in brain regions linked to later stages of central processing (e.g., in the frontostriatal circuits) is also smaller at high rather than low perceptual load, as might be predicted based on the load theory.We studied 24 healthy participants using functional magnetic resonance imaging (fMRI) during a visual target identification task with two perceptual loads (low vs. high). Participants showed distractor-related increases in activation in the midbrain, striatum, occipital and medial and lateral prefrontal cortices at low load, but distractor-related decreases in activation in the midbrain ventral tegmental area and substantia nigra (VTA/SN), striatum, thalamus, and extensive sensory cortices at high load.Multiple levels of central processing involving midbrain and frontostriatal circuits participate in suppressing distractor interference at either low or high perceptual load. For suppressing distractor interference, the processing of sensory inputs in both early and late stages of central processing are enhanced at low load but inhibited at high load

An Open Resource for Non-human Primate Imaging.

Non-human primate neuroimaging is a rapidly growing area of research that promises to transform and scale translational and cross-species comparative neuroscience. Unfortunately, the technological and methodological advances of the past two decades have outpaced the accrual of data, which is particularly challenging given the relatively few centers that have the necessary facilities and capabilities. The PRIMatE Data Exchange (PRIME-DE) addresses this challenge by aggregating independently acquired non-human primate magnetic resonance imaging (MRI) datasets and openly sharing them via the International Neuroimaging Data-sharing Initiative (INDI). Here, we present the rationale, design, and procedures for the PRIME-DE consortium, as well as the initial release, consisting of 25 independent data collections aggregated across 22 sites (total = 217 non-human primates). We also outline the unique pitfalls and challenges that should be considered in the analysis of non-human primate MRI datasets, including providing automated quality assessment of the contributed datasets

The mediodorsal pulvinar coordinates the macaque fronto-parietal network during rhythmic spatial attention.

Spatial attention is discontinuous, sampling behaviorally relevant locations in theta-rhythmic cycles (3-6 Hz). Underlying this rhythmic sampling are intrinsic theta oscillations in frontal and parietal cortices that provide a clocking mechanism for two alternating attentional states that are associated with either engagement at the presently attended location (and enhanced perceptual sensitivity) or disengagement (and diminished perceptual sensitivity). It has remained unclear, however, how these theta-dependent states are coordinated across the large-scale network that directs spatial attention. The pulvinar is a candidate for such coordination, having been previously shown to regulate cortical activity. Here, we examined pulvino-cortical interactions during theta-rhythmic sampling by simultaneously recording from macaque frontal eye fields (FEF), lateral intraparietal area (LIP), and pulvinar. Neural activity propagated from pulvinar to cortex during periods of engagement, and from cortex to pulvinar during periods of disengagement. A rhythmic reweighting of pulvino-cortical interactions thus defines functional dissociations in the attention network