Urs Dahinden: Framing

Wimmer, Jeffrey

doi:10.5771/1615-634x-2007--289

Cited by 19 publications

(30 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Neural oscillations are putatively controlled by neocortical inhibitory interneurons (Cardin et al, 2009;Vierling-Claassen et al, 2010), suggesting that top-down modulations of neural synchrony between brain regions may target cortical inhibitory neurons, thereby affecting brain region's excitability to synaptic inputs and its communication efficacy (Lakatos et al, 2005). A second potential mechanism could involve fronto-parietal regions acting on the thalamus or the thalamic reticular nucleus (Wimmer et al, 2015), which in turn could modulate cortico-cortical communication. In addition to relaying information from peripheral sensory organs to the cerebral cortex, the thalamus has also been proposed to mediate the exchange of information between cortical regions through cortico-thalamic-cortical pathways (Sherman, 2016).…”

Section: Discussionmentioning

confidence: 99%

Fronto-Parietal Interactions with Task-Evoked Functional Connectivity During Cognitive Control

Hwang

D’Esposito

2017

Preprint

View full text Add to dashboard Cite

Flexible interaction between brain regions enables neural systems to transfer and process information adaptively for goal-directed behaviors. In the current study, we investigated neural substrates that interact with task-evoked functional connectivity during cognitive control. We conducted a human fMRI study where participants selectively attended to a category of visual stimuli in the presence of competing distractors from another stimulus category. To study flexible interactions between brain regions, we performed a dynamic functional connectivity analysis to estimate temporal changes in connectivity strength between brain regions under different levels of cognitive control. Consistent with theoretical predictions, we found that cognitive control selectively enhances functional connectivity for prioritizing the processing of task-relevant information. By regressing temporal changes in connectivity strength against activity patterns elsewhere in the brain, we localized frontal and parietal regions that potentially provide top-down biasing signals for influencing, or reading information out from, task-evoked functional connectivity. Our results suggest that in addition to modulating local activity, frontoparietal regions could also exert top-down biasing signals to influence functional connectivity between distributed brain regions.

show abstract

Section: Discussionmentioning

confidence: 99%

Fronto-Parietal Interactions with Task-Evoked Functional Connectivity During Cognitive Control

Hwang

D’Esposito

2017

Preprint

View full text Add to dashboard Cite

show abstract

“…Recent theoretical proposals beating SQL involve CQNC [3] demand additional degrees of freedom (DOF) like OPA [4] , ultra-cold atoms [13] and hybrid-systems with injecting squeezed vacuum noise [14], complicating the conventional OM architecture. Our proposal achieves it not by cancelling back-action noise, but by making it a non-linear function of intensity, requiring no additional DOF as in existing experimental platforms like electro-mechanical [20,21], OM [22] and micro disk-cantilevers [23].…”

Section: Force Noise Spectrum With Qocmentioning

confidence: 99%

“…Classical force sensing with dispersive optomechanical (OM) system has a long history. To realize high sensitive force measurements, many approaches have been studied to reduce quantum noise in the system [1][2][3][4][5][6]. The sensitivity of force measurements are limited by two types of quantum noise: the shot noise of the laser beam at the detection port and the radiation pressure backaction noise introduced by the oscillator [7].…”

mentioning

confidence: 99%

“…However, the SQL is not a fundamental quantum limit. Various schemes involving dispersive interactions were proposed to overcome the SQL in force measurements, such as frequency dependent squeezing of the input beam [10], variational measurement [11], two-mode OM system [12] and coherent quantum noise cancellation (CQNC) [3,4,13,14] etc. On the other hand, a free particle coupled through a dissipative interaction with an OM system was shown to surpass the SQL [15].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Force sensing beyond standard quantum limit with optomechanical “soft” mode induced by nonlinear interaction

Sainadh¹,

Kumar²

2020

Opt. Lett.

View full text Add to dashboard Cite

We consider an optomechanical (OM) system that consists of a mechanical and an optical mode interacting through a linear and quadratic OM dispersive couplings. The system is operated in unresolved side band limit with a high quality factor mechanical resonator. Such a system acts as parametrically driven oscillator, giving access to an intensity assisted tunability of the spring constant. This enables the operation of OM system in its 'soft mode' wherein the mechanical spring softens and responds with a lower resonance frequency. We show that this soft mode can be exploited to nonlinearize backaction noise which yields higher force sensitivity beyond the conventional standard quantum limit.

show abstract

“…The present computational scheme gives a direct insight into the solution of the Schrödinger equation and the obtained transport properties of the system are equivalent to the ones obtained in Greens function approach. 39 …”

Section: B Calculation Of the Conductancementioning

confidence: 99%

Signatures of spin-orbit coupling in scanning gate conductance images of electron flow from quantum point contacts

2014

View full text Add to dashboard Cite

Electron flow through a quantum point contact in presence of spin-orbit coupling is investigated theoretically in the context of the scanning gate microscopy (SGM) conductance mapping. Although in the absence of the floating gate the spin-orbit coupling does not significantly alter the conductance, we find that the angular dependence of the SGM images of the electron flow at the conductance plateaux is substantially altered as the spin-orbit interaction mixes the orbital modes that enter the quantum point contact. The radial interference fringes that are obtained in the SGM maps at conductance steps are essentially preserved by the spin-orbit interaction as backscattering by the tip preserves the electron spin although the effects of the mode mixing are visible.

show abstract

Urs Dahinden: Framing

Cited by 19 publications

References 0 publications

Fronto-Parietal Interactions with Task-Evoked Functional Connectivity During Cognitive Control

Fronto-Parietal Interactions with Task-Evoked Functional Connectivity During Cognitive Control

Force sensing beyond standard quantum limit with optomechanical “soft” mode induced by nonlinear interaction

Signatures of spin-orbit coupling in scanning gate conductance images of electron flow from quantum point contacts

Contact Info

Product

Resources

About