106 research outputs found
Neural correlates of the affect heuristic during brand choice
In this working paper it is investigated how affect and cognition interact in consumer decision making. The research framework is multidisciplinary by applying a neuroscientific method to answer the question which information is processed during brand choice immediately when the decision is computed in the test person’s brain. In a neuroscientific experiment test persons perform binary decision-making tasks between different brands of the same product class. The results suggest that the presence of the respondent’s first choice brand leads to a specific modulation of the neural brain activity, which can be described as neural correlate of Slovic’s affect heuristic concept.Neuroeconomics, brand choice, cognition, affect
Atomic magnetometer for human magnetoencephalograpy.
We have developed a high sensitivity (<5 fTesla/{radical}Hz), fiber-optically coupled magnetometer to detect magnetic fields produced by the human brain. This is the first demonstration of a noncryogenic sensor that could replace cryogenic superconducting quantum interference device (SQUID) magnetometers in magnetoencephalography (MEG) and is an important advance in realizing cost-effective MEG. Within the sensor, a rubidium vapor is optically pumped with 795 laser light while field-induced optical rotations are measured with 780 nm laser light. Both beams share a single optical axis to maximize simplicity and compactness. In collaboration with neuroscientists at The Mind Research Network in Albuquerque, NM, the evoked responses resulting from median nerve and auditory stimulation were recorded with the atomic magnetometer and a commercial SQUID-based MEG system with signals comparing favorably. Multi-sensor operation has been demonstrated with two AMs placed on opposite sides of the head. Straightforward miniaturization would enable high-density sensor arrays for whole-head magnetoencephalography
A waveguide atom beamsplitter for laser-cooled neutral atoms
A laser-cooled neutral-atom beam from a low-velocity intense source is split
into two beams while guided by a magnetic-field potential. We generate our
multimode-beamsplitter potential with two current-carrying wires on a glass
substrate combined with an external transverse bias field. The atoms bend
around several curves over a -cm distance. A maximum integrated flux of
is achieved with a current density of
in the 100- diameter
wires. The initial beam can be split into two beams with a 50/50 splitting
ratio
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Magnetic Switch for Integrated Atom Optics
A magnetic waveguide structure allows switching of neutral atoms between two guides. The switch consists of lithographically patterned current-carrying wires on a sapphire substrate. By selectively sending current through a particular set of wires, we select the desired output port of an incoming beam. We utilize two different magnetic-guiding schemes to adiabatically manipulate the atom trajectory
Cerebral Arterial Stenoses and Stroke: Novel Features of Aicardi-Goutières Syndrome Caused by the Arg164X Mutation in SAMHD1 Are Associated with Altered Cytokine Expression
Aicardi-Goutières syndrome (AGS) is a rare inborn multisystemic disease, resembling intrauterine viral infection and resulting in psychomotor retardation, spasticity and chilblain-like skin lesions. Diagnostic criteria include intracerebral calcifications and elevated interferon-alpha and pterin levels in cerebrospinal fluid (CSF). We report on four adult siblings with unknown neurodegenerative disease presenting with cerebrovascular stenoses, stroke and glaucoma in childhood, two of whom died at the age of 40 and 29 years. Genome-wide homozygosity mapping identified 170 candidate genes embedded in a common haplotype of 8Mb on chromosome 20q11-13. Next generation sequencing of the entire region identified the c.490C>T (p.Arg164X) mutation in SAMHD1, a gene most recently described in AGS, on both alleles in all affected siblings. Clinical diagnosis of AGS was then confirmed by demonstrating intracerebral calcifications on cranial computed tomography in all siblings and elevated pterin levels in CSF in three of them. In patient fibroblasts, lack of SAMHD1 protein expression was associated with increased basal expression of IL8, while stimulated expression of IFNB1 was reduced. We conclude that cerebrovascular stenoses and stroke associated with the Arg164X mutation in SAMHD1 extend the phenotypic spectrum of AGS. The observed vascular changes most likely reflect a vasculitis caused by dysregulated inflammatory stress response. © 2010 Wiley-Liss, Inc
Guiding neutral atoms around curves with lithographically patterned current-carrying wires
Laser-cooled neutral atoms from a low-velocity atomic source are guided via a
magnetic field generated between two parallel wires on a glass substrate. The
atoms bend around three curves, each with a 15-cm radius of curvature, while
traveling along a 10-cm-long track. A maximum flux of 2*10^6 atoms/sec is
achieved with a current density of 3*10^4 A/cm^2 in the
100x100-micrometer-cross-section wires. The kinetic energy of the guided atoms
in one transverse dimension is measured to be 42 microKelvin.Comment: 9 page
High-Performance Silicon Photonic Single-Sideband Modulators for Cold Atom Interferometry
The most complicated and challenging system within a light-pulse atom
interferometer (LPAI) is the laser system, which controls the frequencies and
intensities of multiple laser beams over time to configure quantum gravity and
inertial sensors. The main function of an LPAI laser system is to perform
cold-atom generation and state-selective detection and to generate coherent
two-photon process for the light-pulse sequence. Substantial miniaturization
and ruggedization of the laser system can be achieved by bringing together most
key functions of the laser and optical system onto a photonic integrated
circuit (PIC). Here we demonstrate a high-performance silicon photonic
carrier-suppressed single-sideband (CS-SSB) modulator PIC with dual-parallel
Mach-Zehnder modulators (DP-MZMs) operating near 1560 nm, which can dynamically
shift the frequency of the light for the desired function within the LPAI.
Independent RF control of channels in SSB modulator enables the extensive study
of imbalances in both the optical and RF phases and amplitudes to
simultaneously reach 30 dB carrier suppression and unprecedented 47.8 dB
sideband suppression with peak conversion efficiency of -6.846 dB (20.7 %).
Using a silicon photonic SSB modulator with time-multiplexed frequency shifting
in an LPAI laser system, we demonstrate cold-atom generation, state-selective
detection, and the realization of atom interferometer fringes to estimate
gravitational acceleration, , in a
Rubidium (Rb) atom system.Comment: 18 pages, 9 figure
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