314 research outputs found
p-wave Feshbach molecules
We have produced and detected molecules using a p-wave Feshbach resonance
between 40K atoms. We have measured the binding energy and lifetime for these
molecules and we find that the binding energy scales approximately linearly
with magnetic field near the resonance. The lifetime of bound p-wave molecules
is measured to be 1.0 +/- 0.1 ms and 2.3 +/- 0.2 ms for the m_l = +/- 1 and m_l
= 0 angular momentum projections, respectively. At magnetic fields above the
resonance, we detect quasi-bound molecules whose lifetime is set by the
tunneling rate through the centrifugal barrier
Neurophysiophenomenology – predicting emotional arousal from brain arousal in a virtual reality roller coaster
Arousal is a core affect constituted of both bodily and subjective states that prepares an agent to respond to events of the natural environment. While the peripheral physiological components of arousal have been examined also under naturalistic conditions, its neural correlates were suggested mainly on the basis of simplifed experimental designs.  We used virtual reality (VR) to present a highly immersive and contextually rich scenario of roller coaster rides to evoke naturalistic states of emotional arousal. Simultaneously, we recorded EEG to validate the suggested neural correlates of arousal in alpha frequency oscillations (8-12Hz) over temporo-parietal cortical areas. To fnd the complex link between these alpha components and the participants’ continuous subjective reports of arousal, we employed a set of complementary analytical methods coming from machine learning and deep learning
The potential energy of a K Fermi gas in the BCS-BEC crossover
We present a measurement of the potential energy of an ultracold trapped gas
of K atoms in the BCS-BEC crossover and investigate the temperature
dependence of this energy at a wide Feshbach resonance, where the gas is in the
unitarity limit. In particular, we study the ratio of the potential energy in
the region of the unitarity limit to that of a non-interacting gas, and in the
T=0 limit we extract the universal many-body parameter . We find ; this value is consistent with previous measurements
using Li atoms and also with recent theory and Monte Carlo calculations.
This result demonstrates the universality of ultracold Fermi gases in the
strongly interacting regime
Dissipative production of a maximally entangled steady state
Entangled states are a key resource in fundamental quantum physics, quantum
cryp-tography, and quantum computation [1].To date, controlled unitary
interactions applied to a quantum system, so-called "quantum gates", have been
the most widely used method to deterministically create entanglement [2]. These
processes require high-fidelity state preparation as well as minimizing the
decoherence that inevitably arises from coupling between the system and the
environment and imperfect control of the system parameters. Here, on the
contrary, we combine unitary processes with engineered dissipation to
deterministically produce and stabilize an approximate Bell state of two
trapped-ion qubits independent of their initial state. While previous works
along this line involved the application of sequences of multiple
time-dependent gates [3] or generated entanglement of atomic ensembles
dissipatively but relied on a measurement record for steady-state entanglement
[4], we implement the process in a continuous time-independent fashion,
analogous to optical pumping of atomic states. By continuously driving the
system towards steady-state, the entanglement is stabilized even in the
presence of experimental noise and decoherence. Our demonstration of an
entangled steady state of two qubits represents a step towards dissipative
state engineering, dissipative quantum computation, and dissipative phase
transitions [5-7]. Following this approach, engineered coupling to the
environment may be applied to a broad range of experimental systems to achieve
desired quantum dynamics or steady states. Indeed, concurrently with this work,
an entangled steady state of two superconducting qubits was demonstrated using
dissipation [8].Comment: 25 pages, 5 figure
Decoding subjective emotional arousal from EEG during an immersive Virtual Reality experience
Immersive virtual reality (VR) enables naturalistic neuroscientific studies while maintaining experimental control, but dynamic and interactive stimuli pose methodological challenges. We here probed the link between emotional arousal, a fundamental property of affective experience, and parieto-occipital alpha power under naturalistic stimulation:37 young healthy adults completed an immersive VR experience, which included rollercoaster rides, while their EEG was recorded. They then continuously rated their subjective emotional arousal while viewing a replay of their experience. The association between emotional arousal and parieto-occipital alpha power was tested and confirmed by (1) decomposing the continuous EEG signal while maximizing the comodulation between alpha power and arousal ratings and by (2) decoding periods of high and low arousal with discriminative common spatial patterns and a Long Short-Term Memory recurrent neural network.We successfully combine EEG and a naturalistic immersive VR experience to extend previous findings on the neurophysiology of emotional arousal towards real-world neuroscience.Competing Interest StatementThe authors have declared no competing interest
Socio-cultural norms of body size in Westerners and Polynesians affect heart rate variability and emotion during social interactions
The perception of body size and thus weight-related stigmatization vary between cultures. Both are stronger in Western than in Polynesian societies. Negative emotional experiences alter one’s behavioral, psychological, and physiological reactions in social interactions. This study compared affective and autonomic nervous system responses to social interactions in Germany and American Samoa, two societies with different body-size related norms. German (n = 55) and Samoan (n = 56) volunteers with and without obesity participated in a virtual ball-tossing game that comprised episodes of social inclusion and social exclusion. During the experiment, heart rate was measured and parasympathetic activity (i.e., high-frequency heart rate variability) was analyzed. We found differences in both emotional experience and autonomic cardio-regulation between the two cultures: during social inclusion, Germans but not Samoans showed increased parasympathetic activity. In Germans with obesity, this increase was related to a more negative body image (comprising high rates of weight-related teasing). During social exclusion, Samoans showed parasympathetic withdrawal regardless of obesity status, while Germans with obesity showed a stronger increase in parasympathetic activity than lean Germans. Furthermore, we found fewer obesity-related differences in emotional arousal after social exclusion in Samoans as compared to Germans. Investigating the interplay of socio-cultural, psychological, and biological aspects, our results suggest influences of body size-related socio-cultural norms on parasympathetic cardio-regulation and negative emotions during social interactions
Testing the effect of depth on the perception of faces in an online study
Faces are socially relevant stimuli that can be distinguished by the spatial arrangements of their visual features. However, face perception has been mostly investigated with static 2D images, which differs from everyday life experience. In an online study, we investigate face perception in two viewing conditions (2D & 3D). We compare the cognitive face space for these conditions, by modeling the acquired human similarity ratings with similarity matrices computed from physical face attributes and feature maps of deep learning-based face recognition models. Lastly, we fit these models to the human similarity judgements to explore relevant facial features between the viewing conditions. Unveiling differences between 2D and 3D perception of faces will further our understanding on the role of stimulus presentation on face processing
Stereoscopic depth increases intersubject correlations of brain networks
Three-dimensionalmovies presented via stereoscopic displays have becomemore popular in recent years aiming at a more engaging viewing experience. However, neurocognitive processes associated with the perception of stereoscopic depth in complex and dynamic visual stimuli remain understudied. Here, we investigate the influence of stereoscopic depth on both neurophysiology and subjective experience. Using multivariate statistical learning methods, we compare the brain activity of subjects when freely watching the same movies in 2D and in 3D. Subjective reports indicate that 3D movies are more strongly experienced than 2D movies. On the neural level, we observe significantly higher intersubject correlations of cortical networks when subjects are watching 3D movies relative to the same movies in 2D. We demonstrate that increases in intersubject correlations of brain networks can serve as neurophysiologicalmarker for stereoscopic depth and for the strength of the viewing experience
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