Anxiety and Learning in Dynamic and Static Clock Game Experiments

In clock games, agents receive differently-timed private signals when an asset value is above its fundamental. The price crashes to the fundamental when K of N agents have decided to sell. If selling decisions are private, bubbles can be sustained because people delay selling, after receiving signals, knowing that others will delay too. Our results replicate the main features of the one previous experimental study of clock game (in two subject pools): Selling delays are shorter than predicted, but converge toward equilibrium predictions over repeated trials. We also find that delays are shorter in a dynamic game in which selling decisions unfold over time, compared to a static equivalent in which subjects precommit to selling decisions. A model of learning with growing anxiety after signal arrival can reproduce the empirical observations of shorter-than-predicted delay, smaller delay after later signal arrival, and shorter delays in dynamic games

Measured Anxiety Affects Choices in Experimental "Clock" Games

We measure anxiety by skin conductance response (SCR) in an economic setting. In “clock” games, six agents receive private signals when an asset's price exceeds its fundamental value. They can sell for immediate value or wait to sell at a higher value. Waiting is risky because the price crashes to a lower value when three agents sell. Anxiety could lead people to sell too quickly when the game is played dynamically over time, compared to a static version with precommitted selling. Empirically, delays are shorter in dynamic games than in payoff-equivalent static games, and are associated with anxiety as measured

Hypothetical and Real Choice Differentially Activate Common Valuation Areas

Hypothetical reports of intended behavior are commonly used to draw conclusions about real choices. A fundamental question in decision neuroscience is whether the same type of valuation and choice computations are performed in hypothetical and real decisions. We investigated this question using functional magnetic resonance imaging while human subjects made real and hypothetical choices about purchases of consumer goods. We found that activity in common areas of the orbitofrontal cortex and the ventral striatum correlated with behavioral measures of the stimulus value of the goods in both types of decision. Furthermore, we found that activity in these regions was stronger in response to the stimulus value signals in the real choice condition. The findings suggest that the difference between real and hypothetical choice is primarily attributable to variations in the value computations of the medial orbitofrontal cortex and the ventral striatum, and not attributable to the use of different valuation systems, or to the computation of stronger stimulus value signals in the hypothetical condition

Double resonance of Raman transitions in a degenerate Fermi gas

We measure momentum-resolved Raman spectra of a spin-polarized degenerate Fermi gas of $^{173}$Yb atoms for a wide range of magnetic fields, where the atoms are irradiated by a pair of counterpropagating Raman laser beams as in the conventional spin-orbit coupling scheme. Double resonance of first- and second-order Raman transitions occurs at a certain magnetic field and the spectrum exhibits a doublet splitting for high laser intensities. The measured spectral splitting is quantitatively accounted for by the Autler-Townes effect. We show that our measurement results are consistent with the spinful band structure of a Fermi gas in the spatially oscillating effective magnetic field generated by the Raman laser fields.Comment: 7 pages, 6 figure

Fabrication of (Ga,Mn)N nanowires with room temperature ferromagnetism using nitrogen plasma

Ferromagnetic properties of (Ga,Mn)N nanowires were examined by treating with nitrogen plasma at 200 ??C. Nanowires grown by chemical vapor deposition were n-type and no secondary phases were found. The magnetic moment increased and was maintained at room temperature by this treatment. Synchrotron radiation photoemission spectroscopy revealed that Ga vacancies significantly increased, but N vacancies decreased by plasma treatment, leading to a decrease of MnGa-VN complex and the enhancement of Mn activation.open111

Enhancement of magnetic properties by nitrogen implantation to Mn-implanted p-type GaN

N and Mn ions were co-implanted into p-type GaN and subsequently annealed at 700-900degreesC. Compared with Mn-implanted sample, the (Mn+N)-implanted sample revealed a larger ferromagnetic signal. This was attributed to the increase of Ga-Mn magnetic phases. Mn-N compounds, such as Mn6N2.58 and Mn3N2, decreased and the resistivity significantly increased, meaning a reduction of N vacancies. It is suggested that enhancement in ferromagnetic properties in the (Mn+N)-implanted GaN originated from the reduction of N vacancies and the increase of Ga-Mn magnetic phases.open293

Microstructural, optical, and magnetic properties of Mn-implanted p-type GaN

The microstructural, optical and magnetic properties of Mn-implanted p-type GaN were investigated. Dilute magnetic semiconductor was achieved by implanting Mn ions into p-type GaN and subsequently annealing. The Ga-Mn magnetic phases contributing to the ferromagnetic property were produced after annealing Mn-implanted p-type GaN below 800??C.open151

Positive Solutions and Mann Iterations of a Fourth Order Nonlinear Neutral Delay Differential Equation

This paper deals with a fourth order nonlinear neutral delay differential equation. By using the Banach fixed point theorem, we establish the existence of uncountably many bounded positive solutions for the equation, construct several Mann iterative sequences with mixed errors for approximating these positive solutions, and discuss some error estimates between the approximate solutions and these positive solutions. Seven nontrivial examples are given