Metastability and Eye Movements: A Dynamical‑Systems Interpretation

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  1. Why metastability is a natural language for gaze behavior The idea that perception, attention, and neural activity evolve through transiently stable states has deep roots in cognitive science and neuroscience. Concepts such as attractors , basins , noise‑induced transitions , and escape times appear in work on perceptual switching, decision‑making, and neural population dynamics (Kelso, 1995; Rabinovich et al., 2008; Deco & Jirsa, 2012). Eye movements, especially the alternation between fixations and saccades ,   fit remarkably well into this metastable picture. The Freidlin–Wentzell theory of rare events (Freidlin & Wentzell, 2012) provides a rigorous mathematical language for these intuitions. 2. Fixations as metastable states  Consider the gaze position X t as the state of a stochastic dynamical system. During a fixation the  gaze remains confined to a small region, microsaccades and noise generate small fluctuations, and the gaze tends to return...
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The U.S. GDP Growth Accelerates in Second Quarter, doesn't it ?

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The Bureau of Economic Analysis (BEA) asserts [here]: 
"Real gross domestic product (GDP) increased 1.7 percent in the second quarter of 2013 after increasing 1.1 percent in the first quarter, according to the “advance” estimate released today [July 31, 2013] by the Bureau of Economic Analysis (BEA)." 
One would say that the reported growth of the annualized estimate of the U.S. GDP (+1.7%) outperforms the expected result. 

 We recall that the official GDP is calculated at constant prices, i.e, by applying a deflator to the current values. 

 In practice, it takes account of the specific rate of inflation in the components of GDP. Obviously the lower the GDP deflator the higher the GDP.

 Well, the deflator used by the BEA for the second quarter was a tiny +0.71% whilst in the first quarter it was +1.7% and in the last 14 quarters, the U.S. GDP deflator was +1.75% on average.

 It sounds a bit odd !

 If the GDP deflator were what the market was expecting (i.e., +1.6%), the U.S. GDP would grow in the second quarter only by 0.8% annualized (i.e., just a faint +0.2% quarter-on-quarter). 

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