To assess the effect of deprivation amblyopia on global shape discrimination, sensitivity to radial deformation of circular patterns was assessed in patients treated for congenital (N=7) or developmental (N=1) cataracts. Elevation in radial deformation threshold was dependent on circular contour frequency and the depth of amblyopia. Analysis of thresholds expressed as Weber fractions indicated ...

Contrast thresholds were measured for discriminating left vs right motion of a vertical, 1 c/deg luminance grating lasting for one cycle of motion. This test was presented on a 1 c/deg stationary grating (pedestal) of twice-threshold, flashed for the duration of the test motion. Lu and Sperling [(1995). Vision Research, 35, 2697-2722] argue that the visual system detects the underlying, first-o...

The pedestal or dipper effect is the large improvement in the detectability of a sinusoidal grating observed when it is added to a masking or pedestal grating of the same spatial frequency, orientation, and phase. We measured the pedestal effect in both broadband and notched noise-noise from which a 1.5-octave band centered on the signal frequency had been removed. Although the pedestal effect ...

A simple unified model of intrinsic rotation and momentum transport in high confinement regime H-mode tokamak plasmas is presented. Motivated by the common dynamics of the onset of intrinsic rotation and the L-H transition, this simple model combines E B shear-driven residual stress in the pedestal with a turbulent equipartition pinch to yield rotation profiles. The residual stress is the prima...

Predictions are developed for the structure of plasma parameter profiles of H-mode pedestals in transport quasi-equilibrium in tokamak plasmas. They are based on assuming paleoclassical radial plasma transport processes dominate throughout the pedestal. The key physical process in this model is that the electron temperature gradient in the pedestal increases to the magnitude required for paleoc...

Transport at the pedestal top is important for the inter-ELM pedestal dynamics. Linear gyrokinetic analysis of the pedestal during an ELM cycle on MAST has shown kinetic ballooning modes to be unstable at the knee of the pressure profile and in the steep pedestal region whilst microtearing modes (MTMs) and electron temperature gradient modes (ETGs) dominate in the shallow gradient region inboar...

The pressure at the top of the edge transport barrier (or “pedestal height”) strongly impacts fusion performance, while large edge localized modes (ELMs), driven by the free energy in the pedestal region, can constrain material lifetimes. Accurately predicting the pedestal height and ELM behavior in ITER is an essential element of prediction and optimization of fusion performance. Investigation...

Pattern contrast thresholds for vertical Gabor patterns were measured on pattern pedestals that were vertical or horizontal. Contrast of the pedestal was varied to measure the function relating target contrast threshold to pedestal contrast (TvC function). TvC functions were measured without an adaptor and after adaptation to vertical, horizontal and plaid patterns. For a pedestal with the same...

Fig. 3. Contrast thresholds for direction discrimination as a function of pedestal contrast (measured as in Fig. 1) at 7.43 and 15 Hz. The moving test was presented in 0 or 180° spatial phase with the pedestal (specified at middle of motion). The dashed line in each panel shows the mean threshold of the observers measured without the pedestal. Pedestals of 2–3% contrast produce the greatest fac...

Measurement of the detection thresholds of patterns on pedestals of various kinds has the potential of providing insight into the mechanisms that mediate pattern vision. This study is concerned with chromoluminance patterns, that is, patterns that vary over space in luminance, chromaticity, or both. Contrast thresholds for 1 c/deg Gabor patterns (targets) were measured as a function of the cont...