Spatial perception ability from two-dimensional media

Stability of two-dimensional spatial solitons in nonlocal nonlinear media.

We discuss the existence and stability of two-dimensional solitons in media with spatially nonlocal nonlinear response. We show that such systems, which include thermal nonlinearity and dipolar Bose-Einstein condensates, may support a variety of stationary localized structures, including rotating dipole solitons. We also demonstrate that the stability of these structures critically depends on t...

Reconstructing random media. II. Three-dimensional media from two-dimensional cuts

We report on an investigation concerning the utilization of morphological information obtained from a two-dimensional ~2D! slice ~thin section! of a random medium to reconstruct the full three-dimensional ~3D! medium. We apply a procedure that we developed in an earlier paper that incorporates any set of statistical correlation functions to reconstruct a Fontainebleau sandstone in three dimensi...

The origins of ability and automaticity in tactile spatial perception.

Two-Dimensional Motion Perception in Flies

We study two-dimensional motion perception in flies using a semicircular visual stimulus. Measurements of both the H1-neuron and the optomotor response are consistent with a simple model supposing spatial integration of the outputs of correlation-type motion detectors. In both experiment and model, there is substantial H1 and horizontal (yaw) optomotor response to purely vertical motion of the ...

Breathers in two-dimensional neural media.

In this Letter we show how nontrivial forms of spatially localized oscillations or breathers can occur in two-dimensional excitable neural media with short-range excitation and long-range inhibition. The basic dynamical mechanism involves a Hopf bifurcation of a stationary pulse solution in the presence of a spatially localized input. Such an input could arise from external stimuli or reflect c...