A comparison of monkey and human motion processing mechanisms

Single-cell recording studies have provided vision scientists with a detailed understanding of motion processing at the neuronal level in non-human primates. However, despite the development of brain imaging techniques, it is not known to what extent the response characteristics of motion-sensitive neurons in monkey brain mirror those of human motion sensitive neurons. Using a motion adaptation paradigm, the direction aftereffect, we recently provided evidence of a strong resemblance in the response functions of motion-sensitive neurons in monkey and human to moving dot patterns differing in dot density. Here we describe a series of experiments in which measurements of the direction aftereffect are used to infer the response characteristics of human motion-sensitive neurons when viewing transparent motion and moving patterns that differ in their signal-to-noise ratio (motion coherence). In the case of transparent motion stimuli, our data suggest suppressed activity of motion-sensitive neurons similar to that reported for macaque monkey. In the case of motion coherence, our results are indicative of a linear relationship between signal intensity (coherence) and neural activity; a pattern of activity which also bears a striking similarity to macaque neural activity. These findings strongly suggest that monkey and human motionsensitive neurons exhibit similar response and inhibitory characteristics.

Nonlinear theory of solitary waves associated with longitudinal particle motion in lattices - Application to longitudinal grain oscillations in a dust crystal

The nonlinear aspects of longitudinal motion of interacting point masses in a lattice are revisited, with emphasis on the paradigm of charged dust grains in a dusty plasma (DP) crystal. Different types of localized excitations, predicted by nonlinear wave theories, are reviewed and conditions for their occurrence (and characteristics) in DP crystals are discussed. Making use of a general formulation, allowing for an arbitrary (e.g. the Debye electrostatic or else) analytic potential form phi(r) and arbitrarily long site-to-site range of interactions, it is shown that dust-crystals support nonlinear kink-shaped localized excitations propagating at velocities above the characteristic DP lattice sound speed v(0). Both compressive and rarefactive kink-type excitations are predicted, depending on the physical parameter values, which represent pulse- (shock-)like coherent structures for the dust grain relative displacement. Furthermore, the existence of breather-type localized oscillations, envelope-modulated wavepackets and shocks is established. The relation to previous results on atomic chains as well as to experimental results on strongly-coupled dust layers in gas discharge plasmas is discussed.

Architecture in Cinema: A Relation of Representation Based on Space

Architecture, whether in the foreground or background, is an intrinsic part of any film, and cinema holds a position as a transformative reference in contemporary architecture. This book addresses the role of architecture in cinema, and through a focus on the use of space, it presents a critical overview of the relation between the two. Through framing, flattening and editing, cinematic space, as the representation of architectural space, focuses on its certain qualities, while eliminating others. Thus, cinema emphasizes individual aspects of space that may be overlooked when the whole context is considered. Space 'acts' in the foreground rather than simply filling the background in the films of Peter Greenaway and Wim Wenders, which are used to analyze two significant cinematic approaches to space, space as form and space as symbol. The detailed analysis of Greenaway's The Belly of an Architect and Wenders' Der Himmel über Berlin (Wings of Desire) offers an innovative and original perspective on space to those interested in both fields of architecture and film studies.

Modal Representation of the Resonant Body within a Finite Difference Framework for Simulation of String Instruments

This paper investigates numerical simulation of a string coupled
transversely to a resonant body. Starting from a complete nite
difference formulation, a second model is derived in which the
body is represented in modal form. The main advantage of this hybrid form is that the body model is scalable, i.e. the computational
complexity can be adjusted to the available processing power. Numerical results are calculated and discussed for simplied models
in the form of string-string coupling and string-plate coupling.