Motion Perception During Variable-Radius Swing Motion in Darkness

Using a variable-radius roll swing motion paradigm, we examined the influence of interaural (y-axis) and dorsoventral (z-axis) force modulation on perceived tilt and translation by measuring perception of horizontal translation, roll tilt, and distance from center of rotation (radius) at 0.45 and 0.8 Hz using standard magnitude estimation techniques (primarily verbal reports) in darkness. Results show that motion perception was significantly influenced by both y- and z-axis forces. During constant radius trials, subjects' perceptions of tilt and translation were generally almost veridical. By selectively pairing radius (1.22 and 0.38 m) and frequency (0.45 and 0.8 Hz, respectively), the y-axis acceleration could be tailored in opposition to gravity so that the combined y-axis gravitoinertial force (GIF) variation at the subject's ears was reduced to ∼0.035 m/s2 – in effect, the y-axis GIF was “nulled” below putative perceptual threshold levels. With y-axis force nulling, subjects overestimated their tilt angle and underestimated their horizontal translation and radius. For some y-axis nulling trials, a radial linear acceleration at twice the tilt frequency (0.25 m/s2 at 0.9 Hz, 0.13 m/s2 at 1.6 Hz) was simultaneously applied to reduce the z-axis force variations caused by centripetal acceleration and by changes in the z-axis component of gravity during tilt. For other trials, the phase of this radial linear acceleration was altered to double the magnitude of the z-axis force variations. z-axis force nulling further increased the perceived tilt angle and further decreased perceived horizontal translation and radius relative to the y-axis nulling trials, while z-axis force doubling had the opposite effect. Subject reports were remarkably geometrically consistent; an observer model-based analysis suggests that perception was influenced by knowledge of swing geometry

Intellectual property piracy in a North-South context: empirical evidence

The protection of intellectual property rights (IPR) has been a contentious issue for more than 20 years. Industrialized nations have moved to knowledge-based economies, and simultaneously, trade barriers have fallen, making intellectual property (IP) vulnerable. Adding to this vulnerability are conflicting international institutional environments, belief systems, and economic realities. The debate over IPR protection has become a significant global trade issue pitting the net-technology producing "North" against the net-technology consuming "South." With this in mind, there has been much debate about the impact of alternative IPR regimes (tight or loose) on the welfare of Southern economies. Policy makers, in both the South and the North, search for arguments to convince recalcitrant Southern countries to follow the Northern model of strict IPR regimes. The South, faced with a dilemma, searches for arguments to justify looser regimes or convince its populace that tighter regimes are in the best interest of the nation. The objective of this research is to add empirical clarity about the welfare impacts of weak IPR on the firm and host country. To this end, we employ a novel methodological design and unique context. The research design is deductive, in that we use the empirical setting of Pioneer-Argentina, S.A., a seller of bioengineered agricultural seeds, to test the existing theory of weak IPR impacts in a North-South context. Copyright 2006 International Association of Agricultural Economists.